[Category fluency (animals, professions) in normal cognitive ageing and dementia]

Area of Science:

• Neuropsychology
• Cognitive Neuroscience

Context:

• Semantic verbal fluency tests (VFT) are crucial for assessing cognitive function.
• Demographical variables like age and education significantly impact VFT performance.
• Existing VFT norms may not adequately account for these demographic influences.

Purpose:

• To derive regression-based normative data for semantic VFT scores.
• To evaluate the clinical utility of these new norms in distinguishing normal aging from dementia.
• To investigate the phenomenon of stuck-in-set perseveration in dementia patients.

Summary:

• Regression-based norms for animal naming, profession naming, and summed VFT scores were established using data from 1,825 individuals (ages 24-81).
• The animal naming VFT score demonstrated the highest sensitivity in differentiating normal aging from dementia.
• Stuck-in-set perseveration occurred in 11.3% of Parkinson dementia and frontal variant frontotemporal dementia cases, and was associated with executive control deficits, particularly response inhibition measured by the Alternating Graphical Sequences Test.

Impact:

• Provides updated, demographically adjusted VFT norms for improved clinical assessment.
• Highlights the animal naming VFT as a key measure for early dementia detection.
• Offers insights into perseveration patterns and their relationship with executive dysfunction in various dementia types.