Week 1: Chapter 9 - Organization of the motor system Flashcards
What is the role of the visual system in object grasping?
It identifies the part of the object to be grasped and relays the information to corticomotor regions.
How does the sensory cortex contribute to grasping?
It receives signals from the fingers via the spinal cord and informs the motor cortex that the object is held.
What does the basal ganglia do during movement?
It helps produce the appropriate amount of force.
What role does the cerebellum play in movement?
It regulates timing and corrects errors as movement occurs.
What are the four cortical regions responsible for skilled movements?
Posterior sensory cortex, prefrontal cortex, premotor cortex, and primary motor cortex.
Where are movement goals specified in the neocortex?
In the posterior sensory cortex.
What is the function of the premotor cortex?
Recognizes movements and selects appropriate actions.
What did E. Roland’s blood flow experiment show?
Only the brain regions involved in movement show increased blood flow.
How did Penfield identify motor areas?
Using electrical stimulation on conscious patients to map motor responses.
What is the motor homunculus?
A distorted body map in the motor cortex with large areas for hands, lips, and tongue.
What did Michael Graziano find using stimulation in monkeys?
Ethological categories of movement reflecting everyday actions.
What are the three types of organization in motor maps?
Body part, spatial location, and function.
Which movements are in the dorsal premotor cortex?
Whole-body movements.
What is the role of the ventral parietal cortex?
Encodes hand and mouth movements.
What does the dual visual-parietal-motor pathway do?
Enables grasping by integrating visual and somatosensory data.
What does the parietal cortex identify during grasping?
Which body part will contact the object.
What is the human movement lexicon?
A neural repertoire of species-typical movement patterns.
How is the pincer grip evidence of a movement lexicon?
It appears early in infants and is disrupted by small motor cortex lesions.
What role does the premotor cortex play in movement sequences?
It organizes whole-body and complex movements.
What did Edward Evarts’ monkey experiments reveal?
Motor cortex neurons plan, initiate, and adjust movement force.
What did Georgopoulos discover about movement direction?
Neurons have preferred directions and collectively encode movement.
What are mirror neurons?
Neurons that fire during both action execution and observation.
Where is the monkey mirror neuron system located?
Ventral premotor, motor, and ventral parietal cortex.
How does the human mirror system differ?
Includes a distributed system and Broca’s area for language.
What cognitive functions are linked to mirror neurons?
Movement imagery, BCIs, empathy, and action understanding.
What disorders may be linked to mirror neuron dysfunction?
Autism spectrum disorder (ASD).
What is the role of the visual system in object grasping?
It identifies the part of the object to be grasped and relays the information to corticomotor regions.
How does the sensory cortex contribute to grasping?
It receives signals from the fingers via the spinal cord and informs the motor cortex that the object is held.
What does the basal ganglia do during movement?
It helps produce the appropriate amount of force.
What role does the cerebellum play in movement?
It regulates timing and corrects errors as movement occurs.
What are the four cortical regions responsible for skilled movements?
Posterior sensory cortex, prefrontal cortex, premotor cortex, and primary motor cortex.
Where are movement goals specified in the neocortex?
In the posterior sensory cortex.
What is the function of the premotor cortex?
Recognizes movements and selects appropriate actions.
What did E. Roland’s blood flow experiment show?
Only the brain regions involved in movement show increased blood flow.
How did Penfield identify motor areas?
Using electrical stimulation on conscious patients to map motor responses.
What is the motor homunculus?
A distorted body map in the motor cortex with large areas for hands, lips, and tongue.
What did Michael Graziano find using stimulation in monkeys?
Ethological categories of movement reflecting everyday actions.
What are the three types of organization in motor maps?
Body part, spatial location, and function.
Which movements are in the dorsal premotor cortex?
Whole-body movements.
What is the role of the ventral parietal cortex?
Encodes hand and mouth movements.
What does the dual visual-parietal-motor pathway do?
Enables grasping by integrating visual and somatosensory data.
What does the parietal cortex identify during grasping?
Which body part will contact the object.
What is the human movement lexicon?
A neural repertoire of species-typical movement patterns.
How is the pincer grip evidence of a movement lexicon?
It appears early in infants and is disrupted by small motor cortex lesions.
What role does the premotor cortex play in movement sequences?
It organizes whole-body and complex movements.
What did Edward Evarts’ monkey experiments reveal?
Motor cortex neurons plan, initiate, and adjust movement force.
What did Georgopoulos discover about movement direction?
Neurons have preferred directions and collectively encode movement.
What are mirror neurons?
Neurons that fire during both action execution and observation.
Where is the monkey mirror neuron system located?
Ventral premotor, motor, and ventral parietal cortex.
How does the human mirror system differ?
Includes a distributed system and Broca’s area for language.
What cognitive functions are linked to mirror neurons?
Movement imagery, BCIs, empathy, and action understanding.
What disorders may be linked to mirror neuron dysfunction?
Autism spectrum disorder (ASD).
How many brainstem pathways project to the spinal cord?
About 26 distinct pathways.
What types of movements are typically organized by the brainstem?
Whole-body movements.
What did Walter R. Hess demonstrate?
Stimulating brainstem sites in cats elicited innate behaviors like jumping, stalking, or grooming.
What essential behaviors are coordinated by the brainstem?
Eating, drinking, sexual activity, posture, walking, swimming, and grooming.
What do sequential grooming behaviors in rats reveal?
A structured motor program largely controlled by the brainstem.
What are the two primary input sources to the basal ganglia?
Neocortex/limbic cortex and substantia nigra (via nigrostriatal pathway).
What are hyperkinetic symptoms?
Exaggerated, involuntary movements due to damage to the caudate putamen.
Which disorders exhibit hyperkinetic symptoms?
Huntington’s disease and Tourette’s syndrome.
What are hypokinetic symptoms?
Difficulty initiating movements, as seen in Parkinson’s disease.
What causes Parkinson’s disease?
Loss of dopamine-producing cells in the substantia nigra.
What structure acts as a movement volume control?
The internal part of the globus pallidus (GPi).
What does high inhibitory pathway activity in the GPi cause?
Less inhibition of the thalamus → more excitation of the cortex → more movement.
What does high excitatory pathway activity in the GPi cause?
Strong inhibition of the thalamus → less excitation of the cortex → less movement.
What are two treatments for Parkinson’s disease targeting the GPi?
Surgical lesioning and deep brain stimulation (DBS).
Where is the cerebellum located?
Above the brainstem and below the cerebral cortex.
What are the functional divisions of the cerebellum?
Flocculus, medial areas, and lateral areas.
What does the flocculus control?
Balance and eye movements via vestibular projections.
What happens with midline cerebellar damage?
Impaired balance, posture, walking, and eye movements.
What happens with lateral cerebellar damage?
Impaired coordination of limbs, hands, and fingers.
What are the two main functions of the cerebellum?
Movement timing and movement accuracy.
What did the Thach dart-throwing experiment show?
Cerebellum is essential for error correction in motor learning.
What is the role of the inferior olivary nucleus?
Sends corrective feedback signals to the motor cortex.
What coordination issue occurs with cerebellar damage?
Difficulty synchronizing multiple movements into smooth sequences.
