The Abilities Associated with Verbal Fluency Performance in a Young, Healthy Population Are Multifactorial and Differ Across Fluency Variants

Abstract

Numerous variants of verbal fluency tasks exist within clinical and research domains that purport to measure “executive function.” However, to date, there has been a paucity of research examining what specific abilities are measured by these tasks. In this study, the relationships between a select group of cognitive constructs and phonemic, semantic, alternating, and excluded-letter verbal fluency tests were examined in 93 young healthy individuals (aged 18 to 35 years old). Forward-selection multiple regression analyses were performed for each fluency task. Phonemic fluency was associated with verbal intellectual function and processing speed; semantic fluency was associated with working memory and semantic word retrieval; excluded-letter fluency was associated with processing speed; and alternating fluency was associated with semantic word retrieval. These results highlight verbal intellectual function, processing speed, and semantic word-retrieval contributions to verbal fluency performances. The main conclusion from this study is that the abilities associated with verbal fluency performance in a young healthy population are multifactorial and differ across fluency variants. These findings progress our theoretical understanding of what is measured by different verbal fluency tasks and will assist interpretation of performance.

Key words:

• ability/abilities
• alternating fluency
• excluded-letter fluency
• executive function
• healthy population
• neuropsychological assessment
• phonemic fluency
• semantic fluency
• verbal fluency

ACKNOWLEDGEMENTS

The authors would like to thank the School of Psychology and Psychiatry at Monash University for funding this project. We also thank Monash University for assistance in recruiting participants.

Notes

Note. Each trial is 60 seconds in duration, and repetitions, wrong words, proper nouns, and variations of the same word do not count toward the raw score total (Strauss et al., 2006).

References: (1) Ruff et al., 1997; (2) Ardila et al., 1998; (3) Bittner & Crowe, 2007; (4) Bryan, Luszcz, & Crawford, 1997; (5) Nutter-Upham et al., 2008; (6) Ross et al., 2007; (7) Hughes & Bryan, 2002; (8) Rodriguez-Aranda & Sundet, 2006; (9) Iudicello et al., 2008; (10) Laisney et al., 2009; (11) Rosen & Engle, 1997; (12) Boone et al., 1998; (13) Libon, McMillan, Gunawardena, Powers, Massimo, Khan et al., 2010.

VIQ = predicted Verbal IQ based on NART; SWR = semantic word retrieval as measured by the Graded Naming Test; PS = processing speed as measured by the Symbol–Digit Modalities Test; WM = working memory as measured by Digits Sequencing from WAIS-IV; I = inhibition as measured by the Stroop Color–Word Test.

*p < .05.**p < .01.