Transcript Information Processing Model

William James many years ago said that
perception was 60% a result of internal factors!
Kant
Sensation is unorganized stimulus, perception is
organized sensation, conception is organized perception, .
. . each is a greater degree of order and sequence, and
unity. Whence this order, this sequence, this unity? Not
from the things themselves; for they are known to us only
by sensations that come through a thousand channels at
once in disorderly multitude; it is our purpose that put
order and sequence and unity upon this importunate
lawlessness; it is ourselves, our personalities, our minds,
that bring light upon these seas".
Information Processing Model
Knowledge of Results
Stimulus
Processing
Response
Selection
Memory
Response
Organization
Response
Stimuli
Knowledge of Performance
Response Selection-Decision Process
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Decisions take time - performers who take less time have an
advantage (delays on the order of milliseconds are often very
important)!
– Basketball player must decide whether to pass, shoot or
dribble.
– Squash player must decide on a forehand, backhand, drop,
corner, reverse corner, lob.
– Batter must decide whether to swing or not.
– Diver must decide what to do if her take-off is poor.
Components of Decision Time
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Light - 186,000 miles/sec
inconsequential; Sound
1100'/sec = about 5 msec to go
5'
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Stimulus Processing - 20:40 ms
for light; 10 ms auditory
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Brain to Arm - @ avg. of 75
meters/sec about 13 msec
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Sensory Processing
Time
Brain Time
Nerve Conduction
Stimulus
Reception
Time
Time
Response
Motor Time estimate 40 ms.
IF RT = 180 MS then :180(0+30+13+40) = 97 ms brain
time about 54%
Stimulus
EMG
Premotor
Time
RT
Response
Begins
Motor
Time
Decision Time - Reflex Volley
30' @ 80 mph
256 ms
1'
A
C
RT = 200 ms MT = 50 ms
6'
B
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C
RT = 150 ms MT = 50 ms
Player A must begin to respond when the ball is only 1’ from
player C’s racket.
Player B must begin to respond when the ball is 6’ from player
C’s racket.
Decision Time & the Hick-Hyman Law
C
R
T
CRT = a + b [Log2 (N)
b = slope
a
INFORMATION TO BE PROCESSED
[LOG2 (N)]
How can decision time be controlled?
 Number of alternatives
 Probability of alternatives
 Sequential dependencies
Computations: What change in CRT is expected for
S2 by increasing alternatives from 2 to 8
CRT = a + b [Log2 (N)
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2x = N If N =4, x = 2
Given (Case 1 N=2):
If a = 180, b = 215, N = 2, 2x = 2, x = 1
CRT = 180 + 215 * (1) = 395 ms
Given (Case 2 N = 8)
If a = 180, b = 215, N = 8, 2x = 8, 2x = 8, x=3
CRT = 180 + 215 * (3) = 825 ms
Case 2 - Case 1 = 430 ms!
Hick’s Law can be Generalized:
CRT = a + b (Log2 (1/Pi)
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Pi = probability that a specific event will occur
Given that a pitcher can throw 3 pitches (fast ball, curve, riser)
Fast ball 60% of time (Log2 (1/.60) = Log2 (1.67) = .74 bits
Curve 30% of time (Pi = 1/.30) = Log2 (3.33) = 1.74 bits
Riser 10% of time (Pi = 1/.10) = Log2 (10) = 3.32 bits
For our hypothetical Player:
CRT = 180 + 215 * (0.74) = 339 ms
CRT = 180 + 215 * (1.74) = 554 ms 215
CRT = 180 + 215 * (3.32) = 894 ms 340 555
Hick’s Law Also applies to “Sequential
Dependencies”

When a sequence of events occurs:
– abc, abc, abc, abd
– d occurs only 25% of time after ab Log2 (1/Pi) = 2 bits
– c occurs 75% of the time after ab Log2 (1/Pi) = .42 bits
One Addition: Athletic Intelligence?
Player A
Player B
C
Player C
R
T
Log2 (1/Pi)
Sport Implications?
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We may miss the ball because we start to swing too
late
We may fail to defend because we are too slow to
react
If we are coordinating our actions with another
person's and we are uncertain of what they will do
next, we will be slow to react when the time comes to
move.
Implications for Coaching?
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Scouting (Henry Aaron-phenomenon).
Practice, practice, practice (S-R Compatibility).
– Greg Louganis- "... in diving there's a 'sweet spot' on the board,
right at the end. I can't always hit it perfectly. Sometimes I'm a
little back from it. Sometimes I'm a little over. But the judges
can't tell that. I have to deal with whatever takeoff I have been
given. ... That's why I train so hard - not just to do it right, but to
do it right from all the wrong places.. . "
The Bottom line -- highly skilled people know what
stimuli are likely to be presented, where they will
appear (Space), and when they will occur (Time)- can
predict the response required ahead of time
Knowledge of Results
Stimulus
Processing
Response
Selection
Memory
Response
Organization
Response
Stimuli
Knowledge of Performance
Response Organization & Execution
* Once
the performer decides on an appropriate course
of action, the response(s) must be organized and
executed.
* Whereas response selection is a constructive process
(an image is created of what needs to be done),
response organization requires a decomposition of that
image into component parts that ultimately become a
set of muscular actions
– (Perceptual-Motor Integration Problem).
Henry-Rogers (1960) - Increased Response
Latency Prior to More “Complex” Movements.
Movement
RT (ms) MT (ms)
Finger Lift
159
Single Grasp
195 (+36)
95
Double-Strike
208 (+13)
465
--
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Simple RT situation - Hick’s
Law does not apply
Complexity? Movement
segments, precision, duration,
force production?
Greater time to initiate
response - greater
preparation time in
organizing and initiating
“program”
Response Organization and Execution from a
Behavioral Perspective
Exe cutive
Routine
Te nnis Se r ve
Stance
Gr ip
Tos s
Back
Sw ing
Fore
Sw ing
Follow Thr ough
Subroutine s
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Like a complex computer program: organized
hierarchically and sequentially.
Executive routine controls the selection, sequencing and
timing of more automatic units (subroutines).
Speech and writing require the same type of processes
(idea, words, sequencing, timing).
Response Component
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From a learning perspective - executive and
subroutines are flexible structures. Subroutines are
constantly being created, expanded, and combined so
that response units become “chunked” (what we do in
practice).
*Stance, Grip, Toss are initially separate actions, but
as one learns to execute the spin serve - stance, grip
and toss become intricately related.
*Reduction in Information Load and more
autonomous execution.