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Functional imbalance of visual pathways indicates alternative face processing strategies in autism

Objective: To investigate whether autistic subjects show a different pattern of neural activity than healthy individuals during processing of faces and complex patterns. Methods: Blood oxygen level–dependent (BOLD) signal changes accompanying visual processing of faces and complex patterns were analyzed in an autistic group (n = 7; 25.3 [6.9] years) and a control group (n = 7; 27.7 [7.8] years). Results: Compared with unaffected subjects, autistic subjects demonstrated lower BOLD signals in the fusiform gyrus, most prominently during face processing, and higher signals in the more object-related medial occipital gyrus. Further signal increases in autistic subjects vs controls were found in regions highly important for visual search: the superior parietal lobule and the medial frontal gyrus, where the frontal eye fields are located. Conclusions: The cortical activation pattern during face processing indicates deficits in the face-specific regions, with higher activations in regions involved in visual search. These findings reflect different strategies for visual processing, supporting models that propose a predisposition to local rather than global modes of information processing in autism.

The recognition of facial affect in autistic and schizophrenic subjects and their first-degree relatives

BACKGROUND Autism and schizophrenia are considered to be substantially influenced by genetic factors. The endophenotype of both disorders probably also includes deficits in affect perception. The objective of this study was to examine the capacity to detect facially expressed emotion in autistic and schizophrenic subjects, their parents and siblings. METHOD Thirty-five subjects with autism and 102 of their relatives, 21 schizophrenic subjects and 46 relatives from simplex (one child affected) and multiplex (more than one child affected) families, as well as an unaffected control sample consisting of 22 probands completed a 50-item computer-based test to assess the ability to recognize basic emotions. RESULTS The autistic subjects showed a poorer performance on the facial recognition test than did the schizophrenic and the unaffected individuals. In addition, there was a tendency for subjects from multiplex families with autistic loading to score lower on the test than individuals from simplex families with autistic loading. Schizophrenic subjects and their relatives as well as siblings and parents of autistic subjects did not differ from the sample of unaffected subjects in their ability to judge facial affect. CONCLUSIONS Findings corroborate the assumption that emotion detection deficits are part of the endophenotype of autism. In families with autistic children, the extent of facial recognition deficits probably indexes an elevation in familial burden. It seems unlikely that problems in emotion perception form a consistent part of the endophenotype of schizophrenia or the broader phenotype in relatives of patients with psychosis or autism.

Assessing autistic traits: cross‐cultural validation of the social responsiveness scale (SRS)

The Social Responsiveness Scale (SRS) is a quantitative measure of autistic traits in 4‐ to 18‐year‐olds, which has been used in behavior‐genetic, epidemiological and intervention studies. The US standardization demonstrated a single‐factor structure and good to excellent psychometric properties. The cross‐cultural validity of the German adaptation of the parent‐report SRS in a sample of N=1,436 children and adolescents: 838 typically developing and 527 clinical participants (160 with autism spectrum disorders (ASDs)) was examined. Internal consistency (0.91–0.97), test–retest reliability (0.84–0.97), interrater reliability (0.76 and 0.95) and convergent validity with the Autism Diagnostic Observation Schedule as well as the Autism Diagnostic Interview—Revised and Social Communication Questionnaire (0.35–0.58) were satisfactory to good. The SRS total score discriminated between ASD and other mental disorders. SRS scores proved to be sufficiently independent of general psychopathology. Principal component analyses yielded single‐factor solutions for the normative and clinical subsamples. In addition, construct validity was ensured by consistent correlations with the Vineland Adaptive Behavior Scales, the Child Behavior Checklist and the Junior Temperament and Character Inventory. Normative SRS total scores for girls and boys as well as values for ASD were lower in the German sample, while scores for conduct disorder and attention deficit hyperactivity/conduct disorder combined were higher. Generally, cross‐cultural validity of the SRS seems to be sufficiently assured for a large European sample. However, some discrepancies regarding SRS normative and clinical raw score distributions, reliability and validity findings are critically discussed.

Autism spectrum disorders: sex differences in autistic behaviour domains and coexisting psychopathology

The purpose of the present study was to examine possible differences between high‐functioning males and females with autism spectrum disorder (ASD) regarding the core symptoms of autism and coexisting psychopathology. A total of 23 females and 23 males matched for age, IQ, and ASD diagnoses were recruited(mean age 11y 9mo [SD 4y 5mo], range 5y‐20y 2mo) with an IQ above the range of learning disability (mean IQ 88.8 [SD 18.5], range 70–128). They were compared using the Autism Diagnostic Interview‐Revised, the Autism Diagnostic Observation Schedule, and the Child Behavior Checklist/4–18. We did not identify striking differences between males and females for the triad of autism core dysfunctions (deficits in reciprocal social interaction, communication, and repetitive, stereotyped behaviours) as assessed by expert ratings. However, with regard to several domains of coexisting psychopathology, parent reports revealed significantly more symptoms in females than males, particularly social problems (t=4.47, p<0.01, d=1.20), attention problems (t=3.39, p<0.01, d=0.80), and thought problems (t=3.24, p<0.01, d=0.84). These results are discussed with possible interpreting bias by parents who may expect more socially desired behaviour from daughters than from sons. The severity of social and attention problems in high‐functioning females with autism emphasizes the need for thorough assessments and interventions in these domains. Future research should compare the cognitive phenotype of autism between sexes.

