Cerebral Lateralization for Language as a Potential Biomarker for the Broad Autism Phenotype: A Functional Transcranial Doppler Ultrasonography Investigation.

Abstract

Introduction: Autism spectrum disorder (ASD) is associated with language deficits, while growing evidence suggests that atypical cerebral lateralization for language could serve as a potential neural marker for ASD. The present study seeks to investigate cerebral lateralization for language not only in terms of ASD, but also as a potential biomarker for the broad autism phenotype (BAP)-a sum of subclinical traits similar to those of ASD. BAP is often observed in family members of individuals with ASD, and encompasses personality, linguistic, social, communicative, and behavioral challenges that fall short of the diagnostic threshold for ASD. We hypothesize that individuals with ASD will show atypical patterns of cerebral lateralization for language relative to neurotypical controls, with individuals exhibiting BAP characteristics expected to fall between these two groups.

Methods: To test this hypothesis, neurophysiological and behavioral assessments of cerebral lateralization for language, alongside cerebral lateralization of visuospatial functions-to confirm that the expected differences are specific to language lateralization-will be performed in at least 26 children and adults with high-functioning ASD, 26 BAP-positive siblings (BAP group), and 26 neurotypical controls. Behavioral lateralization, namely handedness, will be assessed through neuropsychological tools, while cerebral lateralization will be measured utilizing functional transcranial Doppler ultrasonography (fTCD), a validated and reliable tool specialized for cerebral lateralization assessment.

Results: This is a Stage-1 registered report; therefore, no results are available at this time point.

Conclusion: Findings are expected to inform improved understanding and, potentially, early identification and screening for both ASD and BAP.