High-functioning Autism Spectrum Disorder Group Research Articles

The Relationship of Text Inference Abilities and Reading Comprehension in Children with High-Functioning Autism Spectrum Disorder

Objectives: Reading comprehension in school-age children is an essential ability facilitates acquisition of information from general education. Yet, even with average or above cognitive and word recognition abilities, children with High Functioning Autism Spectrum Disorder (HF-ASD) demonstrate difficulties with reading comprehension. The purpose of the this study was to investigate that identifying the reading comprehension competence with a focus on text inference abilities (coherence processing, metalinguistic, theory of mind) in children with HF-ASD in the lower grades of elementary school.Methods: 15 HF-ASD and 15 age matched typically developing peers (TD) participated in this study. The participants performed reading comprehension tasks and text inferencing tasks (coherence processing, metalinguistic, theory of mind).Results: First, the reading comprehension accuracy of the HF-ASD group was significantly lower than the TD group. Second, the text inference accuracy of the HF-ASD group was significantly lower compared with the TD group. Third, in the TD group, there was a significant correlation between all text inference abilities (coherence processing, metalinguistic, theory of mind) and reading comprehension competence. In contrast, in the HF-ASD group, there was a positive correlation between coherence processing, metalinguistic and reading comprehension competence; however no significant relationship was found between theory of mind and reading comprehension competence. Finally, the coherence processing task predicted reading comprehension competence of children with HF-ASD by 52.2% and TD children by 42.1%.Conclusion: This study suggests that supporting connecting information within a text, local inferencing, and focusing on the coherence processing intervention is necessary for reading comprehension of children with HF-ASD in the lower grades of elementary school.

Intelligence profiles and adaptive behaviors of high-functioning autism spectrum disorder and developmental speech and language disorders.

The present study was aimed at investigating the intelligence profiles and adaptive behaviors of children with high-functioning autism spectrum disorder (HFASD) and developmental speech and language disorders (DSLDs). We compared the similarities and differences of cognitive capabilities and adaptive functions and explored their correlations in the HFASD and DSLDs groups. 128 patients with HFASD, 111 patients with DSLDs and 114 typically developing (TD) children were enrolled into our study. Wechsler Intelligence Scale for Children-IV (WISC-IV) and Adaptive Behavior Assessment System-II (ABAS-II) were respectively applied to evaluate intelligence profiles and adaptive behaviors. Intelligence quotient (IQ) scores and adaptive functioning scores among the HFASD, DSLDs and TD groups were compared through one-way ANOVA. Pearson correlation coefficient was applied to examine the relationships between WISC indices and ABAS domains. Outcomes showed significantly poorer intelligence profiles and adaptive behaviors in HFASD and DSLDs groups. Both children with HFASD and DSLDs demonstrated impairments in verbal comprehension and executive functions. Processing speed and working memory were the predominant defects of children with HFASD and DSLDs in the field of executive functions, respectively. Whereas perceptual reasoning was a relative strength for them. Children with DSLDs had balanced scores of all the domains in ABAS-II; nevertheless, HFASD individuals demonstrated striking impairments in Social domain. Correlation analysis showed IQs of children with HFASD were positively correlated with all the domains and General Adaptive Composite (GAC) of ABAS-II. Additionally, IQs were positively correlated with Conceptual domain and GAC for children with DSLDs. Compared with DSLDs group, intelligence displayed stronger correlations with adaptive behaviors in HFASD group. Our study expanded insights regarding intelligence profiles and adaptive behaviors of children with HFASD and DSLDs. Moreover, this study made breakthroughs in discovering positive correlations between IQs and adaptive functions in the two neurodevelopmental disorders.

