No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Das Reafferenzprinzip Wechselwirkungen zwischen Zentralnervensystem und Peripherie
... the latter arising from the behavior execution itself. In contrast, humans are capable to estimate the intrinsic forces resulting from the execution of actions by learning predictive models from prior proprioceptive experiences [3], [4]. These predictions are deducted from the actual perceived sensations. ...
... For this, the BSPM methodology as shown in Figure 2 consists of two inter-operable predictive models. 3 youtu.be/60ue0X25S6k • F-BSPM: A behavior-specific proprioception model in forward mode predicts the intrinsic proprioception which originates from the behavior execution itself. ...
Safe and meaningful interaction with robotic systems during behavior execution requires accurate sensing capabilities. This can be achieved by the usage of force-torque sensors which are often heavy, expensive, and require an additional power supply. Consequently, providing accurate sensing capabilities to lightweight robots, with a limited amount of load, is a challenging task. Furthermore, such sensors are not able to distinguish between task-specific regular forces and external influences as induced by human coworkers. To solve this, robots often rely on a large number of manually generated rules which is a time-consuming procedure. This paper presents a data-driven machine learning approach that enhances robotic behavior with estimates of the expected proprioceptive forces (intrinsic) and unexpected forces (extrinsic) exerted by the environment. First, the robot's common internal sensors are recorded together with ground truth measurements of the actual forces during regular and perturbed behavior executions. The resulting data is used to generate features that contain a compact representation of behavior-specific intrinsic and extrinsic fluctuations. Those features are then utilized for deep learning of proprioceptive models which enables a robot to accurately distinguish the amount of intrinsic and extrinsic forces. Experiments performed with the UR5 robot show a substantial improvement in accuracy over force values provided by previous research.
... Second, visual sensitivity is vastly reduced for the high temporal frequency intrasaccadic motion signals (Burr et al., 1982;Castet & Masson, 2000;Castet, 2010). Third, an internal (extraretinal) signal to monitor the oculomotor commands for the initiation of a saccade (Sperry, 1950;von Holst & Mittelstaedt, 1950) initiates the reduction of visual sensitivity even before saccade onset on unstructured backgrounds (Volkmann, 1962;Burr et al., 1994;Diamond et al., 2000). This monitoring signal for the upcoming eye position change by the next saccade is very important for the neural system to disambiguate a self-induced displacement of the retinal image from a displacement caused by an object movement in the external world as suggested by many scientists (for a historical overview see Morrone, 2014). ...
... This monitoring signal for the upcoming eye position change by the next saccade is very important for the neural system to disambiguate a self-induced displacement of the retinal image from a displacement caused by an object movement in the external world as suggested by many scientists (for a historical overview see Morrone, 2014). Von Holst and Mittelstaedt (1950) called this internal signal for self-movements "efference copy" (EC), as a copy of the efferent motor command, whereas Sperry (1950) used the term "corollary discharge" (CD) to indicate the concomitant neuronal activity in different neural structures (Sommer & Wurtz, 2006;Wurtz, 2008;Ibbotson & Krekelberg, 2011). Despite the different terms, the theoretical idea of the authors is similar: even before the initiation of an active voluntary movement, the EC/CD is sent to a comparator stage to cancel the incoming retinal motion signals caused by the movement, i.e. the shift of the whole visual field into the opposite direction. ...
Saccadic eye movements modulate visual perception: they initiate and terminate high acuity vision at a certain location in space, but before and during their execution visual contrast sensitivity is strongly attenuated for 100 to 200 ms. Transient perisaccadic perceptual distortions are assumed to be an important mechanism to maintain visual stability. Little is known about age effects on saccadic suppression, even though for healthy adults other major age-related changes are well documented, like a decrease of visual contrast sensitivity for intermediate and high spatial frequencies or an increase of saccade latencies. Here, we tested saccadic suppression of luminance and isoluminant chromatic flashes in 100 participants from eight to 78 years. To estimate the effect of saccadic suppression on contrast sensitivity, we used a two-alternative forced choice (2AFC) design and an adaptive staircase procedure to modulate the luminance or chromatic contrast of a flashed detection target during fixation and 15 ms after saccade onset. The target was a single horizontal luminance or chromatic line flashed 2° above or below the fixation or saccade target. Compared to fixation, average perisaccadic contrast sensitivity decreased significantly by 66% for luminance and by 36% for color. A significant correlation was found for the strength of saccadic suppression of luminance and color. However, a small age effect was found only for the strength of saccadic suppression of luminance, which increased from 64% to 70% from young to old age. We conclude that saccadic suppression for luminance and color is present in most participants independent of their age and that mechanisms of suppression stay relatively stable during healthy aging.
... Importantly, the fact that we cannot tickle ourselves suggests that this distinction between self and non-self may be much more fundamental than one would at first assume. In their " reafference principle" von Holst and Mittelstä dt famously proposed a mechanism by which animals use efference copies to distinguish between stimuli that are under their control (reafference) from those that are not (exafference) (von Holst and Mittelstaedt, 1950). The reafference principle is a fundamentally operant process by which animals not only distinguish between the stimuli they can control and those they cannot: it is also the beginning of the operant process by which animals learn to bring novel stimuli under their behavioral control. ...
... Efference copies are generally proposed as one mechanism animals use to distinguish between exafferent and reafferent stimuli. If efference copies are also used here to accomplish the generation effect in composite conditioning, it would entail that efference copies not necessarily always reduce the salience of reafferent stimuli as originally proposed (von Holst and Mittelstaedt, 1950), but can also enhance it, under certain circumstances, to accomplish a facilitation of world-learning. From these considerations it is a small step to postulate that when the relationship between a reafferent stimulus and the animal itself is concerned (such as in re-afferent self-motion signals, or in self-tickling attempts) then efference copies serve to reduce the salience of the stimuli. ...
In contrast to the long-held assumption that the organization of behavior is best characterized as the perception of a sensory stimulus followed by appropriate response (i.e., “sensorimotor hypothesis”), recent converging evidence from multiple systems and fields of study instead suggests that both ancestral and extant general brain function is best described in operant terms. Rather than specifyng precise behaviors, sensory information - if at all present - interacts with ongoing neural activity to instruct the organism which type of spontaneous, exploratory behavior to generate. Evaluating the ensuing reafferent feedback modifies the nervous system such that ongoing neural activity patterns become biased towards activity that has generated increased appetitive and decreased aversive feedback in the past. The neurobiological mechanisms underlying both the exploratory, spontaneous behaviors as well as those underlying the modifications caused by the feedback are becoming increasingly understood, even on a molecular level. It is straightforward to hypothesize that the constant interaction between ongoing neural activity and the incoming sensory stream allows the organism to balance behavioral flexibility with efficiency to accomplish adaptive behavioral choice in an often unpredictably changing environment.
... Furthermore, intracellular recordings from individual interneurons of the pattern generators for singing and abdominal ventilation show that subthreshold excitation by corollary discharge from the signing CPG entrains and mostly synchronizes the breathing rhythm of a singing cricket to the chirp pattern of the calling song and vice versa ( Fig. 5C; Schöneich and Hedwig, 2019;Paripovic et al., 1996). These new findings add to the accumulating evidence from research in very different animals suggesting that, besides inhibition of sensory pathways in order to counterbalance the reafferent feedback form self-stimulation (von Holst and Mittelstaedt, 1950), corollary discharge also provides excitatory feedforward coupling between CPG networks (Fig. 5D) -a mechanism that seems to be a common solution for dynamic motor pattern coordination in invertebrates and vertebrates alike (Bartos et al., 1999;Straka et al., 2018). ...
... Despite the different ways of sound production and their more diverse and complex signals, vertebrates from fish to human (Hage and Jürgens, 2006;Jürgens, 2009;Konishi, 1994Konishi, , 2010Bass, 2014;Yamaguchi et al., 2017) use for acoustic communication the same basic neural principles of central motor pattern generation and corollary discharge processing at the sender side as insects do. Therefore, new ideas and general concepts in behavioural neuroscience were often inspired, validated, reconsidered and refined by a broad comparative view across the animal kingdom (von Holst and Mittelstaedt, 1950;Kupfermann and Weiss, 1978;Marder and Calabrese, 1996;Crapse and Sommer, 2008;Straka et al., 2018). At the receiver side, neural detection of temporal cues from the sound envelope are also very important for acoustic communication in vertebrates (Large and Crawford, 2002;Gomez-Alvarez et al., 2018;Comins and Gentner, 2014;Rose et al., 2015;Hanson et al., 2016;Kopp-Scheinpflug et al., 2018) including human speech (Shannon et al., 1995;Oganian and Chang, 2019;Neophytou and Oviedo, 2020). ...
