Laterality of arm movement in full-term newborn

We have investigated 20 healthy full-term newborns between the 4th and the 6th day of life in standard conditions for laterality of arm movements, before and after introduction of a target. The durations of recording were: (a) 5 min continuously before target introduction; (b) five 1-min units during target presentation. The movements studied were extension, flexion, movement with semiflexed arm with hand half-open or open toward the midline of the body, and total movements. Each of these items were counted separately and the counts were compared within and between sides. Spontaneous movements showed no side preference whereas in the presence of the target, movements toward the midline (target directed movements) showed a significant right-hand preference.