Presupplementary motor area activation during sequence learning reflects visuo-motor association.
In preceding studies (Hikosaka et al., 1996; Sakai et al., 1998) we have shown that the presupplementary motor area (pre-SMA), an anterior part of the medial premotor cortex, is active during visuo-motor sequence learning. However, the paradigm required the subjects first to acquire correct visuo-motor association and then to acquire correct sequence, and it was still unknown which of the two processes the pre-SMA is involved in. To further characterize the role of pre-SMA, we have conducted another series of functional magnetic resonance imaging experiments using three learning paradigms. The three were the same in that they involved a visuo-motor association component, but they differed in terms of the involvement of sequential components; one involved no sequence learning, whereas the other two involved learning of motor sequence or perceptual sequence. Comparison of the learning conditions with the any-order button press condition revealed pre-SMA activation in all three paradigms. The pre-SMA activation remained unchanged during learning of visuo-motor associations but decreased during learning of sequences, suggesting that the pre-SMA is related to visuo-motor association rather than sequence. The decrease of pre-SMA activation in the sequential paradigms may reflect the process by which individual visuo-motor associations were replaced by the formation of sequential procedural memory, which occurs outside the pre-SMA. Thus activation of the pre-SMA was related to the extent to which the task performance depended on conscious visuo-motor associations.
Sakai
K
K
Department of Physiology, Juntendo University School of Medicine, Tokyo 113, Japan, Department of Neurology, Division of Neuroscience, Graduate School of Medicine, University of Tokyo, Tokyo 113, Japan, Communications Research Laboratory, Kobe 651-2.
Hikosaka
O
O
Miyauchi
S
S
Sasaki
Y
Y
Fujimaki
N
N
Pütz
B
B
D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*