OPEN LOOP CONTROL MODEL

1
(No Transcript)
2
OPEN LOOP CONTROL MODEL

• SAME AS CLOSED LOOP EXCEPT
• NO FEEDBACK
• NO COMPARATOR

3
MOTOR PROGRAM

• EVIDENCE FOR
• RT AND MOVEMENT COMPLEXITY
• DEAFFERENTATION EXPERIMENTS
• BLOCKING A MOVEMENT

4
Kovar, S., Overdorf, V. (1996). Scholarship
redefined Changing contexts in the
professoriate. Quest, 48(2), 211-220.
5
SPINAL GENERATOR MODEL FOR GAIT
HIGHER CENTERS
FLEXORS
EXTENSORS
SENSORY INPUT
6
PROBLEMS WITH ORIGINAL MOTOR PROGRAM CONCEPT

• STORAGE PROBLEM
• NOVELTY PROBLEM

7
GENERALIZED MOTOR PROGRAM
8
MODULATION OF MOTOR PROGRAM OUTPUT

• VARIATION IN MOVEMENT TIME
• VARIATION IN MOVEMENT AMPLITUDE
• VARIATION IN LIMB USED

9
INVARIANT FEATURES AND PARAMETERS
10
INVARIANCE

• RELATIVE TIMING
• CLASSES OF MOVEMENTS
• Has particular relative timing
• Movements within that class have same relative
  timing
• Movements in different classes have different
  relative timing

11
SHAPIRO ET AL STUDY

• 3-6 KM/HR
• E3 48
• F 10
• E2 10
• E1 28
• 1 GMP
• WALKING

• 8-12 KM/HR
• E3 28
• F 25
• E2 15
• E1 32
• 1 GMP
• RUNNING

12
GMP

• Underlies class of movements and structured in
  memory with rigidly defined temporal
  organization.
• Structure characterized by relative timing, a set
  of ratios among the duration of various events in
  the movement.
• Variations in MT, MA, and limb used represent
  movements surface structure, adjusted with
  different parameters relative timing represents
  deep structure.

13
GMP (cont)

• Movement may be carried out with different
  surface features (e.g., duration, amplitude),
  relative timing remains invariant.
• Surface features are easy to alter by parameter
  adjustment deeper relative timing structure is
  far more difficult to alter.

14
WHAT MUST BE SPECIFIED IN THE PROGRAM?

• Muscles that must participate in the action
• Order of contraction of the involved muscles
• Amount of force output that is necessary
• Relative timing and sequencing among contractions
• Duration of each contraction

15
PROGRAMS CONTRIBUTIONS TO ACTIONS

• POSTURAL ADJUSTMENTS
• CENTRAL PATTERN GENERATORS
• INTEGRATION OF CENTRAL CONTROL AND FEEDBACK
  CONTROL
• REFLEX REVERSAL
• ENHANCING FLEXIBILITY OF MOVEMENT

16
SPEED/ACCURACY TRADEOFF
17
MOVEMENT SPEED AND MOVEMENT DISTANCE
A
W
W
FITTS LAW
SPEED ACCURACY TRADEOFF
18
FITTS LAWAverage movement time increases as
movement amplitude increases and target width
decreases.
19
EXPERIMENTAL APPROACH VSDIFFERENTIAL APPROACH
20
DISTINCTIONS BETWEEN ABILITIES AND SKILLS

• SKILLS
• Developed with practice
• Modified with practice
• Countless in number
• Depend on several abilities

• AB ILITIES Inherited traits
• Stable and enduring
• Perhaps 50 in number
• Underlie many different skills

21
GENERAL MOTOR ABILITY
22
CONCLUSIONS BASED ON CORRELATION ANALYSIS

• CORRELATIONS AMONG DIFFERENT SKILLS ARE GENERALLY
  VERY LOW
• EVEN SKILLS THAT APPEAR QUITE SIMILAR USUALLY
  CORRELATE POORLY.
• THIS OVERALL LACK OF CORRELATION AMONG SKILLS
  ARGUES AGAINST THE CONCEPT OF A GENERAL MOTOR
  ABILITY.
• ON THE OTHER HAND, TWO SKILLS WITH ONLY MINOR
  DIFFERENCES CAN CORRELATE STRONGLY.

23
ASSUMPTIONS OF SPECIFICITY VIEW

• VERY MANY ABILITIES EXIST
• THESE ABILITIES ARE NOT RELATED TO EACH OTHER
  THEY ARE SPECIFIC
• A GIVEN SKILL IS SUPPORTED BY MANY OF THESE
  ABILITIES
• DIFFERENT SKILLS HAVE DIFFERENT PATTERNS OF
  ABILITIES WITH DIFFERENT PATTERNS OF STRENGTH AND
  WEAKNESS

24
Superability
Motor abilities
RT
RO
S.M.
PP
MD
RI
FD
25
INVOLVEMENT OF ABILITIES IN SKILL PRODUCTION

• Any given skill is contributed to by several
  fundamental motor abilities
• Some of the abilities underlying a skill play
  very dominant roles, while others have weaker
  roles
• Two different skills have different patterns of
  underlying abilities
• Two different skills can have a few abilities in
  common.

26
CLASSIFICATION PERMITS

• The application of appropriate learning
  principles to activities
• Giving the learner added assistance in factors
  that should be emphasized for effective movement
  control
• Selecting individuals for advanced training based
  on abilities that relate to task.

27
PREDICTION INVOLVES FOLLOWING COMPONENTS

• Understanding abilities that underlie the
  criterion task
• Estimating strength of these abilities as
  indicators of future capabilities in the
  criterion task
• Estimating future (potential) skill level on some
  criterion task based on present information