Semantic distance abnormalities in mild cognitive impairment: their nature and relationship to function.

Objective: The authors sought to directly examine compromises in the semantic system in mild cognitive impairment and their possible relationship to everyday functional competencies.

Method: Study participants were 25 patients who met criteria for amnestic mild cognitive impairment, 27 patients with mild or moderate Alzheimer's disease, and 70 healthy comparison subjects. The authors administered a novel semantic distance task in which participants make decisions about word or image stimuli that correspond to real-world entities that differ in physical size.