Visual and phonological processes in poor readers' word recognition

Abstract

ABSTRACTIn two experiments, poor and normal Dutch readers, matched for reading age, were presented with visual matching tasks on a computer screen. In Experiment 1, word and pseudoword letter strings were used. The strings consisted of either uppercase/lowercase congruent (e.g., o/O) or uppercase/lowercase incongruent letters (e.g., a/A). Poor readers needed significantly more time to decode uppercase/lowercase incongruent pairs, especially when the pairs consisted of pseudowords. Experiment 2 investigated whether this effect was phonologically or visually mediated. Strings of letters, digit strings, and abstract figure symbols were used. Letter strings included words, pseudowords, and nonwords. Poor readers needed more time to match incongruent letter case pairs, consistent with Experiment 1. Poor readers performed more poorly on letter and digit string matching but not on the figure–symbol matching task. No evidence was found for the differential use of orthographic information in terms of multiletter constraints. The combined data on the letter, digit, and graphic symbol matching experiments suggest that an inadequate command of grapheme–phoneme associations is a critical factor in reading disability. Evidence for poor visual processing as an independent source of reading disability could not be established.