Autism spectrum disorders (ASD) are often associated with impairments in judgment of facial expressions. This impairment is
often accompanied by diminished eye contact and atypical amygdala responses to face stimuli. The current study used a within-subjects
design to examine the effects of natural viewing and an experimental eye-gaze manipulation on amygdala responses to faces.
Individuals with ASD showed less gaze toward the eye region of faces relative to a control group. Among individuals with ASD,
reduced eye gaze was associated with higher threat ratings of neutral faces. Amygdala signal was elevated in the ASD group
relative to controls. This elevated response was further potentiated by experimentally manipulating gaze to the eye region.
Potentiation by the gaze manipulation was largest for those individuals who exhibited the least amount of naturally occurring
gaze toward the eye region and was associated with their subjective threat ratings. Effects were largest for neutral faces,
highlighting the importance of examining neutral faces in the pathophysiology of autism and questioning their use as control
stimuli with this population. Overall, our findings provide support for the notion that gaze direction modulates affective
response to faces in ASD.
Stress has significant adverse effects on health and is a risk factor for many illnesses. Neurobiological studies have implicated the amygdala as a brain structure crucial in stress responses. Whereas hyperactive amygdala function is often observed during stress conditions, cross-sectional reports of differences in gray matter structure have been less consistent. We conducted a longitudinal MRI study to investigate the relationship between changes in perceived stress with changes in amygdala gray matter density following a stress-reduction intervention. Stressed but otherwise healthy individuals (N = 26) participated in an 8-week mindfulness-based stress reduction intervention. Perceived stress was rated on the perceived stress scale (PSS) and anatomical MR images were acquired pre- and post-intervention. PSS change was used as the predictive regressor for changes in gray matter density within the bilateral amygdalae. Following the intervention, participants reported significantly reduced perceived stress. Reductions in perceived stress correlated positively with decreases in right basolateral amygdala gray matter density. Whereas prior studies found gray matter modifications resulting from acquisition of abstract information, motor and language skills, this study demonstrates that neuroplastic changes are associated with improvements in a psychological state variable.
Faces are represented in a more configural or holistic manner than other objects. Substantial evidence indicates that this representation results from face-specific mechanisms, but some have argued that it is produced by configural mechanisms that can be applied to many objects including words. The face-specific hypothesis predicts that non-face configural processes will often be normal in prosopagnosic subjects, whereas the domain-general configural hypothesis predicts they will be deficient on all configural tasks. Although the weight of the evidence favors the face-specific hypothesis, a recent study reopened this issue when it was found that three out of five developmental prosopagnosics showed a larger local processing bias than controls in a global-local task (i.e. a Navon task). To examine this issue more thoroughly we tested a significantly larger sample of prosopagnosics (14 participants) who had severe face memory and face perception deficits. In contrast to the previous report, the developmental prosopagnosics performed normally in the global-local task. Like controls, they showed a typical global advantage and typical global-to-local consistency effects. The results demonstrate that the configural processing required by the Navon task is dissociable from face configural processing.
When we observe the actions of others, certain areas of the brain are activated in a similar manner as to when we perform
the same actions ourselves. This ‘mirror system’ includes areas in the ventral premotor cortex and the inferior parietal lobule.
Experimental studies suggest that action observation automatically elicits activity in the observer, which precisely mirrors
the activity observed. In this case we would expect this activity to be independent of observer's viewpoint. Here we use whole-head
magnetoencephalography (MEG) to record cortical activity of human subjects whilst they watched a series of videos of an actor
making a movement recorded from different viewpoints. We show that one cortical response to action observation (oscillatory
activity in the 7–12 Hz frequency range) is modulated by the relationship between the observer and the actor. We suggest that
this modulation reflects a mechanism that filters information into the ‘mirror system’, allowing only socially relevant information
to pass.
Much past research has focused on how traits related to the behavioral inhibition system (BIS) and avoidance motivation influence
the almost obligatory attentional processing of aversive stimuli as measured as early as 100 ms into stimulus processing.
These results fit with the functional importance assigned to the negativity bias. But do traits related to the behavioral
approach system (BAS) influence attentional processing with similar rapidity? The present study addressed this unanswered
question by testing whether trait BAS relates to event-related potentials (ERP) involved in rapid motivated attentional processing
to appetitive stimuli. Results indicated that individual differences in BAS were correlated with larger ERP amplitudes as
early as 100 ms into the processing of appetitive pictures. These results provide the first evidence linking trait approach
motivational tendencies to very early stages of motivated attentional processing.
In this issue, Terasawa and colleagues used functional neuroimaging to test for common neural substrates supporting conscious
appraisal of subjective bodily and emotional states and explored how the relationship might account for personality and experience
of anxiety symptoms. Their study highlights a role for the same region of anterior insula cortex in appraisal of emotions
and bodily physiology. The reactivity of this region also mediated the relationship between ‘bodily sensibility’ and social
fear, translating a cognitive representation of subjective physical state into an individual personality trait that influences
social interaction. The task used by Terasawa and colleagues taps into conscious aspects to the expression of this dynamic.
