Intentional Constraints on the Dynamics of Human Performance and Behavioral Variability in Motor Control

Manipulation of environmental constraints has been shown to influence the relative amounts of voluntary and involuntary control employed by a person to complete a task, as well as the resulting structure of performance variability. Generally, the voluntary control required when no constraints are present leads to self-similar changes in performance, some constraint provides involuntary control that leads to random fluctuations in performance, and constraint which provides feedback about performance accuracy can result in anti-persistent variability. The current study investigated whether providing two groups of individuals with different intentions for the same task would produce changes in voluntary and involuntary control similar to that observed following the manipulation of task constraints. Results indicated that a difference in intention does result in divergent uses of voluntary and involuntary control and distinctly different structures in performance variability.