Abstract
The present study was designed to investigate the effect of the motor programming and the force parameter applying process on the readiness potential (RP). Nine right-handed male subjects performed the force production task which required them to pull a trigger in an attempt to produce a target force. We investigated three conditions. In the single target condition, the subjects were asked to produce a target force of 1300 gf successively. In the multiple target condition, they were requested to produce two additional targets (i.e., 500 gf and 2100 gf) other than 1300 gf in a random order. In the third tracking condition, they were asked to track a white dot on a sine curve or a horizontal straight line displayed on a CRT in addition to the 1300 gf production task. The EEG measures preceding the 1300 gf production trials were exclusively analyzed. The RP amplitudes ranging from 1300 to 100 ms prior to the movement were significantly larger in the multiple target condition and the tracking condition than in the single target condition. These results suggested that the modification processes of the generalized motor program and force parameter were responsible for the enhanced RP.
