Asperger syndrome: tests of right hemisphere functioning and interhemispheric communication

Influence of Autism and Other Neurodevelopmental Disorders on Cognitive and Symptom Profiles: Considerations for Baseline Sport Concussion Assessment

OBJECTIVE

The presence of neurodevelopmental disorders (ND) such as attention-deficit/hyperactivity disorder (ADHD) and learning disorders (LD) have demonstrated effects on Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) performance. No current research has directly examined whether autism spectrum disorder (ASD) has similar effects. The current study compared ImPACT cognitive and symptom profiles in athletes with self-reported ASD to other NDs and healthy controls using case-control matching.

METHOD

The current study compared ImPACT baselines of high school athletes with ASD to athletes with other NDs (ADHD, LD, and co-occurring ADHD/LD) and healthy controls on cognitive composites and symptom reporting. Participants included 435 athletes (87 controls, 87 with ASD, 87 with ADHD, 87 with LD, and 87 with ADHD/LD) selected from a larger naturalistic sample. Athletes were matched to the ASD group based on age, sex, and sport using randomized case-matched selection from the larger database.

RESULTS

Results revealed that athletes with ASD performed more poorly than healthy controls on the Visual Motor Speed composite. No differences were found for Post-concussion Symptom Scale (PCSS) domain scores. Differences in cognitive and symptom profiles among the athletes with other NDs were also found.

CONCLUSIONS

Results elucidate patterns of baseline performance for athletes with ASD, demonstrating that there may not be significant differences between ASD and healthy controls on four of the five ImPACT composites, and no symptom reporting differences. Cognitive and symptom differences found for other NDs should be considered when interpreting baseline performance and for making return-to-play decisions in the absence of baseline assessment.

Activating the Right Hemisphere Through Left-Hand Muscle Contraction Improves Novel Metaphor Comprehension

The neurotypical brain is characterized by left hemisphere lateralization for most language processing. However, the right hemisphere plays a crucial part when it is required to bring together seemingly unrelated concepts into meaningful expressions, such as in the case of novel metaphors (unfamiliar figurative expressions). The aim of the current study was to test whether it is possible to enhance novel metaphor comprehension through an easy, efficient, and non-invasive method – intentional contraction of the left hand’s muscles, to activate the motor and sensory areas in the contralateral hemisphere. One hundred eighteen neurotypical participants were asked to perform a semantic judgment task involving two-word expressions of four types: literal, conventional metaphors, novel metaphors, or unrelated, while squeezing a rubber ball with their right hand, left hand, or not at all. Results demonstrated that left-hand contraction improved novel metaphor comprehension, as participants were more accurate and quicker in judging them to be meaningful. The findings of the present work provide a simple and efficient method for boosting right hemisphere activation, which can be used to improve metaphoric language comprehension. This method can aid several populations in which right hemisphere function is not fully established, and who struggle with processing figurative language, such as adolescents and individuals on the autistic spectrum.

How Do Children with Autism Spectrum Disorder Encode and Reproduce Visuospatial Stimuli?: Investigation into Visuospatial Processing Abilities and Styles

OBJECTIVE

The purpose of this study was to examine the visuospatial processing abilities of children with autism spectrum disorder (ASD) using the Rey Osterrieth Complex Figure (ROCF).

METHODS

One-hundred thirty-four children with ASD [mean age (MA)=113.56 months], 150 siblings of children with ASD (MA= 111.67 months), and 55 typically developing (TD) children (MA=109.02 months) were included in this study. During their one-time visit, participants completed the ROCF, various autism diagnostic assessments, and the Korean-Leiter International Performance ScaleRevised. Repeated-measures Analysis of Covariance (ANCOVA) and post-hoc Tukey-Kramer comparisons were computed to compare the ROCF scores. Partial correlations and multiple regressions were computed to examine the association between ROCF scores and the severity of autistic symptoms, as measured by the Autism Diagnostic Interview-Revised (ADI-R) among children with ASD.

RESULTS

There were significant main effects of the analysis group in Structural and Incidental Accuracy, Error, and Style. More siblings than TD children drew in a part-oriented way, but the performance of the sibling group was comparable or superior to that of the TD group in all parameters. Social Interaction scores of children with ASD were significantly associated with Organization scores in Copy condition. Whether or not a child drew in the Part-Oriented style significantly predicted his/her repetitive and restricted behavior scores.

CONCLUSION

The findings add to the evidence for altered visuospatial processing patterns of ASD as a potential inherent and genetic trait and suggest that this particular cognitive style should not be considered as a deficit. Educational and theoretical implications are discussed.

Can cerebral lateralisation explain heterogeneity in language and increased non-right handedness in autism? A literature review

BACKGROUND

Autism is characterised by phenotypic variability, particularly in the domains of language and handedness. However, the source of this heterogeneity is currently unclear.

AIMS

To synthesise findings regarding the relationship between language, handedness, and cerebral lateralisation in autistic people and consider how future research should be conducted in order to progress our understanding of phenotypic variability.

METHODS AND PROCEDURES

Following a literature search and selection process, 19 papers were included in this literature review. Studies using behavioural, structural, and functional measures of lateralisation are reviewed.

OUTCOMES AND RESULTS

The studies reviewed provided consistent evidence of differential cerebral lateralisation in autistic people, and this appears to be related to between-group differences in language. Evidence relating this to handedness was less consistent. Many of the studies did not include heterogeneous samples, and/or did not specify the language process they investigated.

CONCLUSIONS AND IMPLICATIONS

This review suggests that further research is needed to fully understand the relationship between cerebral lateralisation and phenotypic variability within autism. It is crucial that future studies in this area include heterogeneous samples, specify the language process they are investigating, and consider taking developmental trajectories into account.

