Cognitive Neuroscience Lecture 14: Motor Planning and Coordination

''L14: Motor Planning and Coord ''

Premotor & supplementary motor cortex: general abstract planning

Motor: specific planning for action

Cerebellum and basal ganglia: every aspect of motor control

Brainstem: more specific

Spinal cord: extend and flex

Primary motor (M1)

Premotor and supplementary: higher level and abstract

Frontal eye field: anterior: motor action and planning

DORSAL: SPATIAL LOCATION

Motor: somatosensory cortex needed to know where your body parts are

SMA is medial part of premotor 

Topographic organization; neural magnification

Pyramidal: send from cortex to sc

-         Decussation: ends in opposite side

Extrampyramidal: from subcortical to sc

-         Decussation: MIXED

Basal ganglia: everything except thalamus

-         Motor cortex and prefrontal

Cerebellum:

-         Motor cortex and output to brainstem: training complex

Parkinsons: loss of dopamine producing cells in substantia nigra (basal ganglia)

Deep brain stimulation in subthalamic nuclei of basal ganglia helps

Hierarchical control of complex actions:

Higher levels: abstract action planning that are effector-independent (doesn’t matter what body part)

Lower levels: effector-specific levels of motor execution

Premotor and SMA = high level abstract (effector independent)

Georgopoulos—Activity prior to onset of reaching shows planning for mvt

Tuning curve: directional (preferred) but fairly broad

In experiment, using same lights and switching direction shows that the same neurons responding to mvt direction

How can they do precise it if it’s broad tuning?

All cells contributing (vote)

-         Direction (preferred direction)

-         Length (strength of response…firing rate)

Sum of vectors is population vector

Response of neuron population recorded while planning mvts to different directions and coded as vectors

Responses of POPULATION recorded while planning mvt to diff directions and coded as vector

Vector sum

1.      Joystic control

2.      Cortical control

a. Target in front of mouth

b. Target in plane

c. Target

d. Gripper control

3.      Different egrees of computer assistance until complete self feeding

4.      Target tracking

5.      Emergent behavior: control

Neural tissue representation critical for instantiating cognition and practical apps