ATYPICAL HEMISPHERIC ASYMMETRY IN FETAL ALCOHOL SPECTRUM DISORDERS: A REVIEW OF THE EFFECTS OF PRENATAL ALCOHOL EXPOSURE ON LANGUAGE LATERALIZATION

Atypical lateralization is evident in developmental disorders, including autism spectrum disorders and dyslexia. Moreover, atypical lateralization is linked to language impairments: reduced or reversed lateralization is associated with poorer language outcomes. Fetal alcohol spectrum disorders (FASD) result from the deleterious effects of prenatal alcohol exposure on the brain, resulting in a range of physical, behavioural, and cognitive abnormalities, including language impairments. To date, little is known about lateralization in FASD. This review examines the effects of prenatal alcohol exposure on lateralization in FASD, seeking to determine the degree to which the language deficits associated with FASD can be attributed to aberrant cortical lateralization. The research reviewed indicates that the left temporo-parietal region is particularly vulnerable to prenatal alcohol exposure, causing atypicalities in structural and functional lateralization. As this region typically controls language processing, the data imply a direct link between atypical lateralization in FASD and language impairment. Knowledge of patterns of altered structural and functional lateralization in FASD has the potential to improve diagnostic efficacy and may facilitate the development of appropriate management and intervention programmes, improving outcomes for people with FASD.