Motor Control: Voluntary Control Lecture (Dr. Karius) TEST 3 Flashcards
Voluntary Motion
1) There are several areas associated with the PRODUCTION of Voluntary Motion:
a) PRIMARY Motor Cortex
b) SUPPLEMENTARY Motor Cortex
c) PRE-MOTOR Cortex
2) Additionally parts of the PRE-FRONTAL Cortex and the PARIETAL CORTEX contribute to Voluntary Motion as well.
***Each of these areas has Multiple Roles and in some cases, Overlapping Roles!!!!
Higher Processing of Visual Inputs
1) The DORSAL PATHWAY:
- Leaving the OCCIPITAL CORTEX and going to the PARIETAL/ FRONTAL CORTEX enables us to COMPLETE MOTOR ACTS BASED ON VISUAL INPUT. This Path allows you to play Catch with your friends
2) The VENTRAL PATHWAY:
- Relays Information to the INFERIOR TEMPORAL COMPLEX and allows us to Process the Visual Image so that we can COPY IT IF NEEDED and NAME/RECOGNIZE IT. This two Functions are SEPARATED. Similar or Related Objects are all Coded for in Localized regions of the Temporal Lobe. There is a Specialized are for RECOGNIZING FACES!
Motor Control: REACHING
1) In order to REACH effectively, you need Information about the Object’s LOCATION in RELATION to YOUR BODY!!!
2) From the VISUAL CORTEX, Information is relayed to the Parietal Cortex, specifically:
- V6A
- The PEc
- The MIP (Medial Intraparietal Area)
- The VIP (Ventral Intraparietal Area)
**END RESULT: the VIP created a ROUGH MAP OF THE SPACE AROUD YOU, Including the Bowl of Candy
3) From the VIP, the Information is sent to the F4 within the PREMOTOR CORTEX
***END RESULT: F4 creates a DETAILED MAP OF THE SPACE AROUND YOU. Neurons here are Particularly Excited by PROXIMITY!!!
4) There is a SECOND PATHWAY at Work here, relying on the SUPERIOR PARIETAL CORTEX. This Receives Visual Information about WHERE YOU ARM IS IN SPACE (Since that’s what’s MOVING).
***This INPUT is sent to F2 in the PREMOTOR CORTEX!!!!!!!!
**END RESULT: F2 CONSTRUCTS a RELATED MAP - but it is of WHERE YOU ARM IS IN RELATIONSHIP TO YOUR BODY and the THINGS AROUND YOU!!!!!!!!!!!!
Motor Control: Grasping
Introduction
- The Visual CUES related to Grasping are quite different, and very DEPENDENT on EXACTLY what you intend to do
- Now we need to PAY ATTENTION to the FEATURES of the ITEM we are INTERESTED IN PICKING UP!!!
Motor Control: GRAPSING
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*****The ANTERIOR INTRAPARIETAL AREA and the PFG (Parts of the Inferior Parietal Cortex) contains NEURONS that Respond to:
a) SEEING an OBJECT to Grasp (VISUAL DOMINANT)
b) GRASPING an Object (MOTOR DOMINANT)
c) Either Condition (VISUOMOTOR Neurons)
1) The ANTERIOR INTRAPARIETAL AREA and the PFG relay their Information to F5
- Interestingly, the F5 Neurons FIRE WITH THE GOAL, NOT with the Motor Act
****This means that the F5 Neurons are likely to be ACTIVE when Holding the Cup to SMELL or Holding the cup to DRINK!!!!
Compare and Contrast the NEURON COMPONENTS for REACHING for an Object vs GRASPING that Object
1) TO REACH:
- Need visual map of the object in relation to you.
- Primary visual cortex via DORSAL PATHWAY!!!!!!
- Ventral Intraparietal Cortex (VIP) CREATES MAP
- Relays it to F4, which CREATES a DETAILED MAP.
- A parallel pathway using the superior parietal cortex sends information to F2, leading to a MAP of WHERE YOUR ARM is in RELATION TO YOU.
2) TO GRASP:
- Areas of the Inferior Parietal Cortex relay information to F5
*** F5 codes the GOAL of the Action!!!!!!
- Both inputs are then sent on to be TURNED ‘INTO’ the MOTION.
PREMOTOR CORTEX
Introduction
PREMOTOR CORTEX:
- Receives the SENSORY INFORMATION required to MOVE (Particularly F4 and F5- the VENTRAL PARTS)
- DORSAL: Applies the “RULES” that determine whether it is APPROPRIATE TO MOVE
- Identifies the INTENT of the MOTION and DECIDES WHAT MOTION TO PRODUCE!!!!!!