Field crickets are best known for the loud calling songs produced by males to attract conspecific females. This review aims to summarize the current knowledge of the neurobiological basis underlying the acoustic communication for mate finding in field crickets with emphasis on the recent research progress to understand the neuronal networks for motor pattern generation and auditory pattern recognition of the calling song in Gryllus bimaculatus. Strong scientific interest into the neural mechanisms underlying intraspecific communication has driven persistently advancing research efforts to study the male singing behaviour and female phonotaxis for mate finding in these insects. The growing neurobiological understanding also inspired many studies testing verifiable hypotheses in sensory ecology, bioacoustics and on the genetics and evolution of behaviour. Over last decades, acoustic communication in field crickets served as a very successful neuroethological model system. It has contributed significantly to the scientific process of establishing, reconsidering and refining fundamental concepts in behavioural neurosciences such as command neurons, central motor pattern generation, corollary discharge processing and pattern recognition by sensory feature detection, which are basic building blocks of our modern understanding on how nervous systems control and generate behaviour in all animals.
... How is it that objects appear stable in extrinsic space despite their translation across the retina? Early theories suggested that afferent sensory information from the eyes and/or a copy of the movement commands issued to them (efference copy or corollary discharge) might compensate for saccades, cancelling out the resultant shift of position (Sperry, 1950;Von Holst and Mittelstaedt, 1950). Alternative, ecologically motivated approaches suggested that the unique quality of retinal information arising from a saccade could unambiguously inform the brain that a saccade is occurring, effectively by-passing the problem (Gibson, 1966 Hence traditional explanations of space constancy face substantial problems (Bridgeman, Van der Hejiden, and Velichkovsky, 1994). ...
... position signal (eye position relative to head, simplifying to ignore the headbody transformation) with the retinal stimulation pattern. Such a process is required to achieve space constancy, at least in the absence of retinal (visual) cues (Sperry, 1950;Von Holst and Mittelstaedt, 1950). Plotting (Duhamel, Colby, and Goldberg, 1992). ...
When saccadic eye movements are made to a silently ticking clock, observers sometimes think that the second hand takes longer than normal to move to its next position. For a short period, the second hand appears to have stopped; then, suddenly, it ticks on. This phenomenon is of intuitive interest as an experience that many people recognise, and formed the starting point of the research described here. A comparison methodology was employed in which subjects judged the perceived duration of a visual stimulus relative to that of subsequent stimuli. The duration of the first stimulus varied across trials, permitting the derivation of a matched time at which subjects felt the stimuli to be of equal duration. When the first stimulus was fixated immediately after a saccade, lower matched times were obtained relative to constant fixation conditions, indicating that subjective time had been stretched out. This effect is termed saccadic chronostasis. The methodology permitted accurate quantification of saccadic chronostasis under various task conditions. Manipulations explored include movement size, movement type (saccades of various types, hand/arm movements), the nature of the stimulus that is to be judged and its relationship to other perceptual objects. Key results include the illusion's dependency upon both saccade size and the continuity of certain components of the visual scene. Similarities and important differences emerged when the paradigm was extended to arm movements (manual chronostasis). Chronostasis offers a novel insight into the integration of action and perception, with implications for theories of perceptual continuity across movements. It is an illusion of time, and must be dealt with by theories that seek to explain temporal perception, but also has more general relevance when considering the manner in which conscious experience emerges from a sequence of sensory events. These issues inform an initial characterisation of the effect.
... To resolve ambiguities of this kind, the central nervous system can consult feedback from other sensory receptors, for example proprioceptive sensors in the neck muscles that signal head movement relative to the trunk. In addition, the nervous system is thought to employ internal models, based on which reafferent feedback arising from voluntary body movements can be internally anticipated and related to the total sensory information inflow (von Holst and Mittelstaedt, 1950;Wolpert et al., 1995;Cullen, 2004;Straka et al., 2018). A mismatch between the anticipated and actual sensory feedback during voluntary action is thought to be a primary cause for the occurrence of postural disorientation and subjective dizziness in pathology or challenging environments (Brandt, 1996;Brandt and Huppert, 2016). ...
... This integration is essential to distinguish between sensory events that arise from changes in the environment (i.e., exafferent information) and sensory inputs that occur as a consequence of self-initiated body movements (i.e., reafferent information) (Cullen, 2004;Straka et al., 2018;Brooks and Cullen, 2019). With respect to balance control, this distinction primarily serves two behavioral goals: (1) to ensure a stable perceptual reference frame for postural control during self-initiated body motion; (2) to avoid an interference between the goals of voluntary action with resisting balance-stabilizing reflex mechanisms, also referred to as the "posture-movement problem" (von Holst and Mittelstaedt, 1950;Stuart, 2005). Both behavioral goals are facilitated by a selective attenuation or elimination of reafferent sensory inputs during active movement, which is thought to be mediated by feed-forward copies of the voluntary motor commands (efference copies, corollary discharge). ...
Synopsis
Postural control is a complex sensorimotor behavior that maintains balance by counteracting gravitational forces and by anticipating postural challenges induced by external demands and perturbations. Postural control is based on biomechanical constraints of the body with its bones, joints, ligaments and muscles. Spinal and supraspinal neuronal networks with strong sensory contributions control anti-gravity muscle activity. Postural control in bipedal humans has some distinctive features, including the larger vestibular contribution to balance and the more prominent supraspinal control of posture. Supraspinal aspects of postural control in humans are also reflected by their sensitivity to cognitive challenges.
... Each motor command is internally stored and compared with reafferent signals, representing sensory feedback associated with turns. [34][35][36][37] This closed loop, from here on referred to as an ''efference-reafferent loop,'' allows the animal to predict sensory changes expected from turns. To test the influence of the efference-reafferent loop on heading coding, we suspended tethered butterflies to a rotation stage, allowing us to control their heading during fixed flights ( Figure 6I; rotation fixed flight; Video S7). ...
... The popular examples of the change or attenuation of the sensory consequences of the actions (due to their status of being voluntary or self-generated) are the space constancy during self-generated eye movements (von Holst and Mittelstaedt, 1950) and lack of tickliness while selftickling (Wolpert and Flanagan, 2001) 7 . It is because of the cancellation of the self-generated sensations that we do not feel ticklish when we tickle ourselves, and we do not experience the visual scene to be moving when we move our eyes although the image of that visual scene on the 6 There are four main theoretical motives behind the SoA assumption; they are: (a) phenomenal difference between voluntary vs passive movements, (b) instances of sensory attenuation such as tickling and eye movements, (c) differences in normal and schizophrenic agency attributions (Feinberg, 1978), (d) epistemic role of SoA experience in self-agency attribution 7 Although the comparator explanation is successful with respect to online motor adaptation, space constancy, and tickling, alternative accounts are still possiblee.g., for motor adaptation due to intermittency (Gawthrop et al., 2011), no space constancy during rapid head yaw and spatial constancy is not due to efference copies (Bruce Bridgeman, 2007Anatol Feldman, 2016), receptor sensitivity and humorous context effects on tickling; other tactile events like pinch may not differ phenomenally irrespective of whether the source of pinching is the self or the other. ...
The Sense of agency (SoA) as conceived in experimental paradigms adheres to “cognitive penetration” and “cognitive phenomenology.” Cognitive penetrability is the assumption that agency states penetrate sensory modalities like time perception – the Intentional binding (IB) hypothesis – and auditory, visual and tactile perceptions – the Sensory attenuation (SA) hypothesis. Cognitive phenomenology, on the other hand, assumes that agency states are perceptual or experiential, akin to sensory states. I critically examine these operationalizations and argue that the SoA is a judgment effect rather than a perceptual/phenomenal state. My thesis criticizes the experimentally operationalized implicit SoA (in chapter 2), explicit SoA (in chapter 3) and cue-integrated SoA (in chapter 4) by arguing that: (a) There is uncertainty in the SoA experimental operationalization (making the participants prone to judgment effects); (b) There are inconsistencies and incoherence between different findings and reports in the SoA domain; (c) The SoA reports are influenced by prior as well as online-generated beliefs (under uncertainty); (d) The SoA operationalizations had inaccuracy or approximation standard for measuring perception/experience of agency; (e) Under certainty and accuracy standard (for perception), the SoA (biased or nonveridical) reports might not have occurred at all; and (f) Reported inconsistencies and, the effects of beliefs can be parsimoniously accounted by compositionality nature of judgment. Thus, my thesis concludes that SoA reports are not instances of feelings/perceptions but are judgments.
