The ontological status of task constraints: implications for research and practice

BACKGROUND: Coherent and ordered movement patterns emerge from the many available degrees-of-freedom and constraints channeling the interactions between them and the environment. AIM: We propose that task constraints have a different ontological status compared to the constraint categories of the environment and organism. METHODS: We argue that environmental and organismic constraints can be characterized as hard constraints as they are alternative descriptions of the dynamics (i.e., they describe the boundaries and characteristics of the system). Task constraints can, instead, be categorized as soft constraints–functions that influence the behavior toward task relevant solutions. Individuals search through the task space (function relating performance and movement parameters) encompassing rules and goal description but, only through learning, do the task constraints become actualized. Thus, in this manuscript, we discuss the ontology of task constraints elaborating how they should be discussed in the literature. CONCLUSION: This modified interpretation leads to an expansion of the concept into two frames (learner-based, experimenter-based) that has a series of consequences to future research on motor behavior.