Particular time-varying patternings of the limbs characterize behavior such as running, juggling, and baseball batting. These movements comprise many degrees of freedom at the neural and muscular level organized as functiona l units. What general principles are at work in the assembly of these units, and what quantities capture their dynamical, macroscopic nature? Movement patterns change to meet task demands, for example, type of pitch (fast ball or curve) or intent of the batter (meet the ball or swing for the fences). Are these changes principled? Given that information guides the assembling of movement patterns and execution of acts, how is this information made available in dynamically relevant and task-specific ways, an d how is it used? Experiments employing unimanual and bimanual rhythmic behaviors assess the underlying dynamics of these actions.

An additional line of research seeks to uncover invariants of motion for movements involving rotations about multiple joints. This work places heavy emphasis on the coupling between the haptic perception of limb (or limb segment) orientation and the performance of the movement, as well as on capturing the relevant perception-action variables in terms of rotational quantities.

Faculty: Bruce Kay, Jeff Kinsella-Shaw, Claire Michaels, Gerri Pellecchia, Michael Turvey

CESPA Fellows: Peter Beek, Ken Holt, Richard C. Schmidt

Graduate Students: Ryan Arzamarski, Alen Hajnal, Theo Rhodes, Mike Richardson

Collins, D., & Turvey, M. T. (1999). Dynamical stability analyses of coordination patterns. In U. Windhorst & W. Johansson, H. (Eds.), Modern techniques in neuroscience r esearch. Berlin: Springer Verlag.

Collins, D., Park, H., & Turvey, M. T. (1998). Relative coordination reconsidered: A stochastic account. Motor Control, 2, 228-240.

Mitra, S., Amazeen, P. G., & Turvey, M. T. (1998). Intermediate motor learning as decreasing active (dynamical) degrees of freedom. Human Movement Science, 17, 17-65.

Turvey, M. T., & Carello, C. (1996). Dynamics of Bernstein's level of synergies. In M. Latash. & M. T. Turvey (Eds.), Dexterity and its development (pp. 339-376). Hillsdale, NJ: Erlbaum.

Turvey, M. T. (1998). Dynamics of effortful touch and interlimb coordination. Journal of Biomechanics, 31, 873-882.