Anxiety-mediated neural response to fear enhances sensory hyperresponsiveness in autism spectrum disorders

The atypical sensory features in individuals with autism spectrum disorder (ASD) and the high comorbidity of anxiety disorders are gaining attention. Individuals with ASD who have enhanced sensory hyperresponsiveness exhibit heightened temporal processing of sensory stimuli. Emotion-related cues modulate cognitive task performance, including timing. This study included 25 participants with ASD and 25 typically developed (TD) participants and used functional magnetic resonance imaging (fMRI) to investigate neural activation during visual temporal order judgments and the effect of facial image presentation on the task. The TD group improved stimulus temporal processing under the fear face condition but the ASD group did not. However, in individuals with ASD, we found a correlation between anxiety level and the emotion-related effect on the performance, as well as sensory hyperresponsiveness. The neural correlate of the effect revealed greater activation of the right caudate in TD versus ASD, and greater functional connectivity between the amygdala and the left supramarginal gyrus in the TD group. The ASD group showed an association between anxiety level and activation of the right angular gyrus, and anxiety mediated the association between the right angular gyrus and sensory hyperresponsiveness. Thus, enhanced timing by fear-relevant cue underlying the emotion-timing related circuit may be disrupted in individuals with ASD. The heightened anxiety and sensory hyperresponsiveness in ASD may involve timing-related regions.