Non-verbal IQ and change in restricted and repetitive behavior throughout childhood in autism: a longitudinal study using the Autism Diagnostic Interview-Revised

Background Restricted and repetitive behavior (RRB) is one of the characteristic features of Autism Spectrum Disorder. This domain of symptoms includes a broad range of behaviors. There is a need to study each behavior individually to better understand the role of each in the development of autistic children. Moreover, there are currently no longitudinal studies investigating change in these behaviors over development. Methods The goal of the present study was to explore the association between age and non-verbal IQ (NVIQ) on 15 RRB symptoms included in the Autism Diagnostic Interview-Revised (ADI-R) over time. A total of 205 children with ASD were assessed using the ADI-R at time of diagnosis, at age 6 years, and at age 11 years, and with the Wechsler Intelligence Scales for Children—Fourth Edition (WISC-IV) at age 8 years. Results The proportion of children showing each RRB tended to diminish with increasing age, except for sensitivity to noise and circumscribed interests, where the proportion increased over time. Although there was no significant main effect of NVIQ, there was a significant interaction between age and NVIQ. This was mainly driven by Difficulties with change in routine, for which higher NVIQ was associated with the behavior remaining relatively stable with age, while lower NVIQ was associated with the behavior becoming more prevalent with age. Limitations The study focused on the presence/absence of each RRB but did not account for potential changes in frequency or severity of the behaviors over development. Furthermore, some limitations are inherent to the measures used. The ADI-R relies on parent report and hence has some level of subjectivity, while the Wechsler intelligence scales can underestimate the intellectual abilities of some autistic children. Conclusions These results confirm that specific RRB are differentially linked to age and NVIQ. Studying RRB individually is a promising approach to better understanding how RRB change over the development of autistic children and are linked to other developmental domains.

#3085 Relationship between variant connective tissue (hypermobility) and autism sensory processing: externally oriented thinking as a mediator

Objectives/AimsAutism is a neurodevelopmental condition characterised by differences in sensory processing, social communication and restricted/repetitive behaviors. Joint hypermobility is a common connective tissue variant, reportedly overrepresented in Autism. Alexithymia is a personality construct characterised by altered emotional awareness which has notably high rates of overlap with autism spectrum disorder. This study tested whether hypermobility was associated with autistic traits and examined alexithymia as a mediator of this association.MethodForty-two people underwent eligibility assessment for a study of joint hypermobility and anxiety (ISRCTN17018615). Hypermobility was assessed using both the Brighton Criteria for Joint Hypermobilty Syndrome (JHS) and 2017 Hypermobile Ehlers Danlos Syndrome (hEDS) Criteria. Participants completed the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS R: sensory/motor, language, social relatedness and circumscribed interest domains) to quantify autistic traits. No participant had a prior diagnosis of Autism. Participants also completed the Toronto Alexithymia Scale (TAS-20) to measure alexithymia. The TAS-20 has three domains: difficulty describing feelings, difficulty identifying feelings and externally oriented thinking.ResultsAll 42 participants met criteria for JHS, 26 participants also met criteria for hEDS. Strikingly, 22/42 (52.4%) scored above threshold for suspected Autism (26/42 in the sensory/motor domain; 22/42 in language domain; 22/42 in social relatedness domain; 17/42 in circumscribed interests domain). There were no significant differences in RAADS-R scores depending on hypermobility diagnosis. The number of connective tissue features (hEDS Criterion 2A) correlated with RAADS-R sensory/motor score (r = 0.418, p = 0.006) but not social relatedness nor circumscribed interests sub-scores. Full mediation of the relationship between the number of connective tissue features and RAADs sensory/motor score by TAS-20 externally oriented thinking was found using the method of Baron-Kenny (1986) and estimation of indirect effects (Hayes, 2018; bootstrapped confidence intervals (n = 5000, do not cross zero)). Difficulty identifying feelings and difficulty describing feelings domains did not mediate this relationship.ConclusionThese results add to evidence linking variant connective tissue to neurodevelopmental conditions (including Autism) and interestingly, specifically to sensory processing differences. Our study provides a strong rationale for screening for neurodevelopmental conditions in people with hypermobility and motivates further to understand symptom expression in this group. Our results also provide an insight into the processes underlying this relationship, which maybe important for informing interventions for people with hypermobility and autistic traits.

Attention capture by trains and faces in children with and without autism spectrum disorder

This study examined involuntary capture of attention, overt attention, and stimulus valence and arousal ratings, all factors that can contribute to potential attentional biases to face and train objects in children with and without autism spectrum disorder (ASD). In the visual domain, faces are particularly captivating, and are thought to have a ‘special status’ in the attentional system. Research suggests that similar attentional biases may exist for other objects of expertise (e.g. birds for bird experts), providing support for the role of exposure in attention prioritization. Autistic individuals often have circumscribed interests around certain classes of objects, such as trains, that are related to vehicles and mechanical systems. This research aimed to determine whether this propensity in autistic individuals leads to stronger attention capture by trains, and perhaps weaker attention capture by faces, than what would be expected in non-autistic children. In Experiment 1, autistic children (6–14 years old) and age- and IQ-matched non-autistic children performed a visual search task where they manually indicated whether a target butterfly appeared amongst an array of face, train, and neutral distractors while their eye-movements were tracked. Autistic children were no less susceptible to attention capture by faces than non-autistic children. Overall, for both groups, trains captured attention more strongly than face stimuli and, trains had a larger effect on overt attention to the target stimuli, relative to face distractors. In Experiment 2, a new group of children (autistic and non-autistic) rated train stimuli as more interesting and exciting than the face stimuli, with no differences between groups. These results suggest that: (1) other objects (trains) can capture attention in a similar manner as faces, in both autistic and non-autistic children (2) attention capture is driven partly by voluntary attentional processes related to personal interest or affective responses to the stimuli.

