Understanding Movement Preparation

1
Understanding Movement Preparation

• Chapter 2

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

3
Information Processing Model
Input Stim. ID - Resp. Select. Resp.
Program. - Output - Feedback
 
4
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

5
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

6
Response Programming Stage

• Stage 3 Lets 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

7
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

8
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?

9
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.

10
Components of Response Time
 
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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

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Factors that influence RT

• Number of stimulus response alternatives
• Simple vs. choice RT
• Hicks 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

13
Relationship Between Number of Stimulus-Response
Alternatives and RT
14
An Important Strategy

• An important strategy that athletes use to slow
  down their opponents 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

15
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

16
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

17
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

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Types of Anticipation

• Spatial event anticipation
• Predicting what will happen in the environment
• Temporal anticipation
• Predicting when an event will happen

19
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

20
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

21
Psychological Refractory Period (PRP)
22
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

23
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

24
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

25
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
26
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

27
Attention Processing Limitations

• - Sometimes people will focus on external
  sensory events (another persons 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?)

28
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.

29

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

30
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

31
Practical Application

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

32
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
  persons ability to attend to meaningful
  information

33
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34
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

35
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

36
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.
37
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.
38
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.