Assessment of procedural memory in Parkinson's disease.

1. Findings in cognitive psychology and neuropsychology have led to consider the existence of several mnestic systems. This study focuses on a now clearly established distinction between the procedural and the declarative memories. 2. The aim of the present study was to try and determine which of the two acquisition steps (learning and automation) is affected by Parkinsonians' mnestic difficulties, and to verify if these difficulties are linked to the skill content (declarative or motor). 3. To answer these questions, 20 Parkinsonians under treatment underwent specific tests: the maze test and the arithmetic alphabet test. 4. Results show that, by comparison with 20 matched healthy individuals, the deficiencies observed in Parkinson's disease affect both the declarative and the motor skills. In addition, Parkinsonians suffer difficulties in both acquisition steps: learning and automation. 5. These results could account for the cognitive and motor disturbances observed in Parkinson's disease; these abnormalities should be among the pharmacological targets in future.