The Differences in Semantic Processing of Pictures and Words between Dyslexic and Typical-Reading University Students

Abstract

The present study compared the semantic processing of pictures and words by dyslexics to that of typical readers utilizing the electro-physiological (ERP) technique during a semantic categorization decision task. ERPs of 40 university students, 20 typical readers and 20 dyslexic readers were recorded while they participated in a categorization decision task. The subjects were presented with two kinds of stimuli—words and pictures. Results revealed longer reaction times in response to words as compared to pictures in both groups. Electrophysiological measures revealed differences in amplitudes and latencies of ERP components in addition to differences in the mean activity. The results illustrated that the differences between processing words and processing pictures were manifested in timing and in the brain areas involved in the tasks. It also illustrated that although dyslexic and typical readers displayed equal ability to read and understand familiar words, dyslexics could not perform as quickly as typical readers. The semantic domain may be one of the compensatory mechanisms which help compensated dyslexic readers reach and succeed in the higher education system.