Assessment of Automatic and Controlled Retrieval Using Verbal Fluency Tasks.

Category and letter verbal fluency assessment is widely used in basic and clinical research. Yet, the nature of the processes measured by such means remains a matter of debate. To delineate automatic (free-associative) versus controlled (dissociative) retrieval processes involved in verbal fluency tasks, we carried out a psychometric study combining a novel lexical-semantic retrieval paradigm and structural equation modeling. We show that category fluency primarily engages a free-associative retrieval, whereas letter fluency exerts executive suppression of habitual semantic associates. Importantly, the models demonstrated that this dissociation is parametric rather than absolute, exhibiting a degree of unity as well as diversity among the retrieval measures. These findings and further exploratory analyses validate that category and letter fluency tasks reflect partially distinct forms of memory search and retrieval control, warranting different application in basic research and clinical assessment. Finally, we conclude that the novel associative-dissociative paradigm provides straightforward and useful behavioral measures for the assessment and differentiation of automatic versus controlled retrieval ability.