Adapting Discrete movements

Question 1

what does the cerebellum do

Answer 1

help measure and correct movement errors

Question 2

how do children Learn to make goal-
directed movements

Learning to make goal-directed movements with altered visual feedback. How do we study goal-directed movements in adults

what is a common task we use to measure this

Answer 2

Children has to learn the mapping between muscle activity and the amount and direction of limb motion.

Shift the visual field – alter the relationship between muscle activity and visual feedback about limb
motion

change movements of the cursor
Rotation transformation means subject has to relearn/adapt mapping between cursor and hand motion

Question 3

when you add a difference or the cursor is rotated
what happens to the errors over time

Answer 3

Subject makes reaching errors when the cursor rotation is introduced. The size of these errors is proportional to the size of the rotation.

Visuomotor adaptation involves changes in the planned reach path using errors experienced in previous trials (i.e., aim point, end point)

Question 4

how do you find out what part of the brain manages what part of the body

Answer 4

The lesion, or temporarily paralyzing
imaging and primate studies have identified several brain regions that are important for visuomotor learning

Question 5

Brain Regions Showing Changes in Activity with Adaptation

changes in blood flow in the brain. SMG, SPL, PFC

Increased rCBF observed in:
* Posterior lobe of cerebellum

Answer 5

change rate of Cerebral Blood Flow observed in:

• (A) Supramarginal gyrus (SMG): (forearm/hand areas) – encoding of movement errors, involved in proprioception for action and visuomotor transformations.
• (B) Superior parietal lobule (SPL; BA 7): possible encoding of reaching errors/mismatch between proprioception and vision.
• PFC (BA 46): Involved in explicit working memory and aiming strategies

Increased rCBF observed in:
* Posterior lobe of cerebellum: (forearm/hand areas) – thought to be involved in learning from movement errors and adapting to properties of the body and/or environment.

Question 6

healthy individual, explain what happens

in a Cerebellar subject, describe what happens

Answer 6

healthy, fairly accurate.
start with bad error, and adapt to new thing. Make it the new baseline
then large error in other way, and slowly adapt to old baseline

Cerebella subject somewhat accurate
do not fix their error with glasses, and they never learn to fix
In washout, very accurate right away because they never learnt or adapted

Question 7

owl using vision and auditory to find prey, break down graph

Answer 7

vision sees dif then audition
audition slowly adapts
vision and audition adapt into the same place
take off glasses, vision goes back to normal but audition needs time to realign

Question 8

sense of limb position before prism adaptation

sense of limb position is rotated 12 degrees

Answer 8

Subject accurately judges sense of limb position

Adapting to prisms alter the perceived position of
the limb!