Being the Subject of Another's Attention; Differences in Skin Conductance Levels in Children with High-Functioning Autism and Asperger Syndrome

Background: Children with autism spectrum disorder (ASD) show hyper-arousal to direct eye contact (Kylliäinen and Hietanen, 2006). Increased level of arousal may in part explain why avoidance of the eye region is common in some children with ASD. Whilst eye contact in itself may not be arousing to typically developing individuals, being the object of another person’s attention is. This is may induce greater levels of self awareness in typically developing adults (Hietanen et al., 2008). Some children with ASD avoid contact with others although it is not known whether such contact is associated with low or high levels of arousal. Low levels of arousal to others in early infancy may result in the child with autism paying less attention to others and also have a detrimental effect on early language development.

Objectives: This study investigated whether children with an ASD displayed similar patterns of arousal to typical controls when the subject of another’s direct attention. It further examined the scores of children with a diagnosis of high-functioning autism (HFA) and Asperger Syndrome (AS) on the same measure and investigated possible associations between these scores and measures of language ability.

Methods: 30 children with ASD and 18 typical controls took part in the study. The ASD group were further analysed by dividing the group into HFA (11) and AS (13) categories based on language onset criteria. Galvanic skin conductance measures were used to record arousal in children during a 10 second viewing of a face looking directly at them or a face looking toward another face and away from the participant. Measures on the Vineland Adaptive Behaviour Scale and the British Picture Vocabulary Scale were used to study associations between language and arousal measures.

Results: Overall skin conductance responses (SCR) were higher for typical controls than for the ASD group. Similarly the AS group also showed significantly higher SCRs than the HFA group. Both the control and the AS group demonstrated higher SCRs when they were the object of another’s attention although this was not significant for the control group. In contrast, the HFA displayed no difference in SCRs between these two conditions. Correlational analysis demonstrated a trend towards higher SCRs being associated with better language skills.

Conclusions: The study suggests that, when compared to typical controls, children with ASD demonstrate hypo-arousal when they are the subject of another’s attention. Further, children with HFA demonstrate similarly low levels of arousal whether they are the object of another’s attention or not. In contrast, the AS group displayed similar patterns of arousal to the control group. It is suggested that normative levels of arousal may be an important mechanism of early joint attention in children with ASD and may play a role in the language onset differences displayed in children with AS and HFA.