... The popular examples of the change or attenuation of the sensory consequences of the actions (due to their status of being voluntary or self-generated) are the space constancy during self-generated eye movements (von Holst and Mittelstaedt, 1950) and lack of tickliness while selftickling (Wolpert and Flanagan, 2001) 7 . It is because of the cancellation of the self-generated sensations that we do not feel ticklish when we tickle ourselves, and we do not experience the visual scene to be moving when we move our eyes although the image of that visual scene on the 6 There are four main theoretical motives behind the SoA assumption; they are: (a) phenomenal difference between voluntary vs passive movements, (b) instances of sensory attenuation such as tickling and eye movements, (c) differences in normal and schizophrenic agency attributions (Feinberg, 1978), (d) epistemic role of SoA experience in self-agency attribution 7 Although the comparator explanation is successful with respect to online motor adaptation, space constancy, and tickling, alternative accounts are still possiblee.g., for motor adaptation due to intermittency (Gawthrop et al., 2011), no space constancy during rapid head yaw and spatial constancy is not due to efference copies (Bruce Bridgeman, 2007Anatol Feldman, 2016), receptor sensitivity and humorous context effects on tickling; other tactile events like pinch may not differ phenomenally irrespective of whether the source of pinching is the self or the other. ...
How does one know that (s)he is the causal agent of their motor actions? Earlier theories of sense of agency have attributed the capacity for perception of self-agency to the comparator process of the motor-control/action system. However, with the advent of the findings implying a role of non-motor cues (like affective states, beliefs, primed concepts, and social instructions or previews of actions) in the sense of agency literature, the perception of self-agency is hypothesized to be generated even by non-motor cues (based on their relative reliability or weighting estimate); and, this theory is come to be known as the cue-integration of sense of agency. However, the cue-integration theory motivates skepticism about whether it is falsifiable and whether it is plausible that non-motor cues that are sensorily unrelated to typical sensory processes of self-agency have the capacity to produce a perception of self-agency. To substantiate this skepticism, I critically analyze the experimental operationalizations of cue-integration—with the (classic) vicarious agency experiment as a case study—to show that (1) the participants in these experiments are ambiguous about their causal agency over motor actions, (2) thus, these participants resort to reports of self-agency as heuristic judgments (under ambiguity) rather than due to cue-integration per se, and (3) there might not have occurred cue-integration based self-agency reports if these experimental operationalizations had eliminated ambiguity about the causal agency. Thus, I conclude that the reports of self-agency (observed in typical non-motor cues based cue-integration experiments) are not instances of perceptual effect—that are hypothesized to be produced by non-motor cues—but are of heuristic judgment effect.
... A major problem that has been recognised since the advent of modern neuroscience is the ubiquitous experience that one perceives the same global scene when one repeatedly returns to the same environment or when there is a change in the direction of gaze. Inspired by studies on invertebrates and fish, respectively, Von Holst and Mittelstaedt (1950), Von Holst (1954; "reafference principle") and Sperry (1950; "corollary discharge") recognised that there must be a potent mechanism that keeps track of the position and movement of one's own sensorium. At that time, the continuous neuronal subtracting of these selfgenerated signals was proposed but this would considerably overload the processing capacity of the brain. ...
Cerebral energy supply is insufficient to support continuous neuronal processing of the plethora of time-constant objects that we are aware of. As a result, the brain is forced to limit processing resources to (the most relevant) cases of change . The neuronally generated world is thus temporally discontinuous. This parallels the fact that, in all relevant microscopic fundamental equations of nature, temporal change plays a dominant role. When a scientist calculates a “solution” to such an equation, integration over time is an essential step. The present Hypothesis expresses that the step from neuronal activity to phenomenal content of consciousness is reflective of a (phenomenal) “solution:” the main source of the incomprehensibility of consciousness is proposed to result from the introduction of phenomenal time-constant entities. These are “filled-in” via integration, even though neuronal data only exists for changes to these entities. In this way, a temporally continuous picture of the world phenomenally appears. Qualia are “initial conditions,” which are required for integration and cannot be deduced from present data. Phenomenal “identity” (vs. “high similarity”) is related to qualia. Inattentive visual perception, which is only rarely investigated, offers insights into these relationships. Introspectively, unattended vision appears rich because percepts are cumulated over long time spans, whereas attentive perception relies purely on present neuronal signals. The present Hypothesis is that a brief neuronal activity can signify long-lasting and constant phenomenal content of consciousness. Experimental support is presented that comes from discrepancies between neuronal activity and perception: transient neuronal responses to sustained stimuli, “filling-in,” change blindness, identity vs. close resemblance.
... Self-motion cues contributing to spatial memory are not only perceived passively, but they are often the result of active motion. The distinction between active and passive motion is crucial for moving organisms, and it is provided by the efference copy of the motor command [15], [16] or corollary discharge [17]. While many authors use these terms interchangeably, others emphasize conceptual differences. ...
Neuroimaging studies have shown great similarities between the cortical networks involved in motor execution and motor imagery. However, none of those studies report data on head or full body motions and only few provide evidence of behavioral consequences of this similarity. Here, we report results from a novel kinesthetic spatial memory task, in which participants encoded a target position by an active, passive or imagined head rotation. During the experiment, participants were seated on a motion platform with a VR headset, which allowed passive motion and head tracking. To compare all three encoding conditions, precision and head velocity in the executions of head movements were analyzed with Bayesian hierarchical generalized linear regression models. We found comparable performance in precision in the active and imagery conditions whereas performance in the passive condition was significantly reduced. Head motion profiles were similar after active and imagined encoding. The results suggest that imagined head rotations provide useful sensorimotor information despite the absence of sensory and motor information during encoding. This can be explained by corollary discharge which is necessary for appropriate motor behavior and is likely also generated when the motor behavior is imagined but not executed.
... adequately responds to all signals from the level of eye movement control (we add that the same can be said about the work of the neck or even torso muscles) [6][7][8][9][10][11][12][13]. ...
Some features of the illusions arising from the movement of the observer's eyes and/or head under the background of the positive afterimage of the entire visual scene (rich afterimage-rAI) when the head and/or afterimage are tilted are described. Under these conditions, there are the violations of the visual direction constancy and stability of not only the visual field but also near extrapersonal space. This happens also under the constant position of the eyes in orbits when changing of the fixation point by the head movements. The illusion of violation of the visual vertical on the background of an inclined rAI is also described. It turns out that the synthesis of the field of rAI does not depend on the state of eye vergence in a wide range. The features of the so-called "residual illusion" are described in detail. In this phase all phenomena that have arisen against the background of rAI persist for tens of seconds in total darkness after the rAI is completely attenuated. This also applies to distorted perception of the visual vertical. Based on the analysis of the rAI illusions and peculiar properties of the rich afterimage itself, it is proposed to consider the hypothesis, suggesting the complete nonparticipation of the efferent oculomotor subsystem signals in the mechanisms of the visual field constancy and the gaze direction constancy. The hypothesis suggests that the structurally rich visual scene allows the visual system to form a stable visual field and to calculate the observer's gaze direction only based on the signals within the visual flow. The hypothesis allows to coherently interpret the main phenomena have been observed in the experiments. And the observation of an oblique 3-D rAI when the head is tilted to the shoulder clearly indicates that not the images on the retinas, but the internal visual space (IVS) model is the object of vision.
... Each motor command is internally stored and compared with reafferent signals, representing sensory feedback associated with turns. [34][35][36][37] This closed loop, from here on referred to as an ''efference-reafferent loop,'' allows the animal to predict sensory changes expected from turns. To test the influence of the efference-reafferent loop on heading coding, we suspended tethered butterflies to a rotation stage, allowing us to control their heading during fixed flights ( Figure 6I; rotation fixed flight; Video S7). ...
