1. On knowing how to do things: a theory of motor imagery John Annett Cognitive Brain Research 3(1996) 65-69 Presenter: Chu-Chun Cheng Advisor: Ru-Jung Cherng

2. Problem of Representation “Knowing how” – Performance – Procedural (implicit) knowledge: unconscious “Knowing that” – Verbal statement – Declarative (explicit) knowledge: conscious

3. The ALI model Relationship between declarative and procedural knowledge and the process of learning motor skills from demonstrations, verbal descriptions, and instruction. ALI = Action, Language, Imagination Representative and executive systems can be decoupled

4. Action Prototypes Action systems vocabulary Elementary acts such as grasping, lifting, pointing, and so on Non-verbal equivalents to familiar phrases or cliches

5. The Action Representation System Conscious and unconscious processes Consciously perceive or imagine action Action prototypes in unconscious long term memory -> activated into consciousness Activated action prototype to provide control signals for executive system Very precisely tuned inhibitory mechanism

6. The Action-Language Bridge Shows the relationship between procedural and declarative knowledge Two-way bridge Action to verbal instruction via conscious images generated by relevant prototypes Verbal instructions translated into action

7. Implications of the ALI model Imitation: action prototypes can be observed, stored, and reproduced Motor imagery: activation of a prototype may bring certain features of the action into consciousness without necessarily involving muscular activity

8. A theory of motor imagery Symbolic: activation of a central action plan Covert action: scaled down version of overt action & includes motor output and some kinesthetic sensation

9. A theory of motor imagery Agent of perceptual changes Distinguishes imagery from hallucination Motor imagery combines activation of the action prototype (shared with overt action) and memories of the perceptual consequences of previous actions of a similar kind (memory recall- substitute for sensory feedback associated with overt action)

10. A theory of motor imagery Woodworth’s classical theory of motor control Action prototypes are modified by the addition of location and timing information In motor imagery, these information are supplied by memory (arbitrary information) Reported imagery highly detailed, suggesting memory recall of specific events

11. Physical bases of motor imagery Functional equivalence Evidence of brain activity in pre-motor cortex during action performance & observation PD patients performed as well as normal controls in verbal report of bow tying – evidence of decoupling action schema from executive system ERPs show imaginary more concerned with spatial perception than primary motor areas

12. Thanks for your attention