Qualitative analysis of verbal fluency in school-age children with high-functioning autism spectrum disorders. Associations with age and IQ

This study analyzes performance on both a Semantic and a Letter verbal fluency (VF) task in school-age children with high-functioning autism spectrum disorder (HF-ASD) (n = 20) and without ASD (n = 20) and investigates the relationship between VF indicators and age, verbal and non-verbal IQ, ASD severity, and attention deficit hyperactivity disorder (ADHD) symptomatology. Furthermore, the Poor Lexical-Semantic Structure Model and the Slow-Retrieval Model are tested if they could account for semantic retrieval difficulties in children with HF-ASD. The HF-ASD group generated significantly fewer correct responses in both VF tasks in comparison to the control group. The type of task significantly affected performance and both groups showed higher word generativity on the Semantic task. The groups did not differ in clustering, switching, and errors. Age significantly correlated with the VF indicators in the ASD group, but in the control group, there was a significant negative correlation with the number of errors. Non-verbal and verbal IQ did not correlate with any VF indicators in both groups, while ASD severity and ADHD symptomatology correlated positively and significantly with error responses in the ASD group. The Slow-Retrieval Model explains VF difficulties in the HF-ASD group indicating that poorer word generativity can be attributed to slower retrieval of words from the semantic network.

An Investigation of Working Memory Profile and Fluid Intelligence in Children With Neurodevelopmental Difficulties.

The present study aims to evaluate the distinct patterns of working memory (WM) capacity of children with Developmental Language Disorder (DLD), High-functioning children with Autism Spectrum Disorder (ASD) and children with Down syndrome (DS). More specifically, the current study investigates the complex relationship of fluid intelligence and WM between 39 children with DLD, 20 H igh-functioning children with ASD, and 15 children with DS. All children were evaluated in different measures of Phonological Working Memory, Visual-spatial Working Memory whereas Fluid Intelligence was measured with Raven Progressive Matrices. The result analysis revealed a significant difference among the three groups, both among each function separately and the correlations among them, as well. The results revealed that the DLD groups and High-functioning ASD group exhibited a common picture or an overlap of performances in all Phonological and Visuo-spatial working memory measures, except Backward Digit Recall task. As for the DS group research findings revealed different and unique working memory patterns in comparison to DLD group and High-functioning ASD. Their differences have been studied and further conclusions have been drawn about the different patterns of working memory among the three clinical groups. The implications of these findings are discussed in light of support for learning. The common profile that characterize the two developmental conditions and the distinct pattern of working memory performance in DS group underlies the need for further research in the field.

Neural Biomarkers Distinguish Severe From Mild Autism Spectrum Disorder Among High-Functioning Individuals

Several previous studies have reported atypicality in resting-state functional connectivity (FC) in autism spectrum disorder (ASD), yet the relatively small effect sizes prevent us from using these characteristics for diagnostic purposes. Here, canonical correlation analysis (CCA) and hierarchical clustering were used to partition the high-functioning ASD group (i.e., the ASD discovery group) into subgroups. A support vector machine (SVM) model was trained through the 10-fold strategy to predict Autism Diagnostic Observation Schedule (ADOS) scores within the ASD discovery group (r = 0.30, P < 0.001, n = 260), which was further validated in an independent sample (i.e., the ASD validation group) (r = 0.35, P = 0.031, n = 29). The neuroimage-based partition derived two subgroups representing severe versus mild autistic patients. We identified FCs that show graded changes in strength from ASD-severe, through ASD-mild, to controls, while the same pattern cannot be observed in partitions based on ADOS score. We also identified FCs that are specific for ASD-mild, similar to a partition based on ADOS score. The current study provided multiple pieces of evidence with replication to show that resting-state functional magnetic resonance imaging (rsfMRI) FCs could serve as neural biomarkers in partitioning high-functioning autistic individuals based on their symptom severity and showing advantages over traditional partition based on ADOS score. Our results also indicate a compensatory role for a frontocortical network in patients with mild ASD, indicating potential targets for future clinical treatments.

Neuropsychiatric Symptoms, Parenting Stress and Social Support in Chinese Mothers of Children with Autism Spectrum Disorder.

