Cerebral Mechanism in the Development of Skill in Manual Work

The cerebral mechanism in the training process of manual work was examined by simultaneous recordings of motion analysis, EMG and EEG of the subjects in the course of acquiring skill in chain-stitching. Four phases of progress were distinguished: 1) the period of increasing speed, 2) agitation period of unrhythmic and inaccurate movement. 3) the period of recovering work accuracy, and 4) the period of established motion regularity. In the discharges of neuro-muscular unit of working muscles, the regularity appeared with the advance of training, and this proved that corticalization changed to spinalization in the central neuro-mechanism. In EEG θ waves of the trained appeared localizing in the left frontal region during work. Previous suggestions on procedure reduced agitation period in the course of training. From these results, it seemed likely that simple repetitive manual work like stitching was sustained by a kind of conditioned reflex and by subcortical reflex mechanism.