Movement-related sensory feedback mediates the learning of a new bimanual relative phase pattern

On the basis of findings emphasizing the role of perceptual consequences in movement coordination, the authors tested the hypothesis that the learning of a new bimanual relative phase pattern would involve the matching of the movement-related sensory consequences (rather than the motor outflow commands) to the to-be-learned pattern. Two groups of participants (n = 10 in each) practiced rhythmically moving their forearms with a phase difference of 30 degrees. In 1 group, a difference in the arms' eigenfrequencies was imposed such that synchronous generation of the left and right motor commands resulted in the required relative phase (30 degrees), yielding incongruence between the motor commands and their sensory consequences. In the other group, the experimenter imposed no eigen-frequency difference so that the sensory consequences were congruent with the motor commands. Throughout the practice period, performance of both groups was assessed repeatedly for the congruent situation (i.e., no eigenfrequency difference). On those criterion tests, both groups performed the required pattern equally well. The authors discuss that result, which corroborated the hypothesis, from a dynamical systems perspective.