Abstract
In executing purposeful actions, adults select sufficient and necessary limbs. But infants often move goal-irrelevant limbs, suggesting a developmental process of motor specialization. Two experiments with 9- and 12-month-olds revealed gradual decreases in extraneous movements in non-acting limbs during unimanual actions. In Experiment 1, 9-month-olds produced more extraneous movements in the non-acting hand/arm and feet/legs than 12-month-olds. In Experiment 2, analysis of the spatiotemporal dynamics of infants' movements revealed developmental declines in the spatiotemporal coupling of movements between acting and non-acting arms. We also showed that the degree of specialization in infants' unimanual actions is associated with individual differences in motor experience and visual attention, indicating the experience-dependent and broad functional nature of these developmental changes. Our study provides important new insights into motor development: as in cognitive domains, motor behaviours are initially broadly tuned to their goal, becoming progressively specialized during the first year of life.
Original language | English |
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Article number | e12409 |
Number of pages | 14 |
Journal | Developmental Science |
Volume | 20 |
Issue number | 4 |
Early online date | 2 Jun 2016 |
DOIs | |
Publication status | Published - Jul 2017 |
Bibliographical note
D'Souza, H. , Cowie, D. , Karmiloff‐Smith, A. and Bremner, A. J. (2017), Specialization of the motor system in infancy: from broad tuning to selectively specialized purposeful actions. Dev Sci, 20: e12409. doi:10.1111/desc.12409© 2016 John Wiley & Sons Ltd.
Keywords
- Child Development/physiology
- Extremities/physiology
- Humans
- Infant
- Learning/physiology
- Motor Activity/physiology
- Movement/physiology
- Psychomotor Performance