Although little is known about the current situation regarding autism spectrum disorder (ASD) in mainland China, psychiatric disorders are common among Chinese mothers of preschool children with ASD. Previous studies showed ASD child's behavioral symptoms, maternal anxiety, and maternal depressive symptoms were associated with overall parenting stress in northern China. In the present study, we retrospectively analyzed medical records at the hospital related to neuropsychiatric symptoms, parenting stress and social support in mothers of children with ASD from southern China. A total of 80 mothers of children with ASD were screened. Among them, 34 mothers were in low-functioning ASD group (L-ASD group) and 46 mothers were in high-functioning ASD group (H-ASD group). Identification of the ASD cases was confirmed with a Revised Autism Diagnostic Inventory. Neuropsychiatric symptoms, parenting stress and social support were measured by neuropsychiatric inventory (NPI), parenting stress index short form (PSI-SF), and multi-dimensional scale of perceived social support (MSPSS). Total mean score of the NPI in the L-ASD group was significantly higher than that in the H-ASD group (P<0.01). The subscale scores of NPI, including depression, anxiety, apathy, irritability, agitation, night time behavior disturbances and change in appetite were significantly higher in the L-ASD group than those in the H-ASD group (P<0.01 or P<0.05). Meanwhile, the total PSI-SF scores and the scores of parental distress (PD), parental-child dysfunctional interaction (PCDI) and difficult child (DC) in the L-ASD group were significantly higher than those in the H-ASD group (P<0.01 or P<0.05). The total score of MSPSS was also higher in the L-ASD group than in the H-ASD group (P<0.01). This study goes further to show the neuropsychiatric symptoms and parenting stress are significantly higher in mothers of children with ASD, and more social supports are needed for mothers of children with ASD from southern China, especially for mothers of children with low-functioning ASD.

Disrupted Cerebrocerebellar Intrinsic Functional Connectivity in Young Adults with High-Functioning Autism Spectrum Disorder: A Data-Driven, Whole-Brain, High-Temporal Resolution Functional Magnetic Resonance Imaging Study.

This study examines the resting-state functional-connectivity (RsFc) in young adults with high-functioning autism spectrum disorder (HF-ASD) using state-of-the-art fMRI data acquisition and analysis techniques. High temporal resolution fMRI using simultaneous multi-slice acquisition aided unbiased whole-brain connectome-wide multivariate pattern analysis (MVPA) techniques for assessing RsFc. MVPA revealed two clusters (Crus I/II and lobule IX) of abnormal connectivity in the cerebellum that are consistent with the notion of a triple representation of nonmotor processing in the cerebellum. Whole-brain seed-based RsFc analyses informed by these clusters showed significant under connectivity between the cerebellar and social, emotional, and language brain regions in the HF-ASD group compared to healthy controls. The results we report are coherent with existing structural, functional, and RsFc literature in autism, extend previous literature reporting cerebellar abnormalities in the neuropathology of autism, and highlight the cerebellum as a potential target for therapeutic, diagnostic, predictive, and prognostic developments in HF-ASD. The description of functional connectivity abnormalities reported in this study using whole-brain, data-driven analyses has the potential to crucially advance the development of ASD biomarkers, targets for therapeutic interventions, and neural predictors for measuring treatment response.

Exploring the relationship between fairness and ‘brain types’ in children with high-functioning autism spectrum disorder

BackgroundExisting research typically focuses on only one domain of cognition with regard to fairness—theory of mind or executive function. However, children with High-functioning autism spectrum disorder (HF-ASD) are cognitively impaired in both domains. Moreover, little is known about fairness characteristics in children with HF-ASD in relation to both domains of cognition. MethodsThirty children with HF-ASD as well as 39 children with typical development (TD) were evaluated in this study. We investigated the development of children's fairness characteristics as a responder in a mini ultimatum game (UG). The different ‘brain types,’ i.e., with or without HF-ASD, were evaluated using the Empathy Questionnaire-Systemizing Questionnaire (E/SC-Q). Furthermore, we explored the relationship between fairness and brain types using Pearson correlation analyses. ResultsChildren in the HF-ASD group were more likely to accept unfair offers than were children in the TD group (χ2 = 17.513, p = .025). In the HF-ASD group, the acceptance rate of unfair offers was correlated with the discrepancy score (r = 0.363, p = .048), while there were no significant correlations in the TD group. In HF-ASD group, compared with Type S, acceptance rate of unfair offer was significant higher in Extreme Type S ‘brain type’ (F = 28.584, p < .001). While dividing TD participants by ‘brain type’, there was no significant difference in acceptance rate of unfair offer among five difference ‘brain types’ (F = 1.131, p = .358). Stepwise regression revealed that Extreme Type S positively predicted acceptance of unfair offers (F [1, 68] = 8.695, p < .001). DiscussionOur findings show that children with HF-ASD were more likely to accept an unfair offer; in particular, the more unbalanced the development of empathy and systemizing was, the more significant the unfairness preference observed. Extreme Type S positively predicted the acceptance of unfair offers by children with HF-ASD. Registration of clinical trialsWorld Health Organization class I registered international clinical trial platform, ChiCTR-ROC-17012877.

