GESTURAL COMMUNICATION IN ALZHEIMERS-DISEASE

Spontaneous communicative hand-arm gestures were evaluated in elderly patients with probable Alzheimer's disease (AD) and healthy controls ( NC). Based on the notion that speech and gestures arise from common se mantic-conceptual representations, qualitatively similar linguistic an d gestural communicative impairments were expected in association with semantic memory impairment in AD. Despite equal quantity and rate of gesturing, AD and NC groups produced qualitatively different types of gestures. Patients with AD produced proportionately more referentially ambiguous gestures, fewer gestures referring to metaphoric as opposed to concrete contents, and fewer conceptually complex bimanual gesture s. Impaired gestural clarity correlated with severity of linguistic/co nceptual impairments and disturbed production of pantomimic movements on a test of ideomotor limb apraxia. Results are consistent with the h ypothesis that a central semantic-conceptual disorder underlies the si milar linguistic and gestural communication impairments in AD.