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
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  youth with 22qDS and  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.