Action (Verb) Fluency Predicts Dependence in Instrumental Activities of Daily Living in Persons Infected With HIV-1

Abstract

Inspired by the hypothesized neural dissociation between the retrieval of nouns and verbs, several studies now support the construct validity of Action (verb) Fluency as a measure of frontostriatal systems function. Relative to traditional noun- and letter-cued verbal fluency tests, Action Fluency is more sensitive to HIV-1-associated neuropsychological impairment, which may reflect inefficiencies engaging motor representations during action retrieval in this population. Accordingly, impaired Action Fluency might adversely impact instrumental activities of daily living (IADL) by disrupting the production and organization of script-based action schemas upon which successful IADL performance depends. The present study thus sought to evaluate the ecological validity of Action Fluency as a predictor of IADL among persons with HIV-1 infection. Action, Letter (FAS), and Noun (animal) fluency were compared in 21 HIV-1-infected participants with self-reported IADL dependence relative to 76 demographically comparable HIV-1-infected participants who reported no IADL declines. Results revealed significant between-group differences in Action and Letter Fluency, but not Noun Fluency. Action Fluency achieved an overall hit rate of 76% and was more sensitive than Letter Fluency in classifying IADL dependent participants. Individuals with impaired Action Fluency performance had a fivefold risk of concurrent IADL dependence as compared to those who performed within normal limits. Findings suggest that Action Fluency may possess incremental ecological validity in the identification of HIV-1-associated neurocognitive disorders.

The HNRC is supported by Center award MH 62512 from the National Institute of Mental Health. The research described was also supported by grants DA12065 and MH59745 from the National Institutes of Health. Note that, the views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the United States Government. The authors thank Jennifer Marquie Beck for her assistance with data coding.

Acknowledgments

The HIV Neurobehavioral Research Center (HNRC) group is affiliated with the University of California, San Diego, the Naval Hospital, San Diego, and the San Diego Veterans Affairs Healthcare System, and includes: Director: Igor Grant, M.D.; Co-Directors: J. Hampton Atkinson, M.D., J. Allen McCutchan, M.D.; Center Manager: Thomas D. Marcotte, Ph.D.; Naval Hospital San Diego: Mark R. Wallace, M.D. (P.I.); Neuromedical Component: J. Allen McCutchan, M.D. (P.I.), Ronald J. Ellis, M.D., Ph.D., Scott Letendre, M.D., Rachel Schrier, Ph.D.; Neurobehavioral Component: Robert K. Heaton, Ph.D. (P.I.), Mariana Cherner, Ph.D., Sharron Dawes, Ph.D., Lei Lu, Ph.D., Steven Paul Woods, Psy.D.; Imaging Component: Terry Jernigan, Ph.D. (P.I.), John Hesselink, M.D., Michael J. Taylor, Ph.D.; Neuropathology Component: Eliezer Masliah, M.D. (P.I.), Dianne Langford, Ph.D.; Clinical Trials Component: J. Allen McCutchan, M.D., J. Hampton Atkinson, M.D., Ronald J. Ellis, M.D., Ph.D., Scott Letendre, M.D.; Data Management Unit: Michelle Frybarger, B.A.; Statistics Unit: Ian Abramson, Ph.D. (P.I.), and Deborah Lazzaretto, M.S.

Notes

The HNRC is supported by Center award MH 62512 from the National Institute of Mental Health. The research described was also supported by grants DA12065 and MH59745 from the National Institutes of Health. Note that, the views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the United States Government. The authors thank Jennifer Marquie Beck for her assistance with data coding.

^aIndicates a chi-square value from a nonparametric Wilcoxon Ranked Sums test.