Voluntary motion Flashcards
(40 cards)
Name the cortical areas associated with voluntary movement.
Primary motor cortex (Precentral gyrus)
Pre-motor cortex
Supplementary motor cortex
Additionally:
Pre-frontal cortex
Parietal cortex
What pathway allows us to complete motor acts based on visual input?
Dorsal visual pathway
Using V3, V2, and V1
Overview of how reaching occurs.
1) Info goes from visual cortex –> parietal cortex using the dorsal visual pathway. Tells you about the space around you.
2) 2nd pathway involving superior parietal cortex. Tells you about where your arm is in space
During reaching, information will be sent from the visual cortex to the parietal cortex. Where specifically in the parietal cortex does the information go to?
V6A
PEc - caudal area of posterior parietal cortex
MIP - medial intraparietal area
VIP - ventral intraparietal area
What is VIP responsible for?
Creating a rough map of the space around you
Where does VIP send information to?
F4 - within the premotor cortex
What is F4 responsible for? How do the neurons respond here?
Creating a detailed map of the space around you. The closer an object is, the more the neurons are excited and fire.
When reaching for an object, where does information travel in the 2nd pathway? What does this pathway tell you?
Information goes from the superior parietal cortex (possibly V6a) to F2 in the premotor cortex.
The pathway tells you about where your arm is in space.
What is F2 responsible for?
Creating a map of where your arm is in relation to your body and the things around you.
The visual cues related to grasping are dependent on what?
They are dependent on what you INTEND TO DO.
Overview how grasping occurs.
Information travels from the inferior parietal cortex to F5 with a goal of an action.
What are the parts of the inferior parietal cortex?
Anterior intraparietal area (AIP)
PFG
The inferior parietal cortex contains neurons that respond to what?
Seeing an object to grasp - visually dominant
Grasping an object - motor dominant
Both seeing and grasping an object - visuomotor neurons
Where do AIP/PFG relay their information?
F5
What is F5 responsible for?
They fire in response to the GOAL of an action. NOT the motor act itself.
Describe the similarities in reaching and grasping paths.
Both use the DORSAL VISUAL PATHWAY
There is no encoding of motor act for both
Describe the differences in reaching and grasping paths.
Areas of parietal cortex required are different:
Reaching = V6a, PEc, MIP/VIP
Grasping = AIP/PFG
Reaching creates a map of space and body:
VIP - rough, F4 - detailed, F2 - where arm is
Grasping involves being AWARE of a GOAL (F5)
Summarize what the premotor cortex does. What information does it need and what does it do with the information?
Receives sensory information to F4 & F5 required for movement.
Identifies intent of motion and decides what motion to produce.
Dorsal pathway - applies rules to determine whether it is appropriate to move
What are the 2 divisions of the supplementary motor cortex? What are they responsible for?
Supplementary motor area (SMA) - postural control
Pre-supplementary area (pre-SMA) - Plans motor program for action
What are the actions of the supplementary motor cortex?
Organize motor sequences
Acquire motor skills
Executive control - decision to switch actions/strategies
So to review really quick… what do the premotor cortex and pre-SMA accomplish?
Premotor cortex = identifies purpose of intended motion and creates map for reaching and ultimately grasping object
Pre-SMA = identifies sequence of how the action is to occur
Where is the primary motor cortex located?
Precentral gyrus
What does the primary motor cortex do?
Controls specific movements
How is the primary motor cortex arranged?
Why is this significant?
It is arranged in columns
Stimulation of any columns produces a specific movement
