Semantic Fluency and Phonemic Fluency: Regression-based Norms for the Portuguese Population

Abstract

The main goal of this study was to produce adjusted normative data for the Portuguese population on two verbal fluency measures: the semantic fluency test (animals category) and the phonemic fluency test (letters M, R, and P). The study included 950 community-dwelling individuals (624 women and 326 men) aged between 18 and 98 (mean = 57.8, SD = 19.0), who had educational backgrounds ranging from 0 to 20 years (mean = 8.8, SD = 5.2). The results showed that age and education were significantly associated with semantic fluency and phonemic fluency performance. These demographic characteristics accounted for 42% of the semantic fluency and between 23% and 31% of the phonemic fluency performance variance. No significant sex effects were found. The normative data are presented as regression-based algorithms to adjust test scores for age and education, with subsequent correspondence between adjusted scores and percentile distribution.

Verbal Fluency Tasks: Effects of Age, Gender, and Education

“…The present study revealed that, with the exception of alternating fluency, all categories were affected by age (a progressive age-related decrease in the number of generated words), as in previous studies [12,13,18,19,20,21,22,23,24,35,36]. Alternating fluency had a negative correlation with age as in other studies [11,27].…”

“…In a healthy population such as the one in the present study, the effect of age probably disappears in the presence of years of education. Moreover, education affects all categories, a finding similar to what was found by other authors [12,13,18,19,20,21,22,23,37,38,39]. Essentially, when an effect of education is found, the assumption is that education increases the individual's exposure to vocabulary.…”

“…Normative data for semantic fluency were collected in order to complement and update the current European Portuguese normative data [20]. Furthermore, each category was analyzed separately in order to provide a tool to evaluate category-specific output.…”

“…For the Italian population, normative data have been collected by Novelli et al [12], Spinnler and Tognoni [13], Capitani et al [14], Costa et al [15,16], and Zarino et al [17]. Apart from the Spanish and German studies [18,19], it was found that education significantly affects fluency performance [20,21,22]. In the European Portuguese and English data, age also affected performance [20,23,24].…”

“…Apart from the Spanish and German studies [18,19], it was found that education significantly affects fluency performance [20,21,22]. In the European Portuguese and English data, age also affected performance [20,23,24]. Findings are, however, somewhat inconsistent, most likely due to variance in both population sampling, the category of verbal fluency tasks, and analysis methods.…”