Motor System 1: Cortex Flashcards
What are the 3 broad types of movement?
Reflexes, rhythmic motions, and voluntary motions.
What are the circuits that allow you to perform rhythmic motions like chewing, walking, swallowing, etc. without having to learn or practice them?
CPGs - more on this next lecture
What’s the process that corrects for errors?
Feedback
What’s the process that anticipates things that are going to happen?
Feedforward
What are the 3 levels of hierarchical control in the motor system?
Highest: Motor cortex, premotor cortex, modulatory influences from basal ganglia and cerebellum
- Motor control centers in brain
- Lower motor neurons.
What are the three medial motor tracts/nuclei in the brain stem?
Tectospinal tract, reticulospinal tract, and vestibulospinal tracts.
Which brain stem medial motor tract is involved with visual balance?
Tectospinal tract.
Which brain stem medial motor tract carried vestibular information?
Vestibulospinal tract
What is the one lateral motor nucleus/tract in the brain stem? Action? How important is it?
Red nucleus -> rubrospinal tract. Ends at shoulders. Used to be used for more, but in humans it’s just for shrugging…
Where are most of the inputs to the primary motor cortex coming from?
Premotor cortex, somatosensory cortex, association area 5 (visual somato-sensory convergence)
Where are most of the inputs to the premotor cortex?
Prefrontal cortex (“maps of surroundings”), asssociation areas 5 and 7
How would the result of stimulating an area of the premotor cortex contrast with stimulating an area of the primary motor cortex?
Primary motor: simple movement
Premotor: more complex movement with multiple joints.
What are the 2 major subcortical inputs to the motor cortices? Does the info go straight there?
Cerebellum and basal ganglia. No, info goes through the thalamus.
How does the cerebellum receive info from the cortex?
Through the middle cerebellar peduncle.
Are muscle innervations in the brain like a switchboard?
No. Muscles are almost never activated individually.
What is the concept for population encoding?
the activation of any given set of muscles is carried out by a distributed population of neurons.
Learned muscle activities get more representation in the cortex.
That’s right they do.
Is the firing of corticospinal neurons related to muscle force exerted or muscle displacement?
Force exerted.
What area can you activate just by thinking about a complex movement?
Supplementary motor area.
What area of the cortex is used in movements triggered by external sensory stimuli?
Lateral premotor areas.
What are PMv neurons?
Mirror neurons -activated when you watch somebody perform an action. (Keisha notes that people with autism tend to have less PMv activity)
