Right Temporoparietal Gray Matter Predicts Accuracy of Social Perception in the Autism Spectrum

Individuals with an autism spectrum disorder (ASD) show hallmark deficits in social perception. These difficulties might also reflect fundamental deficits in integrating visual signals. We contrasted predictions of a social perception and a spatial–temporal integration deficit account. Participants with ASD and matched controls performed two tasks: the first required spatiotemporal integration of global motion signals without social meaning, the second required processing of socially relevant local motion. The ASD group only showed differences to controls in social motion evaluation. In addition, gray matter volume in the temporal–parietal junction correlated positively with accuracy in social motion perception in the ASD group. Our findings suggest that social–perceptual difficulties in ASD cannot be reduced to deficits in spatial–temporal integration.     

Dissociation between face perception and face memory in adults,but not children,with developmental prosopagnosia

Cognitive models propose that face recognition is accomplished through a series of discrete stages, including perceptual representation of facial structure, and encoding and retrieval of facial information. This implies that impaired face recognition can result from failures of face perception, face memory, or both. Studies of acquired prosopagnosia, autism spectrum disorders, and the development of normal face recognition support the idea that face perception and face memory are distinct processes, yet this distinction has received little attention in developmental prosopagnosia (DP). To address this issue, we tested the face perception and face memory of children and adults with DP. By definition, face memory is impaired in DP, so memory deficits were present in all participants. However, we found that all children, but only half of the adults had impaired face perception. Thus, results from adults indicate that face perception and face memory are dissociable, while the results from children provide no evidence for this division. Importantly, our findings raise the possibility that DP is qualitatively different in childhood versus adulthood. We discuss theoretical explanations for this developmental pattern and conclude that longitudinal studies are necessary to better understand the developmental trajectory of face perception and face memory deficits in DP.     

Visual and auditory socio‐cognitive perception in unilateral temporal lobe epilepsy in children and adolescents: a prospective controlled study

Aim. A high rate of abnormal social behavioural traits or perceptual deficits is observed in children with unilateral temporal lobe epilepsy. In the present study, perception of auditory and visual social signals, carried by faces and voices, was evaluated in children or adolescents with temporal lobe epilepsy. Methods. We prospectively investigated a sample of 62 children with focal non‐idiopathic epilepsy early in the course of the disorder. The present analysis included 39 children with a confirmed diagnosis of temporal lobe epilepsy. Control participants (72), distributed across 10 age groups, served as a control group. Our socio‐perceptual evaluation protocol comprised three socio‐visual tasks (face identity, facial emotion and gaze direction recognition), two socio‐auditory tasks (voice identity and emotional prosody recognition), and three control tasks (lip reading, geometrical pattern and linguistic intonation recognition). All 39 patients also benefited from a neuropsychological examination. Results. As a group, children with temporal lobe epilepsy performed at a significantly lower level compared to the control group with regards to recognition of facial identity, direction of eye gaze, and emotional facial expressions. We found no relationship between the type of visual deficit and age at first seizure, duration of epilepsy, or the epilepsy‐affected cerebral hemisphere. Deficits in socio‐perceptual tasks could be found independently of the presence of deficits in visual or auditory episodic memory, visual non‐facial pattern processing (control tasks), or speech perception. A normal FSIQ did not exempt some of the patients from an underlying deficit in some of the socio‐perceptual tasks. Conclusion. Temporal lobe epilepsy not only impairs development of emotion recognition, but can also impair development of perception of other socio‐perceptual signals in children with or without intellectual deficiency. Prospective studies need to be designed to evaluate the results of appropriate re‐education programs in children presenting with deficits in social cue processing.     

Autism: neuroimaging

Autism is a neurodevelopmental disorder with a range of clinical presentations. These presentations vary from mild to severe and are referred to as autism spectrum disorders. The most common clinical sign of autism spectrum disorders is social interaction impairment, which is associated with verbal and non-verbal communication deficits and stereotyped and repetitive behaviors. Thanks to recent brain imaging studies, scientists are getting a better idea of the neural circuits involved in autism spectrum disorders. Indeed, functional brain imaging, such as positron emission tomography, single foton emission tomography and functional MRI have opened a new perspective to study normal and pathological brain functioning. Three independent studies have found anatomical and rest functional temporal lobe abnormalities in autistic patients. These alterations are localized in the superior temporal sulcus bilaterally, an area which is critical for perception of key social stimuli. In addition, functional studies have shown hypoactivation of most areas implicated in social perception (face and voice perception) and social cognition (theory of mind). These data suggest an abnormal functioning of the social brain network in autism. The understanding of the functional alterations of this important mechanism may drive the elaboration of new and more adequate social re-educative strategies for autistic patients.     