Non-complicit: Revisiting Hans Asperger's Career in Nazi-era Vienna

Recent allegations that pediatrician Hans Asperger legitimized Nazi policies, including forced sterilization and child euthanasia, are refuted with newly translated and chronologically-ordered information that takes into account Hitler's deceptive 'halt' to the T4 euthanasia program in 1941. It is highly unlikely that Asperger was aware of the T4 program when he referred Herta Schreiber to Am Spiegelgrund or when he mentioned that institution 4 months later on the medical chart of another (unrelated) girl, Elisabeth Schreiber. Asperger campaigned vigorously from 1938 to 1943 to have his specialization, Curative Education, take priority in the diagnosis and treatment of disabled children over other fields that promoted Nazi racial hygiene policies. He neither disparaged his patients nor was he sexist. By 1938, he had identified the essentials of Asperger syndrome and described an unnamed boy whom he later profiled (as Ernst K.) in 1944. Rather than doing 'thin' research, Asperger made discoveries that were prescient, and some of his activities conformed to definitions of "individual resistance."

Figurative language comprehension in individuals with autism spectrum disorder: A meta-analytic review

We present a meta-analysis of studies that compare figurative language comprehension in individuals with autism spectrum disorder and in typically developing controls who were matched based on chronological age or/and language ability. A total of 41 studies and 45 independent effect sizes were included based on predetermined inclusion criteria. Group matching strategy, age, types of figurative language, and cross-linguistic differences were examined as predictors that might explain heterogeneity in effect sizes. Overall, individuals with autism spectrum disorder showed poorer comprehension of figurative language than their typically developing peers (Hedges' g = -0.57). A meta-regression analysis showed that group matching strategy and types of figurative language were significantly related to differences in effect sizes, whereas chronological age and cross-linguistic differences were not. Differences between the autism spectrum disorder and typically developing groups were small and nonsignificant when the groups were matched based on the language ability. Metaphors were more difficult to comprehend for individuals with autism spectrum disorder compared with typically developing controls than were irony and sarcasm. Our findings highlight the critical role of core language skills in figurative language comprehension. Interventions and educational programmes designed to improve social communication skills in individuals with autism spectrum disorder may beneficially target core language skills in addition to social skills.

Measuring the plasticity of social approach: a randomized controlled trial of the effects of the PEERS intervention on EEG asymmetry in adolescents with autism spectrum disorders

This study examined whether the Program for the Education and Enrichment of Relational Skills (PEERS: Social skills for teenagers with developmental and autism spectrum disorders: The PEERS treatment manual, Routledge, New York, 2010a) affected neural function, via EEG asymmetry, in a randomized controlled trial of adolescents with Autism spectrum disorders (ASD) and a group of typically developing adolescents. Adolescents with ASD in PEERS shifted from right-hemisphere gamma-band EEG asymmetry before PEERS to left-hemisphere EEG asymmetry after PEERS, versus a waitlist ASD group. Left-hemisphere EEG asymmetry was associated with more social contacts and knowledge, and fewer symptoms of autism. Adolescents with ASD in PEERS no longer differed from typically developing adolescents in left-dominant EEG asymmetry at post-test. These findings are discussed via the Modifier Model of Autism (Mundy et al. in Res Pract Persons Severe Disabl 32(2):124, 2007), with emphasis on remediating isolation/withdrawal in ASD.

Asperger syndrome and nonverbal learning difficulties in adult males: self- and parent-reported autism, attention and executive problems

A specific overlap between Asperger syndrome (AS) and nonverbal learning difficulties (NLD) has been proposed, based on the observation that, as a group, people with AS tend to have significantly higher verbal IQ (VIQ) than performance IQ (PIQ), one of the core features of NLD. The primary aim was to assess the longer term outcome of NLD--broken down into persistent and transient forms. The present study of 68 individuals was performed in the context of a larger prospective longitudinal study to late adolescence/early adult life of 100 boys with AS. Using self- and parent-report measures, we studied the longer term outcome of the NLD (defined as VIQ > PIQ by 15 points) as regards social communication, repetitive behaviour, attention, and executive function (EF) was studied. Three subgroups were identified: (1) Persistent NLD (P-NLD), (2) Childhood "only" NLD (CO-NLD) and (3) Never NLD (NO-NLD). The P-NLD group had the worst outcome overall. The CO-NLD group had better reported EF scores than the two other AS subgroups. There were no differences between the subgroups regarding social communication, repetitive behaviour, or attentional skills. Low PIQ increased the risk of ADHD symptoms. In the context of AS in males, P-NLD carries a relatively poor outcome, particularly with regard to self-reported EF. However, CO-NLD appears to entail a significantly better outcome. The results underscore the importance of analysing the cognitive profile both at diagnosis and after several years, so as to be able to formulate a realistic prognosis.

Youth with autism spectrum disorder comprehend lexicalized and novel primary conceptual metaphors

Individuals with autism spectrum disorder (ASD) have difficulty comprehending metaphors. However, no study to date has examined whether or not they understand conceptual metaphors (i.e. mappings between conceptual structures), which could be the building blocks of metaphoric thinking and understanding. We investigated whether 13 participants with ASD (age 7;03-22;03) and 13 age-matched typically developing (TD) controls could comprehend lexicalized conceptual metaphors (e.g., Susan is a warm person) and novel ones (e.g., Susan is a toasty person). Individuals with ASD performed at greater than chance levels on both metaphor types, although their performance was lower than TD participants. We discuss the theoretical relevance of these findings and educational implications.

