Heterogeneity of social approach behaviour in Williams syndrome: The role of response inhibition

The developmental disorder of Williams syndrome (WS) is associated with an overfriendly personality type, including an increased tendency to approach strangers. This atypical social approach behaviour (SAB) has been linked to two potential theories: the amygdala hypothesis and the frontal lobe hypothesis. The current study aimed to investigate heterogeneity of SAB in WS by exploring whether subgroups of SAB profiles could be identified using cluster analytic techniques. Twenty-five children with WS aged 6–15 years completed three behavioural tasks tapping (i) social approach behaviour, (ii) emotion recognition ability and (iii) response inhibition. Cluster analyses revealed preliminary evidence of WS subgroups based on SAB profiles and indicated that response inhibition ability was the key differentiating variable between SAB cluster profiles. The findings provide tentative support for the frontal lobe hypothesis of SAB in WS and highlight the importance of investigating SAB at a heterogeneous level.     

Williams syndrome hypersociability: a neuropsychological study of the amygdala and prefrontal cortex hypotheses

Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS hypersociability was explored using three behavioral tasks - facial emotional recognition task, a social approach task and a go no/go task. Thus, a group 15 individuals with Williams syndrome was compared to two groups of normal developing individuals - a group of 15 individuals matched for chronological age (CA) and 15 individuals matched for mental age (MA), and sex. Individuals with WS present a specific impairment in recognizing negative facial expressions and do not display impairments in response inhibition when compared with typically developing groups. Although these findings partially support the amygdala contribution to WS hypersociability, we found that general cognitive functioning predicted this performance. Additionally, individuals with WS did not differ from both CA and MA groups in the recognition of angry facial expressions, a finding suggesting that they are actually able to identify stimuli associated with social threat. Overall, the results seem to indicate that this social profile must be understood within a developmental framework.     

Social cognition in schizophrenia: similarities and differences of emotional perception from patients with focal frontal lesions

The structural and functional abnormalities of the frontal lobes, the region implicated in social information processing, have been suspected to underlie social cognitive impairments in schizophrenia. However, multiple structures, including the limbic/paralimbic areas that are also important for social cognition, have been reported to be abnormal in schizophrenia. The aim of this study is to investigate the extent to which the frontal lobe dysfunction accounts for social cognitive impairments in schizophrenia by comparing with patients who have focal frontal lobe injuries. Social cognitive abilities, focusing on affective aspects, were examined by an emotion intensity recognition task, which is sensitive to the amygdala function, and the emotion attribution tasks, which rely mainly on the frontal lobe function. Individuals with schizophrenia were impaired on the emotion intensity recognition task as well as on the emotion attribution tasks as compared with healthy subjects. By contrast, the frontal lobe-damaged group was defective in the emotion attribution tasks but not in the emotion intensity recognition task. Our results indicated that social cognitive impairments observed in schizophrenia can be accounted for partly by their frontal lobe pathology. Other aspects of social cognitive impairments could also be associated with the extra-frontal pathology, such as the amygdala.     

Individual differences in social behavior predict amygdala response to fearful facial expressions in Williams syndrome

Williams syndrome (WS) is a genetic condition often paired with abnormal social functioning and behavior. In particular, those with WS are characterized as being relatively hypersocial, overly emotional/empathic, and socially uninhibited or fearless. In addition, WS is associated with abnormal amygdala structure and function. Very little is known however about the relationship between specific social behaviors and altered amygdala function in WS. This study was designed to compare three models that relate abnormal social behavior with amygdala function in WS (indiscriminate sociability, emotional and empathic sociability and social fearlessness). We used a social behavior assessment procedure (Salk Institute Sociability Questionnaire), functional magnetic resonance imaging and an implicit emotion face processing task to test these models. Our findings provide support for a model of abnormal social fearlessness by showing that in WS, abnormal amygdala response to fear is paired with an increased tendency to approach strangers. Specifically, individuals with WS that exhibited less amygdala response to fearful facial expressions (compared to neutral) also exhibited an increased tendency to approach strangers. These findings contribute to our understanding of social and emotional functioning in neurodevelopmental conditions and provide evidence that in WS, amygdala response to fear modulates social behavior.     

Temporal Lobe Structures and Facial Emotion Recognition in Schizophrenia Patients and Nonpsychotic Relatives

Temporal lobe abnormalities and emotion recognition deficits are prominent features of schizophrenia and appear related to the diathesis of the disorder. This study investigated whether temporal lobe structural abnormalities were associated with facial emotion recognition deficits in schizophrenia and related to genetic liability for the disorder. Twenty-seven schizophrenia patients, 23 biological family members, and 36 controls participated. Several temporal lobe regions (fusiform, superior temporal, middle temporal, amygdala, and hippocampus) previously associated with face recognition in normative samples and found to be abnormal in schizophrenia were evaluated using volumetric analyses. Participants completed a facial emotion recognition task and an age recognition control task under time-limited and self-paced conditions. Temporal lobe volumes were tested for associations with task performance. Group status explained 23% of the variance in temporal lobe volume. Left fusiform gray matter volume was decreased by 11% in patients and 7% in relatives compared with controls. Schizophrenia patients additionally exhibited smaller hippocampal and middle temporal volumes. Patients were unable to improve facial emotion recognition performance with unlimited time to make a judgment but were able to improve age recognition performance. Patients additionally showed a relationship between reduced temporal lobe gray matter and poor facial emotion recognition. For the middle temporal lobe region, the relationship between greater volume and better task performance was specific to facial emotion recognition and not age recognition. Because schizophrenia patients exhibited a specific deficit in emotion recognition not attributable to a generalized impairment in face perception, impaired emotion recognition may serve as a target for interventions.     

