Question 1

With regard to motor cortex, a population vector is the

Accepted Answer

A)   summed activity of the neurons in the motor cortex, including cells that are tuned to all directions.
B)   summed activity of the neurons in the motor cortex, including only cells that are tuned to the same preferred direction.
C)   total number of neurons that are tuned to the same preferred direction.
D)   preferred direction of a single neuron. A

Question 2

Lesions to the pyramidal motor tract would produce difficulty in moving effectors on which side of the body?

Accepted Answer

A)   the contralateral side
B)   the ipsilateral side
C)   both the contralateral and ipsilateral sides
D)   neither side: the pyramidal neurons do not innervate effector muscles A

Question 3

What is a population vector? How do population vectors play a role in the initiation of a movement?

Accepted Answer

A population vector refers to the representation of the collective neural activity of a population of neurons in a specific region of the brain. It is essentially a mathematical average of the firing rates of all the neurons in that region at a particular point in time.

Population vectors play a crucial role in the initiation of movement because they provide a way to decode the intention of a movement from neural activity. When we have a specific movement in mind, such as reaching for an object, the neurons in the motor cortex that control that movement become active and their collective activity forms a population vector that represents the intended movement.

By analyzing the population vector, researchers can decode the intended movement and use this information to control external devices such as prosthetic limbs or computer interfaces. This has important implications for the field of neuroprosthetics and has the potential to help individuals with paralysis or limb loss regain movement and independence.

Overall, population vectors are a key tool in understanding the neural basis of movement and in developing new technologies to restore movement in individuals with motor impairments.

Question 4

Lesions to this region of the cerebellum lead to postural instability and difficulty in keeping one's eyes fixed on a visual object despite head or body movements.

Accepted Answer

A)   the spinocerebellum
B)   the vestibulocerebellum
C)   the neocerebellum
D)   the dentate nucleus

Question 5

Keele's work with people with Parkinson's disease suggests that they may have difficulties in which of the following cognitive operations?

Accepted Answer

A)   discriminating scents
B)   spatial memory
C)   facial recognition
D)   set shifting

Question 6

Sherrington 1947) surgically disconnected spinal motor neurons from cortical and subcortical motor centers in laboratory animals. Which of the following statements is true about the subsequent motor behavior of these animals?

Accepted Answer

A)   The animals could still generate voluntary movements, but reflexive responses were disrupted.
B)   Reflexive responses were intact, but complex voluntary movements were disrupted.
C)   The animals showed normal motor function as long as sensory inputs from the dorsal root were also severed.
D)   The animals became completely motionless and unresponsive to stimulation.

Question 7

Before a movement is initiated, the population vector in the motor cortex has already shifted in the direction of the planned movement.

Accepted Answer

A) True 
 B)False

Question 8

Studies of de-afferentation and its effect on movement control in humans and other species demonstrate that

Accepted Answer

A)   movement depends on internal mental representations of the consequences of motor commands.
B)   movement depends on the availability of intact sensory feedback from effectors.
C)   movement is controlled by information from sensory receptors rather than muscles.
D)   movement is controlled differently in humans than in other primate species.

Question 9

Which of the following is NOT an effector?

Accepted Answer

A)   the brain
B)   the jaw
C)   the arm
D)   the back

Question 10

The pyramidal motor tract carries signals from the motor cortex of each cerebral hemisphere to sides) of the spinal cord, whereas the extrapyramidal motor tracts carry signals from various subcortical structures to sides) of the spinal cord.

Accepted Answer

A)   the ipsilateral ; both the ipsilateral and contralateral
B)   both the ipsilateral and contralateral ; the ipsilateral
C)   the contralateral ; both the ipsilateral and contralateral
D)   both the contralateral and ipsilateral ; the contralateral

Question 11

Simple reflexive motor responses to external stimuli rely primarily on the function of the , whereas motor behaviors that are only minimally dependent on such external cues rely primarily on the function of the .

Accepted Answer

A)   basal ganglia ; spinal cord
B)   cerebellum ; brainstem
C)   spinal cord ; motor cortex
D)   motor cortex ; brainstem

Question 12

Argue for or against the future promise of brain-machine interface BMI) systems. Use examples of successes or limitations in your answer.

