Age-related changes in neural responses to sensory stimulation in autism: a cross-sectional study.

This study used brain scans to look at how autistic and non-autistic children and teens respond to mildly unpleasant sensory experiences. Younger autistic children showed very different brain patterns compared to their peers, but these differences became smaller in teenagers. As autistic youth got older, their brains showed increased activity in areas that help process sensory information and manage emotions. This was especially true for teens with more severe sensory sensitivities.

The findings suggest that some autistic teenagers may develop better ways to cope with sensory challenges as their brains mature.

This cross-sectional fMRI study examined neural responses to sensory stimulation in 52 autistic and 41 typically developing youth aged 8.6-18.0 years. Results showed that pre-teen autistic children had widespread brain activation differences compared to typically developing peers, but these differences were reduced in teenagers. While typically developing youth showed decreased prefrontal activation with age, autistic youth showed increased engagement of sensory integration and emotion regulation regions. Orbitofrontal and medial prefrontal cortices demonstrated nonlinear age relationships in autism, with steep increases during mid-to-late teens.

Age-related changes were more pronounced in autistic youth with higher sensory over-responsivity severity, suggesting enhanced prefrontal recruitment may underlie improvements in sensory processing for some autistic adolescents.

Findings suggest that sensory challenges may naturally improve for some autistic adolescents through enhanced prefrontal brain engagement. This supports developmental approaches to intervention and highlights the importance of considering individual sensory profiles when planning support strategies during adolescence.

Cross-sectional design prevents causal interpretations and cannot establish developmental trajectories. Sample size details not fully reported. Results may not generalize to all autistic individuals given heterogeneity in sensory processing challenges.

Sensory over-responsivity (SOR) is an impairing sensory processing challenge in autism spectrum disorder (ASD) which shows heterogenous developmental trajectories and appears to improve into adulthood in some but not all autistic individuals. However, the neural mechanisms underlying interindividual differences in these trajectories are currently unknown. Here, we used functional magnetic resonance imaging (fMRI) to investigate the association between age and neural activity linearly and nonlinearly in response to mildly aversive sensory stimulation as well as how SOR severity moderates this association. Participants included 52 ASD (14F) and 41 (13F) typically developing (TD) youth, aged 8.6-18.0 years.

We found that in pre-teens, ASD children showed widespread activation differences in sensorimotor, frontal and cerebellar regions compared to TD children, while there were fewer differences between ASD and TD teens. In TD youth, older age was associated with less activation in the prefrontal cortex. In contrast, in ASD youth, older age was associated with more engagement of sensory integration and emotion regulation regions. In particular, orbitofrontal and medial prefrontal cortices showed a nonlinear relationship with age in ASD, with an especially steep increase in sensory-evoked neural activity during the mid-to-late teen years.

There was also an interaction between age and SOR severity in ASD youth such that these age-related trends were more apparent in youth with higher SOR. The cross-sectional design limits causal interpretations of the data. Future longitudinal studies will be instrumental in determining how prefrontal engagement and SOR co-develop across adolescence. Our results suggest that enhanced recruitment of prefrontal regions may underlie age-related decreases in SOR for a subgroup of ASD youth.