PURPOSE of MOTION and CREATED a MAP FOR YOU TO REACH/ GRASP the CUP!!!!!****
Supplementary Motor Cortex
Introduction
SUPPLEMENTARY MOTOR CORTEX:
- Two Divisons:
1) Supplementary Motor Area (SMA): POSTURE CONTROL!!!!!!
2) Pre- Supplementary Area (Pre-SMA): PLANS the MOTOR PROGRAM REQUIRED to MAKE the ACTION OCCUR!!!!!!!
Supplementary Motor Cortex
Functions
SUPPLEMENTARY MOTOR CORTEX FUNCTIONS:
1) Organize Motor Sequences
2) Acquire Motor Skills
3) EXECUTIVE CONTROL (Particularly the DECISION to SWITCH ACTIONS/ STRATEGIES)!!!!!!!!!!!!!!!!!!!
The Scenario:
A “Bowl” of candy is being passed around the room. You re free to take a piece of you favorite kind.
For you to think about:
- The PREMOTOR CORTEX has IDENTIFIED the PURPOSE of YOUR INTENDED MOTION and CREATED the MAP to ALLOW you to REACH FOR and GRASP the Piece of Candy.
- The Pre-SMA has IDENTIFIED the SEQUENCE of how this is to Occur… How of the Motornuerons GET ACTIVATED???
The Primary Motor Cortex
Introduction
PRIMARY MOTOR CORTEX:
- PRECENTRAL GYRUS
- Controls Specific Movements
- Regions of Body that do FINE MOTIONS have PROPORTIONALLY HIGH REPRESENTATION!!!!!!!!!!
- Arranged in Columns
A) Stimulation of an Given Column produces a SPECIFIC MOVEMENT
- If we are in an Area that Controls a MORE General Motion, Stimulation may produce CONTRACTION of a GROUP of MUSCLES (Ex: In your back)
B) LAYER 4 of the Primary Motor Cortex:
- Receives SENSORY INPUT!!!!!!!!!!(Muscle and Joint Proprioceptors, among others)
C) LAYER 5 of the Primary Motor Cortex becomes the OUTPUT for the CORTICOSPINAL (Pyramidal) PATHWAY!!!!!!!
D) There appear to be TWO SETS of NEURONS in EACH COLUMN:
1) One to START THE MOTION
2) One set to MAINTAIN THE MOTION AS LONG AS NECESSARY!!!!!!!!
E) NEIGHBORING Columns Control RELATED MOTIONS!!!!!!!! (Not Neighboring Muscles)
F) There seem to be TWO KINDS of COLUMNS:
1) ON/ OFF for AGONIST Muscle
2) OFF/ ON for the ANTAGONIST Muscle
G) Each of the INDIVIDUAL MOTIONS required to Pick up the piece of Candy were CODED for by a COLUMN in the PRIMARY MOTOR CORTEX!!!!!
Describe how Each of the Following Cortical Regions participates in the Control of Voluntary Motion:
- Primary
- Premotor
- Supplementary Motor Cortex
PREMOTOR CORTEX:
- Determines whether it is ‘OKAY’ TO MOVE
- IDENTIFIES the GOAL and the MOTION REQUIRED to MEET THAT GOAL!!!!!!
SUPPLEMENTARY MOTOR CORTEX:
- POSTURAL CONTROLS
- Identifies the SPECIFIC MOTOR SEQUENCE required!!!!!!!!!
- CHANGES TACTICS if necessary
PRIMARY MOTOR CORTEX:
- Codes the INDIVIDUAL MOTIONS REQUIRED to REACH the GOAL!!!!
Cerebellum
Introduction
- Even with the CEREBRAL CORTEX up there PLANNING the Motion, WITHOUT some additional parts of the Brian, you WILL NOT BE ABLE to BRAG a Piece of Candy
- You’ll probably CRUSH the piece of Candy and ISS your Mouth
Cerebellum
ROLE
ROLE of the Cerebellum:
1) SEQUENCE COMPLEX ACTIONS
2) Correct FORCE/ DIRECTION
3) BALANCE and EYE MOVEMENTS
4) Learning of COMPLEX ACTIONS!!!!!!!
Parts of the Cerebellum
1) Spinocerebellum (Vermis)
2) Spinecerebellum (Lateral)
3) Cerebrocerebellum
4) Vestibulocerebellum