Interpersonal competence in young adulthood and right laterality in white matter

The right hemisphere of the human brain is known to be involved in processes underlying emotion and social cognition. Clinical neuropsychology investigations and brain lesion studies have linked a number of personality and social disorders to abnormal white matter (WM) integrity in the right hemisphere. Here, we tested the hypothesis that interpersonal competencies are associated with integrity of WM tracts in the right hemisphere of healthy young adults. Thirty-one participants underwent diffusion tensor imaging scanning. Fractional anisotropy was used to quantify water diffusion. After the scanning session, participants completed the Adolescent Interpersonal Competence Questionnaire. Fractional anisotropy was subsequently correlated with Adolescent Interpersonal Competence Questionnaire scores using tract-based spatial statistics. Higher interpersonal competencies are related to higher WM integrity in several major tracts of the right hemisphere, in specific the uncinate fasciculus, the cingulum, the forceps minor, the infero-fronto occipital fasciculus, the inferior longitudinal fasciculus, and the superior longitudinal fasciculus. These results provide the first direct analysis of the neuroanatomical basis of interpersonal competencies and young adult self-reported skills in social contexts.

Asperger syndrome and "non-verbal learning problems" in a longitudinal perspective: neuropsychological and social adaptive outcome in early adult life

Co-existence of Asperger syndrome (AS) and non-verbal learning disability (NLD) has been proposed based on the observation that people with AS tend to have significantly higher verbal than performance IQ (VIQ > PIQ by ≥ 15 points), one of the core features of NLD. In the present study we examined neuropsychological and social adaptive profiles with "non-verbal learning problems" associated with NLD in a group of individuals with AS followed from childhood into early adult life. The group was divided into three subgroups: (i) persistent NLD (P-NLD), i.e. NLD (VIQ > PIQ) both in childhood and early adulthood occasions, (ii) childhood NLD (CO-NLD), i.e. NLD (VIQ > PIQ) only at original diagnosis, or (iii) No NLD (VIQ > PIQ) ever (NO-NLD). All three subgroups were followed prospectively from childhood into adolescence and young adult life. One in four to one in five of the whole group of males with AS had P-NLD. The P-NLD subgroup had poorer neuropsychological outcome in early adult life than did those with CO-NLD and those with NO-NLD. There were no unequivocal markers in early childhood that predicted subgroup status in early adult life, but early motor delay and a history of early speech-language problems tended to be associated with P-NLD.

Development of autobiographical memory in children with autism spectrum disorders: Deficits, gains, and predictors of performance

Autobiographical memory (AM) was assessed in 63 children (aged 8–17 years) with an autism spectrum disorder (ASD) and compared with 63 typically developing children matched for age, gender, IQ, and verbal ability. A range of methodologies was employed for eliciting past experience with particular focus on the ability to recall (a) specific events, (b) the recent and remote past, and (c) semantic versus episodic memories across different lifetime periods. Results indicated that the ASD group manifested difficulties in retrieving specific memories to word cues and had poorer access to the remote past. Deficits were found in the context of intact recent memory and preserved general memory abilities, with some impairment of visual memory. Problems in retrieving episodic and semantic AMs across the life span were also evident. Qualitative analysis of memory reports suggested that the ASD group was less likely to refer to emotion in their remote memories but more likely to describe emotions in their recent memories. Important predictors of AM performance in the ASD group were central executive abilities, in particular cognitive flexibility and verbal fluency.

Automatic metaphor processing in adults with Asperger syndrome: a metaphor interference effect task

This paper investigates automatic processing of novel metaphors in adults with Asperger Syndrome (AS) and typically developing controls. We present an experiment combining a semantic judgment task and a recognition task. Four types of sentences were compared: Literally true high-typical sentences, literally true low-typical sentences, apt metaphors, and scrambled metaphors (literally false sentences which are not readily interpretable as metaphors). Participants were asked to make rapid decisions about the literal truth of such sentences. The results revealed that AS and control participants showed significantly slower RTs for metaphors than for scrambled metaphors and made more mistakes in apt metaphoric sentences than in scrambled metaphors. At the same time, there was higher recognition of apt metaphors compared with scrambled metaphors. The findings indicate intact automatic metaphor processing in AS and replicate previous findings on automatic metaphor processing in typically developing individuals.

Spatial short-term memory in children with nonverbal learning disabilities: impairment in encoding spatial configuration

The authors investigated whether impaired spatial short-term memory exhibited by children with nonverbal learning disabilities is due to a problem in the encoding process. Children with or without nonverbal learning disabilities performed a simple spatial test that required them to remember 3, 5, or 7 spatial items presented simultaneously in random positions (i.e., spatial configuration) and to decide if a target item was changed or all items including the target were in the same position. The results showed that, even when the spatial positions in the encoding and probe phases were similar, the mean proportion correct of children with nonverbal learning disabilities was 0.58 while that of children without nonverbal learning disabilities was 0.84. The authors argue with the results that children with nonverbal learning disabilities have difficulty encoding relational information between spatial items, and that this difficulty is responsible for their impaired spatial short-term memory.

Thinking in Pictures as a cognitive account of autism

We analyze the hypothesis that some individuals on the autism spectrum may use visual mental representations and processes to perform certain tasks that typically developing individuals perform verbally. We present a framework for interpreting empirical evidence related to this "Thinking in Pictures" hypothesis and then provide comprehensive reviews of data from several different cognitive tasks, including the n-back task, serial recall, dual task studies, Raven's Progressive Matrices, semantic processing, false belief tasks, visual search, spatial recall, and visual recall. We also discuss the relationships between the Thinking in Pictures hypothesis and other cognitive theories of autism including Mindblindness, Executive Dysfunction, Weak Central Coherence, and Enhanced Perceptual Functioning.

