[Relationships among the position in the fetal period, head-turning during three days after birth, and hand activity in infancy].

The purpose of this study was to examine whether or not early indications of lateralization could be found in the perinatal period. The position in the fetal period and spontaneous head-turning soon after birth of one hundred and twenty-two subjects were measured. These subjects' hand activities (preference and manipulation) in infancy were later investigated through a questionnaire given to their parents. Results showed that the position in the fetal period and head-turning soon after birth were related to the functional asymmetries of hand activity in infancy. In addition, the results on the hand activity in infancy suggested that the developmental process of manipulation was different from that of hand preference with respect to functional lateralization.