The effect of inherent and incidental constraints on bimanual and social coordination.

ABSTRACT

The current investigation was designed to examine the influence of inherent and incidental constraints on the stability characteristics associated with bimanual and social coordination. Individual participants (N = 9) and pairs of participants (N = 18, 9 pairs) were required to rhythmically coordinate patterns of isometric forces in 11 in-phase and 12 multi-frequency patterns by exerting force with their right and left limbs. Lissajous information was provided to guide performance. Participants performed 13 practice trials and 1 test trial per pattern. On the test trial, muscle activity from the triceps brachii muscles of each arm was recorded. EMG-EMG coherence between the two EMG signals was calculated using wavelet coherence. The behavioral data indicated that individual participants performed the 11 in-phase pattern more accurately and with less variability than paired participants. The EMG coherence analysis indicated significantly higher coherence for individual participants than for the paired participants during the 11 in-phase pattern, whereas no differences were observed between groups for the 12 coordination pattern. The results of the current investigation support the notion that neural crosstalk can stabilize 11 in-phase coordination when contralateral and ipsilateral signals are integrated via the neuromuscular linkage between two effectors.