Role of the asymmetrical tonic neck reflex in hand visualization in normal infants.

Fourteen infants were each videotaped 7 times within the first 12 weeks of life to determine whether or not the asymmetrical tonic neck reflex had a role in placing their hands within their fields of vision. Infants' arms were more frequently out of the reflex position. Hands were within the peripheral visual field more often than in the focal visual field or not within the visual field. The proportion of observations that hands were in a particular visual field varied in accordance with the presence or absence of the reflex. A higher proportion of reflex observations occurred in the focal visual field, whereas a higher proportion of observations made when the infants were not in the reflex position occurred in the peripheral visual field. Further, the proportion of focal field observations in the reflex position was greater than the proportion of observations out of the reflex position for the first six of the seven ages. This study confirms that when infants are in the asymmetrical tonic neck reflex position, their hands are more likely to be in a position in which they can be visualized.