Decrease in performance on the verbal fluency test as a function of time: evaluation in a young healthy sample.

Participants were asked to generate as many words as possible using large and small category sizes with the initial letter and semantic category search strategies. The production of each participant for each 15-s time slice on each task was recorded. The results revealed that on all fluency tasks, the production in the initial time slice was highest and also of greatest frequency. As time on task increased the production decreased, as did the word frequency of the items produced. The results are consistent with the notion that there is a store of high-frequency words accessed during the early trials of the fluency tasks and as this store becomes exhausted the production and the word frequency decreases.