Abstract
In this study, we tested the movement-related potential of self-paced tapping movements adding a factor of difficulty, which involved tapping the right and left middle finger simultaneously. The purpose of this study was to detect dipole locations during the negative slope to motor potential different levels of task difficulty, analyzed with high time resolution using a dipole tracing method. Subjects performed the following three tasks in randomized order : tapping the right middle finger and then the left middle finger immediately after movement of the right middle finger, the vice versa task, and tapping both the right and left middle fingers simultaneously. Left finger execution showed strong activation of the pre-supplementary motor area at an early onset of negative slope, even in the right-left sequence finger movement and the simultaneous right and left finger movements. Our study suggests that left finger movement in simple and difficult tasks strongly activates the contralateral sensorimotor area, and attention to the movement could be related to activation of the pre-supplementary motor area.
