ArticleLiterature Review
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Recognising and representing one's self as distinct from others is a fundamental component of self-awareness. However, current theories of self-recognition are not embedded within global theories of cortical function and therefore fail to provide a compelling explanation of how the self is processed. We present a theoretical account of the neural and computational basis of self-recognition that is embedded within the free-energy account of cortical function. In this account one's body is processed in a Bayesian manner as the most likely to be "me". Such probabilistic representation arises through the integration of information from hierarchically organised unimodal systems in higher-level multimodal areas. This information takes the form of bottom-up "surprise" signals from unimodal sensory systems that are explained away by top-down processes that minimise the level of surprise across the brain. We present evidence that this theoretical perspective may account for the findings of psychological and neuroimaging investigations into self-recognition and particularly evidence that representations of the self are malleable, rather than fixed as previous accounts of self-recognition might suggest.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... The findings of this study can be framed within the predictive coding model of multisensory body illusions, which has been used to interpret the multisensory illusion phenomena (Apps and Tsakiris, 2014;Zeller et al., 2014Zeller et al., , 2016Rossi Sebastiano et al., 2021, 2024. The predictive coding model suggests that the embodiment of a fake hand results from the top-down modulation of lower inter-sensory conflicts emerging during the illusion procedure. ...
... Based on the argument that depersonalization was a defense mechanism against danger and associated anxiety (Ananthaswamy, 2015(Ananthaswamy, /2018 and interpretation that individuals with depersonalization exhibited responses to suppress perception (including that of one's own body) and cognition to maintain adaptive behavior in anxiety-related situations (Sierra and David, 2011), these results suggested that participants could have attempted to avoid perceiving the virtual body, presented with abdominal pain, as their own body, and thereby attenuated sensory input. Body illusions typically happen when the brain minimizes the mismatch (prediction error) between the predictions and actual sensory input by adjusting the prediction to match the sensory input (Apps and Tsakiris, 2014;Zeller et al., 2014Zeller et al., , 2016Rossi Sebastiano et al., 2021, 2024. However, the attenuation of sensory input by the negative top-down interpretation increased the prediction error between the top-down process "the virtual body in front of me is my body with abdominal pain" and sensory input. ...
... From the perspective of predictive coding, this could be viewed as a mismatch between the predicted state (virtual body experiencing abdominal pain) and actual sensory input (actual self-body not experiencing abdominal pain). The body illusion arose as a result of correcting the prediction error between senses during the illusion procedure by assuming that the object was one's own body (Apps and Tsakiris, 2014;Zeller et al., 2014Zeller et al., , 2016Rossi Sebastiano et al., 2021, 2024. However, owing to the manipulation of the top-down interpretation of the negative self, the above prediction error was also added. ...
Article
Full-text available
Sense of body ownership has been studied using rubber hand illusion (RHI) and full-body illusion (FBI). It has recently become clear that consciously interpreting a fake body as one’s own in a top-down manner influences these body illusions. Furthermore, a study interestingly found that the influence of top-down interpretation was moderated by the degree of depersonalization, which was a symptom of a lack of sense of body ownership. In a case study on depersonalization, the top-down interpretation of one’s body was suggested to be a negative physical state that made it difficult to feel a sense of body ownership. However, this has not been examined. We examined the influence of negative top-down interpretation using an FBI procedure. A fake body was instructed to be viewed as a negative self-body (“view the virtual body’s back while regarding the virtual body as your own experiencing abdominal pain”). To examine the influence of a negative top-down interpretation, participants were instructed to interpret the body as their own (neutral self-body) as a control condition. We used skin conductance responses to a fearful stimulus presented after an illusion procedure to measure the degree of FBI experienced. Results indicated a significant difference in the skin conductance response between the synchronous and asynchronous presentation of visual-tactile stimuli in the control condition, which confirmed the occurrence of the illusion. However, the occurrence of the illusion was not confirmed when the participants were instructed to interpret the virtual body as their own in a negative physical state, and the degree of FBI was smaller than the control condition. Our finding that an FBI was inhibited by manipulation of the top-down interpretation suggested that it could be a factor that inhibited the creation of a sense of body ownership.
... An impressive feature of human consciousness is that while our body changes across the lifespan in shape and functionality, our sense of body ownership, the sense that the body and its parts belong to oneself, remains generally remarkably stable. The bodily self is thought to be adaptive based on a constant interplay and adjustment between momentary weighting and integration of sensorimotor signals, and a more stable conceptual body knowledge (Apps & Tsakiris, 2014). Such adaptive capacity has been termed bodily self plasticity, and has increasingly been studied using multisensory stimulation paradigms, like the rubber hand illusion, where matching visuotactile stimulation on the hidden own hand, and a rubber hand induce the feeling that the rubber hand belongs to oneself (Botvinick & Cohen, 1998). ...
... Spacing within age groups was adjusted accordingly, with narrower ranges where faster changes were expected (Craik & Bialystok, 2006;Li & Lindenberger, 2002). While a degree of bodily self plasticity is present in healthy individuals (Apps & Tsakiris, 2014), some authors have suggested that enhanced plasticity is related to pathology (Brugger & Lenggenhager, 2014). In order to further understand the nuances of healthy and unhealthy bodily self plasticity, it is important to consider how it changes throughout human ontogeny. ...
... Importantly, this finding is extended to a lifespan sample in the present study. It provides evidence that coherent multisensory signals are not only required for the illusory embodiment of external objects (Botvinick & Cohen, 1998), but also for the maintenance of a stable sense of embodiment of one's own body (Apps & Tsakiris, 2014). Here, we observed a reduction in repeated self-reported body ownership with increasing delay from childhood to old age. ...
Article
Full-text available
The sense of a bodily self is thought to depend on adaptive weighting and integration of bodily afferents and prior beliefs. While the physical body changes in shape, size, and functionality across the lifespan, the sense of body ownership remains relatively stable. Yet, little is known about how multimodal integration underlying such sense of ownership is altered in ontogenetic periods of substantial physical changes. We aimed to study this link for the motor and the tactile domain in a mixed-realty paradigm where participants ranging from 7 to 80 years old saw their own body with temporally mismatching multimodal signals. Participants were either stroked on their hand or moved it, while they saw it in multiple trials with different visual delays. For each trial, they judged the visuo-motor/tactile synchrony and rated the sense of ownership for the seen hand. Visual dependence and proprioceptive acuity were additionally assessed. The results show that across the lifespan body ownership decreases with increasing temporal multisensory mismatch, both in the tactile and the motor domain. We found an increased sense of ownership with increasing age independent of delay and modality. Delay sensitivity during multisensory conflicts was not consistently related to age. No effects of age were found on visual dependence or proprioceptive accuracy. The results are at least partly in line with an enhanced weighting of top-down and a reduced weighting of bottom-up signals for the momentary sense of bodily self with increasing age.
... Body perception results from the integration of multisensory signals (such as those emerging from sight, hearing, touch and beyond) and prior knowledge regarding one's body. [6,11,48]. This capacity allows us to keep track and adjust to the arrangement and position of our body parts and our continuously changing appearance and dimensions [36]. ...
... This capacity allows us to keep track and adjust to the arrangement and position of our body parts and our continuously changing appearance and dimensions [36]. Beyond our kinesthetic functioning, the way we perceive our body is related to cognitive (e.g., prior beliefs; social perception; [6,7,42], affective or emotional processes (e.g., selfconcept and self-esteem, [27,97,118,129]. For instance, when we feel happy, we tend to perceive our bodies as lighter and more agile; conversely, we may perceive our bodies as heavier and more sluggish when we feel sad [55]. ...
... As a result, many clinical interventions recommend targeting negative body perceptions [134]. As mentioned before, prior beliefs about one's body influence body perception [6,11,48]. Given the link to negative body concerns and mental health conditions, we aimed to investigate how such concerns might modulate the illusion. ...
Conference Paper
Full-text available
Changes in body perception influence behavior and emotion and can be induced through multisensory feedback. Auditory feedback to one's actions can trigger such alterations; however, it is unclear which individual factors modulate these effects. We employ and evaluate SoniWeight Shoes, a wearable device based on literature for altering one's weight perception through manipulated footstep sounds. In a healthy population sample across a spectrum of individuals (n=84) with varying degrees of eating disorder symptomatology, physical activity levels, body concerns, and mental imagery capacities, we explore the effects of three sound conditions (low-frequency, high-frequency and control) on extensive body perception measures (demographic, behavioral, physiological, psychological, and subjective). Analyses revealed an impact of individual differences in each of these dimensions. Besides replicating previous findings, we reveal and highlight the role of individual differences in body perception, offering avenues for personalized sonification strategies. Datasets, technical refinements, and novel body map quantification tools are provided.
... In line with this account, increased expectation to perceive a stimulus can lead to a liberal decision bias to report the stimulus compared to when expectation is low, based on evidence in other modalities such as vision and audition (Bang & Rahnev, 2017;Dijkstra et al., 2021;Hoskin et al., 2014;Sherman et al., 2015;Wyart et al., 2012;Yon et al., 2020). This explanation would also be in line with predictive coding accounts which posit that a prediction error occurs when there is a conflict between bottom-up and top-down signals and top-down signals are weighted more heavily in decision-making regarding a stimulus (Apps & Tsakiris, 2014;Den Ouden et al., 2012;Summerfield & De Lange, 2014). ...
... While our experiments were not designed to isolate a specific mechanism for the observed criterion effects, it raises the possibility that expectations regarding perceptual states can influence how decisions about the sensory environment are made. There is evidence suggesting that our perceptual system generates top-down templates to predict sensory information from incoming bottom-up signals (Apps & Tsakiris, 2014;Den Ouden et al., 2012). These predictive templates are based on an individual's prior knowledge and experiences of the world and allow the individual to predict future sensory states (Summerfield & De Lange, 2014). ...
Article
Full-text available
Our tactile perception is shaped not only by somatosensory input but also by visual information. Prior research on the effect of viewing touch on tactile processing has found higher tactile detection rates when paired with viewed touch versus a control visual stimulus. Therefore, some have proposed a vicarious tactile system that activates somatosensory areas when viewing touch, resulting in enhanced tactile perception. However, we propose an alternative explanation: Viewing touch makes the observer more liberal in their decision to report a tactile stimulus relative to not viewing touch, also resulting in higher tactile detection rates. To disambiguate between the two explanations, we examined the effect of viewed touch on tactile sensitivity and decision criterion using signal detection theory. In three experiments, participants engaged in a tactile detection task while viewing a hand being touched or approached by a finger, a red dot, or no stimulus. We found that viewing touch led to a consistent, liberal criterion shift but inconsistent enhancement in tactile sensitivity relative to not viewing touch. Moreover, observing a finger approach the hand was sufficient to bias the criterion. These findings suggest that viewing touch influences tactile performance by altering tactile decision mechanisms rather than the tactile perceptual signal.
... Predictive coding believed to be the result of probabilistic knowledge driven inferences from external and internal sensory signals (Seth, 2013). Predictive coding is also linked to a subjective sense of self which includes integrating homeostatic processes, the sense of owning and identifying with a body, first-person perspective, intention and agency, metacognitive aspects that are linked to the experiential self (Seth, 2013;Apps and Tsakiris, 2013). The aINS plays a central role in these processes (Seth, 2013). ...
... Seth argued a healthy or accurate PC framework is linked to unifying mechanisms of selfrepresentation 'what is me' and 'what is not me' by integrating interoceptive processes. With rich connections throughout the brain, the aINS is structurally situated to process internal and external perceptions and work as both a comparator registering top-down and bottom-up processes with future prediction capacities (Apps and Tsakiris, 2013;Seth, 2013;Khalsa et al., 2018). An individual with a well-developed and healthy PC can fluidly integrate bottom up and top-down signals to reduce the mismatch of actual and expected states which would minimize 'prediction error' (Seth, 2013;Sharp et al., 2018). ...
Article
Full-text available
The concept of the self is complex and there is no consensus on what the self is. However, there are emerging patterns in the literature that point to two different selves, the narrative and experiential self. The narrative self refers to a conceptual or representational knowledge of the self that extends across time and manifests in self-reflection and personality assessments. The experiential self refers to first-person perception, moment-to-moment awareness, embodiment, and a sense of agency. These two selves are reliably linked to two distinct neural circuits, the default mode network (DMN) and the insula and salience network (SN). One of the consistent themes in the meditative and mindfulness literature is a change in the perspective of the self. In this paper, I will review how meditation alters those neural circuits providing a plausible mechanism that can explain the changes in the self. I also propose a rudimentary conceptual framework to account for some of the mixed results found throughout meditation literature.
