沢田 康次
東北工業大学教授・工学部通信工学科
Sawada Yasuji
Tohoku Institute of Technology, Sendai, Japan

Abstract; Precise steady and transient experiments of hand-tracking task gave a new insight for the human percepto-motor control. In human as well as the other animals percepto-motor control system has an indispensable time delay necessary for processing and transferring neuronal signals. We found by hand-tracking experiments that, in spite of the delay the hand-motion statistically precedes the target-motion in constant frequency motion runs within a finite frequency range of the target-motion. Furthermore, it was verified that the positional error immediately after a sudden change of the target-frequency takes the minimum value when the phase-difference just before the change is in the vicinity of the mean operating phase-lead point observed in constant frequency runs. The results suggested that the human visual-motor control system, whose characteristic speed is slow, and comparable with that of environmental change, has obtained a proactive control by which dynamic error is minimized at a cost of the instantaneous positional accuracy. We proposed a delayed feed-forward model, which by adjusting only one parameter corresponding to the weight strength of feed-forward loop correctly reproduced the phase-lead phenomena observed in constant frequency runs, as well as the correlation of the transient error after the unexpected change of the target-frequency with the instantaneous phase just before the change. The relation of proactiveness and consciousness will be discussed.