Category and Letter Fluency in Highly Educated Older Adults

Karen I Bolla,Sarah Gray,Susan M Resnick,Regina Galante,Claudia Kawas

doi:10.1076/clin.12.3.330.1986

Abstract

Performance on letter and category fluency was studied in a group of 478 healthy, highly intelligent and educated, older adults (aged 55 to 94 years). The aim of the study was to determine and contrast the effects of age, sex, and intelligence (estimated by the NAART) on letter (FAS) and category (fruits, animal, vegetables) verbal fluency performance. Significant effects were found for age and NAART error score on all fluency scores. However, these effects were small in magnitude. The NAART was found to be a better predictor of verbal fluency scores than education. The relative sensitivity of letter and category fluency to age was not significantly different. Sex was related to performance for the categories of fruits and vegetables, with women outperforming men. Separate mean values for fluency measures are provided for different ages, NAART error scores, educational level, and sex.

Highlights

The Controlled Oral Word Association Test (COWAT; Borkowski, Benton, & Spreen, 1967), known as verbal fluency for categories and letters, is a test of frontal and temporal lobe functioning which involves sustained attention, retrieval of information, speech production fluency, and response initiation and suppression
Effects of Age and Sex on COWAT Scores Multivariate analysis of variance (MANOVA) was performed to determine whether age and sex contributed to COWAT performance gener
Intelligent, older adult population, both semantic category and letter fluency performance are associated with verbal intelligence and age

Summary

Introduction

The Controlled Oral Word Association Test (COWAT; Borkowski, Benton, & Spreen, 1967), known as verbal fluency for categories and letters, is a test of frontal and temporal lobe functioning which involves sustained attention, retrieval of information, speech production fluency, and response initiation and suppression. Bayles et al (1993) reported that both letter and semantic category fluency showed significant decline with age in persons without dementia, with greater age effects observed for letter fluency In addition to these contradictions surrounding age effects, the relative contributions of sex, intelligence, and education on COWAT performance remain unclear. In a previous study, we found significant sex effects on the FAS letter-fluency task, with women performing significantly better than men (Bolla, Lindgren, Bonaccorsy, & Bleecker, 1990). Expected mean category and letter fluency scores based on an individual’s verbal intelligence may prove to be more accurate when assessing for normal versus abnormal cognitive functioning This has not been examined in either of the large sample studies of verbal fluency (Crossley et al, 1997; Ivnik et al, 1996). A second aim was to provide mean performance scores based on these findings

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