Study examines anxiety’s effect on sensory processing in autism

A recent study published in Scientific Reports investigates how anxiety influences sensory processing and temporal perception in individuals with autism spectrum disorder (ASD). Conducted using functional magnetic resonance imaging (fMRI), the study involved 25 participants with ASD and 25 typically developed (TD) individuals. Researchers aimed to understand the connection between heightened sensory sensitivity and anxiety, which is often prevalent among those with ASD.

Individuals with ASD frequently experience atypical sensory responses, with estimates indicating that about 90% endure daily sensory challenges, including hyperresponsiveness to stimuli. Furthermore, the co-occurrence of anxiety disorders among individuals with ASD is reported to range from 20% in adults to over 60% in children. This overlap suggests that anxiety could significantly impact sensory processing in autism.

The study built on previous findings that suggested heightened anxiety may enhance the temporal processing of sensory information, even when detection thresholds remained unchanged. This hypothesis was explored through a visual temporal order judgment (TOJ) task, where participants had to judge the sequence of visual stimuli presented alongside facial emotional cues.

Results indicated that fearful facial expressions improved temporal processing in the TD group but did not yield the same effect in the ASD group. However, a correlation emerged in the ASD group between anxiety levels and performance on the task, as well as their sensory hyperresponsiveness. Specifically, individuals with ASD who reported higher anxiety exhibited increased activation in the right angular gyrus, a brain area linked to timing perception.

Neuroimaging results revealed that the TD group had greater activation in the right caudate compared to the ASD group. Additionally, a functional connection was identified between the amygdala and the left supramarginal gyrus in the TD group, suggesting that emotion-cued stimuli may enhance sensory processing in typically developed individuals, which was not the case for those with ASD.

The findings highlight that individuals with ASD may struggle to process emotion-related cues effectively, which could disrupt their ability to engage with sensory information in their environment. This study also provides evidence that anxiety may mediate the relationship between sensory hyperresponsiveness and the activation of brain regions involved in timing perception.

The implications of this research are important for understanding the challenges faced by individuals with ASD. By identifying the neural correlates associated with anxiety and sensory processing, targeted interventions could be developed to support individuals with ASD, particularly those experiencing high levels of anxiety. Future research may focus on exploring therapeutic approaches that address both sensory hyperresponsiveness and anxiety to improve overall quality of life for individuals with autism.