Date of Award
Doctor of Philosophy in Psychology
The primary goal of this study was to investigate the association between verbal working memory and speech production and to address a number of ongoing questions about the nature of the relationship between these two phonological processes and reading ability. In an effort to clarify these relationships, the following areas were explored. First, previous research has suggested that poor readers generally do not perform as well as their normal-reading peers on phonological processing tasks, but their performance is not consistently worse than younger children reading at the same level. In order to examine this issue, this study compared the performance of less-skilled readers with that of skilled readers of the same age, as well as with the performance of younger children who were reading at the same level. Second, verbal working memory deficits have been found to account for about 10% of the variance in reading ability; however, the relationship between phonological processing skill and the various components of reading has not been clearly delineated. To clarify this relationship, three aspects of reading (i.e., non-word reading, real word reading, comprehension) were assessed in this study. Third, although evidence supports an association between verbal working memory and speech production, the exact nature of this relationship is not clear. This study used a variety of memory and speech production measures to further examine the association between these two phonological processes. And finally, although there is evidence supporting a relationship between accuracy of speech production and reading ability, the link between speed of speech production and reading ability is not as strong. In fact, there are indications that speech rate may be related to chronological age but not to reading. In order to explore this issue, speech production accuracy and speech production speed tasks were administered to skilled and less-skilled readers of the same age, as well as to a group of younger readers.
Ninety second- and third-grade children served as subjects for this study. These children were divided equally among three groups who did not differ significantly in cognitive ability: (1) less-skilled third-grade readers; (2) skilled third-grade readers who were the same age as the less-skilled readers; and (3) second-graders who were reading at the same level as the less-skilled readers. In addition to reading and cognitive ability measures, three verbal working memory tasks, two speech production accuracy tasks, and three speech production speed tasks were individually administered to each of the 90 subjects.
As expected, the less-skilled third-grade readers had significantly lower scores than their age-mates on the verbal working memory and speech production accuracy measures. In addition, their performance was significantly lower than that of the younger readers on two memory and two speech production accuracy tasks. Performance on a pseudo word repetition measure contributed significantly to the prediction of all three components of reading for the 90 subjects in this study. The tasks measuring verbal working memory and speech production accuracy loaded on a common factor. There were no significant group differences on two of the speech production speed measures, but on the third measure, the skilled third-grade readers significantly outperformed both the other groups.
The results of this study indicate that a common factor (e.g., phonological encoding, planning for output) may underlie competence, or the lack of competence, on both verbal working memory and speech production accuracy tasks. The finding that less-skilled readers have phonological processing deficits even when compared to younger children suggests that a deficit, rather than a developmental lag, model of reading disability should be considered.
Stone, Brenda H., "VERBAL WORKING MEMORY AND SPEECH PRODUCTION ABILITIES IN CHILDREN WITH DIFFERENTIAL READING SKILL: A CHRONOLOGICAL- AND READING-AGE COMPARISON" (1992). Open Access Dissertations. Paper 1048.