cortical motor structures. hierarchical organization of motor system
Post on 22-Dec-2015
229 views
TRANSCRIPT
![Page 1: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/1.jpg)
Cortical motor structures
![Page 2: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/2.jpg)
Hierarchical Organization of Motor System
![Page 3: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/3.jpg)
![Page 4: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/4.jpg)
Hierarchical Organization of Motor System
Primary Motor Cortex and Premotor Areas
![Page 5: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/5.jpg)
Hierarchical Organization of Motor System
Premotor area composed of supplementary motor area and lateral Premotor area
![Page 6: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/6.jpg)
Hierarchical Organization of Motor System
Level 3: The CortexPrimary Motor CortexProjects directly
to the spinal cord to regulate movementVia the Corticospinal Tract
Projects indirectlyVia the Brain stem to regulate movement
![Page 7: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/7.jpg)
Hierarchical Organization of Motor System
Level 3: The CortexPremotor AreasReceive information from parietal and prefrontal areasProject to primary motor cortex and spinal cordFor planning and coordination of complex planned movements
![Page 8: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/8.jpg)
PREMOTOR AREAS (6&8)
M1, PRIMARY MOTOR CORTEX
![Page 9: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/9.jpg)
TRANSCORTICAL CIRCUITS
M1 : somatotopically organized input directly fromBrodmann’s 1,2,3 (primary somatosensory)
Posterior parietal area 5 (multiple sensory integration for motor planning)
![Page 10: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/10.jpg)
TRANSCORTICAL CIRCUITS
PREMOTOR AREAS: each its own pattern of inputs from distinct locations in areas 5, 7. Area 46 mainly to ventral premotor area
Posterior areas 5&7
Area 46 (prefrontal)-WM for object location in movement guidance
![Page 11: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/11.jpg)
dense connections between premotor areas (as parts of working memory for motor planning with specific, interconnected aspects)
lesions result in inability to incorporate visuospatial info in kinematic plan
![Page 12: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/12.jpg)
More on premotor areas function:
(Bereitschaft): 1 sec before movement onset, negative shift in supplementary motor regions
(instructed delayed task, touch 3 panels on visual/memory cues, SMA firing in memory condition)
Self-initiated (e.g from memory) sequence learning
(presupplementary motor area, main input to SMA only, no somatotopy)
Proficiency: shift from SMA to M1 ( e.g. monkeys, learning, lesion, relearning)
![Page 13: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/13.jpg)
LATERAL PREMOTOR: ACTION SELECTION & SENSORIMOTOR TRANSFORMATIONS
Set-related activity in lateral premotor, usage of sensory stimuli in motion guidance
Persistent during intervals between anticipatory cue and signal to move (dorsal lateral premotor)
Connected to stimuli not conveying spatial cues
Bilateral lesions, intact execution, NO new associative learning (e.g. pull/push joystick on red/blue light)
![Page 14: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/14.jpg)
Motor cortex
What is represented?MusclesMovementDirectionLocationSequence
![Page 15: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/15.jpg)
– Georgopoulous found directional sensitivity in motor cortex neurons.
– Population coding.
Population Vector (vector sum of everycell in the population)
Each arrow shows preferred direction ofcell associated with arrow. Length of arrow represents strength of preference
![Page 16: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/16.jpg)
Motor cortex
![Page 17: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/17.jpg)
Motor cortex
![Page 18: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/18.jpg)
Motor cortex
![Page 19: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/19.jpg)
Motor cortex
![Page 20: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/20.jpg)
Motor cortex
![Page 21: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/21.jpg)
Motor cortex
![Page 22: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/22.jpg)
Motor cortex
![Page 23: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/23.jpg)
![Page 24: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/24.jpg)
Motor cortex
![Page 25: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/25.jpg)
Motor cortex
![Page 26: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/26.jpg)
11-24
![Page 27: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/27.jpg)
![Page 28: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/28.jpg)
Motor cortex
![Page 29: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/29.jpg)
![Page 30: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/30.jpg)
Comparison of motor planning and execution
• Taken together these results are in accord with a hierarchical control system.– Simple movements
• Minimal processing
• Changes in blood flow limited to primary motor and sensory areas.
![Page 31: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/31.jpg)
Comparison of motor planning and execution
• Taken together these results are in accord with a hierarchical control system.– Greater complexity
• Cortical areas anterior to the primary motor area become activated.
• Activation in both hemispheres– Activation of abstract motor plan not tied to a specific
effector.
– Potential motor plans each viable candidate for achieving a common goal.
![Page 32: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/32.jpg)
The motor hierarchy
![Page 33: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/33.jpg)
11-26
![Page 34: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/34.jpg)
11-27
Adapted from Mushiake, H., Masahiko, I., and Tanji, J., Neuronal activity in the primate premotor, supplementary, and precentral motor cortex during visually guided and internally determined sequential movements, Journal of Neurophysiology 66 (1991): 705–718
![Page 35: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/35.jpg)
W. W. Norton
![Page 36: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/36.jpg)
W. W. Norton
![Page 37: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/37.jpg)
W. W. Norton
![Page 38: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/38.jpg)
W. W. Norton
![Page 39: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/39.jpg)
W. W. Norton
![Page 40: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/40.jpg)
W. W. Norton
![Page 41: Cortical motor structures. Hierarchical Organization of Motor System](https://reader035.vdocuments.net/reader035/viewer/2022062314/56649d805503460f94a63af3/html5/thumbnails/41.jpg)
Motor cortex