Dyslexia Research Today is a free monthly online journal that collates and summarizes the latest research about Dyslexia, including details on learning, reading, education, teaching, treatment.

Cortical categorization failure in 2-month-old infants at risk for dyslexia.

van Leeuwen T, Been P, van Herten M, Zwarts F, Maassen B, van der Leij A

Faculty of Behavioral and Social Sciences, Department of Special Education, University of Amsterdam, Amsterdam, The Netherlands. t.h.vanleeuwen@uva.nl

Cortical auditory categorization was assessed in 2-month-old infants at genetic risk for dyslexia and controls. Manipulated /bAk/ and /dAk/ speech stimuli were used as frequently presented standards. The neuroelectric brain responses of the control infants were highly sensitive to the phoneme boundary that separated these stimuli, but the infants at risk showed no signs of cortical categorical perception. Cortical sources of the responses were predominantly found in the left hemisphere for the control infants, but mainly in the right hemisphere for the infants at risk. The results demonstrate that impaired categorical perception in dyslexia is already present in infants at risk for the disorder.

Published 22 May 2007 in Neuroreport, 18(9): 857-61.
Full-text of this article is available online (may require subscription).

© 2004-2008 Dyslexia Research Today. All Rights Reserved.