Delayed silent phoneme monitoring in adults who do and do not stutter

Abstract

ABSTRACT Previous research employed silent phoneme monitoring tasks to examine differences in phonological encoding in adults who stutter (AWS) compared to adults who do not stutter (AWNS). The primary purpose of this study was to apply a modified version of the task – the delayed silent phoneme monitoring task – to examine the integrity of the phonological speech plan within working memory in AWS and AWNS before and after subvocal rehearsal. The secondary purpose of this study was to examine whether group differences were more apparent when greater phonological demand was placed upon phonological working memory. In Experiment 1, 20 adults (10 AWNS, 10 AWS) identified target phonemes within trochaic nonwords held in memory before the initiation of subvocal rehearsal (1 s) and after subvocal rehearsal (4 s). In Experiment 2, an additional 20 adults (10 AWNS, 10 AWS) monitored identical nonwords with low-frequency iambic stress. Speed and accuracy of manual response was measured, as well as post-trial verbal productions. Both groups identified the initial phoneme of trochaic stimuli fastest, irrespective of stress, and both groups monitored phonemes faster after the 4 s delay. However, AWS identified phonemes within iambic stimuli with less accuracy than AWNS. Group differences in monitoring errors were most evident for phonemes immediately following syllable boundary, and after subvocal rehearsal. Preliminary findings suggest AWS may exhibit distinct difficulties relative to AWNS when accessing segmental information after subvocal rehearsal is required, but only when target words are more phonologically demanding (i.e., low-frequency iambic stress).