Why do responses break down? Pressure: Mechanical (bad position) Pressure: Psychological (real or perceived) Over controlling: Attitude: Fatigue: Injury:

Response Component - Neurophysiological Perspective Muscles are composed of muscle fibers. Muscle fibers within a muscle group are innervated by several motor neurons. Any given muscle fiber is innervated by one motor neuron. A motor neuron and the muscle fibers it innervates form what is called a motor unit. The motor unit is the most basic element of motor control.

Response Component - Neurophysiological Perspective The number of muscle fibers in a motor unit varies from effector to effector: –hand and eye fewer than 100 muscle fibers occupy a motor unit –lower leg a single motor unit may contain as many as 1000 muscle fibers. –generally, the larger the number of muscle fibers in a motor unit, the less precise the movements it allows. It is impossible to activate voluntarily some but not all of the muscle fibers within a motor unit. It is possible to recruit some motor units but not others within a muscle.

Response Component - Neurophysiological Perspective Bartlett (1942) said it best when he wrote: We may, perhaps, see the beginning of skill where nervous mechanisms acquire the character of 'graded' response adjusting the amount of their action to the variable intensity of the stimulus.

The Graded Response Performing motor activities at high levels requires the capacity to adjust activation level during the execution of a response. What are some examples of sport skills in which gradation of response is required in the midst of other movements that are executed at near maximum force?

Response Component The Graded Response - Sequence Throwing Biceps Triceps Biceps Triceps Sequential Co-contraction

Summary Motor Control Complex responses have complex mediating processes: Perceptual, Decision Making, Response Organization. Limited information processing capabilities requires us to develop strategies for reducing information load or increasing capacity: organization of stimuli, rehearsal of situations requiring decisions, “chunking” and autonomous execution of response components, massive amounts of practice. Psychological states and manipulations can enhance or inhibit processing at each stage. Understanding and empathy should dictate the nature of our interactions with athletes.

An Information Processing Model Applied to Teaching: Gentile (1972) Stage 1: getting the Idea: Goal regulatory Selective Attention Motor Plan Formulation Response Execution Feedback Decision Processes Next Response Perceptual Processes Decision & Response Organization and Execution KP & KR

Stage Two: Fixation/Diversification: Was the movement executed as planned? GOALACHGOALACH Yes No Yes No Got the idea Surprise Something’s Wrong Everything’s Wrong Stage Two begins after a few Yes/Yes outcomes

Closed vs. Open Skills: Closed skills: the environment remains constant; need to decrease variability in producing a motor pattern similar to the one learned during Stage 1. (less dependent on monitoring the external environment). Open skills: the environment is variable; need to diversify the original motor pattern.; regulatory stimuli change, and variation of the motor pattern must occur. The learner must develop a larger repertoire of responses. (slight or large modifications of spatial/temporal components within a common generic formula).

Teaching Guidelines (Stage 1): The goal. –Teacher needs to provide goal clarity. If a teacher rushes to the movement, it is possible that the learner thinks that the movement is the goal rather than the outcome to be produced. –Teacher should create a specific environmental problem, and establish an adequate motivational level.

Regulatory stimulus subset (Stage 1) Teacher can identify regulatory stimulus subset; –Should practice be like a game or some subset of the game? –How much non-regulatory stimuli should be available during learning (open vs. closed skills). –Progression from simple to complex?

Selective Attention (Stage 1) Teacher can help student to attend to regulatory stimuli. –Verbally, "guided discovery" or verbal problem solving. Instruction pertaining to orienting movements may be required. Use of peripheral vision, where to be to look! –For open skills, instruction by teacher of what will happen helps learner to know what to look for when it occurs.

Formulation of the Motor Plan (Stage 1): Only when the movement form is the goal (diving and gymnastics) must the teacher actively restrict the learner's responses. –Otherwise any movement that effectively and consistently matches the environmental conditions should be permitted.

Response Execution(Stage 1): Teacher should reduce distracting elements including his/her own verbal comments. –May facilitate the decision process that will follow by providing certain instructional sets regarding the kinds of information that will soon arrive.

Feedback and Decision Making (Stage 1): Feedback: The need for additional information beyond what is normally available is not clear. –The teacher should delay comments for a short period after a response so that the learner can process and encode the information resulting from movement. Decision: May help in decision process. Teacher will be very involved when "everything’s wrong" occurs, and to varying degrees until Yes/Yes.

Stage II. Fixation/Diversification Closed skills: hold regulatory stimuli constant and add non-regulatory stimuli. Open skills: vary regulatory stimuli systematically enabling performer to acquire the repertoire of motor patterns that match the total number of stimulus subsets. –How to do this has not been investigated. Increased variability would seem to be essential. Either by letting things fluctuate randomly or doing it on a probability basis.

Feedback and Decision Processes: Closed Skills: KP is essential. –Perhaps, augmented feedback would be most usable if administered just prior to the next response during when the student is formulating their motor plan (but who knows for sure?). Open Skills:In the diversification phase, try to develop as many motor patterns as is required. –Here S may need help with feedback on the regulatory conditions that existed and the response that was executed. Unclear whether KP is valuable here since he will move differently on the next trial.