Motor System Flashcards
What are the steps to preform motor movement?
- posterior cortex provides sensory information to the frontal cortex
- prefrontal cortex plans movements
- premotor cortex organizes movement sequences
- motor cortex produces specific movements
What is the Edward Evert’s experiment on the movement coding by neutrons in neocortex? What were his 3 major findings?
he recorded activity of neutrons int he wrist region of the motor cortex while monkeys flexed their wrists on a lever
he found that
- m1 neurons plan and initiate movement
- m1 neutrons increase firing to increased force of a movement (i.e. the heavier the pulley connected to the lever, then the more firing)
- motor cortex specifies the direction of the movement
What was Apostles Georgopoulos experiment on the movement of coding by neutrons in the neocortex? What are his 3 findings?
he recorded activity of neutrons in the motor cortex while monkey moved lever in different directions
he found that:
- each m1 neutron is maximally active to a particular direction (i.e. as level mores away from the monkey by 180 degrees then the neuron fires a lot but as it moves towards the monkey by 180 it fires less)
- activity is decreased in proportion to the displacement from the preferred direction
- conclusion: motor neurone calculate distance and direction of movement
What did martin and colleagues find in regards to the role of motor cortex in observing, remembering and imagining movement?
he found that theres increase blood flow to the hand region of the motor cortex when naming tools
What did Haueisen and Knosche find in regards to the role of motor cortex in observing, remembering and imagining movement?
pianists exhibit activation of the motor cortex when listening to music
What did Nyberg and colleagues find in regards to the role of motor cortex in observing, remembering and imagining movement?
that similar brain activation occurs during imagined movement and actual movement i.e. like imagining rolling ball on a table
i.e. in the brain imagining it shows that it will recruit the same cortex’s as the overt movements except without cerebellar activity because u aren’t actually moving and no sensory and motor feedbacks
What is the primary motor cortex? and how does it operate (by which model)
primary motor cortex sends command signals via neuronal population vector model
- theres no individual neuron that codes for each direction and action of movements and its a fluid and dynamic way of producing movements that you have never done before
- you would recruit the same set of neurons every time plus or minus other neuronal actions to get a different movement overtime
- combining different movements will give you a new vector of movement
What three things need to be present in order to create a motor program within a motor plan?
- plan of action … planning of a program for action
- goal information: planning that involves a goal (has an end point)
- neuromuscular control information: muscles have to control this action
- motor plan may or may not be open to sensory feedback, virtually all movements are except for ballistic movements which are quick, goalless movements which are not open to sensory feedback
What is coarticulation in motor plans?
relationship between what we do with our speech and our face muscles when we speak … i.e. vocal muscles
what is the experiment we did on coarticulation in class? what was the result?
the difference between the word “struck” and the word “strike”… we say STRIKE with a smile and STRUCK more non like a smile e
What is the experiment that shows how far in advance motor planning is made?
it basically is aiming to show how far and how advanced motor planning is observed by reading a sentence and then saying it out loud
results show that longer phrases take longer to initiate therefore have a longer motor planning phase
- when we are given the signal to start speaking, we say the shorter and easier sentence almost right away but we say the longer and more complex sentences after a few while
How is the cerebellum organized and what are 3 major regions of it?
- its organized ipsilaterally
1. the vermis region is the medial region of the cerebellum and if its lesioned in monkeys then they fall ipsilateral to that lesion
2. the intermediate zone –> lesion in this area will cause difficulty in smooth movements (action or intentional tremors) … Nose test case –> touching your nose and then touching the experimenter’s nose… intentional tremors occur when person moves finger towards their nose or towards object of focus
3. lateral zone (involved in motor planning) –> involved in ballistic movements (like over shooting the target when trying to reach for it..etc..), and Multi-joint movement (like decomposition of movement, breaking movement processes down into smaller components instead of one full component)
What does the experiment for cerebellum damage and overshooting (hypermetria) show?
in MEG (muscle EEG’s), it shows that in cerebellar lateral zone damage .. the agonist peaks later and has more than one agnost peak which means it shows jerkiness as well as an extended DELAY of the antagonist muscle peaking
in normal patient the agonist peaks first to preform the action and then it QUICKLY dies down after antagonist muscle takes
What was Fatch’s study with cerebellum and motor learning with Prism Goggles?
neurologically intact people learned over time how to throw and aim using prism glasses which shifted their view to the left, and then they also learned to le-learn after the prism was removed
in lateral cerebellum damaged patients, learning and re-learning where not shown upon addition of prism glasses and removal of prism glasses (lateral zone damage)
What are the 5 roles of the Supplementary Motor Area (SMA)?
- motor planning (anterior or primary motor cortex in the medial surface)
- state of readiness for action
- action initiation
- complex movements
- motor imagery
What does the experiment with muscle activation and SMA activation show in monkeys?
300 ms prior to the motor action starting, the SMA area has really high activation and the muscles have low activation
then starting and during the motor action, the SMA is still firing but muscles are firing more
SMA is activated before initiation of action and decreases a bit 50ms prior to the start of the action