... Most notably, active inference extends beyond perceptual inference to explain action and behaviour in terms of inference within generative models; i.e., motor control is described as inference and model optimisation as well, where actions are generated to fulfil predictions, in parallel with the updating of predictions through perceptual inference. Thus, active inference is a framework with intriguing (and partly unique) assumptions about how the brain controls action and behaviour, which has attracted not only theoretical and experimental neuroscientists, but also psychologists and philosophers [7][8][9][10][11][12][13]. ...
... That Entropy 2024, 26, 790 7 of 21 multisensory integration (or cue integration) can be biased by precision estimates has been demonstrated and reviewed extensively elsewhere [15,[51][52][53]. This assumption is also at the core of Bayesian approaches to body ownership [8,9,[54][55][56][57]. Here, a particularly intriguing example is the so-named rubber hand illusion [58], in which a participant experiences illusory ownership over a visible fake hand placed next to the real, unseen hand, and exhibits a recalibration of the perceived real hand position towards the fake hand. ...
Article
Full-text available
Active inference describes (Bayes-optimal) behaviour as being motivated by the minimisation of surprise of one's sensory observations, through the optimisation of a generative model (of the hidden causes of one's sensory data) in the brain. One of active inference's key appeals is its conceptualisation of precision as biasing neuronal communication and, thus, inference within generative models. The importance of precision in perceptual inference is evident-many studies have demonstrated the importance of ensuring precision estimates are correct for normal (healthy) sensation and perception. Here, we highlight the many roles precision plays in action, i.e., the key processes that rely on adequate estimates of precision, from decision making and action planning to the initiation and control of muscle movement itself. Thereby, we focus on the recent development of hierarchical, "mixed" models-generative models spanning multiple levels of discrete and continuous inference. These kinds of models open up new perspectives on the unified description of hierarchical computation, and its implementation, in action. Here, we highlight how these models reflect the many roles of precision in action-from planning to execution-and the associated pathologies if precision estimation goes wrong. We also discuss the potential biological implementation of the associated message passing, focusing on the role of neuromodulatory systems in mediating different kinds of precision.
... Notably, interoceptive sensing of one's own body and exteroceptive sensing of the world are highly interdependent (Zaidel and Salomon, 2023). It is the predictive processing of crossmodal interactions and integration of multisensory signalsexteroceptive (Blanke et al., 2015;Salomon, 2017), volitional (Stern et al., 2020) and interoceptive (Seth et al., 2012;Park et al., 2016;Allen and Tsakiris, 2019), that was suggested to underlie the formation of coherent bodily self models (Clark, 2013;Limanowski and Blankenburg, 2013;Apps and Tsakiris, 2014;Zaidel and Salomon, 2023). ...
... Studies have linked the actions in the PPS to a vast spectrum of functions including body representation, goal-directed movements, defensive movements, and social interactions (Geers and Coello, 2023). Pre-reflective selfhood thus emerges from one's experience through his/her body (Limanowski and Blankenburg, 2013;Apps and Tsakiris, 2014), with a clear link between selfrelated objects and a rewarding/hedonic experience, engaging the mesolimbic reward circuitry (De Greck et al., 2007). ...
Article
Full-text available
Intriguing explorations at the intersection of the fields of neuroscience and psychology are driven by the quest to understand the neural underpinnings of “the self” and their psychotherapeutic implications. These translational efforts pertain to the unique Creative Arts Therapies (CATs) and the attributes and value of the self-related processes they offer. The self is considered as a multi-layered complex construct, comprising bodily and mental constituents, subjective–objective perspectives, spatial and temporal dimensions. Neuroscience research, mostly functional brain imaging, has proposed cogent models of the constitution, development and experience of the self, elucidating how the multiple dimensions of the self are supported by integrated hierarchical brain processes. The psychotherapeutic use of the art-forms, generating aesthetic experiences and creative processes, touch upon and connect the various layers of self-experience, nurturing the sense of self. The present conceptual analysis will describe and interweave the neural mechanisms and neural network configuration suggested to lie at the core of the ongoing self-experience, its deviations in psychopathology, and implications regarding the psychotherapeutic use of the arts. The well-established, parsimonious and neurobiologically plausible predictive processing account of brain-function will be discussed with regard to selfhood and consciousness. The epistemic affordance of the experiential CATs will further be portrayed, enabling and facilitating the creation of updated self-models of the body in the world. The neuropsychological impact of the relational therapeutic encounter will be delineated, acknowledging the intersubjective brain synchronization through communicative verbal and non-verbal means and aesthetic experiences. The recognition and assimilation of neuroscientific, phenomenological and clinical perspectives concerning the nested dimensionality of the self, ground the relational therapeutic process and the neuroplastic modulations that CATs have to offer on the premise of fostering, shaping and integrating selfhood.
... In line with these considerations, we designed a bCFS experiment in which each trial was preceded by an identity-related prime (i.e., self/other-faces) to test whether activating the self/other representation in a top-down fashion would influence the access to awareness of hand stimuli with a given perspective (i.e., first/third) and identity (i.e., self/other). Congruently with the fact that top-down context plays a role in self-recognition, self-other distinction (Apps & Tsakiris, 2014), and conscious perception (Gilbert & Li, 2013), we hypothesized that face primes would have prioritized the breaking of congruent hand stimuli in visual awareness, whereas conscious access would have been slower in incongruent conditions. ...
... A possible useful framework is the predictive coding account of self-recognition (Apps & Tsakiris, 2014;Tsakiris, 2017). It is stated that the own body emerges as a probabilistic representation (i.e., the most likely to be 'me' object) from the interplay between body priors and actual incoming body-related sensory signals. ...
Article
Full-text available
It has been recently demonstrated that hand stimuli presented in a first-, with respect to a third-, person perspective were prioritized before awareness independently from their identity (i.e., self, or other). This pattern would represent an unconscious advantage for self-related bodily stimuli rooted in spatial perspective. To deeper investigate the role of identity, we employed a breaking-Continuous Flash Suppression paradigm in which a self- or other-hand presented in first- or third-person perspective was displayed after a conscious identity-related prime (i.e., self or other face). We replicated the unconscious advantage of the first-person perspective but, crucially, we reported that within the first-person perspective, other-hand stimuli preceded by other-face priming slowed down the conscious access with respect to the other conditions. These findings demonstrate that a top-down conscious identity context modulates the unconscious self-attribution of bodily stimuli. Within a predictive processing framework, we suggest that, by adding ambiguous information, the prime forces a prediction update that slows conscious access.
... Specifically, it combines existing expectations and beliefs as priors with the likelihoods of new sensory input to calculate updated beliefs. At the same time, complementary models stress the role of prediction errors, weighted by precision, in updating perceptions as sensory input is received (Apps & Tsakiris, 2014;Friston 2010). These support experimentally observed malleability and hint at potential clinical translation. ...
... Augmented reality technology strategically exploits these integrative sensorimotor processes by aligning virtual visual feedback with tactile and proprioceptive cues. Supporting predictive models suggest top-down perceptual inferences about bodily actions get reinforced by concordant bottomup confirmation from several senses simultaneously, leading to an update of mental schema around ownership and agency (Apps & Tsakiris, 2014). ...
Article
This paper explores the malleable nature of perceived reality and bodily ownership as demonstrated through multisensory illusions like the rubber hand experiment. Research shows that precisely matching what someone sees and feels can recalibrate neural processing to incorporate fake limbs into one’s sense of bodily boundaries and agency. This means an individual's feelings of having a body and self come from the brain continually tweaking itself based on intersensory correlations. Meanwhile, extensive trauma research reveals significant disruptions when overwhelming experiences prevent smooth processing, storage and understanding in an individual. This manifests in dissociated fragments and dysfunctional encodings splitting from explicit memory and ownership, recreating persisting struggles without awareness. However, early therapeutic approaches using coordinated sensory stimulation suggest the potential for compassionately reshaping rigid implicit perceptions that complicate trauma recovery by tapping into neuroplasticity. Research on bodily illusions, the complexities of trauma, and sensory-based treatments shows that trauma can be framed as a disruption in aligning expectations with sensory input to create a more unified experience. There exists potential for tailored therapeutic exposures through custom sensory feedback to rewrite rigid encodings towards post-traumatic growth. Future research should thoughtfully explore these avenues into practical methods that respect survivors’ agency and dignity. Overall these themes reveal one's perception of reality as fluid, constructed by the brain continuously adjusting its predictions and interpretations to match the incoming flow of sensory information from sight, sound, touch, etc. Trauma strains the integrative system underlying a coherent experience. Therapies strategically recalibrating the senses can help realign stuck implicit perceptions of trauma. Through controlled and empowering sensory exposures, these therapies assimilate past overwhelming impressions into narratives that affirm bodily wholeness and resilience.
... Self-recognition is acknowledged as a derivative of bodily awareness, characterized by the capacity to differentiate oneself from others, and to focus attention on oneself (Gallup, 1982). Aligning our perceived self-image with our actual appearance involves predictive coding mechanisms, where the brain adaptively reconciles expected and received sensory information to maintain a coherent sense of identity (Apps & Tsakiris, 2014;Suddendorf & Butler, 2013). Research highlights that reduced awareness of internal bodily sensations, a fundamental aspect of self-awareness, is frequently observed in individuals with BIDs (Badoud & Tsakiris, 2017). ...
Article
Full-text available
Imagining one's body is crucial for how we perceive our appearance (i.e. imagining how we might appear to others), for imagining movement (motor imagery), navigation, and self-recognition. Mental body representations can be categorized into a perceptual component, known as the body image, and an action-related component, referred to as the body schema. A disturbed body image, involving altered perceptions and attitudes towards appearance, is a diagnostic feature of Anorexia Nervosa (AN) and Bulimia Nervosa (BN). The review identifies experimental paradigms used to measure body-based mental and motor imagery in individuals with AN and BN, investigating body representation beyond perceptual size and shape distortions compared to healthy controls. Three databases (PsycINFO, PubMed, and Embase) were searched, and 19 articles were included. Four characteristics of mental imagery were found to be distorted in individuals with AN and BN: body-scaling, imagined action, mental rotation, and spatial reference frame processing. Fourteen tasks were identified to assess these distortions in body-based mental imagery. This review highlights that altered body representations in AN and BN extend beyond conscious size and shape perceptions to include unconscious representations for movement and action planning. Future research should examine how body-based mental imagery sustains psychopathology in AN and BN.
... After years of use, a prosthetic is still not represented in the same way as a real hand (Maimon-Mor & Makin, 2020). In broad terms, these limits on plasticity can be explained by supposing that novel body parts which differ greatly from one's own original configuration make unreasonable demands on cognitive, attentional, and/or neural mechanisms (Makin et al., 2017), resulting in a rejection of the novel body part through a series of hierarchical comparisons between the original and novel bodies (Tsakiris, 2010), or in more recent formulations a dynamic set of constraints within a probabilistic framework (Apps & Tsakiris, 2014;Chancel et al., 2022). As well as plasticity, therefore, there are also clear limits on body representation. ...
Preprint
This study aimed to investigate whether human embodiment is dependent on the sensorimotor functions of one's body. We hypothesised that body function constrains both the sense of ownership and sensorimotor control of the body movements. We studied these relationships in the context of control of unilateral goal-directed forward arm reaching movements made with a virtual arm. In addition, we expected that children possess more adaptable body representations compared to adults, facilitating greater acceptance of virtual bodies with altered sensorimotor contingencies. We tested 5-7 and 8-10-year-old children, and young adults. Participants took part in an animal feeding game within a Virtual Reality environment. At each age, we manipulated the visual gain of hand movements to alter reaching functionality in three groups: compared to a normal (100%) gain, reaching arm length was slightly reduced (80%); slightly increased (120%); or greatly increased (400%). Parameters representing reach kinematics, subjective perception of arm length, and subjective limb embodiment were assessed during and after reaching with normal and altered control gain. In addition to changes in their reach kinematics, changes in subjective embodiment and reaching affordance were recorded compared to baseline reaching without altered visual gain. We found that the altered reaching functionality reduced Subjective ratings of limb ownership during exposure to the 400% visual gain modification in the group of adults only. In contrast, changes in reach kinematics occurred in all the age groups of children and adults, with age group-specific adjustments in the motor control strategy, characterised by altered magnitude and spatiotemporal placement of peak velocity as well as smoothness of reaching. Finally, at all ages subjective reaching affordance estimates were enhanced following exposure to the two functionality conditions with increased arm length. Our results indicate that the sense of ownership, accuracy of body representations, and characteristics of sensorimotor control are related to bodily function. In addition, it appears that these relationships might be more plastic, or perhaps more tolerant to functional alterations in terms of perceived ownership, in children compared to adults.