For navigation, animals use a robust internal compass. Compass navigation is crucial for long-distance migrating animals like monarch butterflies, which use the sun to navigate over 4,000 km to their overwintering sites every fall. Sun-compass neurons of the central complex have only been recorded in immobile butterflies, and experimental evidence for encoding the animal’s heading in these neurons is still missing. Although the activity of central-complex neurons exhibits a locomotor-dependent modulation in many insects, the function of such modulations remains unexplored. Here, we developed tetrode recordings from tethered flying monarch butterflies to reveal how flight modulates heading representation. We found that, during flight, heading-direction neurons change their tuning, transforming the central-complex network to function as a global compass. This compass is characterized by the dominance of processing steering feedback and allows for robust heading representation even under unreliable visual scenarios, an ideal strategy for maintaining a migratory heading over enormous distances.
... This principle was extended by allostasis Sterling [2004] for regulation of bodily functions over time. To preform this task efficient mechanisms for the prediction of future states are needed to anticipate future environmental constellations von Holst & Mittelstaedt [1950], Bao et al. [2014]. This is done, because the homeostatic state may be violated by unexpected changes in the future. ...
Clues from psychology indicate that human cognition are not only based on classical probability theory as explained by Kolmogorov’s axioms but additionally on quantum probability. Quantum probabilities lead to the conclusion that our brain adapted to the Everett many-worlds reality trough the evolutionary process. The Everett many-worlds theory views reality as a many-branched tree in which every possible quantum outcome is realized. In this context, one of the cognitive brain functions is to provide a causally consistent explanation of events to maintain self-identity over time. Causality is related to a meaningful explanation. For impossible explanations, causality does not exist, and the identity of the self breaks. Only in meaningful causal worlds may personal identities exist.
... Efference signals (or efference commands) prompt the muscles to deliver actions while the efference copies help the motor system to predict the sensory consequences of those actions such that online movement corrections can be made, if necessary. The comparator mechanism is not just ascribed with the function of online motor adaptation and motor control but also with a change in subjective intensity -usually an attenuation -of the perceptual or experiential quality of the sensory consequences of those actions (i.e., due to reafferences). 1 The popular examples of the attenuation of the sensory consequences of actions (due to their status of being voluntary or self-generated) are the space constancies during self-generated eye movements (von Holst and Mittelstaedt, 1950) and lack of tickliness while self-tickling (Wolpert and Flanagan, 2001). It is proposed that because of the cancellation of self-generated sensations we do not feel ticklish when we tickle ourselves, and we do not experience the visual scene to be moving when we move our eyes although the image of that visual scene on the retina is moving. ...
The explicit sense of agency (SoA) is characterized as the unique and exclusive feeling generated by action or agency states (or the comparator process of the motor control system, to be specific), and (thus) this characterization assumes "cognitive phenomenology, " the assumption that non-sensory states like actions or agency states, all by themselves, generate a unique feeling akin to typical sensory processes. However, the assumption of cognitive phenomenology is questionable as it fails to account for the necessity of causal interaction between the sensory organ and the phenomenal object in the production of phenomenology or experience. Thus, this paper criticizes the explicit SoA — as operationalized in experiments — by arguing that: (a) there is uncertainty in the explicit SoA operationalization (making the participants prone to judgment effects), (b) there are non-correlations or dissociations between agency states and explicit SoA reports, (c) explicit SoA reports are influenced by prior beliefs or online-generated heuristics, and (d) were the participants not uncertain about their agency (or the causal contingency between their actions and action-effects), they might not have produced non-veridical explicit SoA reports at all. Thus, this paper concludes that explicit SoA reports are not instances of (cognitive or agentive) phenomenology but are instances of heuristic judgment (under uncertainty).
... They twisted the neck of a blowfly (Eristalis a genus of hoverflies of the family Syrphidae) turning its head through 180 along its longitudinal axis, thus making the positions of the two eyes reversed. The fly behaved quite strangely under these circumstances, circling either clockwise or counterclockwise at random [12]. In a similar vein, Roger Sperry [13] rotated surgically 180 the eye of a fish (Sphoeroides spengleri) and observed too that the animal circled around to the left or to the right until it stopped and freezed in an atypical posture. ...
The Scottish philosopher Thomas Reid and more recently the evolutionary psychologist Nicholas Humphrey argued for a basic distinction between sensation (what is happening to me) and perception (what is happening out there) with the former, but not the latter, being associated with consciousness. Conscious experiences in this view would emerge from changes in the state of the body, i.e. as bodily actions, and would maintain such a primal characteristic nowadays. I argue that the evolutionary reason for the sensation/perception distinction can be traced back to organisms’ movement, and to the consequent need to tell apart two varieties of an otherwise identical local stimulation: namely, either as the outcome of external stimuli passively impinging on body surface or as the outcome of an organism movement giving rise to encountering with external stimuli. The Erich von Holst Reafferenzprinzip effectively modelled such a distinction by postulating that an efference copy is generated in association with the motor command thus nullifying any sensory signal that arises as a by-product of an organism movement. I argue that if sensation originally equates to a bodily action (or its internalized representation), then it could be that an efference copy of local (or internalized) bodily action is generated under stimulation and compared to that associated with active motor command. This way the result would be leaving sensation (what is happening to me) or nullifying it and leaving only perception (what is happening out there) depending on whether or not a motor command has occurred. Implications of this hypothesis for the presence of consciousness in animals or other organisms such as plants are briefly discussed.
... It is known that when an efferent signal is sent from the motor cortex to the muscles, an efference copy, also known as corollary discharge, is created which gets routed to other parts of the sensory cortex [8]. This efference copy can then modify the excitability of other sensory areas. ...
The central nervous system must determine which sensory events occur at the same time. Actively moving the head corresponds with large changes in the relationship between the observer and the environment, sensorimotor processing, and spatiotemporal perception. Numerous studies have shown that head movement onset must precede the onset of other sensory events in order to be perceived as simultaneous, indicating that head movement perception is slow. Active head movement perception has been shown to be slower than passive head movement perception and dependent on head movement velocity, where participants who move their head faster than other participants require the head to move even earlier than comparison stimuli to be perceived as simultaneous. These results suggest that head movement perception is slower (i.e., suppressed) when the head moves faster. The present study used a within-subjects design to measure the point of subjective simultaneity (PSS) between active head movement speeds and a comparison sound stimulus. Our results clearly show that i) head movement perception is faster when the head moves faster within-subjects, ii) active head movement onset must still precede the onset of other sensory events (Average PSS: -123 to -52 ms) in order to be perceived as occurring simultaneously even at the fastest speeds (Average peak velocity: 76°/s to 257°/s). We conclude that head movement perception is slow, but that this delay is minimized with increased speed. While we do not provide evidence against sensory suppression, which requires active versus passive head movement comparison, our results do rule out velocity-based suppression.
... Typically, these observations have been described in terms of a motor control framework (Frith, 2005;Frith, Blakemore, & Wolpert, 2000b). According to this account, the motor system detects discrepancies between planned actions and sensory feedback by means of an efference copy (Bays & Wolpert, 2006;Crapse & Sommer, 2008;Holst & Mittelstaedt, 1950). In recent years, this account has been criticised, as it may not be suffi cient to explain the variety of observations in agency studies (Synofzik et al., 2008a). ...
... Consequently, the expected re-afferent sensory signals due to active movements can be predicted from motor efference copies. By comparing these predictions to the actual sensory signals, external disturbances can be estimated and distinguished from self-generated movements (von Holst and Mittelstaedt, 1950). For improving the estimation of the actual movement, efference copies can, after appropriate transformation, also be fused with sensory feedback signals. ...
Synopsis
Integration of multi-sensory signals is normally required to infer the properties and states of the external world and of the own body. This applies also to vestibular signals, which, when activated are naturally accompanied by other sensory or self-generated signals. Here, we review computational schemes and normative principles that have been proposed to achieve meaningful signal fusion that allows perception and action in the face of uncertain information.
... To recover the objective displacement, the visual system requires information regarding the motion vector that was added to the retinal displacement by smooth pursuit. Generally, extraretinal signals related to pursuit are considered to recover the objective world state during pursuit (e.g., Freeman, 2001;Freeman et al., 2009;Souman et al., 2006;Sperry, 1950;von Holst & Mittelstaedt, 1950;Wurtz, 2008). It is possible that the visual system takes extraretinal signals related to pursuit into account when estimating the additional motion vector by smooth pursuit. ...
