Sex Differences in Spatiotemporal Consistency and Effective Connectivity of the Precuneus in Autism Spectrum Disorder.

This brain imaging study looked at how autism affects brain activity differently in males and females. Researchers scanned the brains of 64 males and 64 females with autism, plus equal numbers without autism. They found that autism affects brain activity patterns differently based on sex - males with autism showed increased activity in certain brain areas while females with autism showed decreased activity in the same areas. This suggests autism may work differently in male and female brains.

This neuroimaging study examined sex differences in brain activity patterns in autism spectrum disorder (ASD) using advanced fMRI analysis. Researchers analyzed brain scans from 128 individuals with ASD (64 males, 64 females) and 128 neurotypical controls, matched by sex. The study focused on spatiotemporal consistency of neural activity and found significant sex-by-diagnosis interactions in several brain regions, particularly the precuneus. Males with ASD showed increased activity consistency in the precuneus compared to neurotypical males, while females with ASD showed decreased consistency compared to neurotypical females.

The findings highlight altered connectivity within the default mode network and suggest that brain differences in autism may manifest differently between males and females.

Findings suggest need for sex-specific considerations in autism assessment and intervention. The differential brain activity patterns between males and females with autism may contribute to diagnostic challenges, particularly in identifying autism in females. Results support developing sex-informed approaches to understanding autism neurobiology.

Study appears to be cross-sectional limiting causal inferences. Sample sizes per subgroup (64 per group) are moderate. The clinical significance of spatiotemporal consistency changes is unclear from the abstract.

Autism spectrum disorder (ASD) has been reported to exhibit altered local functional consistency. However, previous studies mainly focused on male samples and explored the temporal consistency in the ASD brain ignoring the spatial consistency. In this study, FOur-dimensional Consistency of local neural Activities (FOCA) analysis was used to investigate the sex differences of local spatiotemporal consistency of spontaneous brain activity in ASD. This study used resting-state functional magnetic resonance imaging data from the Autism Brain Imaging Data Exchange database, including 64 males/64 females with ASD and 64 male/64 female neurotypical controls (NCs).

Two-way analysis of variance was performed to ascertain diagnosis-by-sex interaction effects on whole brain FOCA maps. Moreover, granger causal analysis was used to investigate effective connectivity between the brain regions with interaction effects and the whole-brain in ASD. Significant diagnosis-by-sex interaction effects on FOCA were observed in the bilateral precuneus (PCUN), bilateral medial prefrontal cortex and right dorsolateral superior frontal gyrus. Specifically, FOCA was significantly increased in males with ASD but decreased in females with ASD in the PCUN compared with the sex-matched NC group.

In addition, the lack of sex differences in the causal influences from the bilateral anterior cingulate cortex/medial prefrontal cortex to the PCUN was observed in ASD. Our results reveal altered sex differences in the spatiotemporal consistency of spontaneous brain activity and functional interaction of the anterior and posterior default mode network (DMN) in ASD, highlighting the critical role of the DMN in the sex heterogeneity of ASD.