Podcast
Questions and Answers
What represents the highest level of the motor control hierarchy?
What represents the highest level of the motor control hierarchy?
- Spinal cord
- Motor cortex and cerebellum
- Forebrain association areas and basal ganglia (correct)
- Alpha motor neurons
Which part of the motor control hierarchy is responsible for the tactics of movement?
Which part of the motor control hierarchy is responsible for the tactics of movement?
- Spinal cord
- Forebrain association areas
- Alpha motor neurons
- Motor cortex and cerebellum (correct)
What is the final common pathway for motor behavior?
What is the final common pathway for motor behavior?
- Basal ganglia
- Spinal interneurons
- Sensory feedback
- Alpha motor neuron (correct)
How does the brain influence the spinal cord's activity?
How does the brain influence the spinal cord's activity?
What role do spinal interneurons play in movement control?
What role do spinal interneurons play in movement control?
What aspect of movement is NOT handled by the middle level of the motor control hierarchy?
What aspect of movement is NOT handled by the middle level of the motor control hierarchy?
Which of the following is considered a part of the central motor system?
Which of the following is considered a part of the central motor system?
Which statements about reflex movements are correct?
Which statements about reflex movements are correct?
What is a common consequence of lesions in the parietal lobes?
What is a common consequence of lesions in the parietal lobes?
Which area works in conjunction with the posterior parietal cortex for motor control?
Which area works in conjunction with the posterior parietal cortex for motor control?
What do areas 4 and 6 primarily contribute to?
What do areas 4 and 6 primarily contribute to?
At what point do actions transition from encoding to specification?
At what point do actions transition from encoding to specification?
Which cognitive processes are thought to involve the anterior frontal lobes?
Which cognitive processes are thought to involve the anterior frontal lobes?
What did the studies by Per Roland and his colleagues primarily support?
What did the studies by Per Roland and his colleagues primarily support?
What is a possible effect of damage to the parietal lobes on spatial relations?
What is a possible effect of damage to the parietal lobes on spatial relations?
Which function does cortical area 6 NOT directly relate to?
Which function does cortical area 6 NOT directly relate to?
Which areas of the brain are primarily known as the motor cortex?
Which areas of the brain are primarily known as the motor cortex?
What is the significance of Wilder Penfield's work in relation to the motor cortex?
What is the significance of Wilder Penfield's work in relation to the motor cortex?
What is the first step in goal-directed movement according to the understanding of motor planning?
What is the first step in goal-directed movement according to the understanding of motor planning?
Which of the following is NOT specifically localized to different regions of the cerebral cortex?
Which of the following is NOT specifically localized to different regions of the cerebral cortex?
What role does memory play in the planning of movement?
What role does memory play in the planning of movement?
Where is area 4 of the motor cortex located?
Where is area 4 of the motor cortex located?
Which aspect of motor control is crucial for understanding where the body intends to go?
Which aspect of motor control is crucial for understanding where the body intends to go?
Which cortical area is immediately anterior to area 4?
Which cortical area is immediately anterior to area 4?
What does behavioral neurophysiology primarily involve?
What does behavioral neurophysiology primarily involve?
Which of the following can be investigated using behavioral neurophysiology techniques?
Which of the following can be investigated using behavioral neurophysiology techniques?
Why are some types of human neurosurgery performed with patients awake?
Why are some types of human neurosurgery performed with patients awake?
What technical development has advanced the field of behavioral neurophysiology?
What technical development has advanced the field of behavioral neurophysiology?
What is a major challenge in neuroscience as mentioned in the content?
What is a major challenge in neuroscience as mentioned in the content?
What type of information can be gathered from the methods used in behavioral neurophysiology?
What type of information can be gathered from the methods used in behavioral neurophysiology?
Which skill has been specifically studied through behavioral neurophysiology in humans?
Which skill has been specifically studied through behavioral neurophysiology in humans?
What enables the investigation of various neuroscientific topics through altered tasks in behavioral neurophysiology?
What enables the investigation of various neuroscientific topics through altered tasks in behavioral neurophysiology?
