Do Human Fetuses Anticipate Self-Oriented Actions? A Study by Four-Dimensional (4D) Ultrasonography
Masako Myowa-Yamakoshi and Hideko Takeshita
University of Shiga Prefecture, Japan

Using four-dimensional (4D) ultrasonography, arm and hand movements toward the face were examined in 27 human fetuses at 19 to 35 weeks of gestation, thereby enabling the continuous monitoring of their faces and other surface features such as the extremities. More than half of the observed arm movements resulted in the hand touching the mouth either directly or indirectly. Moreover, the fetuses opened their mouths before their hands came in contact with their mouths. Such fetal “anticipatory” behavior suggests the possibility that human fetuses perceive the manner in which they should move their hands to make contact with their mouths. Such movements are based on knowledge about intersensorimotor relations in their bodies.