... According to the influential Bayesian brain theory and predictive coding approaches (Friston, 2010), self-representation is probabilistically generated through the integration of top-down representations (so-called beliefs) of the body and bottom-up signals of different sensory modalities (Apps & Tsakiris, 2014). In the context of this framework, Neustadter et al. (2019) argued that BPD-associated enhanced proneness to the rubber hand illusion paradigm, independent of synchronous or asynchronous visuotactile stimulation, could be the consequence of an exteroception-biased body representation. ...
Article
Full-text available
Dissociation describes a state of altered consciousness in which self-related functions are no longer integrated. In its extreme form, the self is perceived as detached from the physical body, resulting in so-called out-of-body experiences (OBEs). It has been previously proposed that altered bottom-up sensory integration contributes to this kind of dissociative self-experience, which is supported by results on the experimental induction of OBEs in nonclinical individuals by appropriate visuotactile stimulation. Borderline personality disorder (BPD) is characterized by disturbed body representation which covaries with clinical dissociation levels; however, whether dissociative self-experiences in BPD also rely on bottom-up sensory processes is unknown. In the present study, we experimentally induced OBEs in a sample of 22 participants with the diagnosis of current BPD (cBPD) as well as 16 individuals with remitted BPD and 20 nonclinical controls. Results revealed higher proneness for OBEs in cBPD compared to both other groups. Processing of affective sensory information, in terms of pain and emotional acoustic stimuli, was not influenced by experimentally provoked dissociative self-experiences. Changes in clinical dissociation were significantly related to the extent of experimentally induced body-self detachment in the cBPD group. Our results suggest that altered processing of exteroceptive sensory information contributes to clinically relevant dissociative self-experiences in BPD, which appears to normalize when the disorder is in its remitted stage. We discuss our results in the context of altered weighting of exteroceptive and interoceptive information in a predictive coding framework.
... Owens and colleagues (2018) approached interoceptive inference empirically by examining the connection between cardiac interoception and autonomic cardiac control. Other approaches to PP highlight the role of bodily experiences in shaping sensory processing and prediction-making (Apps & Tsakiris, 2014;Seth & Friston, 2016). More recently, Badcock, Friston, and Ramstead (2019) developed a 'hierarchically mechanistic mind' with evolutionary systems theory of psychology, which integrates a situated, embodied, Bayesian brain. ...
Article
Full-text available
Molyneux’s problem asks whether a person blind from birth, upon gaining sight, could immediately recognize and distinguish objects by sight alone that were previously known only by touch. Historical and contemporary empirical studies have explored this question with inconclusive results due to empirical limitations. More recently, Held and colleagues (2011) found that treated congenitally blind individuals cannot immediately recognize objects previously familiar through touch. Piller and colleagues (2023) further reported the absence of visual illusions in blind and recently visually-restored individuals. Nevertheless, cross-modal mappings gradually develop post-sight restoration. These findings suggest a reluctance of the mind to make cross-modal inferences, aligning with the predictive processing (PP) framework. PP posits that the mind generates top-down predictions about sensory stimuli, updating internal models through prediction errors when expectations are not met. With no prior visual experience, generative models in congenital blind individuals fail to produce accurate predictions. PP’s representational claims have been challenged by 4E cognitivists, who emphasize embodied, embedded, extended, and enactive aspects of cognition. This paper proposes a Situated Predictive Processing (SPP) framework that integrates PP with 4E cognition through the concept of situated mental representations, offering a new perspective on the Molyneux’s problem and emphasizing the role of experience and situatedness in the gradual development of visual-tactile mappings post-sight restoration.
... During the last decade a number of proposals attempted to explain the self as a neurocognitive structure within the predictive (Bayesian) brain. These theories typically (but not always) refer to more specific frameworks of predictive coding and the free energy principle (Friston, 2005(Friston, , 2010 and target several important aspects of the self, such as body representation (Apps and Tsakiris, 2014;De Vignemont, 2010;Hohwy, 2007Hohwy, , 2013Limanowski, 2022;Limanowski and Blankenburg, 2013;Salomon, 2017;Seth, 2013), the role of interoception (Allen and Tsakiris, 2018;Fotopoulou and Tsakiris, 2017;Seth, 2013;Seth and Tsakiris, 2018), abstract and social aspects of self-knowledge (Allen and Tsakiris, 2018;Bolis and Schilbach, 2020;Fotopoulou, 2012;Fotopoulou and Tsakiris, 2017;Friston and Frith, 2015;Hohwy and Michael, 2017;Moutoussis et al., 2014), as well as the self as present in conscious experience (Ciaunica, Constant, et al., 2021;Ciaunica, Safron, et al., 2021;Letheby and Gerrans, 2017;Seth et al., 2011;Woźniak, 2018). Most Bayesian notions of the self focus on the adult self. ...
Article
Full-text available
The last two decades saw multiple attempts to explain how the self is represented in the brain within the framework of the Bayesian brain. However, these attempts largely focused on describing a developed, adult self-representation. The current paper argues that looking at the developmental trajectory is crucial for understanding the structure of self-representation. It argues that emergence of self-representations should be understood as an instance of the process of acquisition of new internal models of hidden causes of sensory input. The paper proposes how such models emerge and develop over the course of life by looking at different stages of development of bodily and extra-bodily self-representations. It argues that the self arises gradually in a series of discrete steps: from first-person multisensory representations of one’s body to third-person multisensory body representation, and from basic forms of the extended and social selves to progressively more complex forms of abstract self-representation. It discusses how each of them might emerge based on domain-general learning mechanisms, while also taking into account the potential role of innate representations. Finally, it discusses how predictions of the proposed model might be experimentally tested.
... Finally, a cluster of activity in the ACC was also observed in the RSA as well as a small cluster during the univariate task contrast of self > stranger actions. While ACC engagement may be due to multiple reasons including multimodal processing and integration of self-related information (Apps and Tsakiris, 2014;Morita et al., 2014), or salience network involvement (Asakage and Nakano, 2023) a key account of ACC function is related to cognitive conflict (Braver et al., 2001). Prior research has shown that the ACC is involved in discriminating one's own touch from an external touch, with the activity linked to the conflict between expected and actual sensorimotor feedback (Blakemore et al., 1999;Stetson et al., 2006;Kilteni and Ehrsson, 2024). ...
Article
Full-text available
Humans can recognize their whole-body movements even when displayed as dynamic dot patterns. The sparse depiction of whole-body movements, coupled with a lack of visual experience watching ourselves in the world, has long implicated non-visual mechanisms to self-action recognition. We aimed to identify the neural systems for this ability. Using general linear modeling and multivariate analyses on human brain imaging data from male and female participants, we first found that cortical areas linked to motor processes, including frontoparietal and primary somatomotor cortices, exhibit greater engagement and functional connectivity when recognizing self-generated versus other-generated actions. Next, we show that these regions encode self-identity based on motor familiarity, even after regressing out idiosyncratic visual cues using multiple regression representational similarity analysis. Last, we found the reverse pattern for unfamiliar individuals: encoding localized to occipito-temporal visual regions. These findings suggest that self-awareness from actions emerges from the interplay of motor and visual processes. Significance Statement: We report for the first time that self-recognition from visual observation of our whole-body actions implicates brain regions associated with motor processes. On functional neuroimaging data, we found greater activity and unique representational patterns in brain areas and networks linked to motor processes when viewing our own actions relative to viewing the actions of others. These findings introduce an important role of motor mechanisms in distinguishing the self from others.
... The predictive coding theoretical framework (Porciello et al., 2018) highlights the role of multisensory integration mechanisms in constructing bodily self-representation, as well as in facilitating bodily self-recognition and plasticity (Srinivasan et al., 1982;Mumford, 1992;Rao and Ballard, 1999;Kilner et al., 2007;Friston, 2011;Apps and Tsakiris, 2014;Badoud and Tsakiris, 2017). Bastos et al. (2012) and Clark (2013) emphasize an 'action-oriented' perspective on how we perceive the world, aligning with Friston's (2011) notion that our sensory experiences and our self-awareness are understood through a probabilistic lens, supporting the notion of 'predictive coding' in cognition with situated environmental data modalities. ...
Article
Full-text available
This article explores the dynamic interplay between human and non-human entities, focusing on how embodied data representation is distributed. It examines how predictive coding, which utilizes preconceived knowledge, interacts with tangible experiences to shape our understanding of the world. Emphasizing this, I propose the concept of co-Ability as a deep underlying explanatory framework for understanding adaptive behaviors within a networked world. A non-verbal dialog between humans and a data-saturated environment is analyzed through an action-oriented perspective and the predictive coding framework in cognition, utilizing digital craft and rapid prototyping. This transformative approach augments human interaction with digital landscapes through tangible prototypes, bridging physical experience with abstract information, and identifying potential ways to conceptualize data materially. The article discusses the various aspects of connectivity among network agents and the evolving nature of these connections as they adapt to real-world conditions and dynamic shifts in data, highlighting that information exchange in an interconnected network is more than bilateral; it generates ripple effects that extend beyond immediate connections. These reciprocal exchanges simultaneously alter both the digital and analog domains, with data constantly bifurcating into multiple pathways and outcomes. A significant challenge addressed in this article is the question of how to frame information materially, inviting further exploration.
... The observed superiority of naturalistic haptic versus visual feedback can also be explained within the context of the concept and theory of predictive coding (Apps & Tsakiris, 2014;Owens et al., 2018). During perception, incoming sensory information is aligned with a priori models. ...
Article
Full-text available
The perception of signals from within the body, known as interoception, is increasingly recognized as a prerequisite for physical and mental health. This study is dedicated to the development of effective technological approaches for enhancing interoceptive abilities. We provide evidence of the effectiveness and practical feasibility of a novel real‐time haptic heartbeat supplementation technology combining principles of biofeedback and sensory augmentation. In a randomized controlled study, we applied the developed naturalistic haptic feedback on a group of 30 adults, while another group of 30 adults received more traditional real‐time visual heartbeat feedback. A single session of haptic, but not visual heartbeat feedback resulted in increased interoceptive accuracy and confidence, as measured by the heart rate discrimination task, and in a shift of attention toward the body. Participants rated the developed technology as more helpful and pleasant than the visual feedback, thus indicating high user satisfaction. The study highlights the importance of matching sensory characteristics of the feedback provided to the natural bodily prototype. Our work suggests that real‐time haptic feedback might be a superior approach for strengthening the mind–body connection in interventions for physical and mental health.
... According to this concept, the brain is seen as a complex neural system that continually acticipates the next external and internal state (Clark, 2013;Friston, 2010). This includes the body's position (Brown et al., 2011), the physiological state (Apps & Tsakiris, 2014), and mental states (Fotopoulou & Tsakiris, 2017). Within L.F. Barrett's theory of constructed emotions, emotions are associated with interpersonal predictions: an emotional "response" arises due to the expectation of some actions from a partner, even before the actions are performed-or not performed (Barrett, 2017). ...
... The Concept of Predictive Coding and Psychotherapy. Studies in the last decade have explained the functional role of the mentalization and empathy neural networks within the framework of the concept of predictive coding, whereby the brain is represented as a complex neural network system providing accurate prediction of sequential external and internal states [Friston, 2010;Clark, 2013], including body position [Brown et al., 2011], the internal state of the body [Apps and Tsakiris, 2014], and mental states [Fotopoulou and Tsakiris, 2017]. Within the framework of Barrett's theory of constructed emotions, emotions are associated with interpersonal predictions: an emotional "reaction" arises from the expectation of a particular action from a partner even before this action is or is not performed [Barrett, 2017;Barrett, 2018]. ...
Article
The article presents a review and analysis of literature aimed at grounding psychotherapy within the context of contemporary neuroscientific concepts. It is suggested that on the neural level psychotherapy is associated with changes in the mentalizing and empathy networks’ connectivity. Several mechanisms underlying these changes are proposed: enhancement of the prefrontal system’s role in arousal regulation, oxytocin-related modulation of the attachment system, and optimization of predictive coding of interpersonal perception, including the prediction error processing pathway. The hypotheses are supported by studies in social, cognitive, affective and behavioral neuroscience, research in the field of psychotherapy, and neuroimaging data on the effects of psychotherapy.
... This discrepancy in the effect of IMS and avatar weight on subjective and objective measures of self-body image perception can be interpreted in light of predictive coding accounts of self-recognition and embodiment illusion, also taking into consideration the features of the perceptual and affective/cognitive components of Body Image Distortion in anorexia nervosa. In line with the predictive coding theory [65,66], the spatial-temporal alignment between the two touches initially elicits surprise because participants are directed not to move, preventing them from confirming whether the observed body part truly belongs to them [67]. Furthermore, the observed body does not align with the stored visual representation of the self-body [16,17]. ...
