Lecture 10b, Generalized Motor Programs (Parameters)

Question 1

Parameters

Answer 1

features supplied to the GMP that are flexible & define how to produce unique events
- can be modified from one performance to another allows for variations in the response
◦ “adaptable”
◦ primarily solves novelty
problem

Question 2

Three Parameters

Answer 2

1. movement time (absolute duration)
2. movement amplitude (absolute force)
3. effectors (muscle-selection) - generalized motor program can transfer across effectors, can be tuned to left or right side for example

Question 3

Parameters: 1 = Movement time (absolute/overall duration)

Answer 3

total time to perform motor skill
- increased or decreased (e.g., normal, faster, slower speed) and relative time does not change
- absolute or movement time would change
- if we had longer movement time, the relative would stay the same among the muscles but we can adjust the overall movement time so these relative timings can be scaled for longer or shorter movements

Question 4

Parameters: 2 = Movement amplitude (absolute force) - the size or the magnitude

Answer 4

total force produced by muscles can be changed when we make movements bigger or aim for farther distances
- short and long jump shots in basketball require different forces
- even if we are changing timing we are controlling duration of force

Question 5

Force

Answer 5

Force is directly proportional to acceleration… so we can ↑ movement amplitude by uniformly increasing the forces/accelerations of muscles
F = ma (mass x acceleration)
- we can therefore look at acceleration trace to see if forces are proportional across different movements
- looking at relative timing component of forces to give an idea of whether are relatively invariant over time
- scaling in blue of absolute forces (see if forces are proportional across different instances)
- same program but you are scaling forces if you need to make letters larger or smaller

Question 6

How do we select the parameter?

Answer 6

Based on stored relation between parameters & outcomes (“schema”)
throwing a ball (this is our selected GMP): what is the desired outcome, then select parameter
* select a throw with certain invariant features… scale forces for desired outcome
* have a ball and throwing it to the first throw (choose parameter to scale action and know if you are successful or with what amount of force where it landed) - gains a relationship between parameters and outcomes (the more examples you have the stronger the correlational and relationships such that when you need to do knew action you can choose the right parameter to fit desired outcome)
- if there is a relationship between force and outcome we can have a good idea of what parameter we need in order to program our generalize motor program
- the dots are of things the player has experienced before
- rather than storing individual relationship between forces and parameters, the points disappear and we just store the relationship (line)
- the instances get replaced with schema

Question 7

Schema

Answer 7

relation between parameters & outcomes and we may have many schemas for various conditions

Question 8

Parameters: 3 = Effectors (muscle selection)

Answer 8

same GMP can be executed by different limbs or muscles depending on context
* execute the same generalized motor program with different effectors or muscles

Question 9

Which aspects of your signature were flexible and defined how to execute the motor program?
(parameters)

Answer 9

• movement time (duration): slow vs normal fast
• movement amplitude (force): hard vs. normal/soft
• effectors: left vs. right vs. fist-hold

Question 10

Which aspects of the production of your signature remained relatively fixed from trial to trial?
(invariant features)

Answer 10

• relative timing (patterning/rhythm)
• relative force
• order of events (letters always in same order)