Verbal fluency performance of Turkish speaking adults

Verbal fluency is measured by a number of generated words in a limited time according to a given condition. Categorical and phonemic fluency are two common ways to evaluate the verbal fluency. Verbal fluency measures are frequently used by neuropsychologists and speech language therapists in the identification of quality and quantity of linguistic and cognitive impairments, also in the assessment of frontal and/or temporal lobe functions.The aim of this study is to identify the categorical and phonemic fluency performance of different age, gender, educational groups and the differences between them; also to develop word norms for categories and phonemes. To this purpose the categories of `animals, fruits and vegetables, vehicles, clothes, parts of the body, furniture? and the phonemes of /k,b,s,a,p,e,f,n,r,v,z,ü/ were examined.Participants of the study are 382 Turkish speaking healthy adults, with ages ranging from 18 to 90. Participants were divided into 6 age groups (18-24, 25-34, 35-44, 45-54, 55-64 and 65+) and 4 education groups (illiterate, low, intermediate and high).The results showed that the number of generated words differs among categories (body parts > fruits and vegetables > animals> clothes > vehicles > furniture) and among phonemes (/k>b>s>a>p>e>f>n>r>v>z>ü/). Categorical fluency scores are higher than phonemic scores.There is a significant effect of education and age on categorical and phonemic fluency. The 25-34 age group has the highest and the 65+ age group has the lowest scores in both categorical and phonemic fluency. Education has a positive effect on both fluency scores, but no differences were found between illiterates and low educated group. Gender has no effect on categorical and phonemic fluency scores in general; however, in categories of fruits and vegetables, clothes females generate more words than males.A regression model was calculated for education, gender and age to determine which variables made meaningful contribution to fluency scores. Education and gender accounted for 30% of the variance on the categorical fluency, whereas age had no contribution. Education and age but not gender accounted for 40% of the variance on the phonemic fluency.In order to provide norms for generated words, total frequencies and first five response rates were calculated for each category and phoneme.Keywords: Verbal fluency, phonemic fluency, categorical fluency, Turkish.