What kind of synapses are marked with a plus (+)?
What kind of synapses are marked with a plus (+)?
What role does the direct pathway of the basal ganglia play in movement initiation?
What role does the direct pathway of the basal ganglia play in movement initiation?
Which neurons are tonically active at rest and inhibit the VL?
Which neurons are tonically active at rest and inhibit the VL?
What happens when cortical activation excites putamen neurons?
What happens when cortical activation excites putamen neurons?
What effect does activity in VLo have on the SMA?
What effect does activity in VLo have on the SMA?
What type of connections initiate the motor loop through the basal ganglia?
What type of connections initiate the motor loop through the basal ganglia?
Which structure is directly excited by cortical cells in the basal ganglia's motor pathway?
Which structure is directly excited by cortical cells in the basal ganglia's motor pathway?
In the direct pathway of the basal ganglia, which type of synapse do putamen cells make?
In the direct pathway of the basal ganglia, which type of synapse do putamen cells make?
What role do the globus pallidus cells play in the motor pathway through the basal ganglia?
What role do the globus pallidus cells play in the motor pathway through the basal ganglia?
What is the connection called that is made from VLo to SMA in the basal ganglia's motor loop?
What is the connection called that is made from VLo to SMA in the basal ganglia's motor loop?
Which of the following circuits are NOT primarily involved in the motor functions of the basal ganglia?
Which of the following circuits are NOT primarily involved in the motor functions of the basal ganglia?
What is the primary function of the direct pathway through the basal ganglia?
What is the primary function of the direct pathway through the basal ganglia?
What is a notable characteristic of the complexities of the basal ganglia?
What is a notable characteristic of the complexities of the basal ganglia?
Flashcards
Motor Control Hierarchy
Motor Control Hierarchy
The brain's multi-level system for controlling movement, from overall strategy to precise muscle actions.
Forebrain (highest level)
Forebrain (highest level)
Involved in the overall strategy of a movement – deciding what to do and how.
Motor Cortex & Cerebellum (middle level)
Motor Cortex & Cerebellum (middle level)
Responsible for the precise timing and sequence of muscle movements to achieve the forebrain's goal.
Spinal Cord (lowest level)
Spinal Cord (lowest level)
Executes the planned movement by activating the muscles through motor neurons.
Signup and view all the flashcards
Association areas of neocortex
Association areas of neocortex
Part of the forebrain involved in the overall strategy of the movement.
Signup and view all the flashcards
Basal Ganglia
Basal Ganglia
Part of the forebrain that plays a role in movement strategy.
Signup and view all the flashcards
Motor Control
Motor Control
The complex system the brain and body use to plan and execute movements.
Signup and view all the flashcards
Voluntary Movements
Voluntary Movements
The movements that we consciously decide to make.
Signup and view all the flashcards
Motor Cortex Location
Motor Cortex Location
The motor cortex is in the frontal lobe, specifically area 4 (precentral gyrus) and area 6 (anterior to area 4).
Signup and view all the flashcards
Motor Cortex Function
Motor Cortex Function
The motor cortex is responsible for planning and controlling voluntary movements.
Signup and view all the flashcards
Voluntary Movement Planning
Voluntary Movement Planning
Involves understanding body position, target location, and creating a movement plan.
Signup and view all the flashcards
Area 4
Area 4
A part of the motor cortex, anterior to the central sulcus on the precentral gyrus, playing a vital role in motor control.
Signup and view all the flashcards
Area 6
Area 6
Part of the motor cortex, just anterior to area 4, also contributing to movement planning.
Signup and view all the flashcards
Penfield's Research
Penfield's Research
Penfield's experiments stimulated the brain regions to pinpoint their roles in motor control.
Signup and view all the flashcards
Cortical areas for motor planning
Cortical areas for motor planning
Almost all parts of the neocortex is involved in planning and controlling voluntary movement.
Signup and view all the flashcards
Goal-directed Movement
Goal-directed Movement
Movement requires knowledge of the body's position, target destination, and how to reach that destination.
