Invariant relative timing in the learning of a perceptual motor skill

The concept of invariant relative timing has typically been associated with the concept of a generalized motor program. The present study approaches the phenomenon of invariant relative timing from the perspective of learning. The underlying question of concern for this study is "What is learned?". The specific question addressed by the present study is whether relative timing is one of the essential properties of movement that is learned during skill acquisition. In the present experiment, subjects were given extensive practice in learning to visually track and reproduce a criterion waveform using a joystick control for their response. In order to test whether subjects learn the relative timing of a movement, they were transferred to waveforms which were identical to the criterion in terms of relative timing, but different in terms of absolute timing. Measurements were taken on all waveforms in two conditions: 1) in a pursuit tracking condition where subjects were temporally constrained by the stimulus, and 2) in a reproduction condition where subjects' timing was not constrained. Pursuit tracking performance was evaluated using three dependent measures: RMS error, lead-lag index, and variability. Performance in the reproduction condition was subjected to three analyses: 1) an harmonic analysis, which described each response waveform in terms of its phase, frequency, amplitude, and period; 2)proportional interval durations; and 3) proportional interval displacements. The outcome from both conditions gives support to the idea that the invariant relative timing of movement is one of the aspects of a movement that humans learn.Education, Faculty ofCurriculum and Pedagogy (EDCP), Department ofGraduat