Functional Asymmetries in Language Processing and Autism

Functional asymmetries in language processing refer to the unequal engagement of the left and right cerebral hemispheres during speech perception, production and comprehension. In typical development, the left hemisphere predominates for phonological, semantic and syntactic operations, while the right supports prosody, metaphor and contextual inference. In autism spectrum disorder (ASD), this canonical pattern is often disrupted: left-hemisphere dominance may be attenuated or reversed, interhemispheric connectivity may be altered, and compensatory recruitment of non-language regions is frequently observed. Such atypical lateralisation emerges early in life and endures into adulthood, linking directly to language delays, pragmatic difficulties and social communication deficits. Neuroimaging studies have demonstrated that regions such as the superior temporal cortex, inferior frontal gyrus and planum temporale display reduced leftward bias or increased bilateral/rightward activation in ASD populations. Disrupted functional coupling between language areas and networks involved in social cognition, motor planning and visual processing suggests a broad reorganisation of cerebral specialisation. Understanding these neural deviations is crucial for early detection of ASD, stratification of clinical heterogeneity and the design of interventions aimed at reshaping lateralised pathways to improve communicative outcomes.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Functional Asymmetries in Language Processing and Autism publication trend

The graph below shows the total number of articles in functional asymmetries in language processing and autism across all publications each year (not limited to Nature Index journals).

Technical terms

Functional asymmetry: Unequal activation or connectivity of the brain's two hemispheres during specific cognitive or motor tasks.

Hemispheric lateralisation: The tendency for certain neural functions or cognitive processes to be more dominant in one cerebral hemisphere than the other.

Functional connectivity: The statistical association or synchrony between spatially separated brain regions during rest or task performance.

Structural covariance network: A graph of interregional relationships based on correlated anatomical measures such as cortical thickness or volume across individuals.

Salience network: A functional network involving regions such as the anterior insula and dorsal anterior cingulate cortex that detects and filters salient stimuli to guide attention and behaviour.

References

1. Atypical functional connectivity of temporal cortex with precuneus and visual regions may be an early-age signature of ASD. Molecular Autism (2023).
2. Reduced lateralization of multiple functional brain networks in autistic males. Journal of Neurodevelopmental Disorders (2024).
3. Subtly altered topological asymmetry of brain structural covariance networks in autism spectrum disorder across 43 datasets from the ENIGMA consortium. Molecular Psychiatry (2022).