RESPONSE PROGRAMMING IN DEMENTIA OF THE ALZHEIMER-TYPE - A KINEMATIC ANALYSIS

Although planning is important for the functioning of patients with de mentia of the Alzheimer Type (DAT), little is known about response pro gramming in DAT. This study used a cueing paradigm coupled with quanti tative kinematic analysis to document the preparation and execution of movements made by a group of 12 DAT patients and their age and sex ma tched controls. Participants connected a series of targets placed upon a WACOM SD420 graphics tablet, in response to the pattern of illumina tion of a set of light emitting diodes (LEDs). In one condition, parti cipants could programme the upcoming movement, whilst in another they were forced to reprogramme this movement on-line (i.e. they were not p rovided with advance information about the location of the upcoming ta rget). DAT patients were found to have programming deficits, taking lo nger to initiate movements; particularly in the absence of cues. While problems spontaneously programming a movement might cause a greater r eliance upon on-line guidance, when both groups were required to guide the movement on-line, DAT patients continued to show slower and less efficient movements implying declining sensori-motor function; these d ifferences were not simply due to strategy or medication status. (C) 1 997 Elsevier Science Ltd.