Francesca Happé

Autism: beyond “theory of mind”

The theory of mind account of autism has been remarkably successful in making specific predictions about the impairments in socialization, imagination and communication shown by people with autism. It cannot, however, explain either the non-triad features of autism, or earlier experimental findings of abnormal assets and deficits on non-social tasks. These unexplained aspects of autism, and the existence of autistic individuals who consistently pass false belief tasks, suggest that it may be necessary to postulate an additional cognitive abnormality. One possible abnormality-weak central coherence--is discussed, and preliminary evidence for this theory is presented.

Mind reading: neural mechanisms of theory of mind and self-perspective.

Human self-consciousness as the metarepresentation of ones own mental states and the so-called theory of mind (TOM) capacity, which requires the ability to model the mental states of others, are closely related higher cognitive functions. We address here the issue of whether taking the self-perspective (SELF) or modeling the mind of someone else (TOM) employ the same or differential neural mechanisms. A TOM paradigm was used and extended to include stimulus material that involved TOM and SELF capacities in a two-way factorial design. A behavioral study in 42 healthy volunteers showed that TOM and SELF induced differential states of mind: subjects assigned correctly first or third person pronouns when providing responses to the stimuli. Following the behavioral study, we used functional magnetic resonance imaging (fMRI) in eight healthy, right-handed males to study the common and differential neural mechanisms underlying TOM and SELF. The main factor TOM led to increased neural activity in the anterior cingulate cortex and left temporopolar cortex. The main factor SELF led to increased neural activity in the right temporoparietal junction and in the anterior cingulate cortex. A significant interaction of both factors TOM and SELF was observed in the right prefrontal cortex. These divergent neural activations in response to TOM and SELF suggest that these important differential mental capacities of human self-consciousness are implemented at least in part in distinct brain regions. Press

Time to give up on a single explanation for autism

We argue that there will be no single (genetic or cognitive) cause for the diverse symptoms defining autism. We present recent evidence of behavioral fractionation of social impairment, communication difficulties and rigid and repetitive behaviors. Twin data suggest largely nonoverlapping genes acting on each of these traits. At the cognitive level, too, attempts at a single explanation for the symptoms of autism have failed. Implications for research and treatment are discussed.

'Theory of mind' in the brain. Evidence from a PET scan study of Asperger syndrome.

THE ability to attribute mental states to others (‘theory of mind’) pervades normal social interaction and is impaired in autistic individuals. In a previous positron emission tomography scan study of normal volunteers, performing a ‘theory of mind’ task was associated with activity in left medial prefrontal cortex. We used the same paradigm in five patients with Asperger syndrome, a mild variant of autism with normal intellectual functioning. No task-related activity was found in this region, but normal activity was observed in immediately adjacent areas. This result suggests that a highly circumscribed region of left medial prefrontal cortex is a crucial component of the brain system that underlies the normal understanding of other minds.

The neuroanatomy of autism: a voxel-based whole brain analysis of structural scans.

Autism is a biological disorder which affects social cognition, and understanding brain abnormalities of the former will elucidate the brain basis of the latter. We report structural MRI data on 15 high-functioning individuals with autistic disorder. A voxel-based whole brain analysis identified grey matter differences in an amygdala centered system relative to 15 age- and IQ-matched controls. Decreases of grey matter were found in anterior parts of this system (right paracingulate sulcus, left inferior frontal gyrus). Increases were found in posterior parts (amygdala/peri-amygdaloid cortex, middle temporal gyrus, inferior temporal gyrus), and in regions of the cerebellum. These structures are implicated in social cognition by animal, imaging and histopathological studies. This study therefore provides converging evidence of the physiological basis of social cognition.

Autism spectrum disorder

The progress that is now possible by combining cognitive theories, functional and structural brain imaging in genetically sensitive designs, should yield some long awaited answers. In particular, it should become clear which features of autism have separate and independent causes, and which arise from one and the same origin in the brain. When the genes for susceptibility to ASD are identified, the diagnosis may be revolutionized. Then cases that are now considered to fall on the same spectrum may be revealed to belong to completely different etiological subgroups, while previously unidentified cases may be identified within genetic pedigrees. Once genes are isolated, then animal models will become truly useful for identifying the neurophysiological mechanisms and devising means of repairing and preventing neurological abnormalities.All of this progress, however, requires a real understanding of how autism unfolds through development, which are core elements and which merely secondary and avoidable knock-on effects. This long-term aim can only be achieved by integrating bottom-up approaches, such as genome-wide screening, and top-down research such as establishing the neural basis of hypothesised cognitive assets and deficits.

