Dynamic primitives in constrained action: systematic changes in the zero-force trajectory.

Humans substantially outperform robotic systems in tasks that require physical interaction, despite seemingly inferior muscle bandwidth and slow neural information transmission. The control strategies that enable this performance remain poorly understood. To bridge that gap, this study examined kinematically constrained motion as an intermediate step between the widely studied unconstrained motions and sparsely studied physical interactions.

Separating neural influences from peripheral mechanics: the speed-curvature relation in mechanically constrained actions.

While the study of unconstrained movements has revealed important features of neural control, generalizing those insights to more sophisticated object manipulation is challenging. Humans excel at physical interaction with objects, even when those objects introduce complex dynamics and kinematic constraints. This study examined humans turning a horizontal planar crank (radius 10.

Serial processing in human movement production.

Parallel processing is often considered to be synonymous with biological computation, but a great deal of evidence points to serial computation being used by animals to solve specific types of problems. In particular, the observation of movement intermittency (fluctuations in limb kinematic variables that cannot be explained by low-level dynamics of the system) seems to imply a serial temporal segmentation strategy in the planning of arm movements. This paper discusses prior observations of movement intermittency in different task contexts, possible theoretical and physiological origins of the phenomenon, and implications for human movement strategies.