Article
Full-text available
Body image distortion (BID) is a crucial aspect of anorexia nervosa (AN), leading to body overestimation, dissatisfaction, and low self-esteem. BID significantly influences the onset, maintenance, and relapse of the pathology. We assessed whether a Full Body Illusion (FBI) using under and normal-weight avatars’ bodies affects perceptual body image and body schema estimations in both individuals with anorexia nervosa (AN) and healthy controls (HC). After each embodiment procedure, we asked participants to estimate the width of their hips (Perceptual Body Image Task) and the minimum aperture width of a virtual door necessary to pass through it (Body Schema Task). Additionally, we asked participants to rate the avatars in terms of self-similarity, attractiveness, and implicit disgust (i.e., pleasant/unpleasant body odour). Whereas participants with AN (N = 26) showed changes in body schema estimations after embodying the normal-weight avatar, no changes were found in HC (N = 25), highlighting increased bodily self-plasticity in AN. Notably, individuals with AN rated the normal weight avatar as the most similar to their real body, which was also considered the least attractive and the most repulsive. These ratings correlated with BID severity. Furthermore, at the explicit level, all participants reported feeling thinner than usual after embodying the underweight avatar. Overall, our findings suggest that BID in AN engages multiple sensory channels (from visual to olfactory) and components (from perceptual to affective), offering potential targets for innovative non-invasive treatments aimed at modifying flexible aspects of body representation.
... Under the active inference framework, the self has been cast as the globally available partition of a system's "best guess" at the underlying cause of multi-modal sensory information and is encoded at "higher" levels of the hierarchical, predictive system that the organism embodies (Friston, 2012a(Friston, , 2018Limanowski and Blankenburg, 2013;Apps and Tsakiris, 2014;Hohwy and Michael, 2017;Deane, 2020Deane, , 2021Deane et al., 2020;Limanowski and Friston, 2020). Prima facie, this might seem puzzling, since we might be inclined to associate our observations with the apparently external, latent causes that engender them. ...
Article
Full-text available
Flow has been described as a state of optimal performance, experienced universally across a broad range of domains: from art to athletics, gaming to writing. However, its phenomenal characteristics can, at first glance, be puzzling. Firstly, individuals in flow supposedly report a loss of self-awareness, even though they perform in a manner which seems to evince their agency and skill. Secondly, flow states are felt to be effortless, despite the prerequisite complexity of the tasks that engender them. In this paper, we unpick these features of flow, as well as others, through the active inference framework, which posits that action and perception are forms of active Bayesian inference directed at sustained self-organisation; i.e., the minimisation of variational free energy. We propose that the phenomenology of flow is rooted in the deployment of high precision weight over (i) the expected sensory consequences of action and (ii) beliefs about how action will sequentially unfold. This computational mechanism thus draws the embodied cognitive system to minimise the ensuing (i.e., expected) free energy through the exploitation of the pragmatic affordances at hand. Furthermore, given the challenging dynamics the flow-inducing situation presents, attention must be wholly focussed on the unfolding task whilst counterfactual planning is restricted, leading to the attested loss of the sense of self-as-object. This involves the inhibition of both the sense of self as a temporally extended object and higher–order, meta-cognitive forms of self-conceptualisation. Nevertheless, we stress that self-awareness is not entirely lost in flow. Rather, it is pre-reflective and bodily. Our approach to bodily-action-centred phenomenology can be applied to similar facets of seemingly agentive experience beyond canonical flow states, providing insights into the mechanisms of so-called selfless experiences, embodied expertise and wellbeing.
... These models are applied to predict incoming sensory inputs, thus reducing processing effort and facilitating environmental adaptation (Clark, 2013;Hohwy, 2013;Friston, 2010). Although prediction is largely accepted as an explanatory mechanism within numerous cognitive domains (Apps & Tsakiris, 2014;Horga, Schatz, Abi-Dargham, & Peterson, 2014;Koster-Hale & Saxe, 2013), a longstanding debate remains within the cognitive neuroscience of language between prediction-based and integrationist theories of language processing (cf., e.g., Ferreira & Chantavarin, 2018). Prediction theories propose that the brain anticipates upcoming linguistic content in a top-down manner, whereas integrationist theories argue that language comprehension proceeds via the bottom-up integration of linguistic units with the prior context (for summaries and discussion, see Mantegna, Hintz, Ostarek, Alday, & Huettig, 2019;Kuperberg & Jaeger, 2016;Van Petten & Luka, 2012). ...
Article
Full-text available
The extent to which the brain predicts upcoming information during language processing remains controversial. To shed light on this debate, the present study reanalyzed Nieuwland and colleagues' (2018) [Nieuwland, M. S., Politzer-Ahles, S., Heyselaar, E., Segaert, K., Darley, E., Kazanina, N., et al. Large-scale replication study reveals a limit on probabilistic prediction in language comprehension. eLife, 7, e33468, 2018] replication of DeLong and colleagues (2015) [DeLong, K. A., Urbach, T. P., & Kutas, M. Probabilistic word pre-activation during language comprehension inferred from electrical brain activity. Nature Neuroscience, 8, 1117–1121, 2005]. Participants (n = 356) viewed sentences containing articles and nouns of varying predictability, while their EEG was recorded. We measured ERPs preceding the critical words (namely, the semantic prediction potential), in conjunction with postword N400 patterns and individual neural metrics. ERP activity was compared with two measures of word predictability: cloze probability and lexical surprisal. In contrast to prior literature, semantic prediction potential amplitudes did not increase as cloze probability increased, suggesting that the component may not reflect prediction during natural language processing. Initial N400 results at the article provided evidence against phonological prediction in language, in line with Nieuwland and colleagues' findings. Strikingly, however, when the surprisal of the prior words in the sentence was included in the analysis, increases in article surprisal were associated with increased N400 amplitudes, consistent with prediction accounts. This relationship between surprisal and N400 amplitude was not observed when the surprisal of the two prior words was low, suggesting that expectation violations at the article may be overlooked under highly predictable conditions. Individual alpha frequency also modulated the relationship between article surprisal and the N400, emphasizing the importance of individual neural factors for prediction. The present study extends upon existing neurocognitive models of language and prediction more generally, by illuminating the flexible and subject-specific nature of predictive processing.
... According to the predictive processing framework, at all levels of the cognitive hierarchy, the brain is continuously seeking to reduce discrepancies between what is expected and incoming information it receives from the senses [8][9][10][11] . As a result of minimising these discrepancies, a parsimonious explanation of sensory input will result in a model of the self 12 . In combining prior expectations and incoming sensory information iteratively throughout the lifespan to optimise future expectations, this Bayesian approach to self-knowledge blurs boundaries between perception and cognition and unifies traditionally distinct domains of perception and action. ...
Article
Full-text available
Pregnancy is a time of profound upheaval of the self, when in addition to undergoing dramatic physical changes to accommodate a developing foetus, significant cognitive and social transformations occur in preparation for birth and parenthood. So far, research into cognitive constructions of the self has been either infant-centric or psychopathology-focused, so our understanding of the healthy, changing self in pregnancy remains relatively poor. This online experiment uses online questionnaires and two cognitive tasks to investigate how constructs relating to the mental self-model, including body representation, self-concept clarity, sense of agency, general self-efficacy and self-attribute learning, differ between first-time pregnant (n = 100) and never-been pregnant (n = 102) women. Results indicate that first-time pregnancy is associated with a significantly higher sense of body agency, body visibility, and body estrangement. Poorer accuracy for newly learned associations was also observed in the pregnant group. Whilst a typical self-processing bias was observed in both groups as expected, an intentional binding effect was absent. Notably, post-hoc exploratory analyses provide initial evidence for trimester effects, with a decisively higher self-reported sense of negative agency in the first trimester compared to the never-pregnant group and other trimesters. Further, body agency and self-efficacy were higher in the second-trimester group compared to the never-pregnant group, suggesting a period of relative recovery and consolidation of the new self. Taken together, our results suggest that aspects of self-representation and agency undergo significant shifts over the course of pregnancy and provide multiple exciting avenues for future research.
... Close to Friston's is Kiverstein's view (Kiverstein, 2020). Less deflationary are those accounts that see the self as an inferred hidden cause of sensory experience (Apps & Tsakiris, 2014;Letheby & Gerrans, 2017). Through the process of prediction-error minimization, the organism gives "constant evidence for its own existence". ...
Book
Full-text available
I had my first electroencephalogram done when I was eight years old. This uncomfortable ritual involved scrubbing the scalp with alcohol at specific points and attaching electrodes to those points to record the brain activity. After the preparation, the machine started buzzing, an endless sheet of paper was fed in, and the inked waveform patterns emerged. A cryptic chronicle of what I was thinking and feeling, of Me, being written in real-time for everyone to see. Could the doctors observe what I was thinking about them and their tedious procedure? Well, even at that age, I did know that they could not see my thoughts, though they could observe if I was drowsing off, that is, if I was not doing what they had instructed me to do, and this made me anxious and scared. Afterwards, looking at this thick book of wavy etchings, which depicted only half an hour of my conscious life, I was not able to connect it with myself; how was this about Me? What did these waves on paper say about me and my experiences? The disconnection between what is inside and what outside, the first and third-person perspectives, still haunts me today as it did when I was a child, although I did not refer to it as such.
... The studies supporting the predictive models approaches are increasing and-such as, for example, the model of Friston, based on the free-energy principle and Bayesian inference [38]-have also been applied in BA research, for example in the investigation of anosognosia for hemiplegia [39,40] and self-recognition [41]. This framework represents an alternative perspective to the modular view of neural systems, motor functions, and selfawareness. ...
Article
Full-text available
In the last two decades, the scientific literature on so-called body representations has been increasing, and the notion of body awareness (BA) is particularly interesting for neurorehabilitation. In this article, we present results derived from recent studies on this representation, considering the different definitions and explicative models proposed as well as the empirical settings used to test it, providing an extensive overview of these issues. This article discusses the challenge of understanding how we integrate the sensory experiences of proprioception (knowing where our body is in space) and interoception (sensing internal bodily sensations, like hunger of thirst) with our perception of self. This is a difficult problem to analyze because our awareness of our body is inherently linked to our perspective, since the body is the means through which we interact with the world. Presenting the different viewpoints offered by recent theories on this concern, we highlighted that the neurorehabilitation and psychiatric settings offer two important fields useful for the study of BA because in them it is possible to analyze bodily representations by inducing/observing a controlled discrepancy between dysfunctional content and sensory inputs.
... Predictive coding is an influential theory in neuroscience and cognitive science, proposing a framework for understanding how the brain processes information and interacts with the world [10]. Central to this approach is the idea that the brain is constantly generating and updating a model of the environment to predict sensory input, rather than passively receiving and reacting to external stimuli [11]. The predictive coding approach, with its emphasis on the brain's predictive processes and error minimization, offers innovative perspectives and therapeutic strategies for improving mental health [12,13]. ...
Article
Full-text available
Purpose of Review We review the first pilot studies applying metaverse-related technologies in psychiatric patients and discuss the rationale for using this complex federation of technologies to treat mental diseases. Concerning previous virtual-reality applications in medical care, metaverse technologies provide the unique opportunity to define, control, and shape virtual scenarios shared by multi-users to exploit the “synchronized brains” potential exacerbated by social interactions. Recent Findings The application of an avatar-based sexual therapy program conducted on a metaverse platform has been demonstrated to be more effective concerning traditional sexual coaching for treating female orgasm disorders. Again, a metaverse-based social skills training program has been tested on children with autism spectrum disorders, demonstrating a significant impact on social interaction abilities. Summary Metaverse-related technologies could enable us to develop new reliable approaches for treating diseases where behavioral symptoms can be addressed using socio-attentive tasks and social-interaction strategies.
... Recent advances in computational neuroscience have begun to be successfully applied to the study of the "self" (Metzinger, 2004;Seth et al., 2012;Allen and Friston, 2018;Apps and Tsakiris, 2014;Ishida et al., 2015). The self, as understood in the context of active inference, is a probabilistic concept that is based on an agent's ability to process self-related information through a multimodal hierarchical cortical network designed to approximate Bayesian inference (Seth and Tsakiris, 2018a). ...
