PSY2061 Lecture Notes - Lecture 6: Brainstem, Thalamus, Vestibular Nuclei
1 Jun 2018
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Lecture 6 continued
Intention, Plan, Execute
3 phases of Action
1) Intention: Prefrontal cortex!
- inputs from parietal & temporal areas!
- formulates goals!
2) Planning: Premotor cortex!
- dorsal & ventral!
- prepare for action!
- inputs from Prefrontal cortex!
3) Voluntary Activation: SMA, M1!
- move!
- plan-execute sequences
CONCEPT 5: Neurones in primary motor cortex (M1) code movement direction
Primary motor Cortex M1
•provides command to drive motor-neurones to make muscles move
•different subregions control specific body parts
•direction a function of summed activity (vector) across population of neurones
•debate over what M1 neurones code for: !
- trajectory & distance to target!
- sensory motor integration
•Motor cortex also organised for ethnologically relevant behaviour
Cell Firing in Primary Cortex
-5 movements x 8 directions = 40 trials
-each neurone represented by a vector (firing rate / preferred direction)
-Vector sum of all cells = population Vector
-Population Vector specifies movement direction/goal
-Movement direction and trajectories are encoded by integration of large numbers of M1
neurones
-Redundancy
Document Summary
Inputs from prefrontal cortex: voluntary activation: sma, m1. Concept 5: neurones in primary motor cortex (m1) code movement direction. Primary motor cortex m1: provides command to drive motor-neurones to make muscles move, different subregions control speci c body parts, direction a function of summed activity (vector) across population of neurones, debate over what m1 neurones code for: Sensory motor integration: motor cortex also organised for ethnologically relevant behaviour. 5 movements x 8 directions = 40 trials. Each neurone represented by a vector ( ring rate / preferred direction) Vector sum of all cells = population vector. Movement direction and trajectories are encoded by integration of large numbers of m1 neurones. Climbing bres: interacts with all of cortexes, adjusts parameters of movement as a function of success, lesion = inaccuracy, instability. Vestibulocerebellum: innervated by brainstem vestibular nuclei, controls balance, coordination of eye & body movements, lesions- affect re exes essential for balance and stability.
