Reduced interhemispheric coherence in dyslexic adults

Abstract

Introduction: Developmental dyslexia has been associated with reduced interhemispheric neural connectivity in children. The present study investigated functional interhemispheric connectivity in male dyslexic adults.

Methods: A group of 19 dyslexic men were compared to a group of 15 controls on interhemispheric coherence of the dominant frequency in the power spectrum during a visuo-spatial attention task. The coherence between a left hemisphere central-parietal electrode and the respective right hemisphere electrode and surrounding sites was analysed.

Results: Compared to controls, the dyslexic group demonstrated reduced, and more diffuse, interhemispheric coherence of alpha activity in the central-parietal cortex. No group differences in interhemispheric coherence were found on frontal, temporal or central sites.

Conclusions: The deviant pattern of functional connectivity in dyslexics is suggestive of an altered development of neural circuitry that may lead to deficits in magnocellular processing.