Verbal fluency and working memory interaction

Focus of this study was to review which aspects of working memory, and to what extent, are associated with verbal fluency. It is generally believed that working memory consists of the phonological loop, the visuospatial sketchpad and the central executive. The aim of this study was to examine the interaction of the visuospatial sketchpad and central executive with semantic and phonemic fluency. Our research hypotheses were (1) there will be a positive correlation between the visuospatial sketchpad and semantic fluency, (2) the correlation effect sizes will differ depending on semantic category and (3) there will be a positive correlation between the central executive and both fluency tasks. The visuospatial sketchpad was assessed with the Spatial Working Memory test, and the central executive with the Attention Switching Task (both tests are part of the CANTAB test battery). The study included 20 participants, ranging from 18 to 30 years of age. According to Levelt et al. (1999) lexical access is the ability to retrieve grammatical representations and sound forms of words from the mental lexicon, and the executive control ability controls and regulates thought and direct behavior toward a general goal. Furthermore, in performing the semantic fluency task, a validated tool for lexical access assessment, participants rely on existing links between concepts or words in word retrieval (e.g., cat) and can automatically activate semantically associated words (e.g., dog, tiger), while in performing the phonemic fluency task such associations need to be inhibited. In accordance with Levet’s model, the results of this study suggest that the central executive functions may play a great role in the performance of both fluency tasks, and that the visuospatial component has an important role only in semantic fluency. Therefore, differences in the two fluencies likely depend on different mechanisms of the mental lexicon