Motor Control Flashcards
How are behaviors produced by different levels?
Each layer adds new dimentions to behavior. I.e. rats can still groom even without a cortex, so evolution led not to new behaviors but to flexibility
Describe top down vs bottom up
Top down: looking at something voluntary. Frontal/supplemental eye fields (IN THE premotor cortex)
Bottom up: sensory stim coming in and automatically drives behavior (Superior coliculus- orients eyes towards visual stimuli, Boston pizza part of the brain)
What are spinal animals?
good chart on the slides to test yourself on
Reflexes (stepping responses, limb approach/withdrawl. Some of our coordination is built into our spinal circuits
What are low decerebrate animals?
Spinal chord + hindbrain (cerebellum, medulla, pons).
Have sleep stages but not cycles. Narcolepsy…
Decerebrate rigidity (abnormal posture) and postural reflexes.
no voluntary control of the body.
What are high decerebrate animals?
Spinal chord, hind and mid brain
- orient twowards stimlui
- inferior coliculus (sound info)
- no evidence that it’s percieving things tho, just responds to objects.
- no “conscious” vision
- automatic and voluntary (but doesn’t seem driven by any motivation. ie. they will get up and walk but not for any purpose)
What are diencephalic animals?
Has spine, thalamus, hypothalamus, midbrain and hindbrain.
- motivation starts happening
- some spontaneous eating/drinking/emotions
SHAM RAGE: poke the animal and it will be angry for HOURS.
Aimless wandering, motivated behavior but not to do anything for itself (eat/drink)
What are decorticate animals?
Everything except cortex (including basal ganglia)
- super capable.
- eat/drink on their own
- normal sleep wake
- sequency movements (groom)
- classical conditioning is in tact (learn)
- HOWEVER don’t do preparatory behaviors like make nests or hoard food.
- don’t perform complex behaviors.
What is the cortex responsible for?
Amygdala: difference between beeping and dog barking
Cortex: difference between beeping of washing machine and microwave.
- language and motor output
- future planning
= creates a simulation of the world. Uses that model to prepare (you know there is a hallway out there)
more complicated: better simulations of the world.
What is the stretch reflex circuit?
- at spinal level
- nervous system and muscles
- push and pull in different directions
- sensory stretch receptors (to dorsal root to horn which diverges to two muscle groups)
- acetylcholine works at NMJ.
controlling muscle GROUPS not just muscles
relies on proprioception input from stretch reeptors.
activating one usually inhibits another. ^^^
What is the loop of movement?
Think “i want a drink of water”
Have a movement Plan
Motor signal sent to muscles (specific group like hand)
Actual movement
Sensory information to correct behavior (touch/visual)
- visual info improves movement. Proprioception too
Need constant sensory info in order to have movement.
(except for ballistic responses)
Who is pt. GO?
Deficits to somatorsensory cortex, couldn’t pick things up off the ground. Issues with arms.
Don’t adjust for things. SHows that you need sensory input for movement.
What are ballistic responses?
Openloop! So fast that you can’t “course correct” or adjust for them. “punching, or throwing a bat”
What is the heirarchical control of movement
Association cortex Secondary motor cortex Primary motor cortex Brainstem motor nuclei Spinal Motor circuits
Separates what we want to do (have a drink) and the types of actions we can make (not restricted to muscle group- could be your feet) and the more we do things, the lower down it goes freeing up space. (flexibility, why now you can talk and drive but before you couldn’t.)
What is the central sensorimotor program theory?
- Lower levels possess sensorimotor programs which represent a pattern of activity
- A movement produced by activating the oppropriate combination of these sensorimotor programs
- once a level of the heirarchy is activated, it can operate of the basis of sensory feedback without direct control by the higher levels.
IN OTHER WORDS
Simple movements make up larger goals. Once you’ve activated a level, it doesn’t need ongoing effort/concsoius control.
How do we plan out movements?
MOTOR PROGRAMS and INDEPENDANT of MUSCLES in the SECONDARY MOTOR CORTEX.
(we know how to sign our names with our feet if we had to)
Can apply things we’ve learned with our hands. SO WEIRD and awesome.
Motor plans aren’t mapped to body parts.
MOTOR EQUIVALENCE: different muscles and limbs but same behavior.