A review of behavioural evidence for hemispheric asymmetry of visuospatial attention in autism

Most individuals show a small bias towards visual stimuli presented in their left visual field (LVF) that reflects right-hemispheric specialisation of visuospatial functions. Moreover, this bias is altered by some neurodevelopmental disorders, suggesting they may be linked to changes in hemispheric asymmetry. To examine whether autism potentially alters hemispheric asymmetry, we conducted a systematic search of scientific databases to review existing literature on the link between autism and alterations in visuospatial bias. This search identified 13 publications that had explored this issue using a wide range of experimental designs and stimuli. Evidence of reduced LVF bias associated with autism was most consistent for studies examining attentional bias or preference measured using tasks such as line bisection. Findings for studies examining attentional performance (e.g., reaction time) were more equivocal. Further investigation is called for, and we make several recommendations for how this avenue of research can be extended.