This study examines the status of the Sonority Sequencing Principle (SSP) in English-speaking individuals with dyslexia to ascertain whether sonority projection effects on targeted behavioral measures shown in previous findings generalize to facilitate performance on language tasks of known difficulty for these individuals. Three experimental tasks were used: (1) a syllable count task with nonwords, replicated from previous work; (2) a nonword repetition task; and (3) a nonword span task. In all three tasks, sonority differential was manipulated in onset consonant clusters with varying degrees of conformity to the SSP. For the syllable count task, unattested onsets were used, and sonority was manipulated at three levels: rise, plateau and fall. For the nonword repetition and span tasks, attested onsets were used, and sonority was manipulated at four levels for a finer grain measure: large rise, moderate rise, small rise and plateau. Preliminary results from this pilot study showed that, on the whole, individuals with dyslexia showed facilitation effects when nonwords conformed optimally to the SSP and inhibition for less optimal structures. Effects of intervention were also found. These results are discussed within the context of the larger debate regarding the degree of innateness of the Sonority Sequencing Principle and the phonological grammar.