Who's Missing the Point? A Commentary on Claims that Autistic Persons Have a Specific Deficit in Figurative Language Comprehension

It's become a caricature of autistic persons that they don't understand figurative language. Despite empirical evidence to the contrary, three of the four contributions to this special issue endorse this stereotype without question. And all four contributions attribute this supposed deficit to even shakier fallacies, such as the controversial claim that autistic people lack empathy or a 'theory of mind.' In this commentary, we begin by reviewing the literature more exhaustively than the other contributions, and we highlight a point that they missed: Autistic persons are likely to have difficulty comprehending figurative language if they also have difficulty comprehending language in general. There doesn't seem to be a specific deficit in figurative language unique to autism. We also tackle the claim that autistic people lack empathy. And we question the existence of a 'theory of mind area,' while demonstrating the pitfalls that ensnarl researchers when they strain to interpret differences between autistic and non-autistic brain activity as solely autistic deficits.

Can Asperger syndrome be distinguished from autism? An anatomic likelihood meta-analysis of MRI studies

BACKGROUND

The question of whether Asperger syndrome can be distinguished from autism has attracted much debate and may even incur delay in diagnosis and intervention. Accordingly, there has been a proposal for Asperger syndrome to be subsumed under autism in the forthcoming Diagnostic and Statistical Manual of Mental Disorders, fifth edition, in 2013. One approach to resolve this question has been to adopt the criterion of absence of clinically significant language or cognitive delay--essentially, the "absence of language delay." To our knowledge, this is the first meta-analysis of magnetic resonance imaging (MRI) studies of people with autism to compare absence with presence of language delay. It capitalizes on the voxel-based morphometry (VBM) approach to systematically explore the whole brain for anatomic correlates of delay and no delay in language acquisition in people with autism spectrum disorders.

METHODS

We conducted a systematic search for VBM MRI studies of grey matter volume in people with autism. Studies with a majority (at least 70%) of participants with autism diagnoses and a history of language delay were assigned to the autism group (n = 151, control n = 190). Those with a majority (at least 70%) of individuals with autism diagnoses and no language delay were assigned to the Asperger syndrome group (n = 149, control n = 214). We entered study coordinates into anatomic likelihood estimation meta-analysis software with sampling size weighting to compare grey matter summary maps driven by Asperger syndrome or autism.

RESULTS

The summary autism grey matter map showed lower volumes in the cerebellum, right uncus, dorsal hippocampus and middle temporal gyrus compared with controls; grey matter volumes were greater in the bilateral caudate, prefrontal lobe and ventral temporal lobe. The summary Asperger syndrome map indicated lower grey matter volumes in the bilateral amygdala/hippocampal gyrus and prefrontal lobe, left occipital gyrus, right cerebellum, putamen and precuneus compared with controls; grey matter volumes were greater in more limited regions, including the bilateral inferior parietal lobule and the left fusiform gyrus. Both Asperger syndrome and autism studies reported volume increase in clusters in the ventral temporal lobe of the left hemisphere.

LIMITATIONS

We assigned studies to autism and Asperger syndrome groups for separate analyses of the data and did not carry out a direct statistical group comparison. In addition, studies available for analysis did not capture the entire spectrum, therefore we cannot be certain that our findings apply to a wider population than that sampled.

CONCLUSION

Whereas grey matter differences in people with Asperger syndrome compared with controls are sparser than those reported in studies of people with autism, the distribution and direction of differences in each category are distinctive.

Managing complexity: impact of organization and processing style on nonverbal memory in autism spectrum disorders

The contributions of cognitive style and organization to processing and recalling a complex novel stimulus were examined by comparing the Rey Osterrieth Complex Figure (ROCF) test performance of children, adolescents, and adults with ASD to clinical controls (CC) and non-impaired controls (NC) using the Developmental Scoring System. The ROCF task involves a complex structure with strong organizational or integrative processing demands. The individuals with ASD relied on a predominantly part-oriented strategy to cope with the complexity of the task and did not make the typical developmental shift to a configurational approach. Both processing style and organization (whether pieces of information were perceived as connected to one another in a meaningful way) contributed to structural recall in the ASD group.

Neuropsychological differences among children with Asperger syndrome, nonverbal learning disabilities, attention deficit disorder, and controls

Confusion is present as to possible diagnostic differences between Asperger syndrome (AS) and Nonverbal learning disabilities (NLD) and the relation of these disorders to attentional difficulties. Three-hundred and forty-five children participated in this study in 5 groups; NLD, AS, attention deficit hyperactivity disorder (ADHD): Combined type, ADHD: Inattentive type, and controls. The NLD group showed particular difficulty on visual-spatial, visual-motor, and fluid reasoning measures compared to the other groups. There was also a significant verbal-performance IQ split in this group related to difficulty in social functioning. This study extends the findings from previous studies and extends these findings to differences between AS and NLD groups.

The relation of humor and child development: social, adaptive, and emotional aspects

A sense of humor has been linked to social competence, popularity, and adaptability. The purpose of this review was to investigate the extant research in humor in childhood. Emerging work on the neuroanatomy of humor was discussed with findings of right hemispheric involvement for the comprehension and appreciation of humor for the affective network and the left hemisphere for cognitive understanding. These findings are intriguing when examining humor functioning in children with various disabilities, particularly the right hemisphere for children with autistic spectrum disorders or nonverbal learning disabilities. Examination of research in humor in childhood disabilities found most articles on humor in children with autistic spectrum disorder or mental retardation, with few to none in learning disabilities or attention deficit hyperactivity disorder. It was concluded that further study is needed to understand humor in children with disabilities and that such understanding will assist with interventions.

