MEG Correlates of Linguistic Processing at and Below the Word Level in Autism (funded through NAAR)

Magnetoencephalography (MEG) results from past studies have shown delays in automatic neural responses to vowel-sound contrasts in subjects with autism relative to controls. This study focused on the development of a novel MEG experiment (which allows for non-invasive measurement of neural activity in auditory cortical sites) to extend investigation of auditory linguistic processing of speech sounds from isolated sounds to speech sound combinations. The combination of speech sounds is governed by phonotactic rules, language particular constraints on how sequences of segments pattern. This project investigated sensitivity to violations of phonotactic rules of children with autism compared to controls. Literature shows that phonotactic violations cause processing delays for subjects’ task completion in an auditory discrimination experiment. It is important to identify neural correlates of such delays in controls so that we may look for the presence of the same effect in children with autism in an MEG experiment. It was hypothesized that neural activity related to phonotactic violation detection would be significantly delayed in subjects with autism. The researchers adapted existing MEG word recognition experiments to passive paradigms suitable for study with an autistic population to test whether individuals with autism store and access words similarly to healthy age-matched controls.