Movement variability near goal equivalent manifolds: Fluctuations, control, and model-based analysis

Joseph P. Cusumano, Jonathan B. Dingwell
2013 Human Movement Science  
Fluctuations in the repeated performance of human movements have been the subject of intense scrutiny because they are generally believed to contain important information about the function and health of the neuromotor system. A variety of approaches has been brought to bear to study of these fluctuations, however it is frequently difficult to understand how to synthesize different perspectives to give a coherent picture. Here, we describe a conceptual framework for the experimental study of
more » ... or variability that helps to unify geometrical methods, which focus on the role of motor redundancy, with dynamical methods that characterize the error-correcting processes regulating the performance of skilled tasks. We describe how goal functions, which mathematically specify the task strategy being employed, together with ideas from the control of redundant systems, allow one to formulate simple, experimentally testable dynamical models of inter-trial fluctuations. After reviewing the basic theory, we present a list of five general hypotheses on the structure of uctuations that can be expected in repeated trials of goal-directed tasks. We review recent experimental applications of this general approach, and show how it can be used to precisely characterize the error-correcting control used by human subjects.
doi:10.1016/j.humov.2013.07.019 pmid:24210574 pmcid:PMC3858478 fatcat:opefzgzxbfb5bhfvnruhbk7ewy