A Fiber Tractography Study of Social-Emotional Related Fiber Tracts in Children and Adolescents with Autism Spectrum Disorder.

The symptoms of autism spectrum disorder (ASD) have been hypothesized to be caused by changes in brain connectivity. From the clinical perspective, the "disconnectivity" hypothesis has been used to explain characteristic impairments in "socio-emotional" function. Therefore, in this study we compared the facial emotional recognition (FER) feature and the integrity of social-emotional-related white-matter tracts between children and adolescents with high-functioning ASD (HFA) and their typically developing (TD) counterparts. The correlation between the two factors was explored to find out if impairment of the white-matter tracts is the neural basis of social-emotional disorders. Compared with the TD group, FER was significantly impaired and the fractional anisotropy value of the right cingulate fasciculus was increased in the HFA group (P<0.01). In conclusion, the FER function of children and adolescents with HFA was impaired and the microstructure of the cingulate fasciculus had abnormalities.

Social Cognition in Children with High-Functioning Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder. Associations with Executive Functions.

Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are neurodevelopmental disorders characterized by social impairments. The first objective of this study was to analyze social cognition deficits of children with ADHD, high-functioning ASD (HFASD), and typical development (TD) in their performance on explicit and applied measures of theory of mind (ToM). The second objective was to investigate the relationships between executive functions and social cognition in HFASD and ADHD. One hundred and twenty-six 7- to 11-year old children, 52 with HFASD, 35 with ADHD, and 39 with TD, performed the NEPSY-II social perception subtests. Parents estimated their children's ToM skills using the Theory of Mind Inventory (ToMI). Teacher-reported data from the Behavior Rating Inventory of Executive Function (BRIEF) were also obtained. The HFASD and ADHD groups showed worse performance on the verbal ToM task than the TD group, and only the performance of the HFASD group was significantly lower than the TD group on the contextual ToM task. Parents also estimated that the HFASD group had more difficulties on the applied ToM than the ADHD and TD groups. Furthermore, there is a different executive function-theory of mind link in the HFASD and ADHD groups: behavioral regulation processes such as inhibition and emotional control are more associated with social cognition in children with ADHD, whereas metacognitive processes such as initiation and planning have a strong association with social cognition in children with HFASD. These findings have implications for understanding social perception deficits in neurodevelopmental disorders, highlighting the need for early intervention.

Intelligence profiles of Chinese school-aged boys with high-functioning ASD and ADHD

PurposeThis study aimed to explore the intelligence profiles of Chinese school-aged boys with high-functioning autism spectrum disorder (HFASD) and attention-deficit/hyperactivity disorder (ADHD). Additionally, differences in intelligence quotient (IQ) between the HFASD group and the ADHD group were examined.Patients and methodsThirty-two boys with HFASD, 58 boys with ADHD, and 39 typically developing (TD) boys aged 6–16 years participated in this study. The ADHD group was divided into subgroups: ADHD-I (predominantly inattentive) and ADHD-C (combined type). (The ADHD-H [hyperactive] group was excluded because of small sample size). The Wechsler Intelligence Scale for Children-IV Chinese version was administered to every participant, and the FSIQ (Full-Scale IQ) score was used as the measure of IQ.ResultsBoth boys with HFASD and ADHD (ADHD-I and ADHD-C) showed impairments in Processing Speed Index and FSIQ, as compared to the TD group. Lower Verbal Comprehension Index scores were found in the ASD and ADHD-I groups. Interestingly, Working Memory Index was only impaired in children with ADHD. Additionally, equivalent Perceptual Reasoning Index (PRI) scores were found among the HFASD, ADHD, and TD groups.ConclusionResults indicated that both children with ADHD and HFASD have difficulty in processing speed, which may be explained by these children having neurodevelopmental disorders. These results also indicated that working memory appears to only be impacted by having ADHD. Children with ASD are known to have language difficulties while children with ADHD typically display working memory deficits; thus, these findings were expected.

