Variability In Motor Behavior

Question 1

What some of the types and sources of variability within an individual?

Answer 1

1. Variability in the OUTCOME of an action when repeated.
2. Variability in the COORDINATION of solutions.
3. Variability in the FORCES generated

Question 2

Is variability a negative or a positive influence on motor control and motor learning?

Answer 2

Two views:

Negative = Traditional viewpoint, creates ERROR Positive = Dynamic Action perspective, creates OPPORTUNITY

Question 3

How does the TRADITIONAL APPROACH considers variation within and across subjects?

Answer 3

As “noise” or “error”

Question 4

Which methods are used by the TRADITIONAL APPROACH eliminate or control variability?

Answer 4

Study average performance. -Do not consider the nature of the variability that exists

Question 5

How does the DYNAMIC ACTION PERSPECTIVE view movement variation within an individual?

Answer 5

Variation within an individual is an integral part of motor control. Noise and “error” can be beneficial to system by facilitating adaptation to task demands.

Question 6

According to the DYNAMIC ACTION PERSPECTIVE, how can a therapist use variation to move the patient away from a mal-adaptive task solution?

Answer 6

A patient exhibiting variability in their movement pattern presents an opportunity to to shift into a new more efficient ATTRACTOR

Question 7

Is it easier to adjust to perturbations if you’re used to irregular sway pattern?

Answer 7

Yes. Variability may allow you to overcome the effects of internal or external perturbations, i.e. to recover from errors

Question 8

True or false. Those who had development delay showed less variability, and more stereotyped behavior?

Answer 8

true

Question 9

Is there a “structure” to the variability in postural sway?

Answer 9

1. Rigid: equal sways
2. Chaotic: same amount of sways in both directions
3. Random

(Can be quantified as “Approximate Entrophy” or Lyapunov Exponent”)

Question 10

What are the important factor to consider by the therapist when it comes to variability?

Answer 10

1. Consider what roles variability play in current performance
2. Use variability to improve adaptability.
3. Consider the structure of underlying variability, as well as how much variability there is

Question 11

What are ANTHROPOMETRIC differences across individuals?

Answer 11

Measures about body shape and size

(See Tests and Measures lecture: measurement traits
that describe human physical dimensions; a way of understanding physical variation; Size, weight, and proportions)

Question 12

What is “approximate entrophy” or “Lyapunov Exponent”

Answer 12

a method for quantifying rigid, chaotic or random structure in the variability of movement