Visual preference for social vs. non-social images in young children with autism spectrum disorders. An eye tracking study

Autism Spectrum Disorders (ASD) are associated to social attention (SA) impairments. A gaze bias to non-social objects over faces has been proposed as an early marker of ASD. This bias may be related to the concomitant circumscribed interests (CI), which question the role of competing objects in this atypical visual behavior. The aim of this study was to compare visual attention patterns to social and non-social images in young children with ASD and matched typical controls (N = 36; age range 41–73 months) assessing the role of emotion in facial stimuli and the type of competing object. A paired preference task was designed pairing happy, angry, and neutral faces with two types of objects (related or not related to autism CI). Eye tracking data were collected, and three indexes were considered as dependent variables: prioritization (attentional orientation), preference, and duration (sustained attention). Results showed that both groups had similar visual pattern to faces (prioritization, more attention and longer visits to faces paired with objects non-related to their CI); however, the ASD group attended to faces significantly less than controls. Children with ASD showed an emotional bias (late orientation to angry faces and typical preference for happy faces). Finally, objects related to their CI captured attention in both groups, significantly reducing SA in children with ASD. Atypical SA is present in young children with ASD regardless the competing non-social object. Identifying strengths and difficulties in SA in this population may have substantial repercussion for early diagnosis, intervention, and ultimately prognosis.

Non-verbal IQ and change in restricted and repetitive behaviors throughout childhood in autism: A longitudinal study using the Autism Diagnostic Interview-Revised.

Background: Restricted and repetitive behaviors are one of the characteristic features of Autism Spectrum Disorder. This domain of symptoms includes a broad range of behaviors. There is a need to study each behavior individually to better understand the role they each have in the development of autistic children. Moreover, there are currently no longitudinal studies investigating change in these behaviors over development. Methods: The goal of the present study was to explore the association between age and non-verbal IQ (NVIQ) on 15 RRB symptoms included in the Autism Diagnostic Interview-Revised (ADI-R) over time. A total of 205 children with ASD were assessed using the ADI-R at time of diagnosis, at age 6 years, and at age 11 years, and with the addition of the Wechsler Intelligence Scales for Children – Fourth Edition (WISC-IV) at age 8 years.Results: The proportion of children showing each RRB tended to diminish with increasing age (p < 0.001), except for sensitivity to noise and circumscribed interests, where the proportion increased over time. Although there was no significant main effect of NVIQ (p = 0.101), there was a significant interaction between age and NVIQ (p < 0.01). This was mainly driven by Difficulties with change in routine, for which higher NVIQ was associated with the prevalence of the behavior remaining relatively stable with age, while lower NVIQ was associated with the behavior becoming more prevalent with age.Limitations: The study focused on the presence/absence of each RRB but did not account for potential changes in frequency or severity of the behaviors over development. Furthermore, some limitations are inherent to the measures used. The ADI-R relies on parent-report and hence has some level of subjectivity, while the Wechsler intelligence scales can underestimate the intellectual abilities of some autistic children.Conclusions: These results confirm that specific RRBs are differentially linked to age and NVIQ. Studying RRBs individually is a promising approach to better understand how RRBs change over the development of autistic children and are linked to other developmental domains.

Circumscribed interests in autism: are there sex differences?

Purpose Sex differences in circumscribed interests (CI) may delay diagnosis for females with autism spectrum disorder (ASD); therefore, it is important to characterize sex differences in CI to determine if differential approaches to diagnostic assessment are warranted for females with ASD. The purpose of this paper is to examine sex differences in parent-reported quantity, content and functional impairment of children’s interests. Design/methodology/approach Parent responses to the Interests Scale were analyzed using descriptive statistics and ANOVAs to determine diagnostic (ASD vs typical development (TD)) and sex differences between four groups of children ages six to ten years: ASD males, ASD females, TD males and TD females. Findings Groups were comparable on the quantity of interests reported on the Interests Scale. Children with ASD demonstrated significantly more nonsocial interests and had greater functional impairment associated with their interests than TD children. A significant diagnosis×sex effect was found for the number of interests in folk psychology. Descriptively, males with ASD were more likely to have a primary interest in the traditionally male category of physics than females with ASD whose primary interest mainly fell into the categories of TV or the more traditionally female category of psychology. Originality/value These findings strengthen the results of Turner-Brown et al. (2011) by replicating their findings that children with ASD have more nonsocial interests and greater functional impairments related to their interests compared to TD children in a sample that is balanced on biological sex. However, there are distinctions between males and females with ASD in their primary interests that have implications for diagnostic assessment.