Article
Full-text available
Self-esteem, the evaluation of one’s own worth or value, is a critical aspect of psychological well-being and mental health. In this paper, we propose an active inference account of self-esteem, casting it as a sociometer or an inferential capacity to interpret one’s standing within a social group. This approach allows us to explore the interaction between an individual’s self-perception and the expectations of their social environment.When there is a mismatch between these perceptions and expectations, the individual needs to adjust their actions or update their self-perception to better align with their current experiences. We also consider this hypothesis in relation with recent research on affective inference, suggesting that self-esteem enables the individual to track and respond to this discrepancy through affective states such as anxiety or positive affect. By acting as an inferential sociometer, self-esteem allows individuals to navigate and adapt to their social environment, ultimately impacting their psychological well-being and mental health.
... Following the generative model established by Friston (cf. Friston, 2010, and its application to the self, Apps & Tsakiris, 2014;Tsakiris, 2017) one can say that the self, in part, is based on predicting what happens next. This, obviously requires a longer timescale beyond the short one of the actual stimuli or input with its particular point in time. ...
Article
Full-text available
Does artificial intelligence (AI) exhibit consciousness or self? While this question is hotly debated, here we take a slightly different stance by focusing on those features that make possible both, namely a basic or fundamental subjectivity. Learning from humans and their brain, we first ask what we mean by subjectivity. Subjectivity is manifest in the perspectiveness and mineness of our experience which, ontologically, can be traced to a point of view. Adopting a non-reductive neurophilosophical strategy, we assume that the point of view exhibits two layers, a most basic neuroecological and higher order mental layer. The neuroecological layer of the point of view is mediated by the timescales of world and brain, as further evidenced by empirical data on our sense of self. Are there corresponding timescales shared with the world in AI and is there a point of view with perspectiveness and mineness? Discussing current neuroscientific evidence, we deny that current AI exhibits a point of view, let alone perspectiveness and mineness. We therefore conclude that, as per current state, AI does not exhibit a basic or fundamental subjectivity and henceforth no consciousness or self is possible in models such as ChatGPT and similar technologies.
... Recent advances in computational neuroscience have begun to be successfully applied to the study of the "self" [43][44][45][46][47]. The self, as understood in the context of active inference, is a probabilistic concept that is based on an agent's ability to process self-related information through a multimodal hierarchical cortical network designed to approximate Bayesian inference [48]. ...
Preprint
Full-text available
Self-esteem, the evaluation of one's own worth or value, is a critical aspect of psychological well-being and mental health. In this paper, we propose an active inference account of self-esteem, casting it as a sociometer, or an inferential capacity to interpret one's standing within a social group. This approach allows us to explore the interaction between an individual's self-perception and the expectations of their social environment.When there's a mismatch between these perceptions and expectations, the individual needs to adjust their actions or update their self-perception to better align with their current experiences. We also consider this hypothesis in relation to recent research on affective inference, suggesting that self-esteem enables the individual to track and respond to this discrepancy through affective states such as anxiety or positive affect. By acting as an inferential sociometer, self-esteem allows individuals to navigate and adapt to their social environment, ultimately impacting their psychological well-being and mental health.
Preprint
Full-text available
Objective: Self-face perception is critical to physical self-concept, yet its importance in body image disorders among males is underexplored. This study examines how self-face recognition accuracy and evaluations are influenced by the severity of body dysmorphic disorder (BDD) and muscle dysmorphia (MD) symptoms in males and whether symptom severity moderates the relationship between recognition accuracy and evaluations. Methods: Sixty-eight White and East/Southeast Asian males in Australia completed measures assessing BDD and MD symptoms (appearance intolerance, drive for size, and functional impairment), self-face recognition accuracy (self-reported difficulty and objective sensitivity using a video-morphing task), and self-face evaluations (perceived attractiveness, adiposity, and dissatisfaction). Results: Hierarchical regressions revealed that higher BDD symptoms and MD-related appearance intolerance predicted greater self-reported recognition difficulties and more negative evaluations (lower attractiveness, higher dissatisfaction). However, symptoms were unrelated to objective recognition sensitivity and perceived adiposity. Preliminary analyses suggested that recognition accuracy and evaluations were also unrelated, with no moderating effects of symptom severity. Conclusions: These findings suggest that elevated BDD and MD symptoms, particularly appearance intolerance, disrupt self-face recognition and evaluations in males. Addressing these disturbances could enhance theoretical models of body image. Future research should investigate these processes in diverse clinical populations and longitudinal contexts before considering implications for intervention.
Preprint
Full-text available
Embodiment illusion research suggests impaired multisensory integration in individuals with eating disorders (EDs), whilst offering potential therapeutic applications. However, face-related illusions remain unexplored. This study investigated the relationship between ED risk, susceptibility to the enfacement illusion, and improvements in face and body image disturbance after experiencing enfacement. Female Caucasian and Asian participants ( N = 226), categorised as high ED risk ( n = 102, 45.1%) or low ED risk ( n = 124, 54.9%), completed an online assessment featuring a novel enfacement illusion task involving synchronous and asynchronous facial mimicry. We assessed subjective (self-report) and objective (self-face recognition task) enfacement, alongside pre- and post-task self-reported face and body image disturbance. Multilevel modelling revealed successful enfacement induction across participants, with models explaining 3–11% unique variance in enfacement measures. While both groups showed similar illusion susceptibility, the effects of enfacement diverged significantly: high ED-risk participants experienced increased body and head dissatisfaction, whereas low ED-risk participants demonstrated reduced body dissatisfaction and dysmorphic concern (20-29% unique variance explained). These findings suggest a potential dissociation between face and body perception processes, whereby face-related multisensory integration processes may remain intact in ED populations, despite potentially adverse effects of enfacement on face and body image in high-ED-risk individuals.
Article
Full-text available
The paradox of a brain trying to study itself presents a conundrum, raising questions about self-reference, consciousness, psychiatric disorders, and the boundaries of scientific inquiry. By which means can this complex organ shift the focus of study towards itself? We aim at unpacking the intricacies of this paradox. Historically, this question has been raised by philosophers under different frameworks. Thanks to the development of novel techniques to study the brain on a functional and structural level - as well as neurostimulation protocols that can modulate its activity in selected areas - we now possess advanced methods to progress this intricate inquiry. Nonetheless, the broader implications of the brain's pursuit of understanding itself remain unclear to this day. Ultimately, the need to employ both perception and introspection has led to different formulations of consciousness. This creates a challenge, as evidence supporting one formulation does not necessarily support the other. By deconstructing the paradoxical nature of self understanding - from a philosophical and neuroscientific point of view - we may gain insights into the human brain, which could lead to improved understanding of self-awareness and consciousness.
Article
In recent years, the frequent use of beauty filters has attracted interest for its potential impact on body self-awareness, with various psychological and social implications, especially in adolescents and young women. The widespread use of beauty filters on digital platforms allows people to manipulate their facial and physical features, raising concerns about their influence on the perception of one’s body. Indeed, by distorting and altering one’s physical appearance to conform to online beauty standards, these filters could influence individuals’ self-concept, potentially contributing to the emergence of mental disorders. Despite its importance, contemporary literature has yet to comprehensively explore this relationship, which this article aims to briefly discuss with some preliminary evidence.
Article
Physiological needs evoke motivational drives that produce natural behaviors for survival. In previous studies, the temporally intertwined dynamics of need and motivation have made it challenging to differentiate these two components. On the basis of classic homeostatic theories, we established a normative framework to derive computational models for need-encoding and motivation-encoding neurons. By combining the model-based predictions and naturalistic experimental paradigms, we demonstrated that agouti-related peptide (AgRP) and lateral hypothalamic leptin receptor (LH LepR) neuronal activities encode need and motivation, respectively. Our model further explains the difference in the dynamics of appetitive behaviors induced by optogenetic stimulation of AgRP or LH LepR neurons. Our study provides a normative modeling framework that explains how hypothalamic neurons separately encode need and motivation in the mammalian brain.
Chapter
Full-text available
A recent wave of research in psychiatry and neuroscience has re-examined the properties of ‘classic’ psychedelic substances—also known as serotonergic hallucinogens—such as psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT). Evidence to date suggests that psychedelics can be given safely in controlled conditions, at moderate to high doses, and may have potential as therapeutic agents in the treatment of various addictive and mood disorders. The main mechanism of action appears to be the induction of a dramatically altered state of consciousness, but the details of how psychedelic-assisted psychotherapy works are hotly debated, as are the relations between psychedelic experiences themselves and the neural changes induced by the drugs. The chapters collected in this volume address the fascinating philosophical questions raised by the renewed psychiatric use of psychedelics. The topics of these chapters cluster around three main themes, in terms of which the volume is organized. Chapters in Section One, ‘Self and Mind’, ask: what can we learn about the self and the mind from psychedelic science? Chapters in Section Two, ‘Science and Psychiatry’, address methodological, theoretical, and clinical questions concerning how psychedelics can best be studied scientifically and used therapeutically, and how they might work to relieve psychiatric suffering. Finally, chapters in Section Three, ‘Ethics and Spirituality’, address broader questions about the interpretation of psychedelic experience, its ethical implications, and its possible role(s) in the broader culture.
Article
Full-text available
Episodic memories are experienced as belonging to a self that persists in time. We review evidence concerning the nature of human episodic memory and of the sense of self and how these emerge during development, proposing that the younger child experiences a persistent self that supports a subjective experience of remembering. We then explore recent research in cognitive architectures for robotics that has investigated the possibility of forms of synthetic episodic and autobiographical memory. We show that recent advances in generative modeling can support an understanding of the emergence of self and of episodic memory, and that cognitive architectures which include a language capacity are showing progress towards the construction of a narrative self with autobiographical memory capabilities for robots. We conclude by considering the prospects for a more complete model of mental time travel in robotics and the implications of this modeling work for understanding human episodic memory and the self in time. This article is part of the theme issue ‘Elements of episodic memory: lessons from 40 years of research’.
Article
This paper reviews biophysical models of psychotherapeutic change based on synergetics and the free energy principle. These models suggest that introducing sensory surprise into the patient-therapist system can lead to self-organization and the formation of new attractor states, disrupting entrenched patterns of thoughts, emotions, and behaviours. We propose that the therapist can facilitate this process by cultivating epistemic trust and modulating embodied attention to allow surprising affective states to enter shared awareness. Transient increases in free energy enable the update of generative models, expanding the range of experiences available within the patient-therapist phenomenal field. We hypothesize that patterns of disorganization at behavioural and physiological levels, indexed by increased entropy, complexity, and lower determinism, are key markers and predictors of psychotherapeutic gains. Future research should investigate how the therapist's openness to novelty shapes therapeutic outcomes.
Article
Full-text available
The enfacement illusion is a facial version of the rubber hand illusion, in which participants experience tactile stimulation of their own faces synchronously with the observation of the same stimulation applied to another’s face. In previous studies, participants have reported experiencing an illusory embodiment of the other’s face following synchronous compared to asynchronous stimulation. In a series of three experiments, we addressed the following three questions: (i) how does similarity between the self and the other, operationalized here as being of the same or different gender to the other, impact the experience of embodiment in the enfacement illusion; (ii) does the experience of embodiment result from alterations to the self-concept; and (iii) is susceptibility to the experience of embodiment associated with interoceptive processing, i.e. perception of the internal state of the body? Results indicate that embodiment is facilitated by the similarity between the self and the other and is mediated by the incorporation of the other into the self-concept, but sensitivity to one’s own internal states does not impact upon embodiment within the enfacement illusion. This article is part of the theme issue ‘Minds in movement: embodied cognition in the age of artificial intelligence’.
Article
Full-text available
Background: Humans perceive and interpret the world through the lens of self-reference processes, typically facilitating enhanced performance for the task at hand. However, this research has predominantly emphasized the automatic facet of self-reference processing, overlooking how it interacts with control processes affecting everyday situations. Methods: We investigated this relationship between automatic and control self-reference processing in neuropsychological patients performing self-face perception tasks and the Birmingham frontal task measuring executive functions. Results: Principal component analysis across tasks revealed two components: one loaded on familiarity/orientation judgments reflecting automatic self-reference processing, and the other linked to the cross task and executive function indicating control processing requirements. Voxel-based morphometry and track-wise lesion-mapping analyses showed that impairments in automatic self-reference were associated with reduced grey matter in the ventromedial prefrontal cortex and right inferior temporal gyrus, and white matter damage in the right inferior fronto-occipital fasciculus. Deficits in executive control were linked to reduced grey matter in the bilateral inferior parietal lobule and left anterior insula, and white matter disconnections in the left superior longitudinal fasciculus and arcuate fasciculus. Conclusions: The causal evidence suggests that automatic and control facets of self-reference processes are subserved by distinct yet integrated ventral prefrontal–temporal and dorsal frontal–parietal networks, respectively.