These findings add to increasing evidence for the role of anterior insula as the interface between physiologically driven
internal motivational states, emotional awareness and interpersonal behaviour.
22q11.2 Deletion Syndrome (22q11DS) is a genetic mutation associated with disorders of cortical connectivity and social dysfunction. However, little is known about the functional connectivity (FC) of the resting brain in 22q11DS and its relationship with social behavior.
A seed-based-analysis of resting-state functional MRI data was used to investigate FC associated with the posterior cingulate cortex (PCC), in [26] youth with 22qDS and [51] demographically-matched controls. Subsequently, the relationship between PCC-connectivity and Social Responsiveness Scale (SRS) scores was examined in 22q11DS participants.RESULTS: Relative to 22q11DS participants, controls showed significantly stronger FC between the PCC and other default mode network (DMN) nodes, including the precuneus, precentral gyrus, and left frontal pole. 22q11DS patients did not show age-associated FC changes observed in typically-developing controls. Increased connectivity between PCC, medial prefrontal regions, and the anterior cingulate cortex, was associated with lower SRS scores (i.e., improved social competence) in 22q11DS.CONCLUSIONS: DMN integrity may play a key role in social information-processing. We observed disrupted DMN connectivity in 22q11DS, paralleling reports from idiopathic autism and schizophrenia. Increased strength of long-range DMN connectivity was associated with improved social functioning in 22q11DS. These findings support a "developmental-disconnection" hypothesis of symptom development in this disorder.
The fields of personality research and neuropsychology have developed with very little overlap. Gray and McNaughton were among the first to recognize that personality traits must have neurobiological correlates and developed models relating personality factors to brain structures. Of particular note was their description of associations between conditioning, inhibition and activation of behaviours, and specific neural structures such as the hippocampus, amygdala and the prefrontal cortex. The aim of this study was to determine whether personality constructs representing the behavioural inhibition and activation systems (BIS/BAS) were associated with volumetric measures of the hippocampus and amygdala in humans. Amygdalar and hippocampal volumes were measured in 430 brain scans of cognitively intact community-based volunteers. Linear associations between brain volumes and the BIS/BAS measures were assessed using multiple regression, controlling for age, sex, education, intra-cranial and total brain volume. Results showed that hippocampal volumes were positively associated with BIS sensitivity and to a lesser extent with BAS sensitivity. No association was found between amygdalar volume and either the BIS or BAS. These findings add support to the model of Gray and McNaughton, which proposes a role of the hippocampus in the regulation of defensive/approach behaviours and trait anxiety but suggest an absence of associations between amygdala volume and BIS/BAS measures.
Klinefelter syndrome (KS) is a chromosomal condition (47, XXY) that may help us to unravel gene-brain behavior pathways to psychopathology. The phenotype includes social cognitive impairments and increased risk for autism traits. We used functional MRI to study neural mechanisms underlying social information processing. Eighteen nonclinical controls and thirteen men with XXY were scanned during judgments of faces with regard to trustworthiness and age. While judging faces as untrustworthy in comparison to trustworthy, men with XXY displayed less activation than controls in (i) the amygdala, which plays a key role in screening information for socio-emotional significance, (ii) the insula, which plays a role in subjective emotional experience, as well as (iii) the fusiform gyrus and (iv) the superior temporal sulcus, which are both involved in the perceptual processing of faces and which were also less involved during age judgments in men with XXY. This is the first study showing that KS can be associated with reduced involvement of the neural network subserving social cognition. Studying KS may increase our understanding of the genetic and hormonal basis of neural dysfunctions contributing to abnormalities in social cognition and behavior, which are considered core abnormalities in psychiatric disorders such as autism and schizophrenia.
This study examined whether middle-aged adults exposed to poverty in childhood or current financial hardship have detectable brain differences from those who have not experienced such adversity. Structural magnetic resonance imaging (MRI) was conducted as one aspect of the Personality and Total Health (PATH) through life study: a large longitudinal community survey measuring the health and well-being of three cohorts from south-eastern Australia. This analysis considers data from 431 middle-aged adults in the aged 44-48 years at the time of the interview. Volumetric segmentation was performed with the Freesurfer image analysis suite. Data on socio-demographic circumstances, mental health and cognitive performance were collected through the survey interview. Results showed that, after controlling for well-established risk factors for atrophy, adults who reported financial hardship had smaller left and right hippocampal and amygdalar volumes than those who did not report hardship. In contrast, there was no reliable association between hardship and intra-cranial volume or between childhood poverty and any of the volumetric measures. Financial hardship may be considered a potent stressor and the observed results are consistent with the view that hardship influences hippocampal and amygdalar volumes through hypothalamic-pituitary-adrenal axis function and other stress-related pathways.
