Encoding arm and leg movements in the same or opposite direction.

Abstract

This study examined whether working memory performance for arm and leg movements differed when encoding in the same or opposite direction (relative to the observed direction) and which direction was better for encoding these two kinds of movements. The results showed that encoding direction regulated the comparison between arm and leg movements in working memory performance. In the same-direction encoding condition, arm movements performed better than leg movements, whereas in the opposite-direction encoding condition, arm movements performed worse. In addition, arm movements performed better when they were encoded in the same direction, while encoding leg movements in the same direction did not differ from encoding them in the opposite direction. Therefore, we should move appropriate body parts for the same and opposite learning directions. The same direction is suitable for learning arm movements but not leg movements; the opposite direction is suitable for learning leg movements but not arm movements. We should also consider the appropriate learning direction for arm movements rather than leg movements. Arm movements are encoded more effectively in the same direction than in the opposite direction.