Article
Full-text available
To understand how the human brain distinguishes itself from external stimulation, it was examined if motor predictions enable healthy adult volunteers to infer self-location and to distinguish their body from the environment (and other agents). By uniquely combining a VR-setup with full-body motion capture, a full-body illusion paradigm (FBI) was developed with different levels of motion control: (A) a standard, passive FBI in which they had no motion control; (B) an active FBI in which they made simple, voluntary movements; and (C) an immersive game in which they real-time controlled a human-sized avatar in third person. Systematic comparisons between measures revealed a causal relationship between (i) motion control (prospective agency), (ii) self-other identification, and (iii) the ability to locate oneself. Healthy adults could recognise their movements in a third-person avatar and psychologically align with it (action observation); but did not lose a sense of place (self-location), time (temporal binding), nor who they are (self/other). Instead, motor predictions enabled them to localise their body and to distinguish self from other. In the future, embodied games could target and strengthen the brain’s control networks in psychosis and neurodegeneration; real-time motion simulations could help advance neurorehabilitation techniques by fine-tuning and personalising therapeutic settings.
Article
The coherent perceptual experience of one's own body depends on the processing and integration of signals from multiple sensory modalities, including vision, touch, and proprioception. Although nociception provides critical information about damage to the tissues of one's body, little is known about how nociception contributes to own-body perception. A classic experimental approach to investigate the perceptual and neural mechanisms involved in the multisensory experience of one's own body is the rubber hand illusion (RHI). During the RHI, people experience a rubber hand as part of their own body (sense of body ownership) caused by synchronized stroking of the rubber hand in the participant's view and the hidden participant's real hand. We examined whether the RHI can be elicited by visual and “pure” nociceptive stimulation, ie, without tactile costimulation, and if so, whether it follows the basic perceptual rules of the illusion. In 6 separate experiments involving a total of 180 healthy participants, we used a Nd:YAP laser stimulator to specifically target C and Aδ fibers in the skin and compared the illusion condition (congruent visuonociceptive stimulation) to control conditions of incongruent visuonociceptive, incongruent visuoproprioceptive, and no nociceptive stimulation. The illusion was quantified through direct (questionnaire) and indirect (proprioceptive drift) behavioral measures. We found that a nociceptive rubber hand illusion (N-RHI) could be elicited and that depended on the spatiotemporal congruence of visuonociceptive signals, consistent with basic principles of multisensory integration. Our results suggest that nociceptive information shapes multisensory bodily awareness and contributes to the sense of body ownership.
Article
Full-text available
It has been shown that observing a face being touched or moving in synchrony with our own face increases self-identification with the former which might alter both cognitive and affective processes. The induction of this phenomenon, termed enfacement illusion, has often relied on laboratory tools that are unavailable to a large audience. However, digital face filters applications are nowadays regularly used and might provide an interesting tool to study similar mechanisms in a wider population. Digital filters are able to render our faces in real time while changing important facial features, for example, rendering them more masculine or feminine according to normative standards. Recent literature using full-body illusions has shown that participants’ own gender identity shifts when embodying a different gendered avatar. Here we studied whether participants’ filtered faces, observed while moving in synchrony with their own face, may induce an enfacement illusion and if so, modulate their gender identity. We collected data from 35 female and 33 male participants who observed a stereotypically gender mismatched version of themselves either moving synchronously or asynchronously with their own face on a screen. Our findings showed a successful induction of the enfacement illusion in the synchronous condition according to a questionnaire addressing the feelings of ownership, agency and perceived similarity. However, we found no evidence of gender identity being modulated, neither in explicit nor in implicit measures of gender identification. We discuss the distinction between full-body and facial processing and the relevance of studying widely accessible devices that may impact the sense of a bodily self and our cognition, emotion and behaviour.
Article
Sense of ownership and agency are two important aspects of the minimal self, but how self-perception is affected by social conditions remains unclear. Here, we studied how social inclusion or exclusion of participants in the course of a virtual Cyberball game would affect explicit judgments and implicit measures of ownership and agency (proprioceptive drift, skin conductance responses, and intentional binding, respectively) in a virtual hand illusion paradigm, in which a virtual hand moved in or out of sync with the participants’ own hand. Results show that synchrony affected all four measures. More importantly, this effect interacted with social inclusion/exclusion in the Cyberball game for both ownership and agency measure, showing that social exclusion reduces perceived agency and ownership.
Article
In the study of bodily awareness, the predictive coding theory has revealed that our brain continuously modulates sensory experiences to integrate them into a unitary body representation. Indeed, during multisensory illusions (e.g., the rubber hand illusion, RHI), the synchronous stroking of the participant’s concealed hand and a fake visible one creates a visuotactile conflict, generating a prediction error. Within the predictive coding framework, through sensory processing modulation, prediction errors are solved, inducing participants to feel as if touches originated from the fake hand, thus ascribing the fake hand to their own body. Here, we aimed to address sensory processing modulation under multisensory conflict, by disentangling somatosensory and visual stimuli processing that are intrinsically associated during the illusion induction. To this aim, we designed two EEG experiments, in which somatosensory- (SEPs; Experiment 1; N = 18; F = 10) and visual-evoked potentials (VEPs; Experiment 2; N = 18; F = 9) were recorded in human males and females following the RHI. Our results show that, in both experiments, ERP amplitude is significantly modulated in the illusion as compared with both control and baseline conditions, with a modality-dependent diametrical pattern showing decreased SEP amplitude and increased VEP amplitude. Importantly, both somatosensory and visual modulations occur in long-latency time windows previously associated with tactile and visual awareness, thus explaining the illusion of perceiving touch at the sight location. In conclusion, we describe a diametrical modulation of somatosensory and visual processing as the neural mechanism that allows maintaining a stable body representation, by restoring visuotactile congruency under the occurrence of multisensory conflicts.
Article
Full-text available
The ventral striatum is considered an interface between limbic and motor systems. We followed the orbital and medial prefrontal circuit through the monkey basal ganglia by analyzing the projection from this cortical area to the ventral striatum and the representation of orbitofrontal cortex via the striatum, in the globus pallidus and substantia nigra. Following injections of Lucifer yellow and horse radish peroxidase into the medial ventral striatum, there is a very densely labeled distribution of cells in areas 13a and 13b, primarily in layers V and VI, and in medial prefrontal areas 32 and 25. Injections into the shell of the nucleus accumbens labeled primarily areas 25 and 32. The reaction product in the globus pallidus and the substantia nigra supports previous studies demonstrating that efferent projections from the ventral striatum are represented topographically in the ventral pallidum and nontopographically in the substantia nigra, pars compacta. Tritiated amino acid or PHA-L tracer injections into orbitofrontal cortex produce dense patches of terminal labeling along the medial edge of the caudate nucleus and the dorsal part of the nucleus accumbens. These results demonstrate that the orbital prefrontal cortex projects primarily to the medial edge of the ventral striatum and to the core of the nucleus accumbens. The arrangement of terminals in the globus pallidus and substantia nigra show two different patterns. Thus, the orbital and medial prefrontal cortex is represented in a confined region of the globus pallidus but throughout an extensive area of the dorsal substantia nigra. Terminals are extensive throughout the region of the dopaminergic neurons, suggesting that this input may influence a wide area of both the striatum and frontal cortex.
Article
Full-text available
Is it possible to understand the intentions of other people by simply observing their actions? Many believe that this ability is made possible by the brain's mirror neuron system through its direct link between action and observation. However, precisely how intentions can be inferred through action observation has provoked much debate. Here we suggest that the function of the mirror system can be understood within a predictive coding framework that appeals to the statistical approach known as empirical Bayes. Within this scheme the most likely cause of an observed action can be inferred by minimizing the prediction error at all levels of the cortical hierarchy that are engaged during action observation. This account identifies a precise role for the mirror system in our ability to infer intentions from actions and provides the outline of the underlying computational mechanisms.
Article
Full-text available
It is well known that you cannot tickle yourself. Here, we discuss the proposal that such attenuation of self-produced tactile stimulation is due to the sensory predictions made by an internal forward model of the motor system. A forward model predicts the sensory consequences of a movement based on the motor command. When a movement is self-produced, its sensory consequences can be accurately predicted, and this prediction can be used to attenuate the sensory effects of the movement. Studies are reviewed that demonstrate that as the discrepancy between predicted and actual sensory feedback increases during self-produced tactile stimulation there is a concomitant decrease in the level of sensory attenuation and an increase in tickliness. Functional neuroimaging studies have demonstrated that this sensory attenuation might be mediated by somatosensory cortex and anterior cingulate cortex: these areas are activated less by a self-produced tactile stimulus than by the same stimulus when it is externally produced. Furthermore, evidence suggests that the cerebellum might be involved in generating the prediction of the sensory consequences of movement. Finally, recent evidence suggests that this predictive mechanism is abnormal in patients with auditory hallucinations and/or passivity experiences. NeuroReport 11:11-16 (C) 2000 Lippincott Williams & Wilkins.
Article
Full-text available
Brains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing. Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to adaptive success. This target article critically examines this "hierarchical prediction machine" approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency.
Article
Full-text available
After prolonged exposure to their reflected images in mirrors, chimpanzees marked with red dye showed evidence of being able to recognize their own reflections. Monkeys did not appear to have this capacity.
Article
Full-text available
A hypothesized 5-stage developmental sequence of self-recognition behaviors was tested in 48 infants between 6 and 24 mo of age, and the self-recognition sequence was compared to the development of object permanence. The predicted self-recognition sequence consisted of 5 tasks that Ss performed in front of the mirror, with later-developing tasks requiring the coordination of a larger number of behaviors relating to S's mirror image than earlier-developing tasks. The development of object permanence was assessed with the Uzgiris-Hunt scale, and the object-permanence items were assigned to stages that structurally paralleled the 5 stages of self-recognition. The self-recognition tasks formed an almost perfect Guttman scale, with 46 out of 48 Ss fitting the predicted developmental sequence precisely. This finding thus resolves most of the disagreements in previous research on the development of self-recognition: Previous studies examined different behaviors, which develop at distinct stages in the sequence. Object permanence and self-recognition showed a strong correlation, but there was no consistent relationship between the 2 skills across age groups. (18 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Full-text available
Is it possible to understand the intentions of other people by simply observing their movements? Many neuroscientists believe that this ability depends on the brain's mirror-neuron system, which provides a direct link between action and observation. Precisely how intentions can be inferred through movement-observation, however, has provoked much debate. One problem in inferring the cause of an observed action, is that the problem is ill-posed because identical movements can be made when performing different actions with different goals. Here we suggest that this problem is solved by the mirror-neuron system using predictive coding on the basis of a statistical approach known as empirical Bayesian inference. This means that the most likely cause of an observed movement can be inferred by minimizing the prediction error at all cortical levels that are engaged during movement observation. This account identifies a precise role for the mirror-neuron system in our ability to infer intentions from observed movement and outlines possible computational mechanisms.
Article
Full-text available
Background: Recent studies have shown that the well-known effect of multisensory stimulation on body-awareness can be extended to self-recognition. Seeing someone else's face being touched at the same time as one's own face elicits changes in the mental representation of the self-face. We sought to further elucidate the underlying mechanisms and the effects of interpersonal multisensory stimulation (IMS) on the mental representation of the self and others. Methodology/principal findings: Participants saw an unfamiliar face being touched synchronously or asynchronously with their own face, as if they were looking in the mirror. Following synchronous, but not asynchronous, IMS, participants assimilated features of the other's face in the mental representation of their own face as evidenced by the change in the point of subjective equality for morphed pictures of the two faces. Interestingly, synchronous IMS resulted in a unidirectional change in the self-other distinction, affecting recognition of one's own face, but not recognition of the other's face. The participants' autonomic responses to objects approaching the other's face were higher following synchronous than asynchronous IMS, but this increase was not specific to the pattern of IMS in interaction with the viewed object. Finally, synchronous, as compared to asynchronous, IMS resulted in significant differences in participants' ratings of their experience, but unlike other bodily illusions, positive changes in subjective experience were related to the perceived physical similarity between the two faces, and not to identification. Conclusions/significance: Synchronous IMS produces quantifiable changes in the mental representations of one's face, as measured behaviorally. Changes in autonomic responses and in the subjective experience of self-identification were broadly consistent with patterns observed in other bodily illusions, but less robust. Overall, shared multisensory experiences between self and other can change the mental representation of one's identity, and the perceived similarity of others relative to one's self.
