3- cerebral cortex Flashcards
fractionation
the ability to move body parts independently and to localize motor actions to a limited set of muscles
cerebral cortex contributes to this
what structure is involved with goal-directed movemnt
cerebral cortex
I want to do this movement
- It is part of the progress in refining motor learning
primary motor cortex mapping
‘Dynamically mapped’: as for skilled hand movements
The mapping is not for a specific muscle but for movements
primary motor cortex - Mutable
greatest change with skilled use;
rewarded behavior;
(this is all goal-oriented movement)
Motor cortex neurons - force
Force encoded by single neurons
Motor cortex neurons - direction
Direction coding occurs by an ensemble of neurons,
results in 99% accuracy for direction
is the cortex interest more in isolated movement or collective movement
isolated movement
diagram:Coding the proximal and distal movements together
Supplemental motor area (SMA) role
role in plan and program movement
internally triggered motor acts
What is a internally triggered motor acts
creating a motor behavior - I want to do this – this internally triggers an action
Motor set
premovement associated with planning andprogramming
motor set and SMA
50-70% of the neurons are for motor set in SMA
Cortico-cortico connections
extensive with prefrontal and parietal association areas; and connections to basal ganglia, limbic areas, and cerebellum
SMA neurons selectivity
neurons in the SMA are very selective
- Push turn pull > pull push turn
Lateral premotor (PM) responds to
externally-triggered /guided motor programs and plans object cues
External cue
There is a target and I want to get to it
Visually-guided reaching what area
premotor dorsal (PMd)
Visually-informed grasping what area
premotor ventral (PMv)
Visually-guided reaching - what is happening
Translates visual info of object location to reaching direction
Visually-guided reaching - pathway
Extrastriate to dorsal premotor (PMd) via medial dorsal- and medial intra-parietal areas
Visually-informed grasping from what area
premotor ventral (PMv)
Visually-informed grasping - what is happening
Translates visual info about object properties into successful grasping
Visually-informed grasping - pathway
Dorsal extrastriate cortex to premotor ventral (PMv) via anterior intra-parietal area
what are Mirror neurons
special neurons in PMv active when a monkey watches another perform a task; and when the monkey actually performs
where are mirror neurons found
premotor ventral (PMv) area