Over the past 60 years, human intracranial electrophysiology (HIE) has been used to characterize seizures in patients with epilepsy. Secondary to the clinical objectives, electrodes implanted intracranially have been used to investigate mechanisms of human cognition. In addition to studies of memory and language, HIE methods have been used to investigate emotions. The aim of this review is to outline the contribution of HIE (electrocorticography, single-unit recording, and electrical brain stimulation) to our understanding of the neural representations of emotions. We identified 64 papers dating back to the mid-1950s which used HIE techniques to study emotional states. Evidence from HIE studies supports the existence of widely distributed networks in the neocortex, limbic/paralimbic regions, and subcortical nuclei which contribute to the representation of emotional states. In addition, evidence from HIE supports hemispheric dominance for emotional valence. Furthermore, evidence from HIE supports the existence of overlapping neural areas for emotion perception, experience, and expression. Lastly, HIE provides unique insights into the temporal dynamics of neural activation during perception, experience, and expression of emotional states. In conclusion, we propose that HIE techniques offer important evidence which must be incorporated into our current models of emotion representation in the human brain.
Appraisal of fearful stimuli is an integral aspect of social cognition. Neural circuitry underlying this phenomenon has been well-described, and encompasses a distributed network of affective and cognitive nodes. Interestingly, this ability to process fearful faces is impaired in Turner syndrome (TS), a genetic disorder of females in which all or part of an X chromosome is missing. However, neurofunctional correlates for this impairment have not been well-studied, particularly in young girls. Given that the core features of TS include X chromosome gene haploinsufficiency and secondary sex hormone deficiencies, investigation of fearful face processing may provide insights into the influence of X chromosome gene expression on this network. Therefore, we examined behavioral and neural responses during an explicit emotional face labeling task in 14 prepubertal girls with TS and 16 typically developing age-matched controls (6-13 years). We demonstrate that girls with TS have a specific impairment in the identification of fearful faces, and show decreased activation in several cognitive control regions, including the anterior dorsal anterior cingulate cortex, dorsolateral prefrontal cortex and posterior cingulate gyrus. Our results indicate that aberrant functional activation in dorsal cognitive regions play an integral role in appraisal of, and regulation of response to fear in TS.
The ability to form anticipatory representations of ongoing actions is crucial for effective interactions in dynamic environments. In sports, elite athletes exhibit greater ability than novices in predicting other players' actions, mainly based on reading their body kinematics. This superior perceptual ability has been associated with a modulation of visual and motor areas by visual and motor expertise. Here, we investigated the causative role of visual and motor action representations in experts' ability to predict the outcome of soccer actions. We asked expert soccer players (outfield players and goalkeepers) and novices to predict the direction of the ball after perceiving the initial phases of penalty kicks that contained or not incongruent body kinematics. During the task we applied repetitive transcranial magnetic stimulation (rTMS) over the superior temporal sulcus (STS) and the dorsal premotor cortex (PMd). Results showed that STS-rTMS disrupted performance in both experts and novices, especially in those with greater visual expertise (i.e., goalkeepers). Conversely, PMd-rTMS impaired performance only in expert players (i.e., outfield players and goalkeepers), who exhibit strong motor expertise into facing domain-specific actions in soccer games. These results provide causative evidence of the complimentary functional role of visual and motor action representations in experts' action prediction.
Attention bias modification (ABM) procedures typically reduce anxiety symptoms, yet little is known about the neural changes
associated with this behavioral treatment. Healthy adults with high social anxiety symptoms (n = 53) were randomized to receive either active or placebo ABM. Unlike placebo ABM, active ABM aimed to train individuals’
attention away from threat. Using the dot-probe task, threat-related attention bias was measured during magnetic resonance
imaging before and after acute and extended training over 4 weeks. A subset of participants completed all procedures (n = 30, 15 per group). Group differences in neural activation were identified using standard analyses. Linear regression tested
predictive factors of symptom reduction (i.e., training group, baseline indices of threat bias). The active and placebo groups
exhibited different patterns of right and left amygdala activation with training. Across all participants irrespective of
group, individuals with greater left amygdala activation in the threat-bias contrast prior to training exhibited greater symptom
reduction. After accounting for baseline amygdala activation, greater symptom reduction was associated with assignment to
the active training group. Greater left amygdala activation at baseline predicted reductions in social anxiety symptoms following
ABM. Further research is needed to clarify brain-behavior mechanisms associated with ABM training.
Several recent studies suggest that autism may result from abnormal communication between brain regions. We directly assessed
this hypothesis by testing the presence of abnormalities in a model of the functional cerebral network engaged during explicit
emotion processing in adults with high functioning autism or Asperger syndrome. Comparison of structural equation models revealed
abnormal patterns of effective connectivity, with the prefrontal cortex as a key site of dysfunction. These findings provide
evidence that abnormal long-range connectivity between structures of the ‘social brain’ could explain the socio-emotional
troubles that characterize the autistic pathology.
