IS VISUALLY GUIDED REACHING IN EARLY INFANCY A MYTH

The issue examined was whether infants require sight of their hand whe n first beginning to reach for, contact, and grasp objects. 7 infants were repeatedly tested between 6 and 25 weeks of age. Each session con sisted of 8 trials of objects presented in the light and 8 trials of g lowing or sounding objects in complete darkness. Infants first contact ed the object in both conditions at comparable ages (mean age for ligh t, 12.3 weeks, and for dark, 11.9 weeks). Infants first grasped the ob ject in the light at 16.0 weeks and in the dark at 14.7 weeks, a nonsi gnificant difference. Once contact was observed, infants continued to touch and grasp the objects in both light and dark throughout all sess ions. Because infants could not see their hand or arm in the dark, the ir early success in contacting the glowing and sounding objects indica tes that proprioceptive cues, not sight of the limb, guided their earl y reaching. Reaching in the light developed in parallel with reaching in the dark, suggesting that visual guidance of the hand is not necess ary to achieve object contact either at the onset of successful reachi ng or in the succeeding weeks.