Visual information processing in dyslexic children.

OBJECTIVE

Several studies presented evidence for magnocellular deficits in dyslexics both in behavioural as well as in electrophysiological data of local electrode sites. We investigated two well-known paradigms (motion-onset and random-dot-kinematogram) with regard to global electrophysiological parameters.

METHODS

Twenty-one-channel event-related potentials (ERPs) of 16 dyslectic and 15 control children were analyzed with reference-independent methods. For each paradigm quasi stable microstates were identified by means of a data-driven segmentation procedure and compared between both groups.

RESULTS

Differences in global ERP responses between dyslexic and control children could be found for rapid moving gratings but not for the dot coherence.

CONCLUSIONS

Dyslexic children seem to have some highly specific visual deficits in processing moving stimuli. These deficits can be related to the magnocellular system.