People with autism are impaired in their social behavior, including their eye contact with others, but the processes that
underlie this impairment remain elusive. We combined high-resolution eye tracking with computational modeling in a group of
10 high-functioning individuals with autism to address this issue. The group fixated the location of the mouth in facial expressions
more than did matched controls, even when the mouth was not shown, even in faces that were inverted and most noticeably at
latencies of 200–400 ms. Comparisons with a computational model of visual saliency argue that the abnormal bias for fixating
the mouth in autism is not driven by an exaggerated sensitivity to the bottom-up saliency of the features, but rather by an
abnormal top-down strategy for allocating visual attention.
Recent studies of autism have identified functional abnormalities of the default network during a passive resting state. Since the default network is also typically engaged during social, emotional and introspective processing, dysfunction of this network may underlie some of the difficulties individuals with autism exhibit in these broad domains. In the present experiment, we attempted to further delineate the nature of default network abnormality in autism using experimentally constrained social and introspective tasks. Thirteen autism and 12 control participants were scanned while making true/false judgments for various statements about themselves (SELF condition) or a close other person (OTHER), and pertaining to either psychological personality traits (INTERNAL) or observable characteristics and behaviors (EXTERNAL). In the ventral medial prefrontal cortex/ventral anterior cingulate cortex, activity was reduced in the autism group across all judgment conditions and also during a resting condition, suggestive of task-independent dysfunction of this region. In other default network regions, overall levels of activity were not different between groups. Furthermore, in several of these regions, we found group by condition interactions only for INTERNAL/EXTERNAL judgments, and not SELF/OTHER judgments, suggestive of task-specific dysfunction. Overall, these results provide a more detailed view of default network functionality and abnormality in autism.
Human decision-making is remarkably susceptible to commercial advertising, yet the neurobiological basis of this phenomenon
remains largely unexplored. With a series of Coke and Pepsi taste tests we show that patients with damage specifically involving
ventromedial prefrontal cortex (VMPC), an area important for emotion, did not demonstrate the normal preference bias when
exposed to brand information. Both comparison groups (neurologically normal adults and lesion patients with intact VMPC) preferred
Pepsi in a blind taste test, but in subsequent taste tests that featured brand information (‘semi-blind’ taste tests), both
comparison groups’ preferences were skewed toward Coke, illustrating the so-called ‘Pepsi paradox’. Like comparison groups,
the VMPC patients preferred Pepsi in the blind taste test, but unlike comparison groups, the VMPC patients maintained their
Pepsi preference in the semi-blind test. The result that VMPC damage abolishes the ‘Pepsi paradox’ suggests that the VMPC
is an important part of the neural substrate for translating commercial images into brand preferences.
Self-referential evaluation of emotional stimuli has been shown to modify the way emotional stimuli are processed. This study aimed at a new approach by investigating whether self-reference alters emotion processing in the absence of explicit self-referential appraisal instructions. Event-related potentials were measured while subjects spontaneously viewed a series of emotional and neutral nouns. Nouns were preceded either by personal pronouns ('my') indicating self-reference or a definite article ('the') without self-reference. The early posterior negativity, a brain potential reflecting rapid attention capture by emotional stimuli was enhanced for unpleasant and pleasant nouns relative to neutral nouns irrespective of whether nouns were preceded by personal pronouns or articles. Later brain potentials such as the late positive potential were enhanced for unpleasant nouns only when preceded by personal pronouns. Unpleasant nouns were better remembered than pleasant or neutral nouns when paired with a personal pronoun. Correlation analysis showed that this bias in favor of self-related unpleasant concepts can be explained by participants' depression scores. Our results demonstrate that self-reference acts as a first processing filter for emotional material to receive higher order processing after an initial rapid attention capture by emotional content has been completed. Mood-congruent processing may contribute to this effect.
Much work in the field of social cognition shows that adopting an abstract (vs concrete) mindset alters the way people construe the world, thereby exerting substantial effects across innumerable aspects
of human behavior. In order to investigate the cognitive and neural basis of these effects, we scanned participants as they
performed two widely used tasks that induce an abstracting vs concretizing mindsets. Specifically, participants: (i) indicated ‘why’ perform certain activities (a task that involves abstraction)
or ‘how’ the same activities are performed (a task that involves concretization) and (ii) generated superordinate categories
for certain objects (a task that involves abstraction) or subordinate exemplars for the same objects (a task that involves
concretization). We conducted a conjunction analysis of the two tasks, in order to uncover the neural activity associated
with abstraction and concretization. The results showed that concretization was associated with activation in fronto-parietal
regions implicated in goal-directed action; abstraction was associated with activity within posterior regions implicated in
visual perception. We discuss these findings in light of construal-level theory’s notion of abstraction.