Eye-tracking study on facial emotion recognition tasks in individuals with high-functioning autism spectrum disorders

The eye-tracking experiment was carried out to assess fixation duration and scan paths that individuals with and without high-functioning autism spectrum disorders employed when identifying simple and complex emotions. Participants viewed human photos of facial expressions and decided on the identification of emotion, the negative-positive emotion orientation, and the degree of emotion intensity. Results showed that there was an atypical emotional processing in the high-functioning autism spectrum disorder group to identify facial emotions when eye-tracking data were compared between groups. We suggest that the high-functioning autism spectrum disorder group prefers to use a rule-bound categorical approach as well as featured processing strategy in the facial emotion recognition tasks. Therefore, the high-functioning autism spectrum disorder group more readily distinguishes overt emotions such as happiness and sadness. However, they perform more inconsistently in covert emotions such as disgust and angry, which demand more cognitive strategy employment during emotional perception. Their fixation time in eye-tracking data demonstrated a significant difference from that of their controls when judging complex emotions, showing reduced "in" gazes and increased "out" gazes. The data were in compliance with the findings in their emotion intensity ratings which showed individuals with autism spectrum disorder misjudge the intensity of complex emotions especially the emotion of fear.

Name recognition in autism: EEG evidence of altered patterns of brain activity and connectivity.

BackgroundImpaired orienting to social stimuli is one of the core early symptoms of autism spectrum disorder (ASD). However, in contrast to faces, name processing has rarely been studied in individuals with ASD. Here, we investigated brain activity and functional connectivity associated with recognition of names in the high-functioning ASD group and in the control group.MethodsEEG was recorded in 15 young males with ASD and 15 matched one-to-one control individuals. EEG data were analyzed with the event-related potential (ERP), event-related desynchronization and event-related synchronization (ERD/S), as well as coherence and direct transfer function (DTF) methods. Four categories of names were presented visually: one’s own, close-other’s, famous, and unknown.ResultsDifferences between the ASD and control groups were found for ERP, coherence, and DTF. In individuals with ASD, P300 (a positive ERP component) to own-name and to a close-other’s name were similar whereas in control participants, P300 to own-name was enhanced when compared to all other names. Analysis of coherence and DTF revealed disruption of fronto-posterior task-related connectivity in individuals with ASD within the beta range frequencies. Moreover, DTF indicated the directionality of those impaired connections—they were going from parieto-occipital to frontal regions. DTF also showed inter-group differences in short-range connectivity: weaker connections within the frontal region and stronger connections within the occipital region in the ASD group in comparison to the control group.ConclusionsOur findings suggest a lack of the self-preference effect and impaired functioning of the attentional network during recognition of visually presented names in individuals with ASD.Electronic supplementary materialThe online version of this article (doi:10.1186/s13229-016-0102-z) contains supplementary material, which is available to authorized users.

Self-regulation and quality of life in high-functioning young adults with autism.

Background: Autism is generally associated with poor functional outcome but little is known about predictors of quality of life, especially during early adulthood. This study was conducted to assess subjective quality of life during early adulthood in high-functioning autism spectrum disorder and its relation with self-regulating abilities. Individuals with high-functioning autism spectrum disorder who progressed into post-secondary higher education (N = 75) were compared to a typical peer control group (N = 28) based on behavioral self-report questionnaires. The results indicated that individuals with high-functioning autism spectrum disorder reported significantly lower subjective quality of life than typical controls (p < 0.001, effect size (d) = 1.84). In addition, individuals with high-functioning autism spectrum disorder reported more problems with emotion processing (p < 0.05, effect size (d) = 0.79) and daily executive functioning (p < 0.001, effect size (d) = 1.29) than controls. A higher level of executive functioning problems was related to lower quality of life in the high-functioning autism spectrum disorder group, but no significant relation between level of emotion processing and subjective quality of life became apparent in the regression analysis. Our findings show that even in high-functioning young adults with autism, executive functioning, emotion processing, and subjective quality of life are low compared to typically developing peers. Furthermore, these results emphasize the importance of targeting executive functioning problems in individuals with autism to improve subjective quality of life.

Temporal voice areas exist in autism spectrum disorder but are dysfunctional for voice identity recognition.