Article
Full-text available
Visual cortical responses are usually attenuated by repetition, a phenomenon known as repetition suppression (RS). Here, we use multivoxel pattern analyses of functional magnetic resonance imaging (fMRI) data to show that RS co-occurs with the converse phenomenon (repetition enhancement, RE) in a single cortical region. We presented human volunteers with short sequences of repeated faces and measured brain activity using fMRI. In an independently defined face-responsive extrastriate region, the response of each voxel to repetition (RS vs. RE) was consistent across scanner runs, and multivoxel patterns for both RS and RE voxels were stable. Moreover, RS and RE voxels responded to repetition with dissociable latencies and exhibited different patterns of connectivity with lower and higher visual regions. Computational simulations demonstrated that these effects must be due to differences in repetition sensitivity, and not feature selectivity. These findings establish that 2 classes of repetition responses coexist within 1 visual region and support models acknowledging this distinction, such as predictive coding models where perception requires the computation of both predictions (which are enhanced by repetition) and prediction errors (which are suppressed by repetition).
Article
Full-text available
This paper considers state-dependent dynamics that mediate perception in the brain. In particular, it considers the formal basis of self-organized instabilities that enable perceptual transitions during Bayes-optimal perception. The basic phenomena we consider are perceptual transitions that lead to conscious ignition (Dehaene and Changeux, 2011) and how they depend on dynamical instabilities that underlie chaotic itinerancy (Breakspear, 2001; Tsuda, 2001) and self-organized criticality (Beggs and Plenz, 2003; Plenz and Thiagarajan, 2007; Shew et al., 2011). Our approach is based on a dynamical formulation of perception as approximate Bayesian inference, in terms of variational free energy minimization. This formulation suggests that perception has an inherent tendency to induce dynamical instabilities (critical slowing) that enable the brain to respond sensitively to sensory perturbations. We briefly review the dynamics of perception, in terms of generalized Bayesian filtering and free energy minimization, present a formal conjecture about self-organized instability and then test this conjecture, using neuronal (numerical) simulations of perceptual categorization.
Article
Full-text available
Early behavioral studies found that human adults responded faster to their own faces than faces of familiar others or strangers, a finding referred to as self-face advantage. Recent research suggests that the self-face advantage is mediated by implicit positive association with the self and is influenced by sociocultural experience. The current study investigated whether and how Christian belief and practice affect the processing of self-face in a Chinese population. Christian and Atheist participants were recruited for an implicit association test (IAT) in Experiment 1 and a face-owner identification task in Experiment 2. Experiment 1 found that atheists responded faster to self-face when it shared the same response key with positive compared to negative trait adjectives. This IAT effect, however, was significantly reduced in Christians. Experiment 2 found that atheists responded faster to self-face compared to a friend's face, but this self-face advantage was significantly reduced in Christians. Hierarchical regression analyses further showed that the IAT effect positively predicted self-face advantage in atheists but not in Christians. Our findings suggest that Christian belief and practice may weaken implicit positive association with the self and thus decrease the advantage of the self over a friend during face recognition in the believers.
Article
Full-text available
Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one's own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile (VT) stimulation, participants can experience body-ownership over hands that seem to belong to a different racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants' post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition.
Article
Full-text available
If perception corresponds to hypothesis testing (Gregory, 1980); then visual searches might be construed as experiments that generate sensory data. In this work, we explore the idea that saccadic eye movements are optimal experiments, in which data are gathered to test hypotheses or beliefs about how those data are caused. This provides a plausible model of visual search that can be motivated from the basic principles of self-organized behavior: namely, the imperative to minimize the entropy of hidden states of the world and their sensory consequences. This imperative is met if agents sample hidden states of the world efficiently. This efficient sampling of salient information can be derived in a fairly straightforward way, using approximate Bayesian inference and variational free-energy minimization. Simulations of the resulting active inference scheme reproduce sequential eye movements that are reminiscent of empirically observed saccades and provide some counterintuitive insights into the way that sensory evidence is accumulated or assimilated into beliefs about the world.
Article
Full-text available
Recent years have seen the emergence of an important new fundamental theory of brain function. This theory brings information-theoretic, Bayesian, neuroscientific, and machine learning approaches into a single framework whose overarching principle is the minimization of surprise (or, equivalently, the maximization of expectation). The most comprehensive such treatment is the “free-energy minimization” formulation due to Karl Friston (see e.g., Friston and Stephan, 2007; Friston, 2010a,b – see also Fiorillo, 2010; Thornton, 2010). A recurrent puzzle raised by critics of these models is that biological systems do not seem to avoid surprises. We do not simply seek a dark, unchanging chamber, and stay there. This is the “Dark-Room Problem.” Here, we describe the problem and further unpack the issues to which it speaks. Using the same format as the prolog of Eddington’s Space, Time, and Gravitation (Eddington, 1920) we present our discussion as a conversation between: an information theorist (Thornton), a physicist (Friston), and a philosopher (Clark).
Article
Full-text available
In this paper, we review the nature of illusions using the free-energy formulation of Bayesian perception. We reiterate the notion that illusory percepts are, in fact, Bayes-optimal and represent the most likely explanation for ambiguous sensory input. This point is illustrated using perhaps the simplest of visual illusions; namely, the Cornsweet effect. By using plausible prior beliefs about the spatial gradients of illuminance and reflectance in visual scenes, we show that the Cornsweet effect emerges as a natural consequence of Bayes-optimal perception. Furthermore, we were able to simulate the appearance of secondary illusory percepts (Mach bands) as a function of stimulus contrast. The contrast-dependent emergence of the Cornsweet effect and subsequent appearance of Mach bands were simulated using a simple but plausible generative model. Because our generative model was inverted using a neurobiologically plausible scheme, we could use the inversion as a simulation of neuronal processing and implicit inference. Finally, we were able to verify the qualitative and quantitative predictions of this Bayes-optimal simulation psychophysically, using stimuli presented briefly to normal subjects at different contrast levels, in the context of a fixed alternative forced choice paradigm.
Article
Full-text available
Auditory stream segregation involves linking temporally separate acoustic events into one or more coherent sequences. For any non-trivial sequence of sounds, many alternative descriptions can be formed, only one or very few of which emerge in awareness at any time. Evidence from studies showing bi-/multistability in auditory streaming suggest that some, perhaps many of the alternative descriptions are represented in the brain in parallel and that they continuously vie for conscious perception. Here, based on a predictive coding view, we consider the nature of these sound representations and how they compete with each other. Predictive processing helps to maintain perceptual stability by signalling the continuation of previously established patterns as well as the emergence of new sound sources. It also provides a measure of how well each of the competing representations describes the current acoustic scene. This account of auditory stream segregation has been tested on perceptual data obtained in the auditory streaming paradigm.
Article
Full-text available
In this paper, I will try to show that the idea that there can be consciousness without some form of attention, and high-level top-down attention without consciousness, originates from a failure to notice the varieties of forms that top-down attention and consciousness can assume. I will present evidence that: there are various forms of attention and consciousness; not all forms of attention produce the same kind of consciousness; not all forms of consciousness are produced by the same kind of attention; there can be low-level attention (or preliminary attention), whether of an endogenous or exogenous kind, without consciousness; attention cannot be considered the same thing as consciousness.
Article
Full-text available
The nucleus laminaris of the barn owl auditory system is quite impressive, since its underlying time estimation is much better than the processing speed of the involved neurons. Since precise localization is also very important in many technical applications, this paper explores to what extent the main principles of the nucleus laminaris can be implemented in digital hardware. The first prototypical implementation yields a time resolution of about 20 ps, even though the chosen standard, low-cost device is clocked at only 85 MHz, which leads to an internal duty cycle of approximately 12 ns. In addition, this paper also explores the utility of an advanced sampling scheme, known as unfolding-in-time. It turns out that with this sampling method, the prototype can easily process input signals of up to 300 MHz, which is almost four times higher than the sampling rate.
Article
Full-text available
A review on recent experiments on figural face aftereffects reveals that adaptation effects in famous faces can last for hours up to days. Such adaptations seem to be highly reliable regarding test–retest designs as well as regarding the generalizability of adaptation across different adaptation routines and adaptations toward different kinds of facial properties. However, in the studies conducted so far, adaptation and the subsequent test phase were carried out in typical laboratory environments. Under these circumstances, it cannot be ruled out that the observed effects are, in fact, episodic learn–test compatibility effects. To test for ecological validity in adaptation effects we used an adaptation paradigm including environmental and social properties that differed between adaptation and test phase. With matched samples (n1 = n2 = 54) we found no main effects of experimental setting compatibility resulting from varying where the tests where conducted (environmental condition) nor any interaction with effects of stimulus compatibility resulting from varying stimulus similarity between adaptation and test phase using the same picture, different pictures of the same person, or different persons (transfer). This indicates that these adaptation effects are not artificial or merely lab-biased effects. Adaptation to face stimuli may document representational adaptations and tuning mechanisms that integrate new visual input in a very fast, reliable, and sustainable way.
Article
Full-text available
We describe a theoretical model of the neurocognitive mechanisms underlying conscious presence and its disturbances. The model is based on interoceptive prediction error and is informed by predictive models of agency, general models of hierarchical predictive coding and dopaminergic signaling in cortex, the role of the anterior insular cortex (AIC) in interoception and emotion, and cognitive neuroscience evidence from studies of virtual reality and of psychiatric disorders of presence, specifically depersonalization/derealization disorder. The model associates presence with successful suppression by top-down predictions of informative interoceptive signals evoked by autonomic control signals and, indirectly, by visceral responses to afferent sensory signals. The model connects presence to agency by allowing that predicted interoceptive signals will depend on whether afferent sensory signals are determined, by a parallel predictive-coding mechanism, to be self-generated or externally caused. Anatomically, we identify the AIC as the likely locus of key neural comparator mechanisms. Our model integrates a broad range of previously disparate evidence, makes predictions for conjoint manipulations of agency and presence, offers a new view of emotion as interoceptive inference, and represents a step toward a mechanistic account of a fundamental phenomenological property of consciousness.
Article
Full-text available
It has been suggested recently that action and perception can be understood as minimising the free energy of sensory samples. This ensures that agents sample the environment to maximise the evidence for their model of the world, such that exchanges with the environment are predictable and adaptive. However, the free energy account does not invoke reward or cost-functions from reinforcement-learning and optimal control theory. We therefore ask whether reward is necessary to explain adaptive behaviour. The free energy formulation uses ideas from statistical physics to explain action in terms of minimising sensory surprise. Conversely, reinforcement-learning has its roots in behaviourism and engineering and assumes that agents optimise a policy to maximise future reward. This paper tries to connect the two formulations and concludes that optimal policies correspond to empirical priors on the trajectories of hidden environmental states, which compel agents to seek out the (valuable) states they expect to encounter.
Article
Full-text available
Humans can recognize spoken words with unmatched speed and accuracy. Hearing the initial portion of a word such as "formu…" is sufficient for the brain to identify "formula" from the thousands of other words that partially match. Two alternative computational accounts propose that partially matching words (1) inhibit each other until a single word is selected ("formula" inhibits "formal" by lexical competition) or (2) are used to predict upcoming speech sounds more accurately (segment prediction error is minimal after sequences like "formu…"). To distinguish these theories we taught participants novel words (e.g., "formubo") that sound like existing words ("formula") on two successive days. Computational simulations show that knowing "formubo" increases lexical competition when hearing "formu…", but reduces segment prediction error. Conversely, when the sounds in "formula" and "formubo" diverge, the reverse is observed. The time course of magnetoencephalographic brain responses in the superior temporal gyrus (STG) is uniquely consistent with a segment prediction account. We propose a predictive coding model of spoken word recognition in which STG neurons represent the difference between predicted and heard speech sounds. This prediction error signal explains the efficiency of human word recognition and simulates neural responses in auditory regions.
Article
Full-text available
The mismatch negativity (MMN) is thought to index the activation of specialized neural networks for active prediction and deviance detection. However, a detailed neuronal model of the neurobiological mechanisms underlying the MMN is still lacking, and its computational foundations remain debated. We propose here a detailed neuronal model of auditory cortex, based on predictive coding, that accounts for the critical features of MMN. The model is entirely composed of spiking excitatory and inhibitory neurons interconnected in a layered cortical architecture with distinct input, predictive, and prediction error units. A spike-timing dependent learning rule, relying upon NMDA receptor synaptic transmission, allows the network to adjust its internal predictions and use a memory of the recent past inputs to anticipate on future stimuli based on transition statistics. We demonstrate that this simple architecture can account for the major empirical properties of the MMN. These include a frequency-dependent response to rare deviants, a response to unexpected repeats in alternating sequences (ABABAA…), a lack of consideration of the global sequence context, a response to sound omission, and a sensitivity of the MMN to NMDA receptor antagonists. Novel predictions are presented, and a new magnetoencephalography experiment in healthy human subjects is presented that validates our key hypothesis: the MMN results from active cortical prediction rather than passive synaptic habituation.
