The role of visual and phonological representations in the processing of written words by readers with diagnosed dyslexia: evidence from a working memory task.

The aim of the study was to elucidate the nature and efficiency of the strategies that readers with phonological dyslexia use for temporary retention of written words in Working Memory (WM). Data was gathered through a paradigm whereby participants had to identify serially presented written (target) words from within larger word pools according to their presentation order, with word pools containing code-specific distracter (CSD) words and non-code-specific distracter (NCSD) words. Analyses focused on three aspects of performance: (1) false recognition of target words; (2) correct recognition of target words; and (3) retention of word presentation order. Participants were readers with diagnosed phonological dyslexia (n = 20, mean grade level = 9.05 [0.89]) and a control group of regular readers (n = 25, mean grade level = 9.00 [0.76]). Results provide direct evidence that the dyslexic readers and the regular readers used essentially different memory coding strategies for the temporary retention of written words, with the former predominantly relying on a visual strategy and the latter on a phonological strategy. Findings further pinpointed a notably impoverished ability of the dyslexic readers to retain word presentation order. The implication of these findings is discussed in relation to theories predicting the acquisition and mastery of reading.