Assessed infants' and adults' adjustment of hand orientation before grasping objects. Found that infants modified their hand orientation to match the long axis of an object, did not make anticipatory hand adjustments before reaching through a narrow aperture to grasp an object, and oriented their hand to be parallel with the handle of an object.…

Reaching and retrieving, with and without visual feedback of the hand, were observed in 50 infants ranging in age from 2 1/2 to 6 1/2 months. While failure to see the hand did not completely inhibit reaching and retrieving, it did reduce reaching and retrieving for infants 5 1/2 months and older. (Author/JMB)

Reports two experiments which were designed to establish whether errors in infants' manual searches for objects are caused by changes in the location of an object or by the change in the relation between old and new hiding places. (JMB)

Seven infants were tested between the ages of 6 and 25 weeks to see how they would grasp objects presented in full light and glowing or sounding objects presented in total darkness. In all three conditions, the infants first grasped the objects at nearly the same time, suggesting that internal stimuli, not visual guidance, directed their actions.…

Fourteen five- and nine-month-old infants were presented with illuminated toys to reach for in total darkness. In half the trials, a luminescent marker was attached to the reaching hand. The nine-month olds reached just as accurately with or without the hand marker, whereas five-month olds were generally inaccurate and unaffected by the marker.…

Three experiments examined vision's role in infants' grasping of horizontally and vertically oriented rods. Found that infants differentially oriented their hand regardless of lighting and similar to control conditions where they could see rod and hand throughout reach. Findings suggest that infants may use current sight of object's orientation or…