Regionally specific increased volume of the amygdala in Williams syndrome: Evidence from surface‐based modeling

Williams syndrome (WS) is a condition caused by a contiguous deletion of approximately 26–28 genes from chromosome 7, and is characterized by abnormal social and emotional processing and abnormal structure and function of the amygdala. Prior studies show that the amygdala is relatively enlarged in WS, but very little is known regarding the regional specificity of increased amygdalar volume in this condition. Here we investigated the regional specificity of structural alterations of the amygdala in WS, compared to a typically developing (TD) control group. We acquired high resolution brain MRI data from 79 participants (39 WS, 40 TD) and used a surface‐based analytical modeling approach. The WS group exhibited several areas of increased radial expansion of the amygdalar surface and no areas of decreased radial expansion of the amygdalar surface compared to TD controls. The areas found to exhibit particularly increased radial expansion in WS included the bilateral posterior cortical nucleus, lateral nucleus, and the central nucleus. This greater regional and anatomical specificity of altered amygdala structure in WS contributes to a model relating genetic risk in WS to the development of key brain regions for social and emotional functioning. Hum Brain Mapp 35:866–874, 2014. © 2012 Wiley Periodicals, Inc.     

Impaired recognition of negative basic emotions in autism: a test of the amygdala theory

Autism and Asperger Syndrome are autism spectrum conditions (ASC) characterized by deficits in understanding others' minds, an aspect of which involves recognizing emotional expressions. This is thought to be related to atypical function and structure of the amygdala, and performance by people with ASC on emotion recognition tasks resembles that seen in people with acquired amygdala damage. In general, emotion recognition findings in ASC have been inconsistent, which may reflect low numbers of participants, low numbers of stimuli and trials, heterogeneity of symptom severity within ASC groups, and ceiling effects on some tasks. The present study tested 39 male adults with ASC and 39 typical male controls on a task of basic emotion recognition from photographs, in two separate experiments. On a control face discrimination task the group with ASC were not impaired. People with ASC were less accurate on the emotion recognition task compared to controls, but only for the negative basic emotions. This is discussed in the light of similar findings from people with damage to the amygdala.     

Ventral medial prefrontal functional connectivity and emotion regulation in chronic schizophrenia: A pilot study

People with schizophrenia exhibit impaired social cognitive functions, particularly emotion regulation. Abnormal activations of the ventral medial prefrontal cortex (vMPFC) during emotional tasks have been demonstrated in schizophrenia, suggesting its important role in emotion processing in patients. We used the resting-state functional connectivity approach, setting a functionally relevant region, the vMPFC, as a seed region to examine the intrinsic functional interactions and communication between the vMPFC and other brain regions in schizophrenic patients. We found hypo-connectivity between the vMPFC and the medial frontal cortex, right middle temporal lobe (MTL), right hippocampus, parahippocampal cortex (PHC) and amygdala. Further, there was a decreased strength of the negative connectivity (or anticorrelation) between the vMPFC and the bilateral dorsal lateral prefrontal cortex (DLPFC) and pre-supplementary motor areas. Among these connectivity alterations, reduced vMPFC-DLPFC connectivity was positively correlated with positive symptoms on the Positive and Negative Syndrome Scale, while vMPFC-right MTL/PHC/amygdala functional connectivity was positively correlated with the performance of emotional regulation in patients. These findings imply that communication and coordination throughout the brain networks are disrupted in schizophrenia. The emotional correlates of vMPFC connectivity suggest a role of the hypo-connectivity between these regions in the neuropathology of abnormal social cognition in chronic schizophrenia.     

Long-term memory impairment in patients with focal epilepsy

Summary   In temporal lobe epilepsy, long-term memory disturbance starts early in life mainly affecting declarative memory. Primary impairment of episodic memory often results in reduced semantic and autobiographic memory. Neuropsychological performance predicts academic achievement and everyday life functioning while subjective memory complaints are highly correlated with depression. Memory impairment is also influenced by initial brain damage, developmental retardation and dynamic factors (e.g., seizure frequency, medication). Damage of functional tissue, low mental reserve capacity, and poor seizure outcome increase the risk for postsurgical memory impairment whereas functional release due to seizure freedom counteracts negative impact. Preliminary findings indicate that postsurgical training improves memory deficits and encourage further research.     

Hemispheric dominance for emotions, empathy and social behaviour: evidence from right and left handers with frontotemporal dementia

Although evidence from primates suggests an important role for the anterior temporal cortex in social behaviour, human research has to date concentrated almost solely on the orbitofrontal cortex and amygdala. By describing four cases of the temporal variant of frontotemporal dementia we show how this degenerative condition provides an excellent model for investigating the role of the anterior temporal lobe, especially the right, in emotions, empathy and social behaviour. Assessments of semantic memory, processing of emotional facial expression and emotional prosody were made, empathy was measured, and facial expressions of emotion were coded. Of the two right handers described, one subject with predominantly left temporal lobe atrophy had severe semantic impairment but normal performance on all emotional tasks. In contrast, the subject with right temporal lobe atrophy showed severely impaired recognition of emotion from faces and voices that was not due to semantic or perceptual difficulties. Empathy was lost, interpersonal skills were severely affected and facial expression of emotion was characterized by a fixed expression that was unresponsive to situations. Additionally, two left handers with right temporal lobe atrophy are described. One demonstrated the same pattern of hemispheric lateralization as the right handers and had emotional impairment. The other left hander showed the opposite pattern of deficits, suggesting a novel presentation of anomalous dominance with reversed hemispheric specialization of semantic memory and emotional processing.