Right hemisphere dysfunction and metaphor comprehension in young adults with Asperger syndrome

This study examined whether the known difficulties in metaphor comprehension exhibited by persons with Asperger syndrome (AS) can be explained by a dysfunctional right hemisphere (RH). Using the divided visual field paradigm, 27 AS participants and 36 matched controls were presented with word pairs of four types (literal, conventional metaphors, novel metaphors, and unrelated word pairs), and were asked to perform a semantic judgment task. The main hypothesis was that whereas the control group participants will show RH superiority for novel metaphor processing, no RH superiority will be found in the AS group. Results indeed indicate much less RH contribution to novel metaphor comprehension in AS, and are discussed in light of linguistic models and the neurobiology of autism.

Brain asymmetry in emotional processing in Asperger syndrome

The role of brain asymmetry in emotional processing in Asperger syndrome (AS) is still largely unknown. Although the valence hypothesis predicts that positive emotions are processed preferentially by the left hemisphere and negative emotions by the right hemisphere, reports concerning laterality of emotion point to a left hemisphere advantage for complex emotion versus a right hemisphere advantage for basic emotions (the "type hypothesis"). In this study, we investigated the lateralization of basic versus complex (negative and positive) eye expressions in adults with AS in 2 consecutive experiments: in the first experiment, the performance of AS and healthy controls were compared in a divided visual field task. In the second experiment, the ability of participants with AS to identify eye expressions varying in valence and type was compared with that of patients with localized lesions in either the right or the left hemispheres. Controls were better in recognizing negative emotions presented to the left visual field and positive emotions presented to the right visual field, whereas individuals with AS failed to show this interaction effect. Lateralization of basic versus complex emotions was less evident although indeed controls identified better basic emotions presented to the right visual field. Furthermore, participants with AS exhibited a similar pattern of recognition of negative versus positive emotions to that of patients with left hemisphere damage. It is suggested that the pattern of performance of individuals with AS resembles that of patients with left hemisphere dysfunction.

Childhood autism and auditory system abnormalities

Hearing disorders are common among children with autism, ranging from peripheral and sensorineural hearing deficit or loss to auditory hypersensitivity with bizarre reactions to sounds. The auditory abnormalities and consequent sensory deprivation exacerbate the communication deficit of autism, and early auditory assessment holds an important place in the planning of intervention and the overall prognosis of patients. Physiologic, pathologic, imaging, and neurochemical studies have revealed an array of aberrations in the perception and processing of the audiologic stimuli, including (among others) maturational defects, atypical lateralization, and serotonin dysfunction.

Autism and anorexia nervosa: Two facets of the same disease?

We compiled data included in the Primal Health Research Database (www.primalhealthresearch.com) to test the hypothesis that when two pathological conditions or personality traits share the same critical period for gene-environment interaction, we should expect further similarities, particularly from clinical and pathophysiological perspectives. The keywords 'autism' and 'anorexia nervosa' (but not bulimia nervosa) lead to studies suggesting that for both conditions the perinatal period is critical. We take this example to look at other possible links between these pathological entities. From a clinical perspective, several teams have independently emphasized the importance of autistic traits in anorexia nervosa. Deficits in the processing of oxytocin have been demonstrated in both cases. Autistic groups have significantly lower blood oxytocin levels than normal groups, and oxytocin levels increase with age in the normal group only. In autistic groups there is a high ratio of intermediates of oxytocin synthesis (OX-T) to the nonapeptide oxytocin (OT). On the other hand, it has been reported that the level of oxytocin in the cerebrospinal fluid of anorexic women is significantly lower than the level of oxytocin in bulimic and control subjects. Scanning data reveal similar asymmetric functions with left hemisphere preponderance in autistic spectrum disorders and anorexia. A comparative study of the mirror neurons systems is another promising avenue for research. Such an accumulation of similarities from a great diversity of perspectives suggests that anorexia nervosa might be considered a female variant of the autistic spectrum. A plausible interpretation is that prenatal exposure to male hormones might protect against the expression of this disease: girls who have a twin brother are at low risk for anorexia nervosa, compared with girls who have a twin sister, and with controls; furthermore genetic linkage analyses do not detect change on the X chromosome. From an overview of the database, the perinatal period appears to be critical for all disorders related to the capacity to love (including love of oneself), to the potential for aggression (including self-destructive behaviours), or to sociability. Is the perinatal period critical for the organisation of the oxytocin system? This is an important question at a time when we learn that the widely used synthetic oxytocin can probably diffuse across the placenta. On the other hand, where the genesis of metabolic types is concerned, it is prenatal life that appears to be critical.

Differential effects on white-matter systems in high-functioning autism and Asperger's syndrome

BACKGROUND

Whether autism spectrum maps onto a spectrum of brain abnormalities and whether Asperger's syndrome (ASP) is distinct from high-functioning autism (HFA) are debated. White-matter maldevelopment is associated with autism and disconnectivity theories of autism are compelling. However, it is unknown whether children with ASP and HFA have distinct white-matter abnormalities.

METHOD

Voxel-based morphometry mapped white-matter volumes across the whole brain in 91 children. Thirty-six had autism spectrum disorder. A history of delay in phrase speech defined half with HFA; those without delay formed the ASP group. The rest were typically developing children, balanced for age, IQ, gender, maternal language and ethnicity. White-matter volumes in HFA and ASP were compared and each contrasted with controls.

