| Abstract: | Head orientation was investigated in a longitudinal study of 37 infants, who were observed at ages 2, 4, 8, and 12 weeks, during a 60-second period that followed each of four (60 second) midline or lateral holds. When newborn, the infants tended to lie with their heads to the right, but this bias weakened over the first 3 postnatal months. This rightward motor bias was constrained further by such factors as sex and holding position; both factors had their strongest effect at 8 weeks. Finally, evidence was found for behavioral reorganization of postural orientation such that head orientation was less influenced by prior head positioning after than prior to 8 weeks. |