Various kinds of normative judgments are an integral part of everyday life. We extended the scrutiny of social cognitive neuroscience into the domain of legal decisions, investigating two groups, lawyers and other academics, during moral and legal decision-making. While we found activation of brain areas comprising the so-called 'moral brain' in both conditions, there was stronger activation in the left dorsolateral prefrontal cortex and middle temporal gyrus particularly when subjects made legal decisions, suggesting that these were made in respect to more explicit rules and demanded more complex semantic processing. Comparing both groups, our data show that behaviorally lawyers conceived themselves as emotionally less involved during normative decision-making in general. A group × condition interaction in the dorsal anterior cingulate cortex suggests a modulation of normative decision-making by attention based on subjects' normative expertise.
Trait impulsivity is characterized by behavioral disinhibition and rash decision-making that contribute to many maladaptive behaviors. Previous research demonstrates that trait impulsivity is related to the activity of brain regions underlying reward sensitivity and emotion regulation, but little is known about this relationship in the context of immediately available primary reward. This is unfortunate, as impulsivity in these contexts can lead to unhealthy behaviors, including poor food choices, dangerous drug use, and risky sexual practices. In addition, little is known about the relationship between integration of reward and affective neurocircuitry, as measured by resting-state functional connectivity, and trait impulsivity in everyday life, as measured with a commonly used personality inventory. We therefore asked healthy adults to undergo a fMRI task in which they saw cues indicating the imminent oral administration of rewarding taste, as well as a resting-state scan. Trait impulsivity was associated with increased activation during anticipation of primary reward in the anterior cingulate cortex (ACC) and amygdala. Additionally, resting-state functional connectivity between the ACC and the right amygdala was negatively correlated with trait impulsivity. These findings demonstrate that trait impulsivity is related not only to ACC-amygdala activation, but also how tightly coupled these regions are to one another.
We developed an ecologically valid virtual peer interaction paradigm—the Chatroom Interact Task in which 60 pre-adolescents and adolescents (ages 9–17 years) were led to believe that they were interacting with other youth
in a simulated internet chatroom. Youth received rejection and acceptance feedback from virtual peers. Findings revealed increased
pupil dilation, an index of increased activity in cognitive and affective processing regions of the brain, to rejection compared
to acceptance trials, which was greater for older youth. Data from a cell-phone Ecological Momentary Assessment (EMA) protocol
completed following the task indicated that increased pupillary reactivity to rejection trials was associated with lower feelings
of social connectedness with peers in daily life. Eyetracking analyses revealed attentional biases toward acceptance feedback
and away from rejection feedback. Biases toward acceptance feedback were stronger for older youth. Avoidance of rejection
feedback was strongest among youth with increased pupillary reactivity to rejection, even in the seconds leading up to and
following rejection feedback. These findings suggest that adolescents are sensitive to rejection feedback and seek to anticipate
and avoid attending to rejection stimuli. Furthermore, the salience of social rejection and acceptance feedback appears to
increase during adolescence.
Previous studies have documented the positive effects of mindfulness meditation on executive control. What has been lacking,
however, is an understanding of the mechanism underlying this effect. Some theorists have described mindfulness as embodying
two facets—present moment awareness and emotional acceptance. Here, we examine how the effect of meditation practice on executive
control manifests in the brain, suggesting that emotional acceptance and performance monitoring play important roles. We investigated
the effect of meditation practice on executive control and measured the neural correlates of performance monitoring, specifically,
the error-related negativity (ERN), a neurophysiological response that occurs within 100 ms of error commission. Meditators
and controls completed a Stroop task, during which we recorded ERN amplitudes with electroencephalography. Meditators showed
greater executive control (i.e. fewer errors), a higher ERN and more emotional acceptance than controls. Finally, mediation
pathway models further revealed that meditation practice relates to greater executive control and that this effect can be
accounted for by heightened emotional acceptance, and to a lesser extent, increased brain-based performance monitoring.
The effect of social rejection on cardiac and brain responses was examined in a study in which participants had to decide
on the basis of pictures of virtual peers whether these peers would like them or not. Physiological and behavioral responses
to expected and unexpected acceptance and rejection were compared. It was found that participants expected that about 50%
of the virtual judges gave them a positive judgment. Cardiac deceleration was strongest for unexpected social rejection. In
contrast, the brain response was strongest to expected acceptance and was characterized by a positive deflection peaking around
325 ms following stimulus onset and the observed difference was maximal at fronto-central positions. The cardiac and electro-cortical
responses were not related. It is hypothesized that these differential response patterns might be related to earlier described
differential involvement of the dorsal and ventral portion of the anterior cingulate cortex.
The current research examined the viability of the N400, an event-related potential related to the detection of semantic incongruity, as an index of both stereotype accessibility and interracial prejudice. Participants' EEG was recorded while they completed a sequential priming task, in which negative or positive, stereotypically Black (African-American) or White (Caucasian-American) traits followed the presentation of either a Black or White face acting as a prime. ERP examination focused on the N400, but additionally examined N100 and P200 reactivity. Replicating and extending previous N400 stereotype research, results indicated that the N400 can indeed function as an index of stereotype accessibility in an inter-racial domain, as greater N400 reactivity was elicited by trials in which the face prime was incongruent with the target trait than when primes and traits matched. Furthermore, N400 activity was moderated by participants' self-reported explicit bias. More explicitly biased participants demonstrated greater N400 reactivity to stereotypically White traits following Black faces than Black traits following Black faces. P200 activity was additionally associated with participants' implicit biases, as more implicitly biased participants similarly demonstrated greater P200 reactivity to stereotypically White traits following Black faces than Black traits following Black faces.
