Infants Return to Two-Handed Reaching When They Are Learning to Walk

TLDR

The study investigated whether 1‑year‑old infants resume two‑handed reaching upon independent walking. Nine infants were followed longitudinally before, during, and after transition to upright locomotion, with weekly assessments of reaching responses and interlimb coordination across three tasks. Two‑handed reaching increased after walking onset but declined as balance improved, indicating that the return to two‑handed reaching is experience‑dependent and reflects integration of new motor skills.

Abstract

Abstract The authors examined whether infants of about 1 year return to 2-handed reaching when they begin to walk independently. Infants (N = 9) were followed longitudinally before, during, and after their transition to upright locomotion. Every week, the infants' reaching responses and patterns of interlimb coordination were screened in 3 tasks involving different adaptive reaching responses. Before the onset of upright locomotion, the infants responded to each task adaptively. Following walking onset, they increased their rate of 2-handed responses in all tasks. The 2-handed responses declined when the infants gained better balance control. The results suggest that infants' return to 2-handed reaching is experience dependent. Those findings are discussed in terms of the integration of new developing motor skills into existing cognitive and motor repertoires.