Article
Full-text available
The articles in this special issue provide a rich and thoughtful perspective on the brain as an inference machine. They illuminate key aspects of the internal or generative models the brain might use for perception. Furthermore, they explore the implications for a sense of agency and the nature of false inference in neuropsychiatric syndromes. In this review, I try to gather together some of the themes that emerge in this special issue and use them to illustrate how far one can take the notion of predictive coding in understanding behaviour and agency.
Article
Full-text available
The ability to attribute mental states to others and understand the basis of their decisions is essential for human social interaction. A controversial theory states that this is achieved by simulating another's information processing in one's own neural circuits. The anterior cingulate cortex (ACC) is known to play an important role in the registration of discrepancies between the predicted and actual outcomes of decisions (prediction errors).When positive and negative feedback fails altogether, the failure may also signal errors in the prediction that the outcome of that decision would be informative and guide future decisions. Does the ACC signal that an outcome is unexpectedly uninformative? When an outcome directed to others is uninformative, do we understand their mental states by simulating them in the circuits of the ACC in our own brain? The aim of our study was to test for these two possibilities in the human brain with event-related fMRI. We tested whether the ACC processes errors in the prediction of informative feedback and whether the ACC is also activated when scanned subjects process the same outcomes of another's decisions. We show that each is processed by a separate subregion of the ACC.
Article
We recorded electrical activity from 532 neurons in the rostral part of inferior area 6 (area F5) of two macaque monkeys. Previous data had shown that neurons of this area discharge during goal-directed hand and mouth movements. We describe here the properties of a newly discovered set of F5 neurons ("mirror neurons', n = 92) all of which became active both when the monkey performed a given action and when it observed a similar action performed by the experimenter. Mirror neurons, in order to be visually triggered, required an interaction between the agent of the action and the object of it. The sight of the agent alone or of the object alone (three-dimensional objects, food) were ineffective. Hand and the mouth were by far the most effective agents. The actions most represented among those activating mirror neurons were grasping, manipulating and placing. In most mirror neurons (92%) there was a clear relation between the visual action they responded to and the motor response they coded. In approximately 30% of mirror neurons the congruence was very strict and the effective observed and executed actions corresponded both in terms of general action (e.g. grasping) and in terms of the way in which that action was executed (e.g. precision grip). We conclude by proposing that mirror neurons form a system for matching observation and execution of motor actions. We discuss the possible role of this system in action recognition and, given the proposed homology between F5 and human Brocca's region, we posit that a matching system, similar to that of mirror neurons exists in humans and could be involved in recognition of actions as well as phonetic gestures.
Article
This article examines the functions performed by each of the "core" face processing regions: the fusiform face area (FFA), occipital face area (OFA), and superior temporal sulcus (fSTS). It reviews the data from two complementary sources: functional imaging in healthy subjects and behavioral data from neurological subjects with damage to these regions. Data from functional neuroimaging allows for the determination of which regions are specifically engaged by which stimuli and which tasks; functional magnetic resonance imaging (fMRI) adaptation and pattern classification methods even allow for the characterisation of the representations extracted in each. However, fMRI can only tell that a given region is sensitive to a particular stimulus property. fMRI cannot depict if the processing requires perceiving that property occurs in that area. In contrast, lesion data can answer the crucial question of whether a given brain region is necessary for a given computation.
Chapter
The chapter reviews recent advances in experimental and computational cognitive neuroscience and argues that there is ample scope for a new discipline within the neurosciences, hereafter called Psychodynamic Neuroscience. This new, specialised field will focus on generating and testing the predictions of classic and contemporary metapsychological models by using the methods and tools of the neurosciences. Advances in both the ‘what’ and the ‘how’ neuroscientists study the brain make psychodynamic neuroscience possible in ways that simply did not exist, even 20 years ago. For starters, the assumption prevailing until the early 90s to the effect that the human mind can be understood by examining exclusively cognitive functions and their neural correlates has undergone considerable criticism. A growing community of researchers claim that mental abilities are defined also by emotions and motivation, are embedded in the acting, sensing and feeling body, and are subject to intricate couplings between organisms and their interpersonal, social and technological environments. In addition to this change in ‘what’ neuroscientists study, there is the dramatic development in ‘how’ they study the brain, and thus what kind of knowledge about brain-mind relations they can arrive at. Recent theoretical and methodological developments in neuroimaging, neurodynamics and computational neuroscience allow direct, large-scale measurement of complex, dynamic and hierarchically organised brain networks. Consequently, this progress calls for a theory of the mind that entails dynamically and hierarchically organised mental processes. Unlike the strictly modular, cognitive models of the mind, Freudian metapsychology, and subsequent psychoanalytic models seem more suitable candidates for interdisciplinary investigation. At the same time, as psychoanalytic concepts have been applied to and modified by explorations of subjective meaning and its vicissitudes in psychopathology, studies in psychodynamic neuroscience can counter the atheoretical and reductionistic approach of some contemporary studies in cognitive neuroscience. The chapter outlines existing examples of interdisciplinary work in order to illustrate how progress can be achieved in psychodynamic neuroscience. First, a neurocomputational model is presented, which synthesises insights about the Freudian distinction between primary and secondary process and parallel economic aspects of metapsychology, with current findings from theoretical neuroscience and neuroimaging research. This is then further enhanced and specified by considerations of neuropsychological work on wishful reality distortions following ventromedial frontal lesions and of the role of the pleasure principle in cognition. These few examples do not, of course, reflect the full scope of psychodynamic neuroscience but they serve as illustrative examples of the potential of this new field and the broader scope of this book.
Article
The rubber hand illusion is one reliable way to experimentally manipulate the experience of body ownership. However, debate continues about the necessary and sufficient conditions eliciting the illusion. We measured proprioceptive drift and the subjective experience (via questionnaire) while manipulating two variables that have been suggested to affect the intensity of the illusion. First, the rubber hand was positioned either in a posturally congruent position, or rotated by 180°. Second, either the anatomically same rubber hand was used, or an anatomically incongruent one. We found in two independent experiments that a rubber hand rotated by 180° leads to increased proprioceptive drift during synchronous visuo-tactile stroking, although it does not lead to feelings of ownership (as measured by questionnaire). This dissociation between drift and ownership suggests that proprioceptive drift is not necessarily a valid proxy for the illusion when using hands rotated by 180°.
Article
Recognition of one's own reflection in a mirror qualifies as an objective test of self-awareness. Although most primates appear incapable of learning that their behavior is the source of the behavior depicted in a mirror, the present study replicates previous reports showing that both chimpanzees and orangutans are capable of self-recognition. As the only remaining species of great ape, gorillas were also systematically tested with mirrors. Using a specially designed control procedure which provides independent evidence of interest in and motivation to touch unobtrusively applied marks used to assess self-recognition, gorillas appeared unable to correctly decipher mirrored information about themselves.
Article
The common thread between all complex systems may not be cooperation but rather the irresolvable coexistence of opposing tendencies.
Article
This Perspective considers the influential notion of a canonical (cortical) microcircuit in light of recent theories about neuronal processing. Specifically, we conciliate quantitative studies of microcircuitry and the functional logic of neuronal computations. We revisit the established idea that message passing among hierarchical cortical areas implements a form of Bayesian inference-paying careful attention to the implications for intrinsic connections among neuronal populations. By deriving canonical forms for these computations, one can associate specific neuronal populations with specific computational roles. This analysis discloses a remarkable correspondence between the microcircuitry of the cortical column and the connectivity implied by predictive coding. Furthermore, it provides some intuitive insights into the functional asymmetries between feedforward and feedback connections and the characteristic frequencies over which they operate.
Article
Mirror self-recognition is often considered as an index of self-awareness. Neuroimaging studies have identified a neural circuit specialised for the recognition of one's own current facial appearance. However, faces change considerably over a lifespan, highlighting the necessity for representations of one's face to continually be updated. We used fMRI to investigate the different neural circuits involved in the recognition of the childhood and current, adult, faces of one's self. Participants viewed images of either their own face as it currently looks morphed with the face of a familiar other or their childhood face morphed with the childhood face of the familiar other. Activity in areas which have a generalised selectivity for faces, including the inferior occipital gyrus, the superior parietal lobule and the inferior temporal gyrus, varied with the amount of current self in an image. Activity in areas involved in memory encoding and retrieval, including the hippocampus and the posterior cingulate gyrus, and areas involved in creating a sense of body ownership, including the temporo-parietal junction and the inferior parietal lobule, varied with the amount of childhood self in an image. We suggest that the recognition of one's own past or present face is underpinned by different cognitive processes in distinct neural circuits. Current self-recognition engages areas involved in perceptual face processing, whereas childhood self-recognition recruits networks involved in body ownership and memory processing.
Article
Recent research has linked bodily self-consciousness to the processing and integration of multisensory bodily signals in temporoparietal, premotor, posterior parietal and extrastriate cortices. Studies in which subjects receive ambiguous multisensory information about the location and appearance of their own body have shown that these brain areas reflect the conscious experience of identifying with the body (self-identification (also known as body-ownership)), the experience of where 'I' am in space (self-location) and the experience of the position from where 'I' perceive the world (first-person perspective). Along with phenomena of altered states of self-consciousness in neurological patients and electrophysiological data from non-human primates, these findings may form the basis for a neurobiological model of bodily self-consciousness.
Article
Illusions have historically been of great use to psychology for what they can reveal about perceptual processes. We report here an illusion in which tactile sensations are referred to an alien limb. The effect reveals a three-way interaction between vision, touch and proprioception, and may supply evidence concerning the basis of bodily self-identification.
Article
Cortical projections to subdivisions of the cingulate cortex in the rhesus monkey were analyzed with horseradish peroxidase and tritiated amino acid tracers. These projections were evaluated in terms of an expanded cytoarchitectural scheme in which areas 24 and 23 were divided into three ventrodorsal parts, i.e., areas 24a–c and 23a–c. Most cortical input to area 25 originated in the frontal lobe in lateral areas 46 and 9 and orbitofrontal areas 11 and 14. Area 25 also received afferents from cingulate areas 24b, 24c, and 23b, from rostral auditory association areas TS2 and TS3, from the subiculum and CA1 sector of the hippocampus, and from the lateral and accessory basal nuclei of the amygdala (LB and AB, respectively). Areas 24a and 24b received afferents from areas 25 and 23b of cingulate cortex, but most were from frontal and temporal cortices. These included the following areas: frontal areas 9, 11, 12, 13, and 46; temporal polar area TG as well as LB and AB; superior temporal sulcus area TPO; agranular insular cortex; posterior parahippocampal cortex including areas TF, TL, and TH and the subiculum. Autoradiographic cases indicated that area 24c received input from the insula, parietal areas PG and PGm, area TG of the temporal pole, and frontal areas 12 and 46, Additionally, caudal area 24 was the recipient of area PG input but not amygdalar afferents. It was also the primary site of areas TF, TL, and TH projections. The following projections were observed both to and within posterior cingulate cortex. Area 29a–c received inputs from area 46 of the frontal lobe and the subiculum and in turn it projected to area 30. Area 30 had afferents from the posterior parietal cortex (area Opt) and temporal area TF. Areas 23a and 23b received inputs mainly from frontal areas 46, 9, 11, and 14, parietal areas Opt and PGm, area TPO of superior temporal cortex, and areas TH, TL, and TF. Anterior cingulate areas 24a and 24b and posterior areas 29d and 30 projected to area 23. Finally, a rostromedial part of visual association area 19 also projected to area 23. The origin and termination of these connections were expressed in a number of different laminar patterns. Most corticocortical connections arose in layer III and to a lesser extent layer V, while others, e.g., those from the cortex of the superior temporal sulcus, had an equal density of cells in both layers III and V. In one instance projections to area 24 arose almost entirely from layer V of areas TH, TL, and TF. Furthermore, although most projections terminated in layers I–III of cingulate cortex, those of the amygdala to rostral area 24 terminated in deep layer I and layer II while area Opt projections to area 23 terminated mainly in layers I, II, and IV. Four classes of cortical connections have been characterized and each may play a role in the sensorimotor functions of cingulate cortex. These include connections with sensory association and multimodal areas, projections to and from premotor area 24c, subicular termination in areas 25, 24, and 29, and intracingulate connections that may transmit sensory input to areas 24 and 23 into area 24c.