Trail Making Test, Stroop, and Verbal Fluency: Regression-Based Norms for the Icelandic Population.

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Executive functions are crucial cognitive processes.
• Existing normative data for cognitive tests may not adequately account for demographic variations.
• Accurate normative data is essential for reliable clinical assessment.

Purpose of the Study:

• To establish regression-based normative standards for three key executive function tests: Trail Making Test, Stroop, and Verbal Fluency.
• To investigate the influence of age, gender, and education on performance across these tests.
• To develop a tool for predicting executive function test scores adjusted for demographic factors.

Main Methods:

• Utilized a sample of 1,034 healthy Icelandic adults aged 18-64 years.
• Employed regression analyses to model test scores based on age, gender, and education, including their interactions.
• Calculated predicted scores for Trail Making Test, Stroop, and Verbal Fluency measures.

Main Results:

• Age, gender, and education significantly affected most executive function test measures.
• Older age and lower educational attainment were associated with poorer cognitive performance.
• Women generally demonstrated superior performance compared to men on these tests.

Conclusions:

• Normative data for executive function tests must incorporate adjustments for age, gender, and educational level.
• Relying solely on age-adjusted norms may lead to inaccurate interpretations in clinical practice.
• A practical program is available for generating demographically adjusted executive function scores.