ANOSOGNOSIA AND PROCEDURAL LEARNING IN ALZHEIMERS-DISEASE

Awareness of cognitive deficits may rely on the implicit learning of i ntellectual limitations, and anosognosia in Alzheimer's disease (AD) m ay result from deficits in implicit learning, To examine this hypothes is, a consecutive series of 55 patients with probable AD were divided into groups with mild (n = 13), severe (n = 12), Or no anosognosia (n = 30) and were assessed with a neuropsychological battery that include d tests of declarative and procedural learning. Whereas there were no significant between-group differences in tests of declarative learning (the Buschke Selective Reminding Test and the Benton Visual Retention Test), patients with severe anosognosia showed a significantly worse performance on procedural learning (as measured with the Maze Learning Test) and a lest assessing set shifting abilities (the Wisconsin Card Sorting Test) than AD patients without anosognosia. The authors' resu lts suggest that deficits in procedural learning and anosognosia in AD may result from dysfunction in habit-learning systems.