Disordered connectivity associated with memory deficits in children with autism spectrum disorders

The present study examined the memory performance and cortical connectivity of children with ASD, and investigated whether the memory deficits exhibited by these children were associated with the cortical connectivity. Twenty-one children with ASD and 21 children with normal development (NC), aged 5-14 years, participated in the study. Each child was administered a neuropsychological battery that included the Test of Non-verbal Intelligence (TONI-III), Digit Span test (DS), Rey-Osterrieth Complex Figure Test (Rey-O), and Hong Kong List Learning Test (HKLLT); and an EEG recording session when performing the visual encoding Object Recognition (OR) task. Six neuropsychological measures from the test battery and six EEG coherence measures in the theta band were compared between the children with ASD and normal children. Results indicated that children with ASD performed at comparable levels with normal children in the DS and Rey-O, but were significantly poorer in HKLLT and OR. They also exhibited significantly elevated long-range coherences in the fronto-posterior connections involving the left hemisphere (left anterior-left posterior; left anterior-right posterior). Pearson correlation showed significant negative associations between the anterior-posterior EEG coherences and memory performance.