Judgment in Older Adults with Normal Cognition, Cognitive Complaints, MCI, and Mild AD: Relation to Regional Frontal Gray Matter

Abstract

We investigated regional gray matter (GM) reduction as a predictor of judgment ability in 120 non-depressed older adults with varying degrees of cognitive complaints and/or impairment (including those with MCI and mild AD). Participants underwent neuropsychological assessment, including the Test of Practical Judgment (TOP-J), a recently developed instrument that evaluates judgment and problem solving related to safety, medical, social/ethical, and financial issues. Structural MR scanning included T1-weighted SPGR volumes acquired at 1.5 Tesla. We used voxel-based morphometry to analyze the relationship between GM density and TOP-J scores, controlling for age, education, gender, intracranial volume, verbal memory, and crystallized knowledge. Consistent with our hypothesis, judgment ability correlated with GM density in prefrontal regions (left inferior and superior frontal gyri). Findings extend previous observations of frontal involvement in higher-order cognitive abilities/executive functions and provide initial validation of the TOP-J's sensitivity to the integrity of these brain regions in individuals at risk for dementia.