RESULTS

White-matter volumes around the basal ganglia were higher in the HFA group than ASP and higher in both autism groups than controls. Compared with controls, children with HFA had less frontal and corpus callosal white matter in the left hemisphere; those with ASP had less frontal and corpus callosal white matter in the right hemisphere with more white matter in the left parietal lobe.

CONCLUSIONS

HFA involved mainly left hemisphere white-matter systems; ASP affected predominantly right hemisphere white-matter systems. The impact of HFA on basal ganglia white matter was greater than ASP. This implies that aetiological factors and management options for autism spectrum disorders may be distinct. History of language acquisition is a potentially valuable marker to refine our search for causes and treatments in autism spectrum.

Exploration of core features of a human face by healthy and autistic adults analyzed by visual scanning

Autism is a neurodevelopmental disorder characterized by disorders in social interaction and emotional reciprocity which can be explained by impairments of the ability to understand the mental states of others ("theory of mind") and recognition of facial expressions. These impairments may be related to the difficulties with face recognition characteristic of this disorder. Face perception plays a critical role in the development of social interaction and understanding of the internal emotional state of others. It depends on initial oculomotor exploration. The aim of this study was to quantify ocular behaviour in 11 adults with autism and 23 healthy subjects (15-35 years) while exploring neutral faces and faces expressing an emotion using an eye tracking method. The strategy used to explore faces was also studied. All subjects spent significantly more time on the eye region than on the rest of the face. However, subjects with autism spent less time on the eye region than healthy subjects. The latter used a strategy based on their own eye dominance when exploring faces. All healthy subjects significantly began their exploration of a face by looking at the eye in the contralateral visual field to their dominant eye. This strategy seemed to be impaired in patients with autism. To conclude, these results contrast with earlier reports regarding the lack of interest in the eye region in patients with autism, and demonstrate for the first time that perception of the face is dependent on eye dominance.

Psychosis and autism as diametrical disorders of the social brain

Autistic-spectrum conditions and psychotic-spectrum conditions (mainly schizophrenia, bipolar disorder, and major depression) represent two major suites of disorders of human cognition, affect, and behavior that involve altered development and function of the social brain. We describe evidence that a large set of phenotypic traits exhibit diametrically opposite phenotypes in autistic-spectrum versus psychotic-spectrum conditions, with a focus on schizophrenia. This suite of traits is inter-correlated, in that autism involves a general pattern of constrained overgrowth, whereas schizophrenia involves undergrowth. These disorders also exhibit diametric patterns for traits related to social brain development, including aspects of gaze, agency, social cognition, local versus global processing, language, and behavior. Social cognition is thus underdeveloped in autistic-spectrum conditions and hyper-developed on the psychotic spectrum.;>We propose and evaluate a novel hypothesis that may help to explain these diametric phenotypes: that the development of these two sets of conditions is mediated in part by alterations of genomic imprinting. Evidence regarding the genetic, physiological, neurological, and psychological underpinnings of psychotic-spectrum conditions supports the hypothesis that the etiologies of these conditions involve biases towards increased relative effects from imprinted genes with maternal expression, which engender a general pattern of undergrowth. By contrast, autistic-spectrum conditions appear to involve increased relative bias towards effects of paternally expressed genes, which mediate overgrowth. This hypothesis provides a simple yet comprehensive theory, grounded in evolutionary biology and genetics, for understanding the causes and phenotypes of autistic-spectrum and psychotic-spectrum conditions.

Abnormal EEG lateralization in boys with autism

OBJECTIVE

Functional brain abnormalities associated with autism in 3-8-year-old boys were studied with EEG recorded under controlled experimental condition of sustained visual attention and behavioral stillness.

METHODS

EEG was recorded in two independent samples of boys with autism (BWA) from Moscow (N=21) and Gothenburg (N=23) and a corresponding number of age-matched typically developing boys (TDB). EEG spectral power (SP) and SP interhemispheric asymmetry within delta, theta and alpha bands were analyzed.

RESULTS

BWA comprised a non-homogeneous group in relation to theta and alpha SP. When four outliers were excluded the only between-group difference in absolute SP was a higher amount of prefrontal delta in BWA. BWA of both samples demonstrated atypical leftward broadband EEG asymmetry with a maximum effect over the mid-temporal regions. Concurrently, the normal leftward asymmetry of mu rhythm was absent in BWA.

CONCLUSIONS

The abnormal broadband EEG asymmetry in autism may point to a diminished capacity of right temporal cortex to generate EEG rhythms. The concurrent lack of normal leftward asymmetry of mu rhythm suggests that abnormalities in EEG lateralization in autism may be regionally/functionally specific.

SIGNIFICANCE

The data provide evidence for abnormal functional brain lateralization in autism.

Communicative Competence and Metalinguistic Ability: Performance by Children and Adults with Autism Spectrum Disorder

The Test of Language Competence-Expanded Edition (TLC-E) was administered to children and adults with a diagnosis of autism spectrum disorder (ASD). Relative to controls, those with ASD were less competent on a range of TLC-E tasks. No differences were found for either child or adult ASD groups on any of the TLC-E measures when re-classified as Asperger syndrome (AS) and high functioning autism (HFA) using DSM-IV language criterion. Hierarchical cluster analyses of individuals with ASD identified subgroups within the spectrum. The use of developmental language history as an identifying marker in autism is questioned. The findings suggest that comprehensive language assessments on individuals with ASD can provide clinically relevant information regarding the heterogeneity of language skills within the autistic spectrum.

