Specialization of the motor system in infancy: From broad tuning to selectively specialized purposeful actions

D'Souza, H.; Cowie, D.; Karmiloff-Smith, A.; Bremner, A.

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.

Citation

D'Souza, H., Cowie, D., Karmiloff-Smith, A., & Bremner, A. (2016). Specialization of the motor system in infancy: From broad tuning to selectively specialized purposeful actions. Developmental Science, 20(4), Article e12409. https://doi.org/10.1111/desc.12409

• Journal Article Type: Article
• Acceptance Date: Jan 4, 2016
• Online Publication Date: Jun 2, 2016
• Publication Date: Jun 2, 2016
• Deposit Date: May 24, 2016
• Publicly Available Date: Jun 2, 2017
• Journal: Developmental Science
• Print ISSN: 1363-755X
• Electronic ISSN: 1467-7687
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 4
• Article Number: e12409
• DOI: https://doi.org/10.1111/desc.12409
• Public URL: https://durham-repository.worktribe.com/output/1383911