Signup and view all the flashcards
Behavioral Neurophysiology
Behavioral Neurophysiology
Recording brain cell activity in awake, behaving animals.
Signup and view all the flashcards
Brain activity and behavior
Brain activity and behavior
The relationship between how the brain functions and how an animal acts.
Signup and view all the flashcards
Microelectrodes in brain
Microelectrodes in brain
Tiny electrodes used to record from many neurons at once.
Signup and view all the flashcards
Neurosurgical Patients
Neurosurgical Patients
Human patients undergoing surgery with parts of the procedure performed while awake.
Signup and view all the flashcards
Awake, behaving animals
Awake, behaving animals
Animals studied while conscious and performing tasks.
Signup and view all the flashcards
Neuroscience
Neuroscience
Study of the nervous system.
Signup and view all the flashcards
Animal tasks
Animal tasks
Specific actions that animals perform while researchers record their brain activity
Signup and view all the flashcards
Human skills
Human skills
Unique cognitive abilities found only in humans.
Signup and view all the flashcards
Parietal Lobe Lesions
Parietal Lobe Lesions
Damage to the parietal lobes can cause strange body image and spatial perception problems.
Signup and view all the flashcards
Neglect Syndrome
Neglect Syndrome
A severe case of parietal lobe damage, causing the individual to ignore one side of their body and the world.
Signup and view all the flashcards
Parietal-Frontal Connections
Parietal-Frontal Connections
The parietal lobes are connected to frontal lobes, crucial for complex thoughts and actions.
Signup and view all the flashcards
Prefrontal Cortex
Prefrontal Cortex
Part of the brain that helps plan actions and predict outcomes.
Signup and view all the flashcards
Cortical Area 6
Cortical Area 6
Brain region where movement plans are transformed into specific actions.
Signup and view all the flashcards
Descending Corticospinal Tract
Descending Corticospinal Tract
A neural pathway that carries signals from the brain to control body movements.
Signup and view all the flashcards
Motor Planning Studies
Motor Planning Studies
A series of studies conducted by Dr. Per Roland which strengthened the understanding of higher-order motor planning in humans.
Signup and view all the flashcards
What's the role of basal ganglia in movement?
What's the role of basal ganglia in movement?
The basal ganglia are involved in planning and executing movements - they help initiate, modulate, and refine movements.
Signup and view all the flashcards
Direct Pathway
Direct Pathway
A pathway through the basal ganglia that enhances movement by facilitating thalamocortical activity.
Signup and view all the flashcards
Indirect Pathway
Indirect Pathway
A pathway through the basal ganglia that inhibits movement by suppressing thalamocortical activity.
Signup and view all the flashcards
Putamen
Putamen
A structure within the basal ganglia that receives input from the cortex and sends signals to the globus pallidus.
Signup and view all the flashcards
Globus Pallidus
Globus Pallidus
A structure within the basal ganglia that receives signals from the putamen and sends signals to the thalamus.
Signup and view all the flashcards
VLo (Ventral Lateral Nucleus of Thalamus)
VLo (Ventral Lateral Nucleus of Thalamus)
A nucleus in the thalamus that receives signals from the globus pallidus and sends signals to the motor cortex.
Signup and view all the flashcards
SMA (Supplementary Motor Area)
SMA (Supplementary Motor Area)
A part of the motor cortex that receives signals from the thalamus and is involved in planning and sequencing movements.
Signup and view all the flashcards
Thalamocortical Connection
Thalamocortical Connection
A connection between the thalamus and the motor cortex that facilitates movement.
Signup and view all the flashcards
Putamen (in Direct Pathway)
Putamen (in Direct Pathway)
A structure in the basal ganglia that receives input from the cortex and excites the internal segment of the globus pallidus (GPi), leading to movement facilitation.
Signup and view all the flashcards
GPi (in Direct Pathway)
GPi (in Direct Pathway)
Part of the basal ganglia that tonically inhibits the thalamus, but when inhibited itself by putamen activation, releases the thalamus to excite the motor cortex.