Many studies have investigated various effects of smooth pursuit on visual motion processing, especially the effects related to the additional retinal shifts produced by eye movement. In this article, we show that the perception of apparent motion during smooth pursuit is determined by the interelement proximity in retinal coordinates and also by the proximity in objective world coordinates. In Experiment 1, we investigated the perceived direction of the two-frame apparent motion of a square-wave grating with various displacement sizes under fixation and pursuit viewing conditions. The retinal and objective displacements between the two frames agreed with each other under the fixation condition. However, the displacements differed by 180 degrees in terms of phase shift, under the pursuit condition. The proportions of the reported motion direction between the two viewing conditions did not coincide when they were plotted as a function of either the retinal displacement or of the objective displacement; however, they did coincide when plotted as a function of a mixture of the two. The result from Experiment 2 showed that the perceived jump size of the apparent motion was also dependent on both retinal and objective displacements. Our findings suggest that the detection of the apparent motion during smooth pursuit considers the retinal proximity and also the objective proximity. This mechanism may assist with the selection of a motion path that is more likely to occur in the real world and, therefore, be useful for ensuring perceptual stability during smooth pursuit.
... Early neuroethological work (5) proposed that sensorimotor coupling between perception and action generally involves internal "reafference" (or feedback) of the sensory signal for interaction with motor signals. The idea was later taken up by modern motor control theory (6,7) and contributed to the concept of "internal models," which compute sensorimotor transformations as part of feedback control systems (8,9). ...
Human speech production requires the ability to couple motor actions with their auditory consequences. Nonhuman primates might not have speech because they lack this ability. To address this question, we trained macaques to perform an auditory–motor task producing sound sequences via hand presses on a newly designed device (“monkey piano”). Catch trials were interspersed to ascertain the monkeys were listening to the sounds they produced. Functional MRI was then used to map brain activity while the animals listened attentively to the sound sequences they had learned to produce and to two control sequences, which were either completely unfamiliar or familiar through passive exposure only. All sounds activated auditory midbrain and cortex, but listening to the sequences that were learned by self-production additionally activated the putamen and the hand and arm regions of motor cortex. These results indicate that, in principle, monkeys are capable of forming internal models linking sound perception and production in motor regions of the brain, so this ability is not special to speech in humans. However, the coupling of sounds and actions in nonhuman primates (and the availability of an internal model supporting it) seems not to extend to the upper vocal tract, that is, the supralaryngeal articulators, which are key for the production of speech sounds in humans. The origin of speech may have required the evolution of a “command apparatus” similar to the control of the hand, which was crucial for the evolution of tool use.
... Efference copies are internal copies of efferent commands produced by the motor system (cf. Sperry, 1950;von Holst and Mittelstaedt, 1950). The forward prediction appears to regulate the activation of auditory cortex (Houde et al., 2002; for covert speech see Poeppel, 2010, 2012;Ylinen et al., 2015). ...
Language learning relies on both short-term and long-term memory. Phonological short-term memory (pSTM) is thought to play an important role in the learning of novel word forms. However, language learners may differ in their ability to maintain word representations in pSTM during interfering auditory input. We used magnetoencephalography (MEG) to investigate how pSTM capacity in better and poorer pSTM groups is linked to language learning and the maintenance of pseudowords in pSTM. In particular, MEG was recorded while participants maintained pseudowords in pSTM by covert speech rehearsal, and while these brain representations were probed by presenting auditory pseudowords with first or third syllables matching or mismatching the rehearsed item. A control condition included identical stimuli but no rehearsal. Differences in response strength between matching and mismatching syllables were interpreted as the phonological mapping negativity (PMN). While PMN for the first syllable was found in both groups, it was observed for the third syllable only in the group with better pSTM. This suggests that individuals with better pSTM maintained representations of trisyllabic pseudowords more accurately during interference than individuals with poorer pSTM. Importantly, the group with better pSTM learned words faster in a paired-associate word learning task, linking the PMN findings to language learning.
... The relationship between the activity-dependent modulation of vestibular influences and changes in HMP suggests that during human locomotion an intrinsic feed-forward mechanism based on locomotor efference copies plays a significant part in balance regulation, which was previously thought to be predominantly governed by sensorimotor reflexes. Traditionally, motor efference copies are primarily considered to serve as predictors of sensory consequences arising from one's own actions, thereby enabling the brain to distinguish self-generated sensory signals (reafference) from sensory inputs caused by unpredictable external influences (exafference) [50][51][52] . Recent research, however, has expanded this view, suggesting that internal motor predictions are also involved in coordinating action of different motor systems that are otherwise functionally and anatomically unrelated 14 . ...
Foreleg trajectory in the mantis strike varies depending on prey distance. To examine how muscle activities affect foreleg trajectory, we recorded strike behaviours of the Chinese mantis with a high-speed camera and electromyograms of the foreleg trochanteral extensor and flexor. At the approach phase of the mantis strike, the prothorax-coxa (P-C) joint elevated and the femur-tibia (F-T) joint extended. At the sweep phase, the coxa-trochanter (C-T) joint rapidly extended, then, the F-T joint rapidly flexed to capture the prey. At capture initiation, the C-T joint extended more with greater prey distance. After cutting the tendon of the trochanteral flexor, the C-T joint extended similarly to that of the intact foreleg but did not flex after it reached its peak angle. After cutting the tendon of the trochanteral extensor, the C-T joint did not extend as much as that of the intact foreleg. During rapid extension of the C-T joint, a burst of spikes from the coxal trochanteral extensor was observed in electromyograms. Among several parameters, burst duration was the best predictor of C-T joint angular change during strike. Unexpectedly, trochanteral flexor activity was also observed during rapid extension of the C-T joint. These results indicated that the coxal trochanteral extensor mainly contributed to the rapid C-T extension during strike, but other muscles also contributed at the beginning of extension. The trochanteral flexor appeared to contribute to C-T flexion by countering the rapid extension.
Une très grande majorité de nos activités quotidiennes (lire un livre, conduire une voiture, apprécier une œuvre d’art) sont guidées par la vision active, c’est-à-dire l’interaction dynamique et constante entre notre système visuel, qui nous permet d’acquérir la représentation de la scène qui nous entoure et notre système oculomoteur, qui nous permet de déplacer notre regard de façon brève et rapide (‘saccades oculaires’) d’un objet à un autre au sein de cette scène. L’interaction entre ces deux systèmes est éminemment remarquable puisque malgré ces déplacements balistiques de l’œil, nous arrivons systématiquement à : (1) diriger notre regard de façon précise sur le stimulus d’intérêt en dépit de perturbations physiologiques ou pathologiques et (2) à maintenir une représentation visuelle stable de l’environnement malgré l’exécution de la saccade qui pourrait générer une image floutée ou instable en raison de sa haute vitesse. Ceci est respectivement permis par deux processus : (1) un mécanisme de plasticité sensori-motrice appelé adaptation saccadique qui assure le contrôle permanent de nos mouvements oculaires et (2) un système prédictif qui permet d’anticiper l’image visuelle post-saccadique. L’objectif de cette thèse était de mieux comprendre comment les prédictions de nos actions oculomotrices structurent -du moins en partie- notre perception visuelle par trois études. La première a été menée auprès d’un patient présentant une lésion du cortex pariétal postérieur. Elle a permis de valider deux hypothèses : (1) un signal de prédiction du mouvement oculaire est -sous certaines conditions- nécessaire pour localiser de façon précise une cible visuelle après une saccade et (2) le cortex pariétal postérieur joue un rôle clé dans son intégration. Les études 2 et 3 ont été menées respectivement auprès d’un groupe de volontaires sains et de patients cérébelleux. Elles visaient à comprendre comment une phase de plasticité oculomotrice (induisant une discordance systématique entre l’image prédite et réelle de la scène visuelle post-saccadique -qui devait nécessairement être corrigée par le mécanisme d’adaptation-) altérait notre capacité à localiser précisément un objet dans l’espace. Les résultats obtenus ont montré que la correction oculomotrice de cette discordance était effective chez le sujet sain et entraînait en contrepartie un biais perceptif de localisation. En revanche, la lésion du cervelet entravait la capacité de ces patients à corriger cette discordance, ce qui leur permettait de maintenir des jugements de localisation précis. Enfin, deux patients présentaient une dissociation entre capacité d’adaptation et performances de localisation spatiale. Dans l’ensemble, ces données suggèrent que le cervelet joue un rôle clé à la fois dans les fonctions motrices mais aussi dans la transmission de signaux prédictifs au cortex cérébral pour la perception visuo-spatiale et que ces deux fonctions sont sous-tendues par des territoires cérébelleux distincts. Au-delà de l’aspect fondamental, les tâches expérimentales que nous avons utilisées dans ces études pourraient s’avérer utiles en tant que biomarqueurs afin d’identifier une atteinte précoce de ce codage prédictif, ce qui a été couramment documenté en contexte psychiatrique, notamment dans le cas de schizophrénie.
