Spatiotemporal linkage in infant interlimb coordination
Insights
Infant reaching develops significantly between 7 and 11 months. Young infants coordinate both hands simultaneously and in the same direction, while older infants use complementary movements.
Area of Science:
- Developmental psychology
- Motor control
- Infant behavior
Background:
- Bimanual reaching is a complex motor skill that emerges in infancy.
- Understanding the developmental trajectory of bimanual coordination is crucial for assessing motor development.
Purpose of the Study:
- To investigate the developmental changes in the timing and direction of arm and hand movements during bimanual reaching in infants.
- To compare the coordination patterns of bimanual reaching in 7-month-old and 11-month-old infants.
Main Methods:
- Observational study analyzing video recordings of infants reaching for a transparent cube.
- Frame-by-frame video analysis to assess the temporal linkage and directional movements of both hands.
Main Results:
- Seven-month-old infants demonstrated more temporally linked hand movements compared to 11-month-old infants.
- At 7 months, infants' hands moved towards the object in the same direction; at 11 months, hands moved in opposite, complementary directions.
Conclusions:
- Infant bimanual reaching undergoes significant developmental changes in coordination between 7 and 11 months.
- The transition from same-direction to complementary-direction hand movements reflects increasing motor control and planning capabilities.
Abstract:
Timing and direction of movement of the arms and hands of 7- and 11-month-old infants were examined during bimanual reaching for a transparent cube. Videotape analysis of frames from release of the hands to initial contact of one hand with the cube revealed that hand movement was more often temporally linked for 7-month infants than for 11-month infants. Also, at 7 months, the hands moved toward the cube in the same direction, whereas at 11 months, they moved in opposite (complementary) directions. Thus, although both 7- and 11-month infants perform bimanual reaching, at 7 months the 2 hands are linked both in timing and direction of movement in a fashion different than at 11 months.
