Difficulty of crossmodal processing in individuals with autism spectrum disorders: An audio-visual gap/overlap paradigm study

Evidence suggests that individuals with autism spectrum disorders (ASD) exhibit difficulty in integrating crossmodal information. However, few previous studies have investigated crossmodal attention switching in individuals with ASD. The present study investigates whether children with ASD have difficulty in crossmodal processing across auditory and visual modalities. For this study, we observed 10 children with ASD and 11 IQ-, age-, and gender-matched, healthy, control children. We used a modified gap/overlap task that required the simultaneous allocation of attention to auditory and visual stimuli (audio-visual gap/overlap task). In addition, the visual-only gap/overlap task used a classical gap/overlap procedure. In the visual-only gap/overlap task, children with ASD exhibited the same performance as control children. In contrast, in the audio-visual condition, children with ASD were significantly slower to respond than control children in both the gap and overlap tasks. In addition, the gap effects between the ASD and control groups were observed in each condition, but no significant group differences were observed. These results suggest that children with ASD exhibit difficulty in simultaneously allocating attentional resources to auditory and visual modalities although children with ASD are intact in disengagement of attention. These findings provide important insights regarding crossmodal processing in ASD.