It has been widely assumed that internal forward models use efference copies to create predictions about the sensory consequences of our own actions. While these predictions have frequently been associated with a reduced blood oxygen level dependent (BOLD) response in sensory cortices, the timing and duration of the hemodynamic response for the processing of video feedback of self-generated (active) versus externally generated (passive) movements is poorly understood. In the present study, we tested the hypothesis that predictive mechanisms for self-generated actions lead to early and shorter neural processing compared with externally generated movements. We investigated active and passive movements using a custom-made fMRI-compatible movement device. Visual video feedback of the active and passive movements was presented in real time or with variable delays. Participants had to judge whether the feedback was delayed. Timing and duration of BOLD impulse response was calculated using a first (temporal derivative [TD]) and second-order (dispersion derivative [DD]) Taylor approximation. Our reanalysis confirmed our previous finding of reduced BOLD response for active compared to passive movements. Moreover, we found positive effects of the TD and DD in the supplementary motor area, cerebellum, visual cortices, and subcortical structures, indicating earlier and shorter hemodynamic responses for active compared to passive movements. Furthermore, earlier activation in the putamen for active compared to passive conditions was associated with reduced delay detection performance. These findings indicate that efference copy-based predictive mechanisms enable earlier processing of action feedback, which might have reduced the ability to detect short delays between action and feedback.
There is a long-lasting controversy concerning our mind and consciousness. Mind, Brain, Quantum AI, and the Multiverse proposes a connection between the mind, the brain, and the multiverse. The author introduces the main philosophical ideas concerning mind and freedom, and explains the basic principles of computer science, artificial intelligence of brain research, quantum physics, and quantum artificial intelligence. He indicates how we can provide an answer to the problem of the mind and consciousness by describing the nature of the physical world. His proposed explanation includes the Everett Many-Worlds theory. This book tries to avoid any non-essential metaphysical speculations. The text is an essential compilation of knowledge in philosophy, computer science, biology, and quantum physics. It is written for readers without any requirements in mathematics, physics, or computer science.
Sensory events appear reduced in intensity when we actively produce them. Here, we investigated sensory attenuation in a virtual reality setup that allowed us to manipulate the time of tactile feedback when pressing a virtual button. We asked whether tactile motor attention might shift to the tactile location that makes contact with the button. In experiment one, we found that a tactile impulse was perceived as more intense when button pressing. In a second experiment, participants pushed a button and estimated the intensity of sounds. We found sensory attenuation for sounds only when tactile feedback was provided at the time the movement goal was reached. These data indicate that attentional prioritization for the tactile modality during a goal-directed hand movement might lead to a transient reduction in sensitivity in other modalities, resulting in sensory attenuation for sounds.
Actions modulate sensory processing by attenuating responses to self- compared to externally generated inputs, which is traditionally attributed to stimulus-specific motor predictions. Yet, suppression has been also found for stimuli merely coinciding with actions, pointing to unspecific processes that may be driven by neuromodulatory systems. Meanwhile, the differential processing for self-generated stimuli raises the possibility of producing effects also on memory for these stimuli; however, evidence remains mixed as to the direction of the effects. Here, we assessed the effects of actions on sensory processing and memory encoding of concomitant, but unpredictable sounds, using a combination of self-generation and memory recognition task concurrently with EEG and pupil recordings. At encoding, subjects performed button presses that half of the time generated a sound (motor-auditory; MA) and listened to passively presented sounds (auditory-only; A). At retrieval, two sounds were presented and participants had to respond which one was present before. We measured memory bias and memory performance by having sequences where either both or only one of the test sounds were presented at encoding, respectively. Results showed worse memory performance - but no differences in memory bias -, attenuated responses, and larger pupil diameter for MA compared to A sounds. Critically, the larger the sensory attenuation and pupil diameter, the worse the memory performance for MA sounds. Nevertheless, sensory attenuation did not correlate with pupil dilation. Collectively, our findings suggest that sensory attenuation and neuromodulatory processes coexist during actions, and both relate to disrupted memory for concurrent, albeit unpredictable sounds.
Awareness or consciousness in the context of stimulus perception can directly be assessed in well controlled test situations with humans via the persons’ reports about their subjective experiences with the stimuli. Since we have no direct access to subjective experiences in animals, their possible awareness or consciousness in stimulus perception tasks has often been inferred from behavior and cognitive abilities previously observed in aware and conscious humans. Here, we analyze published human data primarily on event-related potentials and brain-wave generation during perception and responding to sensory stimuli and extract neural markers (mainly latencies of evoked-potential peaks and of gamma-wave occurrence) indicating that a person became aware or conscious of the perceived stimulus. These neural correlates of consciousness were then applied to sets of corresponding data from various animals including several species of mammals, and one species each of birds, fish, cephalopods, and insects. We found that the neural markers from studies in humans could also successfully be applied to the mammal and bird data suggesting that species in these animal groups can become subjectively aware of and conscious about perceived stimuli. Fish, cephalopod and insect data remained inconclusive. In an evolutionary perspective we have to consider that both awareness of and consciousness about perceived stimuli appear as evolved, attention-dependent options added to the ongoing neural activities of stimulus processing and action generation. Since gamma-wave generation for functional coupling of brain areas in aware/conscious states is energetically highly cost-intensive, it remains to be shown which animal species under which conditions of lifestyle and ecological niche may achieve significant advantages in reproductive fitness by drawing upon these options. Hence, we started our discussion about awareness and consciousness in animals with the question in how far these expressions of brain activity are necessary attributes for perceiving stimuli and responding in an adaptive way.
Die meisten Schwindelformen und vestibulären Syndrome des Erwachsenen können sich ebenso in der Kindheit manifestieren, weshalb wir in diesem Kapitel die spezifischen Punkte der richtungsgebenden Anamnese, Befunde, Verläufe und der Therapie beim Kind hervorheben. Die Beschreibung der Beschwerden ist bei Kindern jedoch – je nach Alter – weniger präzise als bei Erwachsenen. Auch hängen die Untersuchungsbefunde der Gleichgewichtsfunktion und Okulomotorik bei Kindern (Devaraja 2018) stärker von der konzentrierten Mitarbeit ab.
Funktioneller Schwindel ist der neue Begriff für Schwindelsyndrome, die vestibuläre Symptome wie Schwindel, Stand- und Gangunsicherheit aufweisen, ohne dass eine organische Ursache feststellbar ist. Diese wurden früher somatoform oder psychogen genannt (◘ Abb. 5.1). In der Internationalen Klassifikation von Erkrankungen (ICD-11; WHO 2015) wird der Begriff „vestibuläre Symptome“ nun unabhängig von der Ursache für organische, psychiatrische und funktionelle Schwindelformen eingesetzt.
Interpreting sensory information requires its integration with the current behavior of the animal. However, how motor-related circuits influence sensory information processing is incompletely understood. Here, we report that current locomotor state directly modulates the activity of BAG CO2 sensory neurons in Caenorhabditis elegans. By recording neuronal activity in animals freely navigating CO2 landscapes, we found that during reverse crawling states, BAG activity is suppressed by tyraminergic corollary discharge signaling. We provide genetic evidence that tyramine released from the RIM reversal interneurons extrasynaptically activates the inhibitory chloride channel LGC-55 in BAG. Disrupting this pathway genetically leads to excessive behavioral responses to CO2 stimuli. Moreover, we find that LGC-55 signaling cancels out perception of self-produced CO2 and O2 stimuli when animals reverse into their own gas plume in ethologically relevant aqueous environments. Our results show that sensorimotor integration involves corollary discharge signals directly modulating chemosensory neurons.
