Atypical hemispheric lateralization of brain function and structure in autism: a comprehensive meta-analysis study

Area of Science:

• Neuroscience
• Neuroimaging
• Developmental Neuroscience

Background:

• Brain asymmetry is altered in autism spectrum disorder (ASD).
• These structural and functional brain differences in autism are not fully understood.
• Investigating brain lateralization is crucial for characterizing ASD neurobiology.

Purpose of the Study:

• To comprehensively meta-analyze brain structure and function lateralization in autism.
• To identify specific brain regions and functions affected by atypical lateralization in autism.
• To explore the relationship between atypical lateralization and autism symptom severity.

Main Methods:

• Utilized resting-state functional and structural MRI data from 370 individuals with autism and 498 controls.
• Applied meta-analysis to examine lateralization of gray matter volume (GMV), fractional amplitude of low-frequency fluctuation (fALFF), and regional homogeneity (ReHo).
• Correlated atypical laterality with autism symptom scores using indirect and direct analysis approaches.

Main Results:

• Significant diagnostic effects on lateralization observed in 85% (GMV), 51% (fALFF), and 51% (ReHo) of brain regions in individuals with autism.
• Overlapping lateralization differences in GMV, fALFF, and ReHo found in 35.7% of regions, particularly those involved in language, motor, and perceptual functions.
• Autism group showed reduced variability in structural lateralization but increased variability in functional lateralization compared to controls.

Conclusions:

• Atypical hemispheric lateralization is a consistent neurobiological feature across diverse autism datasets.
• These findings suggest that altered brain lateralization patterns can serve as a potential neurobiological marker for autism.
• Further research can leverage these insights for improved diagnostic and therapeutic strategies in autism.