Signup and view all the flashcards
VL (in Direct Pathway)
VL (in Direct Pathway)
A thalamic nucleus that receives signals from the basal ganglia and relays them to the motor cortex, playing a crucial role in movement initiation.
Signup and view all the flashcards
SMA (in Direct Pathway)
SMA (in Direct Pathway)
The supplementary motor area, a part of the motor cortex that receives input from the thalamus and contributes to planning and executing complex movements.
Signup and view all the flashcardsStudy Notes
Descending Spinal Tracts
- Two major groups of pathways carry signals from the brain to motor neurons in the spinal cord
- Lateral pathways are for voluntary movement of distal muscles, under direct cortical control
- Ventromedial pathways are for posture and locomotion, under brainstem control
- Lateral pathways crucial component is the corticospinal tract
- Originates in the neocortex, the longest and one of the largest central nervous system (CNS) tracts
- Two-thirds of axons originate in areas 4 and 6 of the frontal lobe, collectively called the motor cortex
- Somatosensory areas of the parietal lobe also contribute, regulating the flow of somatosensory information
- Axons pass through the internal capsule, cerebral peduncle, pons, and form the medullary pyramid in the medulla
- The pyramidal tract's triangular cross-section gives it its name
Planning of Movement by the Cerebral Cortex
- Motor cortex is a region of the frontal lobe (areas 4 and 6)
- Area 4 is primary motor cortex (M1), anterior to the central sulcus on the precentral gyrus
- Area 6 lies anterior to area 4, including the premotor area (PMA) and supplementary motor area (SMA)
- These areas are involved in the control of voluntary movement
- Penfield electrically stimulated the cortex to identify regions vital for movement
- Somatotopic organization in M1, similar to sensory areas
The Basal Ganglia
- Major subcortical input to area 6, located within the telencephalon
- Consists of caudate nucleus, putamen, globus pallidus (internal/external segments), and subthalamic nucleus
- Involved in selection and initiation of willed movements
- Striatum (caudate and putamen) is the target of cortical input
- Globus pallidus sends output to the thalamus
- Subthalamic nucleus and substantia nigra participate in side loops that modulate the main direct pathway
Initiating Movement by Primary Motor Cortex
- Motor pathway begins in cortical layer V, with large pyramidal neurons (Betz cells)
- Neurons in layer V project to ventral horns of the spinal cord
- Excite extensor motor neurons, inhibit flexor motor neurons
- Major inputs to layer V pyramidal cells are from other cortical areas (especially those adjacent to area 4) and the thalamus, specifically the ventral lateral nucleus (VLc), which relays information from the cerebellum
Coding of Movement in M1
- Motor cortex consists of a detailed mapping of individual muscles
- More recent studies show many motor neuron pools are controlled by individual pyramidal cells
- Activity precedes movement, encoding force and direction
- Movement direction is encoded by the collective activity of a population of neurons (population coding)
The Cerebellum
- Crucial for precise motor control
- Responsible for coordinated movements and accurate timing
- Damage results in ataxia (uncoordinated/inaccurate movements), dyssynergia, and dysmetria
Paresis, Paralysis, Spasticity, and Babinski
- Paresis is weakness
- Paralysis is complete loss of movement
- Spasticity is excessive muscle tone and hyperreflexia
- Babinski sign: upward flexion of the big toe when the sole of the foot is stroked, indicating upper motor neuron damage
Mirror Neurons
- Some neurons in motor areas respond when movement is performed/imagined.
- Neurons also respond when observing another individual perform the same action, even a human
- May be involved in understanding others' actions and intentions, empathy, and autism
Basal Ganglia Disorders
- Parkinson's disease is characterized by slowness of movement, rigidity, and tremor, often affecting people over 60
- Damage to dopamine-producing neurons in the substantia nigra
- Huntington's disease (hereditary, progressive) is characterized by hyperkinesia, dementia, and personality disorder (usually after adulthood)
- Damage to neurons in the caudate nucleus, putamen, and globus pallidus
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.