The ability to recognise the identity of others is a key requirement for successful communication. Brain regions that respond selectively to voices exist in humans from early infancy on. Currently, it is unclear whether dysfunction of these voice-sensitive regions can explain voice identity recognition impairments. Here, we used two independent functional magnetic resonance imaging studies to investigate voice processing in a population that has been reported to have no voice-sensitive regions: autism spectrum disorder (ASD). Our results refute the earlier report that individuals with ASD have no responses in voice-sensitive regions: Passive listening to vocal, compared to non-vocal, sounds elicited typical responses in voice-sensitive regions in the high-functioning ASD group and controls. In contrast, the ASD group had a dysfunction in voice-sensitive regions during voice identity but not speech recognition in the right posterior superior temporal sulcus/gyrus (STS/STG)—a region implicated in processing complex spectrotemporal voice features and unfamiliar voices. The right anterior STS/STG correlated with voice identity recognition performance in controls but not in the ASD group. The findings suggest that right STS/STG dysfunction is critical for explaining voice recognition impairments in high-functioning ASD and show that ASD is not characterised by a general lack of voice-sensitive responses.

Decreased Modulation of EEG Oscillations in High-Functioning Autism during a Motor Control Task.

Autism spectrum disorders (ASD) are thought to result in part from altered cortical excitatory-inhibitory balance; this pathophysiology may impact the generation of oscillations on electroencephalogram (EEG). We investigated premotor-parietal cortical physiology associated with praxis, which has strong theoretical and empirical associations with ASD symptomatology. Twenty five children with high-functioning ASD (HFA) and 33 controls performed a praxis task involving the pantomiming of tool use, while EEG was recorded. We assessed task-related modulation of signal power in alpha and beta frequency bands. Compared with controls, subjects with HFA showed 27% less left central (motor/premotor) beta (18–22 Hz) event-related desynchronization (ERD; p = 0.030), as well as 24% less left parietal alpha (7–13 Hz) ERD (p = 0.046). Within the HFA group, blunting of central ERD attenuation was associated with impairments in clinical measures of praxis imitation (r = −0.4; p = 0.04) and increased autism severity (r = 0.48; p = 0.016). The modulation of central beta activity is associated, among other things, with motor imagery, which may be necessary for imitation. Impaired imitation has been associated with core features of ASD. Altered modulation of oscillatory activity may be mechanistically involved in those aspects of motor network function that relate to the core symptoms of ASD.

A Psychometric Evaluation of the Danish Version of the Theory of Mind Storybook for 8-14 Year-Old Children.

Background: Theory-of-Mind (ToM) keeps on developing in late childhood and early adolescence, and the study of ToM development later in childhood had to await the development of sufficiently sensitive tests challenging more mature children. The current study aimed to investigate the psychometric properties of the Danish version of the Theory-of-Mind Storybook Frederik (ToM-Frederik).Methods: We assessed whether ToM-Frederik scores differed between a group of 41 typically developing (TD) children and a group of 33 children with High Functioning Autism Spectrum Disorder (HFASD). A lower mean ToM-Frederik score was expected in the HFASD group. To determine the convergent validity of ToM-Frederik, potential associations with Strange Stories and Animated Triangles (AT) were analyzed. Furthermore, potential associations between ToM-Frederik and the Social Responsiveness Scale (SRS) and between ToM-Frederik and the Social Emotional Evaluation (SEE) Total score were analyzed.Results: A significantly higher ToM-Frederik score was observed in the TD group compared to the HFASD group. Furthermore, the convergent validity of ToM-Frederik as a measure of ToM was supported by significant and positive associations with the Strange Stories and the AT scores in the HFASD group, whereas ToM-Frederik was significantly correlated with Strange Stories, but not with AT in the TD group. ToM-Frederik was not significantly associated with SRS in neither the HFASD nor the TD group.Conclusion: The findings are supportive of ToM-Frederik as a valid indicator of deficits at the group level in children with HFASD between 7 and 14 years of age. Furthermore, the convergent validity is supported.

Full-field electroretinogram in autism spectrum disorder.

