Specialization of the brain for language in children with Fragile X Syndrome: A functional Near Infrared Spectroscopy study

Abstract

Specialization of the brain for language is early emerging and essential for language learning in young children. Fragile X Syndrome (FXS) is a neurogenetic disorder marked by high rates of delays in both expressive and receptive language, but neural activation for speech and language processing is unknown. We report results of a functional Near Infrared Spectroscopy (fNIRS) study of neural responses to speech sounds in children with FXS. Hemodynamic changes in the auditory cortex during blocks of speech and non-speech matched noise were measured in children with FXS and age-matched controls. Similar to controls, children with FXS showed activation of the primary auditory regions for speech and showed strong leftward lateralization. However, while controls showed neural differentiation of speech and nonspeech, children with FXS did not differentiate the two conditions. In addition, the children with FXS showed a greater response to the non-speech condition overall, which was associated with reduced verbal abilities.