PARKINSONIAN-PATIENTS WITHOUT DEMENTIA OR DEPRESSION DO NOT SUFFER FROM BRADYPHRENIA AS INDEXED BY PERFORMANCE IN MENTAL ROTATION TASKS WITH AND WITHOUT ADVANCE INFORMATION

A predominant symptom of Parkinson's disease is akinesia and bradykine sia, slowing in the initiation and execution of voluntary movement. Th ere has long been speculation as to whether cognitive processes underg o similar processes, but findings may be confounded by the frequent co occurrence of dementia and/or depression. Mental rotation provides an internal or cognitive analogue of real movement, and enables us to det ermine the speed of such mental processes independent of any concurren t motor slowing in response initiation and execution. Medicated patien ts with Parkinson's disease who were Free of dementia and depression w ere found to be able to mentally rotate alphanumeric or figural stimul i, with and without advance information as to the view (front or back) of a stick figure shortly to be shown, as rapidly as normal healthy c ontrols. We conclude that cognitive processes involved in mental relat ion are not necessarily slowed in Parkinson's disease.