Accepted Answer

The answer of Argue for or against the future promise...

Question 13

What disorder is characterized by a loss of dopaminergic fibers in the substantia nigra, which results in deficits in initiating voluntary movements, bradykinesia, and the progressive emergence of a resting tremor?

Accepted Answer

A)   Huntington's disease
B)   Parkinson's disease
C)   hemiballism
D)   cogwheeling

Question 14

How is the planning of a complex movement hierarchical? Provide an example.

Accepted Answer

The answer of How is the planning of a complex...

Question 15

What is the hypothesized function of a "mirror neuron"? Describe at least two studies that support this idea.

Accepted Answer

The answer of What is the hypothesized function of a...

Question 16

Single axons of the corticospinal tract can extend for more than one meter.

Accepted Answer

A) True 
 B)False

Question 17

The term decussation refers to

Accepted Answer

A)   a type of cerebrovascular accident that frequently damages motor structures.
B)   the shift in involvement from the premotor cortex to the supplementary motor area SM
A)   with motor learning.
C)   the crossing of nerve fibers from one side of the body to the other.
D)   a type of rapid involuntary movement made by people with Huntington's disease.

Question 18

One major difference between the pyramidal and the extrapyramidal motor tracts is their points of origin. The pyramidal tracts carry messages from to the spinal cord, whereas the extrapyramidal tracts carry messages from to the spinal cord.

Accepted Answer

A)   cortical structures ; subcortical structures
B)   cranial nerves ; peripheral nerves
C)   basal ganglia ; the cerebral cortex
D)   subcortical structures ; the cerebral cortex

Question 19

In the most general sense, scientists use the term mirror system to refer to a distributed network of neural regions involved in both

Accepted Answer

A)   the perception of the self and the perception of others.
B)   action production and action interpretation.
C)   the control of specific effectors as well as abstracted movement plans.
D)   proprioception and somatosensation.

Question 20

Parkinson's disease results from cell death in the , which is a part of the .

Accepted Answer

A)   substantia nigra ; cerebellum
B)   substantia nigra ; basal ganglia
C)   striatum ; cerebellum
D)   striatum ; basal ganglia

Exam 8: Action

With regard to motor cortex, a population vector is the

Lesions to the pyramidal motor tract would produce difficulty in moving effectors on which side of the body?

What is a population vector? How do population vectors play a role in the initiation of a movement?

Lesions to this region of the cerebellum lead to postural instability and difficulty in keeping one's eyes fixed on a visual object despite head or body movements.

Keele's work with people with Parkinson's disease suggests that they may have difficulties in which of the following cognitive operations?

Sherrington 1947) surgically disconnected spinal motor neurons from cortical and subcortical motor centers in laboratory animals. Which of the following statements is true about the subsequent motor behavior of these animals?

Before a movement is initiated, the population vector in the motor cortex has already shifted in the direction of the planned movement.

Studies of de-afferentation and its effect on movement control in humans and other species demonstrate that

Which of the following is NOT an effector?

The pyramidal motor tract carries signals from the motor cortex of each cerebral hemisphere to sides) of the spinal cord, whereas the extrapyramidal motor tracts carry signals from various subcortical structures to sides) of the spinal cord.

Simple reflexive motor responses to external stimuli rely primarily on the function of the , whereas motor behaviors that are only minimally dependent on such external cues rely primarily on the function of the .

Argue for or against the future promise of brain-machine interface BMI) systems. Use examples of successes or limitations in your answer.

What disorder is characterized by a loss of dopaminergic fibers in the substantia nigra, which results in deficits in initiating voluntary movements, bradykinesia, and the progressive emergence of a resting tremor?

How is the planning of a complex movement hierarchical? Provide an example.

What is the hypothesized function of a "mirror neuron"? Describe at least two studies that support this idea.

Single axons of the corticospinal tract can extend for more than one meter.

The term decussation refers to

One major difference between the pyramidal and the extrapyramidal motor tracts is their points of origin. The pyramidal tracts carry messages from to the spinal cord, whereas the extrapyramidal tracts carry messages from to the spinal cord.

In the most general sense, scientists use the term mirror system to refer to a distributed network of neural regions involved in both

Parkinson's disease results from cell death in the , which is a part of the .