Visually guided reaching in infant monkeys after restricted rearing

Infant macaques were reared from birth in an apparatus which pre cluded sight of their body parts. At 35 days postpartum one hand was exposed to view. Visual fixation of this hand was insistent and prolonged; visually guided reaching was poor, but it improved during ten succeeding hours of exposure. Little concomitant improvement occurred in the reaching of the unexposed hand.