Spring 2010. Trends in Motor Control. S-R approaches (Black Box) Hierarchical models (Active Processor) Dynamic systems (Dynamic interplay among systems). Study of Motor Behavior in the 20th Century. Prior to the 1900’s – introspection and self report measures
In stimulus response models the stimulus triggers a chain of individual reflex circuits that create a response. In this view is a passive recipients responding to the stimuli present in the environment and to which he or she is confronted
Goal directed????S-R Theory
Motor programs began with the definition of a fixed set of commands that could be structured prior to movement initiation. Schmidt (1975, 1991) provided the concept of a generalized motor program (GMP).
“…existence of parameters, some variant, some invariant, that are applied to the GMP in order to specify how a particular movement pattern is to be expressed. These parameters specify overall duration of a movement, the overall force need to accomplish the movement, the temporal phasing of the movement pattern and, the spatial and temporal order in which the components of the movement are to be executed” (Schmdt, p. 5)Hierarchical models
Hierarchical control mechanisms
Dynamic control mechanisms
A fixed program that can be run off uninterrupted by peripheral feedback.
“The little man inside the head”How is the motor program defined?
Coordinative Structure Theory
Dynamic Pattern Theory
Dynamic systems focus on the interaction between the performer and the environment.
Dynamic systems differ from information processing systems by the way the action is produced.
The dynamics result from the interaction of neurological, biological, musculoskeletal systems. These constantly change.
Dynamic systems are emergent.Dynamic Systems
In a self-organizing system no subsystem has higher order control. The model is not a hierarchical one.A Dynamic System is Self-organizing
“… The process by which an individual constrains or, condenses his or her available degrees of freedom into the smallest number possible to achieve the goal… (Rose, 1996; P11).Coordination
Synergies result from organizational structures that coordinate the degrees of freedom for a particular movement. Some are ready-built and available at birth but the majority are developed throughout the lifespan and learned.
Muscles are not controlled individually but are functionally linked with other muscles so as to form autonomous systems.Coordinative Structures or Synergies