Role of Processing Speed and Cognitive Control during Word Retrieval in Persons with Aphasia

Abstract

It is possible that word retrieval is not associated with general processing speed but is associated with a highly specific cognitive process - that of inhibiting competing alternative words. This study aims to measure domain general processing speed, domain general cognitive control, domain specific linguistic processing, and domain specific linguistic selection control. Twelve PWA and 15 neurotypical controls completed all four tasks. Results: domain general processing speed and domain general cognitive control response times differed between the groups but were nonsignificant. In neurotypical adults, word retrieval response time was predicted by domain general measures. However, this pattern was not observed in PWA – rather, word retrieval was predicted by domain specific linguistic measures. The implications of these findings indicate that aphasia is ultimately defined by language deficits, and increased word retrieval times in PWA cannot be attributed to a generalized processing speed deficit.