Abstract/Summary

Background: Stuttering and cluttering are related but contrasting disorders of fluency. Whilst stuttering has received a great deal of attention in the research literature over the last 100 years, cluttering has remained relatively neglected. There is ongoing debate regarding whether there is a language/phonological component to cluttering or whether it is solely a motoric and/or rate-based disorder. The following thesis aims to investigate the phonological encoding skills of both adults who stutter (AWS) and adults who clutter (AWC) in contrast to fluent controls. Method: Three groups were used, comprising 14 AWS, 14 AWC and 15 matched controls. A variety of phoneme monitoring and syllable detection tasks designed to eliminate possible motor influences were used. Results: It was found that AWS and AWC performed in a similar manner; they were both less accurate in detecting phonemes in real words than controls and in detecting phonemes in silent picture naming. There were no differences (between AWS, AWC and controls), however, in syllable detection accuracy or in time taken to make judgments on monitoring for phonological differences, nor were there any differences in phoneme monitoring in non-words or in the accuracy of phoneme monitoring in silent reading. Discussion: Findings lend some support to the notion that phonological encoding may be impaired in both AWS and AWC. Findings are discussed in relation to phonological theories such as the covert repair hypothesis. Alternative interpretations, wider implications and the impact on participants accuracy of factors such as the type of phoneme being monitored for and the length of the word used are all discussed in greater depth.