Neural implementations of visual behaviors in Drosophila have been dissected intensively in the past couple of decades. The availability of premiere genetic toolkits, behavioral assays in tethered or freely moving conditions, and advances in connectomics have permitted the understanding of the physiological and anatomical details of the nervous system underlying complex visual behaviors. In this review, we describe recent advances on how various features of a visual scene are detected by the Drosophila visual system and how the neural circuits process these signals and elicit an appropriate behavioral response. Special emphasis was laid on the neural circuits that detect visual features such as brightness, color, local motion, optic flow, and translating or approaching visual objects, which would be important for behaviors such as phototaxis, optomotor response, attraction (or aversion) to moving objects, navigation, and visual learning. This review offers an integrative framework for how the fly brain detects visual features and orchestrates an appropriate behavioral response.
Une très grande majorité de nos activités quotidiennes (lire un livre, conduire une voiture, apprécier une œuvre d’art) sont tributaires de notre vision active, c’est-à-dire de l’interaction dynamique et constante entre notre système visuel, qui nous permet d’acquérir la représentation de la scène qui nous entoure et notre système oculomoteur, qui nous permet de déplacer notre regard entre les éléments d’intérêt de cette scène. L’interaction entre ces deux systèmes est éminemment remarquable puisque : (1) diriger notre regard sur des stimuli d’intérêt s’effectue de façon brève et rapide par des mouvements balistiques (‘saccades’) et néanmoins précis de l’œil en dépit de perturbations physiologiques ou pathologiques et (2) une représentation visuelle stable de l’environnement est maintenue malgré les très fortes perturbations des images captées par les rétines que génère l’exécution des saccades. Cette performance est respectivement permise par deux processus : (1) un mécanisme de plasticité sensorimotrice appelé adaptation saccadique qui assure le contrôle permanent de nos mouvements oculaires et (2) un système prédictif qui permet d’anticiper l’image visuelle post-saccadique.
L’objectif de cette thèse était de mieux comprendre comment et dans quelle mesure les prédictions de nos actions oculomotrices structurent notre perception visuelle. Trois études ont été conduites dans ce but. La première a été menée auprès d’un patient présentant une lésion du cortex pariétal postérieur. Elle a permis de démontrer que : (1) un signal de prédiction du mouvement oculaire est nécessaire pour localiser de façon précise une cible visuelle après une saccade et (2) le cortex pariétal postérieur joue un rôle clé dans la prise en compte de ce signal pour maintenir une image post-saccadique cohérente de l’environnement. Les études 2 et 3 ont été menées respectivement auprès d’un groupe de volontaires sains et de patients cérébelleux. Elles visaient à comprendre comment l’induction d’une plasticité oculomotrice peut altérer notre capacité à localiser précisément un objet dans l’espace. Les résultats obtenus chez les sujets sains ont montré que la correction oculomotrice adaptative de la discordance induite entre l’image prédite et réelle de la scène visuelle post-saccadique était effective et s’accompagnait d’un biais perceptif de localisation. En revanche, la lésion du cervelet entravait la capacité des patients à corriger cette discordance, ce qui leur permettait paradoxalement de réaliser des jugements de localisation plus précis que les sujets sains. Enfin, deux patients présentaient une dissociation entre capacité d’adaptation et performance de localisation spatiale. Ces données suggèrent que le cervelet joue un rôle clé à la fois dans les fonctions motrices mais aussi dans la transmission de signaux prédictifs au cortex cérébral pour la perception visuo-spatiale. Au-delà de l’aspect fondamental de ces résultats, nous proposons que les tâches expérimentales que nous avons utilisées dans ces études pourraient s’avérer utiles afin de mieux comprendre certains troubles psychiatriques (e.g., la schizophrénie) où la perturbation de ce codage prédictif a été documenté.
The sense of agency (SoA) is characterized as the sense of being the causal agent of one's own actions, and it is measured in two forms: explicit and implicit. In the explicit SoA experiments, the participants explicitly report whether they have a sense of control over their actions or whether they or somebody else is the causal agent of seen actions; the implicit SoA experiments study how do participants' agentive or voluntary actions modify perceptual processes (like time, vision, tactility, and audition) without directly asking the participants to explicitly think about their causal agency or sense of control. However, recent implicit SoA literature reported contradictory findings of the relationship between implicit SoA reports and agency states. Thus, I argue that the purported implicit SoA reports are not agency-driven perceptual effects per se but are judgment effects, by showing that (a) the typical operationalizations in implicit SoA domain lead to perceptual uncertainty on the part of the participants, (b) under uncertainty, participants' implicit SoA reports are due to heuristic judgments which are independent of agency states, and (c) under perceptual certainty, the typical implicit SoA reports might not have occurred at all. Thus, I conclude that the instances of implicit SoA are judgments (or response biases)—under uncertainty—rather than perceptual effects.
The ultimate tool, it could be said, is the brain and body. Therefore, a way to understand tool use is to study the brain's control of the body. A more manageable aim is to use the tools of cognitive science to explore the planning of physical actions. Here, I focus on two kinds of physical acts which directly or indirectly involve tool use: producing finger‐press sequences, and walking and reaching for objects. The main question is how people make choices between finger‐press sequences, and how people make choices between walk‐and‐reach sequences. Are the choices made with reference to motor imagery, in which case the longer the sequences are the longer it takes to choose between them, or are shortcuts taken which rely on distinctive features of the alternatives? The reviewed experiments favor the latter alternative. The general view of action planning emerging from this work is one in which action features are highlighted and held in memory, not just to choose between potential actions but also to control the unfolding of long actions over time. Speculations are offered about tool use.
It has been widely assumed that internal forward models use efference copies to create predictions about the sensory consequences of our own actions. While these predictions had been frequently associated with reduced neural processing in sensory cortices, the timing and duration of the hemodynamic response of self-generated as opposed to externally generated movements is poorly investigated. In the present study we tested the hypothesis that predictive mechanisms for self-generated actions lead to early and shorter neural processing compared with externally generated movements. Using a first and second-order Taylor approximation in terms of the temporal (TD) and dispersion (DD) derivatives of a canonical hemodynamic response function, we investigated the timing and duration of activation for self-generated and externally generated movements using a custom-made fMRI-compatible movement device. Visual video feedback of the active and passive hand movements were presented in real time or with variable delays (0 - 417 ms). Participants had to judge, whether the feedback was delayed. We found earlier feedback processing for self-generated compared to externally generated movements in several regions including the supplementary motor area, cerebellum, subcortical structures such as the putamen and visual cortices. Shorter processing was found in areas, which show also lower blood oxygen level dependent (BOLD) amplitudes, such as the SMA, occipital and parietal cortex. Specifically, earlier activation in the putamen, of self-generated movements was associated with worse performance in detecting delays. These findings support our hypothesis, that efference copy based predictive mechanisms enable earlier processing of action feedback, as potential source for behavioral effects.
Abstract The purpose of this study was to determine whether smooth pursuit eye movements affect visual motion prediction using a time‐to‐contact task where observers anticipate the exact instant that a partially occluded target would coincide with a stationary object. Moreover, we attempted to clarify the influence of second‐order motion on visual motion prediction during smooth pursuit. One target object moved to another stationary object (6 deg apart) at constant velocity of 3, 4, and 5 deg/s, and then the two objects disappeared 500 ms after the onset of target motion. The observers estimated the moment the moving object would overlap the stationary object and pressed a button. For the pursuit condition, both a Gaussian window and a random dots texture moved in the same direction at the same speed for the first‐order motion, whereas a Gaussian window moved over a static background composed of random dots texture for the second‐order motion. The results showed that the constant error of the time‐to‐contact shifted to a later response for the pursuit condition compared to the fixation condition, regardless of the object velocity. In addition, during smooth pursuit, the constant error for the second‐order motion shifted to an earlier response compared to the first‐order motion when the object velocity was 3 deg/s, whereas no significant difference was found at 4 and 5 deg/s. Therefore, our results suggest that visual motion prediction using a time‐to‐contact task is affected by both eye movements and motion configuration such as second‐order motion.
