Influence of age and education on neuropsychological test results

Attribute variables of age and education were evaluated with relation to the General Neuropsychological Scale (GNDS), a comprehensive measure of neuropsychological functions. A brain-damaged group and a control group, each composed of 50 subjects, were studied. The GNDS clearly differentiated the two groups, and was significantly related to age and education among the controls. However, the effects of age and education were minimal among brain-damaged subjects. These results suggest that adjusting raw scores according to age and education may not be a clinically valid procedure for brain-damaged subjects, and may only tend to invalidate the raw scores of neuropsychological tests.