A reward or punishment can seem better or worse depending on what else might have happened. Little is known, however, about how neural representations of an anticipated incentive might be influenced by the available alternatives. We used event-related FMRI to investigate the activation in the nucleus accumbens (NAcc), while we varied the available alternative incentives in a monetary incentive delay task. Some task blocks included only uncertain gains and losses; others included the same uncertain gains and losses intermixed with certain gains and losses. The availability of certain gains and losses increased NAcc activation for uncertain losses and decreased the difference between uncertain gains and losses. We suggest that this pattern of activation can result from reference point changes across blocks, and that the worst available loss may serve as an important anchor for NAcc activation. These findings imply that NAcc activation represents anticipated incentive value relative to the current context of available alternative gains and losses.
Recent studies have reported inconsistent results regarding the loss of reward sensitivity in the aging brain. Although such
an age effect might be due to a decline of physiological processes, it may also be a consequence of age-related changes in
motivational preference for different rewards. Here, we examined whether the age effects on neural correlates of reward anticipation
are modulated by the type of expected reward. Functional magnetic resonance images were acquired in 24 older (60–78 years)
and 24 young participants (20–28 years) while they performed an incentive delay task offering monetary or social rewards.
Anticipation of either reward type recruited brain structures associated with reward, including the nucleus accumbens (NAcc).
Region of interest analysis revealed an interaction effect of reward type and age group in the right NAcc: enhanced activation
to cues of social reward was detected in the older subsample while enhanced activation to cues of monetary reward was detected
in the younger subsample. Our results suggest that neural sensitivity to reward-predicting cues does not generally decrease
with age. Rather, neural responses in the NAcc appear to be modulated by the type of reward, presumably reflecting age-related
changes in motivational value attributed to different types of reward.
The ability to accurately infer others' mental states from facial expressions is important for optimal social functioning and is fundamentally impaired in social cognitive disorders such as autism. While pharmacologic interventions have shown promise for enhancing empathic accuracy, little is known about the effects of behavioral interventions on empathic accuracy and related brain activity. This study employed a randomized, controlled and longitudinal design to investigate the effect of a secularized analytical compassion meditation program, cognitive-based compassion training (CBCT), on empathic accuracy. Twenty-one healthy participants received functional MRI scans while completing an empathic accuracy task, the Reading the Mind in the Eyes Test (RMET), both prior to and after completion of either CBCT or a health discussion control group. Upon completion of the study interventions, participants randomized to CBCT and were significantly more likely than control subjects to have increased scores on the RMET and increased neural activity in the inferior frontal gyrus (IFG) and dorsomedial prefrontal cortex (dmPFC). Moreover, changes in dmPFC and IFG activity from baseline to the post-intervention assessment were associated with changes in empathic accuracy. These findings suggest that CBCT may hold promise as a behavioral intervention for enhancing empathic accuracy and the neurobiology supporting it.
Despite the dominant role of the hormone oxytocin (OT) in social behavior, little is known about the role of OT in the perception
of social relationships. Furthermore, it is unclear whether there are sex differences in the way that OT affects social perception.
Here, we employed a double-blind, placebo-controlled crossover design to investigate the effect of OT on accurate social perception.
Following treatment, 62 participants completed the Interpersonal Perception Task, a method of assessing the accuracy of social
judgments that requires identification of the relationship between people interacting in real life video clips divided into
three categories: kinship, intimacy and competition. The findings suggest that OT had a general effect on improving accurate
perception of social interactions. Furthermore, we show that OT also involves sex-specific characteristics. An interaction
between treatment, task category and sex indicated that OT had a selective effect on improving kinship recognition in women,
but not in men, whereas men's performance was improved following OT only for competition recognition. It is concluded that
the gender-specific findings reported here may point to some biosocial differences in the effect of OT which may be expressed
in women's tendency for communal and familial social behavior as opposed to men's tendency for competitive social behavior.
The present study investigated whether emotionally expressive faces guide attention and modulate fMRI activity in fusiform gyrus in acquired prosopagnosia. Patient PS, a pure case of acquired prosopagnosia with intact right middle fusiform gyrus, performed two behavioral experiments and a functional imaging experiment to address these questions. In a visual search task involving face stimuli, PS was faster to select the target face when it was expressing fear or happiness as compared to when it was emotionally neutral. In a change detection task, PS detected significantly more changes when the changed face was fearful as compared to when it was neutral. Finally, an fMRI experiment showed enhanced activation to emotionally expressive faces and bodies in right fusiform gyrus. In addition, PS showed normal body-selective activation in right fusiform gyrus, partially overlapping the fusiform face area. Together these behavioral and neuroimaging results show that attention was preferentially allocated to emotional faces in patient PS, as observed in healthy subjects. We conclude that systems involved in the emotional guidance of attention by facial expression can function normally in acquired prosopagnosia, and can thus be dissociated from systems involved in face identification.
