specificity of practice

Question 1

schmidt history

Answer 1

-previous beliefs concerning motor control and learning
-feedback contribution to motor control decreases as learning increases
-because of legs in rpcessing feedback, subjects would become less dependant upon feedback
-open loop system
modified position:
-recognized feedback might be used after all
-closed loop system

Question 2

proteau history

Answer 2

• determine whether with relatively extensive practice, as skill theoretically starts becoming open-loop, there would be evidence for a decreasing emphasis on visual feedback for motor control
• proposition tested though aiming task

Question 3

root mean square error

Answer 3

represents best overall measure of performance accuracy

Question 4

RMSE

Answer 4

• found that the movement became dependant on feedback with greater amounts of practice rather than less dependant
• role of visual info from the environment and ongoing limb does not diminish as amount of practice increases
• higher RMSE in the 2000 trial condition groups, suggests that it took more practice to use the visual feedback info more effectively

Question 5

bootsma and wieringen history

Answer 5

• some expert tennis players used visual info to modulate acceleration of their racket to adapt movement to ball trajectory
• indicates that importance of visual feedback still exists even in highly trained individuals

Question 6

specificity of practice

Answer 6

• learning is most effective when practice sessions include environment and movement conditions which closely resemble those required during performance of the task
• the learning process results in the creation of a representation of the task where all relevant info pertaining to the task is integrated
• learning is specific to the conditions that prevail during acquisition

Question 7

theory

Answer 7

hypothesis: at the base of motor learning is a sensorimotor representation that consists of integrated info from the central processes and sensory feedback derived from previous experiences on the movement task
testing hypothesis: prediction that for an aiming task, the addition of vision, after moderate and relatively extensive practice without vision, would lead to an increasingly large movement decrement, relative to appropriate controls

Question 8

study supporting hypothesis

Answer 8

• transfer test: groups performed under identical conditions from acquisition phases, although switching conditions
• demonstrated that performance in transfer task suffered an increase in error due to the difference in conditions between acquisition phase and transfer test
• adding a relevant source of movement control info to a task that was previously learned without that info present will result in: performance decrement, until the performer can integrate the new info into the existing store

Question 9

primary study

Answer 9

subjects: 13 undergrad students, naïve to the experimental tasks and conditions
- magnitude of decrement related to the number of subjects, tasks, apparatus, and procedures related to the study

Question 10

methods of study

Answer 10

task: displacement of a stylus by 80 cm in 550msec, 5-cm lateral displacement of the stylus towards the subjects body midline and a 35-cm vertical displacement of stylus
- subjects movement was mechanically perturbed during its course, purpose was make task more complex and therefore more learning to occur
- perturbation involved the introduction of a restive torque at shoulder, applied 225 msec post movement initiation, lasted for 150 msec

Question 11

apparatus

Answer 11

• 5 elements
  1. Defined start position
  2. Adjustable manipulation with a stylus at the er
  3. pre-assembled clutch-brake module
  4. Target to be reached
  5. An apple microcomputer

Question 12

procedures

Answer 12

three conditions

1. Vision of moving limb and target
2. Vision of target only
3. Control group- not given practice
   - all groups underwent a pre-test prior to the acquisition

Question 13

acquisition phase

Answer 13

-total of 1,200 trials in six acquisition sessions- twice a day over the course of three days
transfer tests
-test 1: following first acquisition session (200 trials)
-test 2: at the end of acquisition phase (1,200 trials)

Question 14

what was the activity

Answer 14

• Online mouse accuracy game
• 1st trials: lights on
• 2nd trials: lights off
• should notice a difference
• 3rd trials: change target to small & lights on
• 4th trials: small target & lights off
• 2 conditions in activity:
  1. View of target and limb (T+L)
  2. View of target only (T only)
• lights shut off to impair view of subject’s limbs

Question 15

results: the acquisition phase

Answer 15

The acquisition phase

• increase in accuracy from first 2 acquisition sessions to last 2 with the L+T outperforming T group in overall accuracy
• negative correlation between error and practice in the acquisition phase of the experiment

Question 16

results: acquisition vs transfer performance

Answer 16

acquisition vs transfer performance
temporal accuracy: subjects generally more accurate in the acquisition phase vs transfer phase
spatial accuracy:
L+T group: no increase in error when going from acquisition to transfer for
T-group: substantial increase of error was noted going from acquisition to transfer

Question 17

results: pre test vs transfer performance

Answer 17

temporal accuracy:
-only transfer 2 phase reached differential significance
-control group: most errors
-target: second erroneous
-target + limb group: least errors
Spatial accuracy:
-1st block of trials: largest error
-L+T group: increase in accuracy in transfer 2 test
T group: continuous increase in errors
control group: did not reach significance

Question 18

primary hypothesis

Answer 18

1. primary hypothesis: specificity of learning hypothesis; learning is most effective when practice includes environment and movement conditions similar to those required during performance of the task
   - movement time: although the subjects were unable to complete their movement within a required temporal bandwidth, they did not truly develop a finer temporal representation of the movement
   - spatial accuracy: results supports the specificity of learning hypothesis
   - presentation of vision after 1200 trials produced an increase in error for T only group
   - increase in spatial error from pre-test to transfer 1 & 2
   - vision may have an interference effect may on pervious learning

Question 19

secondary hypothesis

Answer 19

2. Secondary hypothesis: concerned either error found I performance when full vision is permitted and its relation to the amount of practice given without full vision
   - error found in task performance with full vision is independent of the amount of practice given without full vision
   - difference in trials rom transfer 1 to transfer 2 (1000 trials) was insufficient to solicit stimulus discrimination
   - ceiling effect reached at transfer 1
   - the sensory channels used for the evaluation of the movement outcome may also be specific to the practice conditions
   - vision in an aiming task requires practice with KR so that vision becomes integrated with other sources of sensory info as well as with info derived from central sources
   - for an aiming task, vision of environment and or limb cannot be substituted for by extensive practice

Question 20

current research

Answer 20

purpose: learning a sport skill is specific to the sources of afferent visual info available during learning
results: performance decrement in groups when tested at a visual condition that differed from what was experienced when learning the task

Question 21

conclusion of current research

Answer 21

• if one of the sources of info used to learn the movement is withdrawn, the representation that has been developed becomes inefficient
• withdrawing in visual in visual info causes significant deterioration in performance
• the results reported do not, however, support out hypothesis of increased specificity as a function of learning. It might be the fact that the subjects were permitted to see where the stylus landed on the target area resulted in a ceiling effect that was already reached 200 trials of practice
• at the present time both these interpretation are hypothetical and further work is recommended

Question 22

the theory

Answer 22

All about feedback sources: mostly visual
no vision vs with vision
people who did not have vision in acquisition transfer task error increased when they did have vision- performed decreased
Acquisition: practice
transfer: after testing