Multidimensional exploration of bimanual coordination

Bimanual coordination was examined in three experiments. Both spatial and temporal influences on bimanual movement coordination were investigated. Experiment 1 examined the coordination of symmetrical movement patterns, Experiment 2 examined voluntary transitions between coordination patterns, and Experiment 3 examined the coordination of asymmetrical movement patterns.Five healthy, right handed adult subjects participated in all three experiments. An opto-electronic tracking system was used to record the movement trajectories of the arms. From these recordings spatial and temporal stability, accuracy, and performance variables were analyzed.In Experiment 1, 12 symmetrical bimanual shoulder movement patterns and 8 single shoulder movement patterns were used to examine the general influence of relative phase and the influence of spatial orientation within various relative phase groups. Vertical, horizontal, and diagonal movements were used to produce in-phase, out-of-phase, and hetero-phase combinations. The results indicated that in-phase patterns were most stable and accurate, both spatially and temporally. The out-of-phase patterns were least stable temporally, and the hetero-phase patterns were least stable spatially. Spatial orientation influenced stability and accuracy within the various relative phase groups.Experiment 2 examined the voluntary transition between coordination patterns. Transition duration was influenced by relative spatial orientation, relative phase, and the relative stability of the involved patterns. With a fixed pre-transition pattern, more stable post-transition patterns resulted in shorter transition durations. When the post-transition pattern was fixed, more stable pre-transition patterns resulted in shorter transition durations.Experiment 3 examined 36 bimanual coordination patterns where the two arms performed movements in different spatial orientations. The temporal stability of the patterns correlated with the degree to which homologous muscles participated in the movements. From this experiment it was also evident that mechanical perturbations played an important role in spatial performance.The results from the three experiments indicate that spatial orientation has a significant influence on bimanual movement performance. The present data provide an empirical basis for the inclusion of spatial orientation in future theoretical models of bimanual coordination. These data may also explain the difficulty in performing certain bimanual movement coordination (e.g., the backstroke in swimming), and may provide a basis for the diagnosis of dysfunctional motor coordination.U of I OnlyETDs are only available to UIUC Users without author permissio