The influence of instruction modality on brain activation in teenagers with nonverbal learning disabilities: two case histories

Teenagers with nonverbal learning disabilities (NLD) have difficulty with fine-motor coordination, which may relate to the novelty of the task or the lack of "self-talk" to mediate action. In this study, we required two teenagers with NLD and two control group teenagers to touch the thumb of each hand firmly and accurately to the fingertips of the same hand, in an order specified by verbal or tactile instruction. Brain activity patterns (measured using functional magnetic resonance imaging) suggest that unlike control participants, the NLD participants used internalized speech to facilitate the novel task only when instructions were verbal. NLD participants also showed activity in a more widely distributed network of neural structures. These findings provide preliminary evidence for remediation strategies that encourage internal speech.

The Modifier Model of Autism and Social Development in Higher Functioning Children

The study of phenotypic variability in social impairments and comorbid emotional disorders in autism is important because it provides information on phenotypic differences that currently complicate diagnosis, research, and treatment of this disorder. Currently, though, relatively little is known about the processes that contribute to individual differences in social impairments and comorbidity in autism. In this paper, we present a model that suggests modifier processes (MPs), which are not necessarily specific to the syndrome refractor alter the expression of autism and contribute to fundamental behavioral and psychological differences in children diagnosed with this disorder. One MPs involves the somewhat surprising tendency of some children with higher functioning autism (HFA) to make attributions about other peoples thoughts, although they have social cognitive deficits Just as in other children, the attributions of children with HFA are linked to some of their behavioral problems Another MP involves the influence of differences in motivation associated with the behavioral activation and inhibition systems that can be assessed with measures of anterior EEG asymmetry. This dimension of motivation may be linked to how active but inappropriate and withdrawn children with HFA may appear. Third, differences in the self-monitoring of errors among children with HFA appear to be related to individual differences in IQ and social symptom severity in these children. The possible role of these MPs in diagnostic subgroups and differences in treatment responses among children with HFA are discussed. In addition, the role of MPs in understanding the effects associated with specific genetic functions in autism, such as those associated with the serotonin transporter gene (5-HTTLPR), is discussed. A conclusion of this paper is that the varied expression of autism may require that we understand how autism interacts with other non-syndrome-specific processes that are related to individual differences in all people.

Auditory perception and attention as reflected by the brain event-related potentials in children with Asperger syndrome

OBJECTIVE

Language development is delayed and deviant in individuals with autism, but proceeds quite normally in those with Asperger syndrome (AS). We investigated auditory-discrimination and orienting in children with AS using an event-related potential (ERP) paradigm that was previously applied to children with autism.

METHODS

ERPs were measured to pitch, duration, and phonetic changes in vowels and to corresponding changes in non-speech sounds. Active sound discrimination was evaluated with a sound-identification task.

RESULTS

The mismatch negativity (MMN), indexing sound-discrimination accuracy, showed right-hemisphere dominance in the AS group, but not in the controls. Furthermore, the children with AS had diminished MMN-amplitudes and decreased hit rates for duration changes. In contrast, their MMN to speech pitch changes was parietally enhanced. The P3a, reflecting involuntary orienting to changes, was diminished in the children with AS for speech pitch and phoneme changes, but not for the corresponding non-speech changes.

CONCLUSIONS

The children with AS differ from controls with respect to their sound-discrimination and orienting abilities.

SIGNIFICANCE

The results of the children with AS are relatively similar to those earlier obtained from children with autism using the same paradigm, although these clinical groups differ markedly in their language development.

Autobiographical Memory and Social Problem-solving in Asperger Syndrome

Difficulties in social interaction are a central feature of Asperger syndrome. Effective social interaction involves the ability to solve interpersonal problems as and when they occur. Here we examined social problem-solving in a group of adults with Asperger syndrome and control group matched for age, gender and IQ. We also assessed autobiographical memory, on a cueing task and during social problem-solving, and examined the relationship between access to specific past experiences and social problem-solving ability. Results demonstrated a social problem-solving impairment in the Asperger group. Their solutions were less detailed, less effective and less extended in time. Autobiographical memory performance was also impaired with significantly longer latencies to retrieve specific memories and fewer specific memories retrieved in comparison to controls.

Case Illustration of a Boy With Nonverbal Learning Disorder and Asperger's Features: Neuropsychological and Personality Assessment

I present a case study of a latency-age boy referred for assessment of a nonverbal learning disability/disorder (NLD) who also had features of Asperger's syndrome (AS). I review NLD terminology, presumed brain-behavior relationship, neuropsychological profile, and diagnosis/classification issues. I discuss the challenge of differentiating NLD from AS in relation to the client's pattern of visual-spatial, communication, social-emotional, and behavioral NLD correlates. I integrate neuropsychological and personality assessment data with interviews, observations, prior testing, and input from teacher and therapist in formulating a diagnostic impression. I discuss Rorschach (Exner, 2003) and neuropsychological consultations in relation to subtle language and interpersonal features of the client's communication style. I provide parent feedback at 18 and 24 months posttesting. I discuss implications relative to a model of school neuropsychological assessment that includes the Rorschach test.

Laterality biases to chimeric faces in Asperger syndrome: what is 'right' about face-processing?

People show a left visual field (LVF) bias for faces, i.e., involving the right hemisphere of the brain. Lesion and neuroimaging studies confirm the importance of the right-hemisphere and suggest separable neural pathways for processing facial identity vs. emotions. We investigated the hemispheric processing of faces in adults with and without Asperger syndrome (AS) using facial emotion and identity chimeric tasks. Controls showed an LVF bias in both tasks, but no perceptual bias in a non-social control task. The AS group showed an LVF bias during both tasks, however the bias was reduced in the identity condition. Further, the AS group showed an LVF bias in the non-social condition. These results show a differential pattern of hemispheric processing of faces in AS.