Do triangles play tricks? Attribution of mental states to animated shapes in normal and abnormal development

Computer-presented animations were used to elicit attributions of actions, interactions and mental states. Two triangles moved around the screen according to one of three conditions. Descriptions of the animations were rated according to accuracy and type of description. Adults predominantly used action descriptions for Random animations (e.g. bouncing), interaction descriptions for Goal-directed (G-D) sequences (fighting), and mentalising descriptions for Theory of Mind (ToM) sequences (tricking). High-functioning children with autism used mentalising descriptions less often than normally developing 8-year-olds, but as often as did children with general intellectual impairment. However, the autism group frequently referred to mental states that were inappropriate to the animation. Even those children with autism who passed standard false belief tasks showed inappropriate descriptions of ToM animations, revealing continuing impairments in mentalising on-line.

The ‘Fractionable Autism Triad’: A Review of Evidence from Behavioural, Genetic, Cognitive and Neural Research

Autism is diagnosed on the basis of a triad of impairments in social interaction, communication, and flexible imaginative functions (with restricted and repetitive behaviors and interests; RRBIs). There has been a strong presumption that these different features of the syndrome are strongly intertwined and proceed from a common cause at the genetic, cognitive and neural levels. In this review we examine evidence for an alternative approach, considering the triad as largely ‘fractionable’. We present evidence from our own twin studies, and review relevant literature on autism and autistic-like traits in other groups. We suggest that largely independent genes may operate on social skills/impairments, communication abilities, and RRBIs, requiring a change in molecular-genetic research approaches. At the cognitive level, we suggest that satisfactory accounts exist for each of the triad domains, but no single unitary account can explain both social and nonsocial features of autism. We discuss the implications of the fractionable-triad approach for both diagnosis and future research directions.

Feeling, caring, knowing: different types of empathy deficit in boys with psychopathic tendencies and autism spectrum disorder

Background Empathy dysfunction is one of the hallmarks of psychopathy, but it is also sometimes thought to characterise autism spectrum disorders (ASD). Individuals with either condition can appear uncaring towards others. This study set out to compare and contrast directly boys with psychopathic tendencies and boys with ASD on tasks assessing aspects of affective empathy and cognitive perspective taking. The main aim of the study was to assess whether a distinct profile of empathy deficits would emerge for boys with psychopathic tendencies and ASD, and whether empathy deficits would be associated with conduct problems in general, rather than psychopathic tendencies or ASD specifically. Methods Four groups of boys aged between 9 and 16 years (N = 96) were compared: 1) psychopathic tendencies, 2) ASD, 3) conduct problems and 4) comparison. Tasks were included to probe attribution of emotions to self, empathy for victims of aggression and cognitive perspective-taking ability. Results Boys with psychopathic tendencies had a profile consistent with dysfunctional affective empathy. They reported experiencing less fear and less empathy for victims of aggression than comparison boys. Their cognitive perspective-taking abilities were not statistically significantly different from those of comparison boys. In contrast, boys with ASD had difficulties with tasks requiring cognitive perspective taking, but reported emotional experiences and victim empathy that were in line with comparison boys. Boys with conduct problems did not differ from comparison boys, suggesting that the affective empathy deficit seen in boys with psychopathic tendencies was specific to that group, rather than common to all boys with conduct problems. Conclusions Although both groups can appear uncaring, our findings suggest that the affective/information processing correlates of psychopathic tendencies and ASD are quite different. Psychopathic tendencies are associated with difficulties in resonating with other people’s distress, whereas ASD is characterised by difficulties in knowing what other people think.

How Different Are Girls and Boys Above and Below the Diagnostic Threshold for Autism Spectrum Disorders

OBJECTIVE This study aimed to explore sex differences in autistic traits in relation to diagnosis, to elucidate factors that might differentially impact whether girls versus boys meet diagnostic criteria for autism or a related autism spectrum disorder (ASD). METHOD Data from a large population-based sample of children were examined. Girls and boys (aged 10-12 years) meeting diagnostic criteria for an ASD were compared with those failing to meet diagnostic criteria despite very high scores on a trait measure of ASD, the Childhood Autism Spectrum Test (CAST). Information about behavioral difficulties as reported by teachers, and early estimates of intellectual functioning, were compared. RESULTS Girls, but not boys, meeting diagnostic criteria for ASD showed significantly more additional problems (low intellectual level, behavioral difficulties) than peers with similarly high CAST scores who did not meet diagnostic criteria. CONCLUSIONS These data suggest that, in the absence of additional intellectual or behavioral problems, girls are less likely than boys to meet diagnostic criteria for ASD at equivalently high levels of autistic-like traits. This might reflect gender bias in diagnosis or genuinely better adaptation/compensation in girls.