The Relation Between General Cognitive Level and Adaptive Behavior Domains in Individuals with Autism with and Without Co-Morbid Mental Retardation

This study examined the association between adaptive behavior and general cognitive level in individuals with autism or PDD-NOS with and without comorbid mental retardation. Data from the screening version of the Vineland Adaptive Scales and the Wechsler Intelligence Scales were analysed in a sample of 67 subjects. While in the higher functioning individuals (IQ > 70, n = 34) IQ and adaptive behavior level differed significantly, performances were fairly comparable in subjects showing lower cognitive functioning (IQ < 70, n = 33). Regression models revealed a higher correlation between IQ and single adaptive behavior domains in the non-mentally retarded participants, with the domain Communication reaching the highest predictive power of the single adaptive behavior areas. Findings indicate, the relationship between adaptive and cognitive function in autistic disorders is mediated by the presence of a qualitative reduction of intelligence. Methodological limitations of the study are discussed.

Facial affect recognition training in autism: can we animate the fusiform gyrus?

One of the most consistent findings in the neuroscience of autism is hypoactivation of the fusiform gyrus (FG) during face processing. In this study the authors examined whether successful facial affect recognition training is associated with an increased activation of the FG in autism. The effect of a computer-based program to teach facial affect identification was examined in 10 individuals with high-functioning autism. Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) changes in the FG and other regions of interest, as well as behavioral facial affect recognition measures, were assessed pre- and posttraining. No significant activation changes in the FG were observed. Trained participants showed behavioral improvements, which were accompanied by higher BOLD fMRI signals in the superior parietal lobule and maintained activation in the right medial occipital gyrus.

Attention deficit hyperactivity disorder symptoms in pervasive developmental disorders : Association with autistic behavior domains and coexisting psychopathology

Background: Symptoms as in attention deficit hyperactivity disorder (ADHD) are frequent among individuals with pervasive developmental disorders (PDD). The aim of the present study was to examine the impact of inattention, hyperactivity and impulsivity on the clinical phenotype of children and adolescents with PDD. Sampling and Methods: A total of 182 subjects (41 females) diagnosed as having PDD were split into a high (PDD+) and a lower (PDD) attention problem group using the median of the Child Behavior Checklist (CBCL) syndrome scale ‘attention problems’ (median T score = 75). The groups were compared with regard to the degree of coexisting psychopathology, as measured by the remaining 7 CBCL subscales, and autistic core features assessed by the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule using a multivariate analysis of covariance adjusted for age, IQ and socioeconomic status. Results: The PDD+ subjects exhibited a significantly higher degree of general psychopathology than the subjects in the PDD subgroup, regarding both internalizing and externalizing symptoms. In addition, the PDD+ subgroup tended to exhibit more impairments on the social interaction scale of the ADI-R. Conclusions: Clinicians should adjust treatment plans to ensure comprehensive and effective treatment for both PDD and associated ADHD. A dual diagnosis may be essential to the implementation of effective treatments.

A 15q13.3 microdeletion segregating with autism

Autism and mental retardation (MR) show high rates of comorbidity and potentially share genetic risk factors. In this study, a rare ∼2 Mb microdeletion involving chromosome band 15q13.3 was detected in a multiplex autism family. This genomic loss lies between distal break points of the Prader–Willi/Angelman syndrome locus and was first described in association with MR and epilepsy. Together with recent studies that have also implicated this genomic imbalance in schizophrenia, our data indicate that this CNV shows considerable phenotypic variability. Further studies should aim to characterise the precise phenotypic range of this CNV and may lead to the discovery of genetic or environmental modifiers.

THE DEVELOPMENT AND EVALUATION OF A COMPUTER-BASED PROGRAM TO TEST AND TO TEACH THE RECOGNITION OF FACIAL AFFECT

Autism is a chronic pervasive neurodevelopmental disorder characterized by the early onset of social and communicative impairments as well as restricted, ritualized, stereotypic behavior. The endophenotype of autism includes neuropsychological deficits, for instance a lack of “Theory of Mind” and problems recognizing facial affect. In this study, we report the development and evaluation of a computer-based program to teach and test the ability to identify basic facially expressed emotions. 10 adolescent or adult subjects with high-functioning autism or Asperger-syndrome were included in the investigation. A priori the facial affect recognition test had shown good psychometric properties in a normative sample (internal consistency: rtt=.91-.95; retest reliability: rtt=.89-.92). In a prepost design, one half of the sample was randomly assigned to receive computer treatment while the other half of the sample served as control group. The training was conducted for five weeks, consisting of two hours training a week. The trained individuals improved significantly on the affect recognition task, but not on any other measure. Results support the usefulness of the program to teach the detection of facial affect. However, the improvement found is limited to a circumscribed area of social-communicative function and generalization is not ensured.

Impaired Gamma-Band Activity during Perceptual Organization in Adults with Autism Spectrum Disorders: Evidence for Dysfunctional Network Activity in Frontal-Posterior Cortices

Current theories of the pathophysiology of autism spectrum disorders (ASD) have focused on abnormal temporal coordination of neural activity in cortical circuits as a core impairment of the disorder. In the current study, we examined the possibility that gamma-band activity may be crucially involved in aberrant brain functioning in ASD. Magneto-encephalographic (MEG) data were recorded from 13 adult human participants with ASD and 16 controls during the presentation of Mooney faces. MEG data were analyzed in the 25–150 Hz frequency range and a beamforming approach was used to identify the sources of spectral power. Participants with ASD showed elevated reaction times and reduced detection rates during the perception of upright Mooney faces, while responses to inverted stimuli were in the normal range. Impaired perceptual organization in the ASD group was accompanied by a reduction in both the amplitude and phase locking of gamma-band activity. A beamforming approach identified distinct networks during perceptual organization in controls and participants with ASD. In controls, perceptual organization of Mooney faces involved increased 60–120 Hz activity in a frontoparietal network, while in the ASD group stronger activation was found in visual regions. These findings highlight the contribution of impaired gamma-band activity toward complex visual processing in ASD, suggesting atypical modulation of high-frequency power in frontoposterior networks.