To explore early findings that individuals with autism spectrum disorder (ASD) have reduced scotopic ERG b-wave amplitudes. Light-adapted (LA) and dark-adapted (DA) ERGs were produced by a range of flash strengths that included and extended the ISCEV standard from two subject groups: a high-functioning ASD group N = 11 and a Control group N = 15 for DA and N = 14 for LA ERGs who were matched for mean age and range. Flash strengths ranged from DA -4.0 to 2.3 log phot cd s m(-2) and LA -0.5 to 1.0 log phot cd s m(-2), and Naka-Rushton curves were fitted to DA b-wave amplitude over the first growth limb (-4.0 to -1.0 log phot cd s m(-2)). The derived parameters (V max, K m and n) were compared between groups. Scotopic 15-Hz flicker ERGs (14.93 Hz) were recorded to 10 flash strengths presented in ascending order from -3.0 to 0.5 log Td s to assess the slow and fast rod pathways, respectively. LA 30-Hz flicker ERGs, oscillatory potentials (OPs) and the responses to prolonged 120-ms ON-OFF stimuli were also recorded. The ISCEV LA b-wave amplitude produced by 0.5 log phot cd s m(-2) was lower in the ASD group (p < 0.001). Repeated measures ANOVA for the LA b-wave amplitude series forming the photopic hill was significantly (p = 0.01) different between groups. No group differences were observed for the distributions of the time to peaks of LA a-wave, b-wave or the photopic negative responses (phNR) (p > 0.08) to the single flash stimuli, but there was a significant difference in the distribution for the LA b-wave amplitudes (corrected p = 0.006). The prolonged 120-ms ON responses were smaller in the ASD group (corrected p = 0.003), but the OFF response amplitude (p > 0.6) and ON and OFF times to peaks (p > 0.4) were similar between groups. The LA OPs showed an earlier bifurcation of OP2 in the younger ASD participants; however, no other differences were apparent in the OPs or 30-Hz flicker waveforms. DA b-wave amplitudes fell below the control 5th centile of the controls for some individuals including four ASD participants (36 %) at the 1.5 log phot cd s m(-2) flash strength and two (18%) ASD participants at the lower -2 log phot cd s m(-2) flash strength. However, across the 13 flash strengths, there were no significant group differences for b-wave amplitude's growth (repeated measures ANOVA p = 0.83). Nor were there any significant differences between the groups for the Naka-Rushton parameters (p > 0.09). No group differences were observed in the 15-Hz scotopic flicker phase or amplitude (p > 0.1), DA ERG a-wave amplitude or time to peak (p > 26). The DA b-wave time to peak at 0.5 log phot cd s m(-2) was longer in the ASD group (p = 0.04). Under LA conditions, the b-wave is reduced across the ASD group, along with the ON response of the prolonged flash ERG. Some ASD individuals also show subnormal DA ERG b-wave amplitudes. These exploratory findings suggest there is altered cone-ON bipolar signalling in ASD.

Biological motion and the animate–inanimate distinction in children with high-functioning Autism Spectrum Disorder

The current study examined whether children with high-functioning Autism Spectrum Disorder (HF-ASD) preferentially attend to point-light displays of biological, compared to mechanical motion. We hypothesized that children’s attentional patterns toward the motion of living things would be reduced compared to typically developing (TD) children. Children also completed two categorization tasks measuring the animate–inanimate distinction. Children with HF-ASD were matched with TD children (n=18 per group) on age, gender, and verbal ability. Overall, children with HF-ASD attended to biological and non-biological motion equally, whereas TD children demonstrated a preference for inanimate motion. Children with HF-ASD were also unimpaired in the formation of animate and inanimate concepts. Among children with HF-ASD, a link between attention to motion and categorization ability was observed, but only for inanimate objects. TD and HF-ASD groups differed in that visual exploration of the motion videos (e.g., saccades) was related to animate–inanimate categorization only among children with HF-ASD. These results are discussed as a low-level test of the social attention/orienting hypothesis.

Nasal voice in boys with high-functioning autism spectrum disorder

This study compared speech samples of 29 boys aged 6–13 with high-functioning autism spectrum disorder (HFASD) to those of 29 typically developing (TD) boys matched on age and ethnicity. Ten listeners blind to speakers’ diagnoses rated speech samples for nasality and reported their perceptions of the speaker on a 6-point Likert-type scale. Results indicated significantly greater listener-perceived nasality in the HFASD than the TD group. Listeners rated the HFASD group significantly higher than the TD group on negative socially relevant adjectives, a finding which was mediated by nasality. In addition, compared to TD speakers, speakers with HFASD were rated lower on dominance and perceived age, as well as higher on perceived disability.