2016 Volume 36 Issue 4 Pages 484-491
A word fluency test (WFT) is a task requiring the subjects to say as many words as possible in the designated time. There are two types of WFT, one of which is a category fluency test and the other a letter fluency test. Osawa et al. (2006) revealed the usefulness of WFT to diagnose dementia and suggested that WFT is an efficient tool in clinical situations.
WFT is reported to be constructed by auditory attention, word knowledge and memory (Ruff & Levin, 1997) . Moreover, the performance of WFT is said to be linked to specific brain activation, such as dorsolateral prefrontal cortex or basal ganglia (Warkentin et al., 1991) . The dorsolateral prefrontal cortex is also regarded as one of the regions used for working memory (WM) (Baddeley, 2000) .
Our aim in this study was to explore the relationship between WFT and WM in order to know whether WM could be evaluated by the performance of WFT in dementia.
We studied fifty-two patients, including probable Alzheimerʼs disease (AD) and frontotemporal dementia (FTD) . All subjects executed WFT, and 23 subjects conducted the Reading Span Test (RST) and digit span backward as WM tasks, and digit span forward as a short-term memory task in addition to WFT.
As results, Spearmanʼs rank correlation coefficient indicated significant correlations between WFT and both WM tasks. However, there was no significant correlation between WFT and the short-term memory task. Moreover, the type of WM task indicating significant correlations relative to WFT differed depending on the type of dementia.
Though WM was related to WFT as reported in previous research, the aspect of WM in relation to WFT may possibly differ between AD and FTD. We discussed the characteristic performances on WFT in each type of dementia from the perspective of WM.
