Motor and non-motor sequence learning in patients with basal ganglia lesions: the case of serial reaction time (SRT)

In order to address the question of whether the basal ganglia are involved exclusively in regulation of motor sequence learning, or if they are involv ed in non-motor sequence learning as well, two versions of the serial react ion time (SRT) task were administered: First is the standard version of the SRT task in which the sequence is executed motorically, and the second is a non-motor version of the task which requires response only to a particula r position of the sequence. Sixteen patients with damage restricted to the region of the basal ganglia and 16 matched control subjects participated in this study. In addition to the motor and non-motor SRT tasks, two declarat ive memory tests (Visual Paired Associates and Rey Auditory-Verbal Learning Test) were administered to the participants. Results indicate that the two groups did not differ either on learning rate of the two declarative tasks , or on the declarative component of the SRT tasks (i.e., 'generate'). Howe ver, the control group was significantly superior to the basal ganglia (BG) group in learning a specific sequence in the motor and non-motor SRT tasks . Results suggest that the basal ganglia are involved in the regulation of non- motor as well as motor sequence learning. (C) 1999 Elsevier Science Lt d. All rights reserved.