Visual control of hand approach movements in new‐borns

Abstract

Studies on the possible eye‐hand coordination of the new‐born to date have only examined forward extensions of the hand. Views are divided as to whether eye‐hand coordination exsits in neonates, even though Von Hofsten (1982) has provided strong evidence for its existence. The following experiment was conducted to investigate possible eye‐hand coordination. We observed the hand and eye movements of 10 new‐borns. A small ball was presented at 25° to the left or the right of the median line for 40 s, followed by 20 s during which the visual field was empty. The neonate was seated, and able to move freely. Movements were filmed continuously by three video‐cameras, two with frontal views and one with an overhead view. Hand and eye movements were coded frame by frame. The latency, timing and direction of hand and eye movements were compared. We found that contacts with the object were rare and that hand movements appeared slow, complex and erratic in direction. Fixations of the object were made up of successive short bouts. Directional adjustments of the hand towards the object only occurred under visual fixation. A pertinent correction in hand trajectory was found at the beginning of each eye fixation.