Exposure therapy builds on the mechanism of fear extinction leading to decreased fear responses. How the stress hormone cortisol
affects brain regions involved in fear extinction in humans is unknown. For this reason, we tested 32 men randomly assigned
to receive either 30 mg hydrocortisone or placebo 45 min before fear extinction. In fear acquisition, a picture of a geometrical
figure was either partially paired (conditioned stimulus; CS+) or not paired (CS−) with an electrical stimulation (unconditioned
stimulus; UCS). In fear extinction, each CS was presented again, but no UCS occurred. Cortisol increased conditioned skin
conductance responses in early and late extinction. In early extinction, higher activation towards the CS− than to the CS+
was found in the amygdala, hippocampus and posterior parahippocampal gyrus. This pattern might be associated with the establishment
of a new memory trace. In late extinction, the placebo compared with the cortisol group displayed enhanced CS+/CS− differentiation
in the amygdala, medial frontal cortex and nucleus accumbens. A change from early deactivation to late activation of the extinction
circuit as seen in the placebo group seems to be needed to enhance extinction and to reduce fear. Cortisol appears to interfere
with this process thereby impairing extinction of recently acquired conditioned fear.
When making decisions, individuals must often compensate for cognitive limitations, particularly in the face of advanced age.
Recent findings suggest that age-related variability in striatal activity may increase financial risk-taking mistakes in older
adults. In two studies, we sought to further characterize neural contributions to optimal financial risk taking and to determine
whether decision aids could improve financial risk taking. In Study 1, neuroimaging analyses revealed that individuals whose
mesolimbic activation correlated with the expected value estimates of a rational actor made more optimal financial decisions.
In Study 2, presentation of expected value information improved decision making in both younger and older adults, but the
addition of a distracting secondary task had little impact on decision quality. Remarkably, provision of expected value information
improved the performance of older adults to match that of younger adults at baseline. These findings are consistent with the
notion that mesolimbic circuits play a critical role in optimal choice, and imply that providing simplified information about
expected value may improve financial risk taking across the adult life span.
The processing of personal changes across time and the ability to differentiate between representations of present and past selves are crucial for developing a mature sense of identity. In this study, we explored the neural correlates of self-reflection across time using functional magnetic resonance imaging (fMRI). College undergraduates were asked to reflect on their own psychological characteristics and those of an intimate other, for both the present time period (i.e. at college) and a past time period (i.e. high school years) that involved significant personal changes. Cortical midline structures (CMS) were commonly recruited by the four reflective tasks (reflecting on the present self, past self, present other and past other), relative to a control condition (making valence judgments). More importantly, however, the degree of activity in CMS also varied significantly according to the target of reflection, with the ventral and dorsal medial prefrontal cortex and the posterior cingulate cortex being more recruited when reflecting on the present self than when reflecting on the past self or when reflecting on the other person. These findings suggest that CMS may contribute to differentiate between representations of present and past selves.
Ostracism is ubiquitous across the lifespan. From social exclusion on the playground, to romantic rejection, to workplace expulsion, to social disregard for the aged, ostracism threatens a fundamental human need to belong that reflexively elicits social pain and sadness. Older adults may be particularly vulnerable to ostracism because of loss of network members and meaningful societal roles. On the other hand, socioemotional selectivity theory suggests that older adults may be less impacted by ostracism because of an age-related positivity bias. We examined these hypotheses in two independent studies, and tested mechanisms that may account for age differences in the affective experience of ostracism. A study of 18- to 86-year-old participants in the Time-Sharing Experiments for the Social Sciences program showed an age-related decrease in the impact of ostracism on needs satisfaction and negative affectivity. A study of 53- to 71-year-old participants in the Chicago Health, Aging, and Social Relations Study (CHASRS) showed that ostracism diminished positive affectivity in younger (<60 years) but not older adults. Age group differences in response to ostracism were consistent with the positivity bias hypothesis, were partly explained by age differences in the impact of physical pain, but were not explained by autonomic nervous system activity, computer experience, or intimate social loss or stressful life experiences.
There is evidence that the right hemisphere is involved in processing self-related stimuli. Previous brain imaging research
has found a network of right-lateralized brain regions that preferentially respond to seeing one's own face rather than a
familiar other. Given that the self is an abstract multimodal concept, we tested whether these brain regions would also discriminate
the sound of one's own voice compared to a friend's voice. Participants were shown photographs of their own face and friend's
face, and also listened to recordings of their own voice and a friend's voice during fMRI scanning. Consistent with previous
studies, seeing one's own face activated regions in the inferior frontal gyrus (IFG), inferior parietal lobe and inferior
occipital cortex in the right hemisphere. In addition, listening to one's voice also showed increased activity in the right
IFG. These data suggest that the right IFG is concerned with processing self-related stimuli across multiple sensory modalities
and that it may contribute to an abstract self-representation.
