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The development of prehension in normal infants
Insights
Infant prehension develops longitudinally through three phases, from whole-hand use to specialized finger grasps. Object size influences but doesn
Area of Science:
- Developmental Psychology
- Motor Skill Acquisition
- Infant Motor Development
Background:
- Prehension, the act of grasping, is a fundamental developmental milestone in infancy.
- Understanding the typical trajectory of prehensile skill development is crucial for identifying potential delays.
Purpose of the Study:
- To longitudinally investigate the developmental progression of prehension in typically developing infants.
- To analyze the influence of object characteristics on grasp patterns.
- To compare current findings with historical data on infant prehension.
Main Methods:
- Filmed spontaneous prehensile responses of 10 infants (4-12 months) to various objects (cubes, raisins, keys).
- Utilized slow-motion video analysis for detailed examination of grasp techniques.
- Compared object-specific grasp data with established research by Henry Halverson.
Main Results:
- Infants demonstrated a consistent three-phase developmental progression in prehension: unspecialized whole-hand use, partial hand specialization, and specialized distal finger pad use.
- Object size and shape influenced grasp selection but did not rigidly determine it.
- While grasp patterns for identical objects varied (34% consistency), infants consistently utilized the same developmental phase of prehension (65% consistency).
- Infants in this study generally acquired grasps at slightly earlier ages than those in Halverson's study.
Conclusions:
- Infant prehension follows a predictable developmental sequence, characterized by increasing specialization of hand use.
- Object properties play a role in modulating grasp strategies within these developmental phases.
- The findings offer valuable insights for assessing and supporting the prehensile development of infants, including those with developmental disabilities.
Abstract:
This study investigated the longitudinal development of prehension in 10 normal infants, 4 through 12 months of age. The infants' spontaneous prehensile responses to 2.54-centimeter (1-inch) red cubes, 1.27-centimeter (1/2-inch) red cubes, raisins, and plastic keys on chains were filmed with a Kodak Super 8 movie camera, transferred to videotape in slow motion, and analyzed. The 2.54-centimeter (1-inch) red cube data were compared to data gathered by Henry Halverson, noted authority in the area of prehension. Infants in both studies followed the same trend in their acquisition of prehensile skills, but the infants in the current study used most grasps at slightly earlier ages. The size and shapes of the objects presented influenced, but did not dictate, the grasps used. All grasps used by infants fall into three developmental phases: 1. using whole hands in an unspecialized manner; 2. using parts of hands as some specialization begins to develop; and 3. using the pads of distal phalanges or the tips of fingers in a specialized manner. The infants responded to the 3 presentations of like objects with the same grasp only 34 percent of the time, yet they were 65 percent consistent in using the same phase of prehensile development for the 3 presentations. Implications of these findings for developmentally disabled infants are discussed.