Related Experiment Video
Updated: Apr 7, 2026
Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment
Published on: June 25, 2019
Normative data and clinical validity of verb and phonemic fluency tasks in Turkish-speaking older adults
Samet Tosun1, Fenise Selin Karalı1, Elif İkbal Eskioğlu1
1Department of Speech and Language Therapy, Biruni University.
Objective:
Verbal fluency tasks are commonly used in clinical neuropsychology to assess language and executive functions. Verb fluency and phonemic fluency are sensitive to age-related cognitive decline and neurodegenerative conditions such as mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, normative data for these tasks remain limited in Turkish-speaking populations, especially when culturally adapted phonemic fluency measures are employed. This study aimed to (a) provide normative data for verb fluency and Turkish-adapted K-A-S phonemic fluency tasks in healthy middle-aged and older adults, and (b) examine the discriminant validity of these tasks in distinguishing healthy controls from individuals with MCI and AD.
Method:
In the normative phase, 357 healthy adults were assessed and stratified by age and education. Norms were reported as regression-based z scores and percentile tables.
Results:
In the clinical phase, 150 participants (50 healthy, 60 MCI, and 40 AD) completed the tasks. Kruskal-Wallis and post hoc analyses revealed significant group differences across all fluency measures. Healthy controls outperformed both clinical groups, and the MCI group scored higher than the AD group, especially on K fluency and total K-A-S scores.
Conclusions:
These findings highlight the diagnostic value of verb and phonemic fluency tasks and the importance of using culturally appropriate norms in Turkish-speaking populations for early detection of cognitive impairment. (PsycInfo Database Record (c) 2026 APA, all rights reserved).