Auf die Psyche des Menschen wirken sich mit unterschiedlicher Bedeutung verschiedene Ordnungsparameter aus: biologische, physiologische, entwicklungsdynamische, soziologische, kulturelle, - reifungs- und integrations-förderliche wie fragmentierende, traumatisierende oder auch chaotisierende. Die entwicklungspsychologischen Phasen spiegeln schubweise Reifungsschritte. Ihre Überlagerungen ergeben facettenreiche Erscheinungsbilder. Das energetische Verwandlungsmuster der Grundsubstanz, das Einstein in seine allseits bekannte Formel brachte, E= mc2, scheint ein durchgehendes Prinzip, das sich auf allen Komplexitätsebenen sowohl im Inneren der menschlichen Organisation, im äußeren Miteinander, wie in übergeordneten, ideellen Bezogenheiten verwirklicht. Die gestaltpsychologische Entsprechung dazu ist Kurt Lewins Erkenntnis von der Gleichrangigkeit und grundsätzlichen Einheit von Struktur und Feld als Seinsweise. Dieser verwandlungsfreudige Ansatz erleichtert die Übersetzungsarbeiten im Rahmen der Psychotherapie und Psychosomatik.
Auf die Psyche des Menschen wirken sich mit unterschiedlicher Bedeutung verschiedene Ordnungsparameter aus: biologische, physiologische, entwicklungsdynamische, soziologische, kulturelle, – reifungs- und integrations-förderliche wie fragmentierende, traumatisierende oder auch chaotisierende. Die entwicklungspsychologischen Phasen spiegeln schubweise Reifungsschritte. Ihre Überlagerungen ergeben facettenreiche Erscheinungsbilder. Das energetische Verwandlungsmuster der Grundsubstanz, das Einstein in seine allseits bekannte Formel brachte, E= mc2, scheint ein durchgehendes Prinzip, das sich auf allen Komplexitätsebenen sowohl im Inneren der menschlichen Organisation, im äußeren Miteinander, wie in übergeordneten, ideellen Bezogenheiten verwirklicht. Die gestaltpsychologische Entsprechung dazu ist Kurt Lewins Erkenntnis von der Gleichrangigkeit und grundsätzlichen Einheit von Struktur und Feld als Seinsweise. Dieser verwandlungsfreudige Ansatz erleichtert die Übersetzungsarbeiten im Rahmen der Psychotherapie und Psychosomatik
While humans have developed a sophisticated and unique system of verbal auditory communication, they also share a more common and evolutionarily important nonverbal channel of voice signaling with many other mammalian and vertebrate species. This nonverbal communication is mediated and modulated by the acoustic properties of a voice signal, and is a powerful – yet often neglected – means of sending and perceiving socially relevant information. From the viewpoint of dyadic (involving a sender and a signal receiver) voice signal communication, we discuss the integrated neural dynamics in primate nonverbal voice signal production and perception. Most previous neurobiological models of voice communication modelled these neural dynamics from the limited perspective of either voice production or perception, largely disregarding the neural and cognitive commonalities of both functions. Taking a dyadic perspective on nonverbal communication, however, it turns out that the neural systems for voice production and perception are surprisingly similar. Based on the interdependence of both production and perception functions in communication, we first propose a re-grouping of the neural mechanisms of communication into auditory, limbic, and paramotor systems, with special consideration for a subsidiary basal-ganglia-centered system. Second, we propose that the similarity in the neural systems involved in voice signal production and perception is the result of the co-evolution of nonverbal voice production and perception systems promoted by their strong interdependence in dyadic interactions.
Synopsis
The goal of this article is to complement the comprehensive account Spatial Vision in Arthorpods provided by Wehner R. (1981) in the Handbook of Sensory Physiology. We will confine ourselves to review a selection of examples where over the last decades an integrated approach of quantitative behavioral studies in combination with electrophysiology and modeling best illustrates neural mechanisms underlying visually guided behavior. Many of these studies have been successfully carried out in a variety of flying insects, namely flies.
The purpose of this review is to analyze scientific ideas about the regularities of regulatory processes in schizophrenia. Various pathogenetic theories of schizophrenia have been traced, from attempts to isolate the "main disorder" to modern neurobiological concepts. It is shown that the main link in the mechanism of development of psychopathological symptoms, neurophysiological and pathopsychological phenomena, i.e. manifested at different levels of the organization of mental processes, can be considered a violation of the actualization of previous experience.
We present the Sensory Island Task (SIT), a new freely moving search paradigm to study sensory processing and perception. In SIT, animals explore an open-field arena to find a sensory target relying solely on changes in the presented stimulus, which is controlled by closed-loop position tracking in real-time. Within a few sessions, animals are trained via positive reinforcement to search for a particular area in the arena (“target island”), which triggers the presentation of the target stimulus. The location of the target island is randomized across trials, making the modulated stimulus feature the only informative cue for task completion. Animals report detection of the target stimulus by remaining within the island for a defined time (“sit-time”). Multiple “non-target” islands can be incorporated to test psychometric discrimination and identification performance. We exemplify the suitability of SIT for rodents (Mongolian gerbil, Meriones unguiculatus) and small primates (mouse lemur, Microcebus murinus) and for studying various sensory perceptual performances (auditory frequency discrimination, sound source localization, visual orientation discrimination).
Synopsis
This chapter reviews the discovery history of the mechanosensory and electrosensory lateral line and the magnetic sense. In addition, it discusses some of the more recent findings about the physiology and behavioral relevance of these sensory systems. The meaning of these findings for general neurobiology and behavioral physiology and the respective volume chapters that provide more detailed information about these findings are pointed out. Finally, for each sensory system important gaps in our knowledge are shown, followed by suggestions how these gaps might be filled.
Synopsis
A way in which animals can control or select the sensory information they obtain depends on context-specific modulations of their behavior that change their sensory input. When this is done purposively it is considered as an active sensing strategy. In this chapter we focus on weakly electric fish as an example for active sensory systems, as they offer several advantages when studying active sensing strategies. Starting at the behavioral level we discuss the role and sensory consequences of varying active sensing strategies in weakly electric fish. This is linked to a discussion of the role of these movements in neural processing.
Relatively little is known about how the human brain identifies movement of objects while the observer is also moving in the environment. This is, ecologically, one of the most fundamental motion processing problems, critical for survival. To study this problem, we used a task which involved nine textured spheres moving in depth, eight simulating the observer’s forward motion while the ninth, the target, moved independently with a different speed towards or away from the observer. Capitalizing on the high temporal resolution of magnetoencephalography (MEG) we trained a Support Vector Classifier (SVC) using the sensor-level data to identify correct and incorrect responses. Using the same MEG data, we addressed the dynamics of cortical processes involved in the detection of the independently moving object and investigated whether we could obtain confirmatory evidence for the brain activity patterns used by the classifier. Our findings indicate that response correctness could be reliably predicted by the SVC, with the highest accuracy during the blank period after motion and preceding the response. The spatial distribution of the areas critical for the correct prediction was similar but not exclusive to areas underlying the evoked activity. Importantly, SVC identified frontal areas otherwise not detected with evoked activity that seem to be important for the successful performance in the task. Dynamic connectivity further supported the involvement of frontal and occipital-temporal areas during the task periods. This is the first study to dynamically map cortical areas using a fully data-driven approach in order to investigate the neural mechanisms involved in the detection of moving objects during observer’s self-motion.
The term pseudohallucination was originally introduced to characterize hallucinatory phenomena not exhibiting the paradigmatic features of hallucinations. In our context, and directly following Jaspers ‘ description, the term has been used to characterize a specific type of auditory hallucination in schizophrenic patients i.e. the so-called voices. However, this formation is not shared in other contexts. This paper suggests that Jaspers ‘ formulation is inexact and problematic when trying to describe the semiology, philosophical foundations, and aetiology of the phenomenon. In addition, we claim that this lack of etiological and nosological clarity lead to serious doubts about the real utility of the use of the term within current descriptive psychopathology. We conclude by proposing two potential alternatives that the use of the term might have within the field.
The aim of this review is considering the role of situation in regulation of behavior. Conceptions of personal-situational interaction are described. It is shown that attempts to classify situations are fraught with serious predicament, since the perception of specific context is very variable. Subjective and personal understanding of the situation is determined by the unique history of interactions with the environment. The experience gained throughout life determines the hypotheses about the world what the subject will form, his predictions in specific circumstances about the possible outcomes of the situation. The correct perception of the world is not in the objective reflection of it, but in the successful adaptation to it, accurate predictions which were made.
ResearchGate has not been able to resolve any references for this publication.