Phonemic deficits in developmental dyslexia.

Abstract

The present study explored a possible relationship between reading difficulties and speech difficulties. Dyslexic and normal readers, matched for Reading Age, were compared first on a reading task and secondly on a speaking task. In the first experiment, the two groups were asked to read nonsense words aloud. Both groups were able to read one-syllable nonwords equally well but the dyslexics had more difficulty than the normal readers when asked to read two-syllable nonwords. Moreover, they found two-syllable nonwords containing consonant clusters particularly difficult. The probability of their making an error increased with the number of consonant clusters. In the second experiment, the subjects were required to repeat real words and nonsense words of two, three, or four syllables. Both groups found nonsense words more difficult to repeat than real words. However, the relative difficulty of nonsense words over real words was greater for the dyslexic group. Their difficulty was especially marked when they had to repeat four-syllable nonsense words. Thus, in both experiments the dyslexic readers were more affected by the phonological complexity of the stimuli than the normal readers were. Hence, it was suggested that the dyslexic readers tested were subject to a general phonemic deficit which affected their ability to process both written and spoken words.