REACTION-TIMES AND DYSLEXIA

Five groups of children, including two groups of dyslexics (aged 15 an d 11 years), were tested on simple reaction, selective choice reaction , and lexical decision tasks. In simple reactions to a pure tone, the dyslexic children responded as quickly as their chronological age cont rols and significantly faster than their reading age controls. In sele ctive choice reactions to pure tones, the dyslexic children were signi ficantly impaired compared with their chronological age controls and n o faster than their reading age controls. This speed impairment obtain ed even though a selective choice reaction task has only one positive response. In ''by-item'' analyses of lexical decisions to spoken words , the dyslexic children were significantly impaired compared even with their reading age controls. The pattern of results suggests that at l east two factors contribute to slowness of dyslexic children: a genera l deficit reflected in slower stimulus classification speed and a ling uistic deficit reflected in slower lexical access speed.