This thesis extends a previous pilot study with children who stutter (CWS) to include children with specific language impairment (CSLI). The current study examines lexical-semantic organization in these two clinical populations in hopes of comparing and contrasting behavioral profiles. The study employed a list-recall task to assess the lexical-semantic organization of 9 CWS, 5 CSLI, and 20 typically developing children matched for age and vocabulary. Similar to previous investigations, our child participants demonstrated the well-documented list position effects. With regard to recall accuracy, by-participant analyses revealed significant differences between CSLI and their age-matched peers; however, they did not reveal significant differences between the CWS and either of their control groups nor between the CSLI and CWS groups. Further, inspection of error distribution suggested significant differences in the number and types of errors the CSLI and control groups produced. The prevalence of unrelated and previous list errors in CSLI suggest that deficits in inhibitory processes as well as perseveration may have affected their performance. Areas of overlap and divergence in the profiles of CWS and CSLI indicate continuity in the degree of lexical-semantic weakness as well as differences in lexical retrieval and executive functions among CSLI and CWS. / text

This report investigated the various types of memory intrusion errors of adults with language learning disability (LLD) in comparison to age- and gender-matched typically developing (TD) adults using lists that are specifically designed to induce memory intrusions adapted from Roediger and McDermott (1995) and modified by Watson et al. (2001; 2003). The 28 participants between the ages of 18:9 - 24:3 listened to pre-recorded lists of twelve words that converged on a critical lure either semantically, phonologically, or dually with a hybrid list. This report tested the hypotheses that 1) hybrid lists would be more likely to induce memory intrusions of the critical lure than either semantic or phonological lists for each group; 2) adults with LLD would demonstrate more intrusion errors than their TD counterparts; 3) the error profiles of the LLD and TD groups should be largely similar; however, the adults with LLD might show deficits in extracting the semantic gist of word lists in light of such patterns in children with specific language impairment (Sheng & McGregor, 2010a). Results showed that the hybrid lists induced the greatest number of critical lure intrusions producing a super-additive effect. Contrary to our hypothesis, the LLD group did not produce more memory intrusions than the TD group. The fact that the two groups performed similarly on all standardized measures suggests that the participants with LLD may have outgrown their disability. Results also revealed that interference and intrusions increased when there was an increase in phonological similarity among words for both groups. Lastly, our preliminary evidence suggests that adults with LLD are not as efficient as their TD counterparts at extracting the gist of semantically-related words. The inclusion of a greater number of participants may provide stronger support for the hypothesis that lexical-semantic organization is less efficient in young adults with LLD. / text