In the scope of the research project 246/20 - The hidden rhythm of interpersonal (sub-)movement coordination, supported by the BIAL Foundation, the research team led by Alice Tomassini studied the submovement coordination at an individual- and dyadic-level. Participants performed a series of bimanual tasks in coordination with a partner (dyadic task) or alone (solo task) and, in the latter case, with or without visual feedback. Data, presented in the paper The microstructure of intra- and interpersonal coordination published in the Proceedings of the Royal Society B, showed that distinct coordinative structures emerged at the level of submovements, as a result of feedback properties. Specifically, the relative timing of submovements (between partners/effectors) shifted from alternation to simultaneity and a mixture of both when coordination is achieved using vision (interpersonal), proprioception/efference-copy only (intrapersonal, without vision) or all information sources (intrapersonal, with vision), respectively.
ABSTRACT
Movements are naturally composed of submovements, i.e. recurrent speed pulses (2–3 Hz), possibly reflecting intermittent feedback-based motor adjustments. In visuomotor (unimanual) synchronization tasks, partners alternate submovements over time, indicating mutual coregulation. However, it is unclear whether submovement coordination is organized differently between and within individuals. Indeed, different types of information may be variably exploited for intrapersonal and interpersonal coordination. Participants performed a series of bimanual tasks alone or in pairs, with or without visual feedback (solo task only). We analysed the relative timing of submovements between their own hands or between their own hands and those of their partner. Distinct coordinative structures emerged at the submovement level depending on the relevance of visual feedback. Specifically, the relative timing of submovements (between partners/effectors) shifts from alternation to simultaneity and a mixture of both when coordination is achieved using vision (interpersonal), proprioception/efference-copy only (intrapersonal, without vision) or all information sources (intrapersonal, with vision), respectively. These results suggest that submovement coordination represents a behavioural proxy for the adaptive weighting of different sources of information within action-perception loops. In sum, the microstructure of movement reveals common principles governing the dynamics of sensorimotor control to achieve both intra- and interpersonal coordination.
