Lecture 4: Motor Learning & Control

Question 1

Deliberate control of movement

Answer 1

• Visual info: eyes -> visual cortex -> motor cortex -> action for muscles (muscle units)

Question 2

Degrees of freedom problem

Answer 2

• Control of motor actions
• > 100 joints, >750 muscles, >10,000 motor units
• Reducing DoF = so that effective control is possible
• In motor learning: 1st stage = DoF are temporarily frozen or coupled
  2nd stage: increase number of DoF are actively involved in control
  3rd stage: forces related to movement are incorporated in control and execution of movement

Question 3

Attentional demand in skill execution

Answer 3

Stages of learning of Fitts & Posner (1967)
1) Verbal-cognitive stage = lot of attention for verbalisation & thinking about task solution
2) Associative-motor stage = attention devoted to refinement of skill
= more effective movement execution & more consistency
= fluency of movement
3) Autonomous stage = automatic movement execution without much strain on attentional processes
= attentional demand decreases

Question 4

Visual attention

Answer 4

• Key
• The quiet eye = for far-aiming tasks
  = Final fixation on single location/object during critical phase of motor task
• Longer fixations with expertise + proficiency (hits vs. misses)

Question 5

How to discover key visual info?

Answer 5

1) Visual occlusion = temporal
= spatial
2) Eye tracking

Question 6

Vision for action & for perception

Answer 6

• Dorsal stream = control of movement

- Ventral stream = perception of env. & action selection

Question 7

Study: Mann et al., (2010)

Answer 7

• Cricket = respond whether in or not
• Expertise differences increasingly visible as dorsal processing is involved
• Verbal response = similar accuracy between skilled vs. novice
• Verbal -> foot movement -> shadow batting -> batting = increase response accuracy vs. novice

Question 8

Study - At what distance from suspect should policeman shoot?

Answer 8

• Shooting distance increases with verbal response
• Perceptual accuracy decreases with verbal response
• Real gun vs. fake plastic gun

Question 9

Individual differences

Answer 9

• Not everyone needs same visual info to get to same outcome

- Match training to level of expertise & techniques

Question 10

Study: Navia et al. (2017)

Answer 10

• Gaze behaviour dependent on situational constraints
• Env. (e.g. time available) and person (e.g. time required) with penalty shots
• At 6m, looking more at body vs, 10m, looking more at ball