Visual search strategies during facial recognition in children with ASD

Facial recognition is a complex skill necessary for successful human interpersonal and social interactions. Given that the most prevalent disorder of social interaction is autism spectrum disorder (ASD), a number of studies have investigated and found impaired facial recognition abilities in people with ASD. Further, this impairment may be critically involved in mediating the deficits in interpersonal and social interactions in people with ASD. We sought to address the question of whether face processing is impaired in children with ASD in the current study. While there were a number of differences in visual search behaviours between the 19 children with ASD and the 15 controls, this did not manifest in deficits in facial recognition accuracy. In addition, there were notable differences with respect to eye fixation behaviours and recognition accuracy in this study compared to the findings in a previous similar study conducted in adults with ASD. These differences suggest a performance enhancing developmental trajectory in facial processing in controls that may not be present in individuals with ASD.     

Disrupted action perception in autism: behavioral evidence, neuroendophenotypes, and diagnostic utility

Disruptions in the visual perception of biological motion are emerging as a hallmark of autism spectrum disorder (ASD), consistent with the pathognomonic social deficits of this neurodevelopmental disorder. Accumulating evidence suggests an early and marked divergence in ASD from the typical developmental tuning of brain regions to process social information. In this review, we discuss a relatively recent yet substantial literature of behavioral and neuroimaging studies that consistently indicates impairments in biological motion perception in ASD. We then illustrate the fundamental disruption in this form of social perception in autism, drawing connections between a genetic liability to develop autism and disrupted associated brain mechanisms, as we describe neuroendophenotypes of autism derived from an fMRI study of biological motion perception in children with autism and their unaffected siblings. Finally, we demonstrate the diagnostic utility of brain responses to biological motion. With the ability to measure brain function in the first year of life comes the potential to chart the development of disrupted biological motion processing in ASD and to specify the gene-brain-behavior interactions shaping this atypical trajectory. We propose that a comprehensive understanding of the development of impaired responses to biological motion in ASD can inform future diagnosis and treatment approaches.     

Divergent Patterns of Social Cognition Performance in Autism and 22q11.2 Deletion Syndrome (22q11DS)

Individuals with developmental disorders frequently report a range of social cognition deficits including difficulties identifying facial displays of emotion. This study examined the specificity of face emotion processing deficits in adolescents with either autism or 22q11DS compared to typically developing (TD) controls. Two tasks (face emotion recognition and weather scene recognition) were used to explore group differences in visual scanpath strategy and concurrent recognition accuracy. For faces, the autism and 22q11DS groups demonstrated lower emotion recognition accuracy and fewer fixations compared to the TD group. Individuals with autism demonstrated fewer fixations to some weather scene stimuli compared to 22q11DS and TD groups, yet achieved a level of recognition accuracy comparable to the TD group. These findings provide evidence for a divergent pattern of social cognition dysfunction in autism and 22q11DS.     

The “Eye Avoidance” Hypothesis of Autism Face Processing

Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: (1) the holistic hypothesis, (2) the local perceptual bias hypothesis and (3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a increased physiological response as indicated by heightened skin conductance and amygdala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, exacerbating the social challenges for persons with ASD.     

Abnormal Use of Facial Information in High-Functioning Autism

Altered visual exploration of faces likely contributes to social cognition deficits seen in autism. To investigate the relationship between face gaze and social cognition in autism, we measured both face gaze and how facial regions were actually used during emotion judgments from faces. Compared to IQ-matched healthy controls, nine high-functioning adults with autism failed to make use of information from the eye region of faces, instead relying primarily on information from the mouth. Face gaze accounted for the increased reliance on the mouth, and partially accounted for the deficit in using information from the eyes. These findings provide a novel quantitative assessment of how people with autism utilize information in faces when making social judgments.     

Comparison of Form and Motion Coherence Processing in Autistic Spectrum Disorders and Dyslexia

A large body of research has reported visual perception deficits in both people with dyslexia and autistic spectrum disorders. In this study, we compared form and motion coherence detection between a group of adults with high-functioning autism, a group with Asperger's disorder, a group with dyslexia, and a matched control group. It was found that motion detection was intact in dyslexia and Asperger. Individuals with high-functioning autism showed a general impaired ability to detect coherent form and motion. Participants with Asperger's syndrome showed lower form coherence thresholds than the dyslexic and normally developing adults. The results are discussed with respect to the involvement of the dorsal and ventral pathways in developmental disorders.