1. Principles of Motor Control and Movement Accuracy
Chapter 6
Principles of Motor Control and Movement Accuracy

2. Invariant Features Also known as deep structure
Relative timing and relative force
Relative timing = the temporal structure of a movement, the duration of the sub-segments compared to the whole

3. Relative Timing See figure 6.1 on page 150
Look at relative timing of walking and running on page 151

4. Phonograph example Page 153 Identify invariant characteristics
Relative timing and force
Identify parameters (surface features)
Absolute timing and force
Identify executive and effectors

5. Speed-accuracy trade off
Fitts’ Law
Activity example
Movement time is linearly related to index of difficulty
Open-loop or closed-loop control?
Sources of error? – page 159
Violations of the Fitts’ Law
Timing errors
Maximum force