Understanding Movement Preparation Chapter 2

Overview In chapter one we talked about the abilities (or ‘hardware’) that people bring with them to motor performance In chapter two we address the processes (or software) people use when attempting skilled movements If you will work with individuals with physical or mental challenges, the performance problems are often caused by impairments in one or more of the processes

Information Processing Model   Input – Stim. ID - Resp. Select. – Resp. Program. - Output - Feedback

Stimulus Identification Stage Stage 1: Has a stimulus been presented and what is it? Environmental information is analyzed through senses Performers categorize the information according to patterns Types of objects, pattern of movement, colors

Response Selection Stage Stage 2: What response, if any, should be made to the stimulus? Based on the identification of the stimulus, the performer translates the information to the possible forms of movement output to be made A decision is made

Response Programming Stage Stage 3: Let’s get ready to do something! The motor system is organized for the production of the desired movement Get the brain and spinal cord ready for movement, get a plan of action to control the movement ready, send a plan to the muscles to contract in the proper order and with the proper amount of force and timing

The End Result Output! Execution of the movement determined to be appropriate The execution can be successful or unsuccessful The next component of information processing is important to the next attempt to be made

Feedback! As movement is initiated, intrinsic feedback can be used to make adjustments to the movement (if time permits) Intrinsic and extrinsic feedback that occurs after the output occurs should influence the next attempt What differences in processing demands might exist for open and closed skills?

Practical Application Describe the information-processing activities that might occur through the three stages for a soccer goalie. Describe the information-processing activities that might occur through the three stages for an individual who uses a walker and gets out of bed in the middle of the night to answer the phone in the kitchen.

Components of Response Time  

Preparing a Response Reaction Time (RT) Interval of time between the moment that a stimulus is presented to when a response is initiated. Is a good indicator of the speed and effectiveness of decision making Indicative of the amount of time needed to prepare a response. Influenced by several factors. Number of choices Strategies to create or reduce uncertainty to response

Factors that influence RT Number of stimulus response alternatives Simple vs. choice RT Hick’s Law Relationship between the number of movement choices and the time needed to prepare a response The higher the degree of uncertainty in a given situation, the longer the time needed to decide which response to make In choice RT, RT is a measure of the time needed to detect the stimulus, decide which response to make, and initiate the movement

Relationship Between Number of Stimulus-Response Alternatives and RT

An Important Strategy An important strategy that athletes use to slow down their opponent’s decision making is to increase the number of SR choices Increase the number of different pitches Increase the variety of spiking positions from a setter Increase the variety of serves in racquetball or tennis

Stimulus Response Compatibility The extent to which a stimulus and its required response are naturally related Low SR compatibility = increased response time High SR compatibility = decreased response time Lo SR: showing a forehand stroke, but does forehand drop shot Hi SR: presentation of a red light, the foot puts on the brake

Practice and SR Compatibility Amount of practice The greater the amount of practice, the shorter the choice RT Extreme amounts of practice, high level performers can become almost automatic Nature of practice When the same SR combinations are practiced, choice RT becomes faster

Dealing with decision-making delays Anticipation! The more predictable a stimulus, the quicker and more accurately a response can be made Related to reducing the number of response choices as possible options are narrowed down

Types of Anticipation Spatial event anticipation Temporal anticipation Predicting what will happen in the environment Temporal anticipation Predicting when an event will happen

Effective anticipation Regularity of events affects our capability to predict Precues: warning signal or action given by a person to help us predict ‘telegraphing’ a movement “always” done in a particular way

Costs of Anticipation Cost/benefit tradeoff: 80% probability = decreased RT If wrong prep, RT will be slower as you must ‘unprepare’ the movement If wrong movement is initiated: even longer response delay Must inhibit incorrect response, prepare the correct response, and execute in the correct fashion

Psychological Refractory Period (PRP)

The Fake in Sports For fakes to be effective they must: Appear to be identical to the expected action Precede the goal movement by 60-100ms Be employed infrequently

Creating or reducing uncertainty Having a large number of choices to perform will increase uncertainty in opponent Facilitate skill learning by decreasing the number of alternate responses (start with a more closed skill environment) With increased practice, performers can begin to approach automatic processing When practice uses the same S-R combinations, choice RT becomes faster

Reducing response time Successful performance may not always come by reducing movement prep time Slow responses may be the result of prolonged movement time Increase movement speed Reduce length of movement (shorten backswing) Alternate view: give more time to respond by increasing distance or changing to slower equipment

Attention: Processing Limitations Limited attentional capacity Sing a song Sing a song Apply Make up Drive a car Drive a car Performance is hindered or Task may be ignored

Attention: Processing Limitations Bottleneck theory Stimuli that need a response are processed is serial fashion A bottleneck can occur if too much information must be processed; response time slows down

Attention: Processing Limitations - Sometimes people will focus on external sensory events (another person’s movement), sometimes they focus on internal mental operations (what they need to do next), sometimes they focus on internal sensory info (how their body feels) Very difficult to focus on more than one of these sources at a time (pat head and rub stomach?)

Limited Attentional Capacity Stand with dominant side next to the desk. Lift your non-dominant foot slightly off ground and make a figure 8. Repeat continuously. Keep making the figure 8 with foot. Trace a numeral ‘6’ on the desktop with your dominant hand index finger.

What happened when you attempted to perform the two tasks simultaneously? What does this say about attentional capacity?

Attention Things to consider: Environmental and task complexity: as complexity increases, attentional space for additional tasks is reduced Skill level: Beginners have trouble focusing on more than one thing at a time; give sufficient practice before adding new tasks Number of cues: focus on one cue at a time

Practical Application For a skill of your choice, explain how you might design the learning environment to reduce the attentional demands on the learner.

Attention Selective attention: being able to focus on one specific stimuli even though there are lots of stimuli in the environment ‘tailgate party phenomenon’ We are able to focus on relevant stimuli and disregard irrelevant stimuli Successful motor performance is dependent on person’s ability to attend to meaningful information

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Decision making and arousal Arousal and anxiety are common aspects in daily situations If one thinks the demands exceed his/her capability to meet them, the situation becomes more threatening and anxiety is experienced Level of arousal is an important determinant of performance especially if the situation requires fast and accurate decision-making

Arousal and nature of the task A task requiring fine muscle control or important decision-making, prefer lower arousal level Skills with large muscle actions or lower level of cognitive complexity, better performed at higher arousal level

Arousal: Inverted U Principle   As a task increases in complexity, lower arousal levels will be optimal. Higher arousal levels are better for tasks that require little attention or decision-making.

Cue Utilization Hypothesis Perceptual narrowing Over-arousal can narrow the focus too much, so the performer misses some relevant stimuli. Performance may be hindered. Under low arousal, attention focus is broad. Too much competition for attention resources may result in slow movement response and hindered performance.

Practical Application From your own experience, generate a list of the following: Irrelevant stimuli that might draw the attention of an individual with low arousal and thereby affect overall performance. Professions that might find individuals susceptible to poor decision-making when perceptual narrowing occurs.