Intrinsic emotional expressions such as those communicated by faces and vocalizations have been shown to engage specific brain regions, such as the amygdala. Although music constitutes another powerful means to express emotions, the neural substrates involved in its processing remain poorly understood. In particular, it is unknown whether brain regions typically associated with processing "biologically-relevant" emotional expressions are also recruited by emotional music. To address this question, we conducted an event-related fMRI study in 47 healthy volunteers in which we directly compared responses to basic emotions (fear, sadness and happiness, as well as neutral) expressed through faces, nonlinguistic vocalizations and short, novel musical excerpts. Our results confirmed the importance of fear in emotional communication, as revealed by significant BOLD signal increased in a cluster within the posterior amygdala and anterior hippocampus, as well as in the posterior insula across all three domains. Moreover, subject-specific amygdala responses to fearful music and vocalizations were correlated, consistent with the proposal that the brain circuitry involved in the processing of musical emotions might be shared with the one that have evolved for vocalizations. Overall, our results show that processing of fear expressed through music, engages some of the same brain areas known to be crucial for detecting and evaluating threat-related information.
This functional magnetic resonance imaging study examined the neural correlates of punishment and forgiveness of initiators
of social exclusion (i.e. ‘excluders’). Participants divided money in a modified Dictator Game between themselves and people
who previously either included or excluded them during a virtual ball-tossing game (Cyberball). Participants selectively punished
the excluders by decreasing their outcomes; even when this required participants to give up monetary rewards. Punishment of
excluders was associated with increased activation in the pre-supplementary motor area (pre-SMA) and bilateral anterior insula.
Costly punishment was accompanied by higher activity in the pre-SMA compared with punishment that resulted in gains or was
non-costly. Refraining from punishment (i.e. forgiveness) was associated with self-reported perspective-taking and increased
activation in the bilateral temporoparietal junction, dorsomedial prefrontal cortex, dorsal anterior cingulate cortex, and
ventrolateral and dorsolateral prefrontal cortex. These findings show that social exclusion can result in punishment as well
as forgiveness of excluders and that separable neural networks implicated in social cognition and cognitive control are recruited
when people choose either to punish or to forgive those who excluded them.
Neurophysiological and imaging studies suggest that the inferior frontal cortex (IFC) implements a mechanism that matches perceived actions to one's motor representation of similar actions (mirror mechanism) and recent lesion studies have also established that IFC is critical for action perception. However, to date causative evidence that action perception requires activation within the same populations of IFC neurons involved in action execution is lacking. In this issue, Cattaneo and colleagues provide the first direct evidence that mirror mechanisms in IFC influence action perception. We discuss the implications of these findings for the understanding of the functional role of mirror mechanisms.
Is a short visuomotor associative training sufficient to reverse the visuomotor tuning of mirror neurons in adult humans? We tested the effects of associative training on corticospinal modulation during action observation in the 100-320 ms interval after action onset. In two separate experiments, the acceleration of transcranial magnetic stimulation (TMS)-induced movements was recorded before and after training participants to respond to observed acts with an opposite or similar behavior. Before training, TMS-induced accelerations mirrored the observed action at 250 and 320 ms. After training, responses at 250 ms were unchanged and still mirrored the stimuli, without any effect of training direction. Only at 320 ms, we observed training-dependent changes in evoked responses. A control experiment with non-biological rotational movements as visual stimuli indicated that spatial stimulus-response compatibility is not sufficient to account for the results of the two main experiments. We show that the effects of a short visuomotor associative training are not pervasive on the automatic mirror responses. 'Early' (250 ms) responses were not influenced by training. Conversely only 'late' (320 ms) responses changed according to the training direction. This biphasic time course indicates that two distinct mechanisms produce the automatic mirror responses and the newly learned visuomotor associations.
The discovery of the mirror neuron system (MNS) has led researchers to speculate that this system evolved from an embodied visual recognition apparatus in monkey to a system critical for social skills in humans. It is accepted that the MNS is specialized for processing animate stimuli, although the degree to which social interaction modulates the firing of mirror neurons has not been investigated. In the current study, EEG mu wave suppression was used as an index of MNS activity. Data were collected while subjects viewed four videos: (1) Visual White Noise: baseline, (2) Non-interacting: three individuals tossed a ball up in the air to themselves, (3) Social Action, Spectator: three individuals tossed a ball to each other and (4) Social Action, Interactive: similar to video 3 except occasionally the ball would be thrown off the screen toward the viewer. The mu wave was modulated by the degree of social interaction, with the Non-interacting condition showing the least suppression, followed by the Social Action, Spectator condition and the Social Action, Interactive condition showing the most suppression. These data suggest that the human MNS is specialized not only for processing animate stimuli, but specifically stimuli with social relevance.