Humor in autism and Asperger syndrome

Research has shown that individuals with autism and Asperger syndrome are impaired in humor appreciation, although anecdotal and parental reports provide some evidence to the contrary. This paper reviews the cognitive and affective processes involved in humor and recent neurological findings. It examines humor expression and understanding in autism and Asperger syndrome in the context of the main psychological theories (Theory of Mind, Executive Functions, Weak Central Coherence and Laterization models) and associated neural substrates. In the concluding sections, examples of humor displayed by individuals with autism/Asperger syndrome which appear to challenge the above theories are analyzed and areas for further research are suggested.

Structural white matter deficits in high-functioning individuals with autistic spectrum disorder: a voxel-based investigation

A number of imaging and neuropathological studies have reported structural abnormalities in white matter areas such as the corpus callosum in autism spectrum disorder (ASD). Differences in both global brain volume and the size of specific neural structures have been reported. In order to expand these previously reported findings and to describe more precisely the nature of such structural changes, we performed a voxel-based morphometric whole brain analysis, using a group-specific template, in male adolescents with ASD. Fifteen individuals with normal intelligence and ASD, and a group of 16 controls, matched for age, sex, and IQ, were investigated. High-resolution T1-weighted 3D data sets were acquired and analysed. Local white matter volume deficits were found in the corpus callosum, particularly in the anterior splenium and isthmus, and right hemisphere. White matter volume deficits were also found in the left middle temporal, right middle frontal, and left superior frontal gyri. No significant areas of increased white matter volume were found. Our findings support the hypothesis that reduced white matter volume in the corpus callosum and right hemisphere may play a role in the pathophysiology of ASD.

Nonverbal neurodevelopmental dysfunctions

Although perhaps not as well-studied or well-known as other learning disorders, the possible academic and social sequelae of math, writing, motor, or visuospatial dysfunction, as well as difficulties with nonverbal processing and understanding, are readily identifiable and worthy of identification. While pediatricians should not feel compelled to attempt to identify all of the variables of these difficulties, an understanding of them will allow pediatricians to maintain their role as an advocate for patients and families and to feel comfortable communicating with others who are equally dedicated to children.

Atypical sleep architecture and the autism phenotype

A growing body of evidence indicates that people with autism frequently experience sleep disorders and exhibit atypical sleep architecture. In order to establish whether sleep disorders truly belong to the autism spectrum disorder (ASD) phenotype, we conducted a subjective and objective study of sleep in a group of high-functioning adults with ASD but without sleep complaints, psychiatric disorders or neurological comorbidity. We compared the subjective data of 27 ASD participants with those of 78 healthy controls matched for chronological age and gender. Subjective measures of sleep in the clinical group were compatible with insomnia and/or a tolerable phase advance of the sleep-wake cycle. Subjective data were confirmed by objective laboratory sleep recordings in a subset of 16 patients and 16 controls. Persons with autism presented with a longer sleep latency (P < 0.04), more frequent nocturnal awakenings (P < 0.03), lower sleep efficiency (P < 0.03), increased duration of stage 1 sleep (P < 0.02), decreased non-REM sleep (stages 2 + 3 + 4, P < 0.04) and slow-wave sleep (stages 3 + 4, P < 0.05), fewer stage 2 EEG sleep spindles (P < 0.004), and a lower number of rapid eye movements during REM sleep (P < 0.006) than did control participants. On clinical scales, the scores of persons with ASD on the Beck Depression Inventory were similar to those of persons without, but their trait anxiety scores on the Spielberger Anxiety Scale were higher (P < 0.02). The state anxiety scores of the Spielberger scale and cortisol levels were the same in the two groups. Objective total sleep time correlated negatively with the Social (-0.52, P < 0.05) and Communication (-0.54, P < 0.02) scales of the Autism Diagnostic Interview-Revised. The sleep of clinical subgroups (10 with high-functioning autism, six with Asperger syndrome) did not differ, except for the presence of fewer EEG sleep spindles in the Asperger syndrome subgroup (P < 0.05). In conclusion, these findings indicate that atypicalities of sleep constitute a salient feature of the adult ASD phenotype and this should be further investigated in younger patients. Moreover, the results are consistent with an atypical organization of neural networks subserving the macro- and microstructure of sleep in ASD. We are furthering this research with quantified analysis of sleep EEG.

Resting cortical brain activity and social behavior in higher functioning children with autism

BACKGROUND

Psychophysiological measurement of processes related to social behavior may be valuable for research on individual differences and subgroups among children with autism spectrum disorders (Coleman, 1987; Dawson, Klinger, Panagiotides, Lewy, & Castelloe, 1995; Modahl et al., 1998). In particular, recent research and theory suggests that measures of resting anterior EEG asymmetry reflect complex brain processes associated with individual differences in approach or avoidance motivation that may be associated with social and emotional interaction tendencies among children with autism.

METHOD

This hypothesis was examined in a study of the relations among resting anterior asymmetry, social impairment, and social anxiety in 23 high functioning children with autism (HFA) and 20 controls (age range 9-14 years).

RESULTS

These groups were significantly different on the measures of anterior asymmetry, social symptoms and anxiety-related measures. Moreover, HFA children who displayed right frontal asymmetry (RFA group) displayed more symptoms of social impairments and better visual analytic skills than did children who displayed left frontal asymmetry (LFA group). Alternatively, while the LFA group displayed fewer symptoms of social impairment they also reported greater levels of social anxiety, social stress, and lower satisfaction with interpersonal relations than did the RFA group.

CONCLUSIONS

These observations indicate that anterior EEG asymmetry may be a marker of motivation and emotion processes that refract the autism taxon into important individual differences in social presentation among higher functioning children.