DEVELOPMENTAL-CHANGES IN PREHENSION OF DR AWING DEVICE DURING FIGURE COLORING

This study aims at clarifying developmental changes of prehension duri ng early childhood. Two hundred and twenty seven infants ranged from 3 0 to 69 months of age were asked to fill a circle with a felt-tip pen, and their processis were simultaneously monitored through four video cameras located at various position from the subjects. Reproducing the video tape, their prehensions of the pen were evaluated and were clas sified into seven different types. As the age increased, the infant te nded to show ''tripod grip''. Upper limb-desk contacts were also class ified into four different types. The more the age increased the more t he distal upper limb tended to touch the desk. These results suggested that an acquisition of the tripod grip and a stable suspension made i t possible to manipulate a pen effectively during early childhood.