Action (verb naming) fluency as an executive function measure: convergent and divergent evidence of validity

Numerous studies have demonstrated dissociable neuroanatomic underpinnings for the retrieval of grammatical classes of words such as nouns and verbs. Whereas retrieval of common and proper nouns is primarily mediated by poste rior and anterior temporal regions: respectively, verb retrieval is primari ly mediated by frontal regions. The majority of studies evaluating verb pro duction have utilized tasks requiring subjects to name a graphically depict ed action (i.e. action naming), leaving tests of verb generation in the abs ence of prompting stimuli (i.e. action fluency) largely unexamined. In a re cent study, Piatt, Fields, Paolo, Koller and Troster (in press) found that an action fluency task discriminated demented Parkinson's disease (PD) pati ents from non-demented PD patients and healthy control subjects, whereas le xical and categorical fluency tasks did not. These authors suggested that a ction fluency was sensitive to the fronto-striatal pathophysiology associat ed with PD dementia, and thus, that action fluency might serve as an indica tor of executive functioning. This study was undertaken to evaluate the con struct validity of action fluency as an executive function measure in. grou p of healthy elderly control subjects. Findings revealed modest to moderate relationships between action fluency and several putative executive measur es. Action fluency was unrelated to indices of semantic and episodic memory . Results support the construct validity of action fluency as an executive function measure and suggest that this task may provide some unique informa tion not tapped by traditional executive function tasks. (C) 1999 Elsevier Science Ltd. All rights reserved.