Deck 8: Action

Question 1

The excitatory command to contract the biceps muscle of the arm is normally accompanied by an inhibitory command to relax the antagonist triceps muscle. If this inhibitory signal failed to occur,

A)the passive stretching of the triceps would trigger a stretch reflex that would return the arm to its original position.
B)the contraction of the biceps would be irreversible, and the limb would remain frozen in the resulting position.
C)the contraction of the biceps would cause tearing of fibers in the triceps and severe muscle damage.
D)the fibers that make up the triceps muscle would shorten and thicken during the resulting passive stretch.

Answer 1

A

Question 2

The primary interaction of muscles and the nervous system involves the alpha motor neurons, which originate in the _______, exit through the _______, and terminate in the muscles.

A)brain; dorsal root
B)brain; ventral root
C)spinal cord; dorsal root
D)spinal cord; ventral root

Answer 2

D

Question 3

Loss of blood flow in the _______ is the most common cause of hemiplegia.

A)anterior cerebral artery
B)vertebral artery
C)middle cerebral artery
D)circle of Willis

Answer 3

C

Question 4

The loss of a motor skill that cannot be attributed to hemiplegia, muscle weakness, sensory deficits, or motivation is called

A)hemiparesis.
B)hypermetria.
C)apraxia.
D)akinetopsia.

Question 5

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

A)the contralateral side
B)the ipsilateral side
C)both the contralateral and ipsilateral sides
D)neither the contralateral nor the ipsilateral side: the pyramidal neurons do not innervate effector muscles

Question 6

Single-cell recording studies have indicated that the _______ may be especially important in the control of internally guided motor sequences, whereas the _______ may be especially important in the control of externally guided motor sequences.

A)supplementary motor cortex; premotor cortex
B)premotor cortex; supplementary motor cortex
C)basal ganglia; cerebellum
D)cerebellum; basal ganglia

Question 7

Corticospinal fibers originate primarily in the

A)cerebellum.
B)supplementary motor area.
C)premotor cortex.
D)primary motor cortex.

Question 8

Hemiplegia is the

A)paralysis of the side of the body that is contralateral to the injured brain region.
B)paralysis of the side of the body that is ipsilateral to the injured brain region.
C)loss of sensory feedback from the side of the body that is contralateral to the injured brain region.
D)loss of sensory feedback from the side of the body that is ipsilateral to the injured brain region.

Question 9

Neurons in each half of the cerebellum synapse on _______ targets in the thalamus and other subcortical structures, and therefore regulate the effectors on the _______ side of the body.

A)ipsilateral; ipsilateral
B)ipsilateral; contralateral
C)contralateral; ipsilateral
D)contralateral; contralateral

Question 10

Which of the following is NOT an effector?

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

Question 11

A laboratory dog has had surgery to separate the spinal components of its motor system from the cortical and subcortical components. Which of the following best describes the motor abilities of this animal?

A)The dog is able to sit and roll over in response to commands.
B)The dog can move proximal effectors normally, but not distal effectors.
C)The dog demonstrates reflexive withdrawal of its foot in response to sudden stimulation.
D)The dog is completely paralyzed from the neck down.

Question 12

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.

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

Question 13

After suffering a focal brain injury, a patient has great difficulty in pantomiming particular motor actions such as turning a key in a lock. Because other problems like hemiplegia, muscle weakness, sensory deficits, and lack of motivation have been ruled out, your diagnosis would be

A)agnosia.
B)apraxia.
C)anomia.
D)akinetopsia.

Question 14

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

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 15

When a voluntary movement such as contracting one's right biceps is generated, what other signals, if any, must accompany this command?

A)A signal to antagonist muscles, such as the right triceps, to relax.
B)A signal to antagonist muscles, such as the right triceps, to flex simultaneously.
C)A signal to antagonist muscles, such as the left biceps, to relax.
D)No other signal is necessary.

Question 16

The neurotransmitter responsible for translating action potentials into mechanical actions at muscles is

A)norepinephrine.
B)dopamine.
C)acetylcholine.
D)serotonin.

Question 17

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.

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

Question 18

Which of the following is NOT a part of the basal ganglia?

A)the putamen
B)the claustrum
C)the caudate
D)the globus pallidus

Question 19

The term decussation refers to

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 (SMA) 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 20

Alpha motor neurons in the spinal cord communicate with muscle fibers by releasing acetylcholine, which influences muscle activity by

A)depolarizing neurons in the peripheral nervous system.
B)directly causing muscle contractions.
C)hyperpolarizing peripheral motor neurons.
D)inhibiting neurons in the dorsal root of the spinal cord.

Question 21

Studies of deafferentation and its effect on movement control in humans and other species demonstrate that

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 22

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 _______.

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

Question 23

Chapin's early work on a brain-machine interface (BMI) in rats used an online population vector that matched the _______ of the rats' movement.

A)direction
B)force
C)velocity
D)complexity

Question 24

The fact that the population vector recorded in the motor cortex precedes the corresponding reaching movement indicates that motor cortex activity

A)is primarily involved in the planning of movement.
B)is independent of voluntary movement.
C)automatically leads to movement.
D)is related to the movement of specific muscle groups.

Question 25

With regard to motor cortex, a population vector is the

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.

Question 26

Which of the following types of motor behavior probably relies most on the function of a central pattern generator?

A)walking
B)speaking
C)drawing
D)juggling

Question 27

Once a BMI takes on the ability to reward a rat that was previously rewarded by pressing a lever, how will the rat's lever-pressing rate change?

A)There will be no change.
B)Lever-pressing will slightly increase.
C)Lever-pressing will slightly decrease.
D)Lever-pressing will eventually stop.

Question 28

One limitation of most BMI systems is that they

A)do not use motor cortex activity from the individual controlling the prosthetic.
B)use only visual feedback and not somatosensory feedback.
C)are not capable of improved precision with user practice.
D)require input from literally millions of neurons in order to work effectively.

Question 29

In the period of time immediately following focal brain injury to the supplementary motor cortex, patients may reach out and grasp objects with the affected arm when they have not been asked to do so, or even when they have been explicitly told not to do so. This is an example of

A)apraxia.
B)hemiplegia.
C)Huntington's disease.
D)alien hand syndrome.

Question 30

When you first learn how to execute the complex motor sequence that comprises a slam dunk in basketball, a circuit including the _______ is active. After much practice, once you have learned the sequence well, a second circuit involving the _______ is active.

A)parietal cortex; lateral premotor area
B)lateral premotor area; supplementary motor area
C)supplementary motor area; parietal cortex
D)basal ganglia; parietal cortex

Question 31

Franz and colleagues (1996) asked a patient who had had his corpus callosum surgically severed to draw figures like the ones here, each simultaneously with a different hand. Compared to neurologically intact control participants, they found that this patient

A)was better at producing movements simultaneously with both hands, even when they differed in direction.
B)was selectively impaired when simultaneously producing movements with each hand when they differed in direction.
C)performed poorly and was especially impaired when the figures closely resembled each other.
D)was better at producing movements simultaneously with both hands only when they differed in direction.

Question 32

Which of the following sets of elements is sufficient to produce an effective brain-machine interface?

A)a computer to generate artificial neuronal activity and a prosthetic limb
B)an electrode array to record neural activity, a robotic arm, and a lever
C)an electrode array to record neural activity, a prosthetic limb, and computer software that can interpret intended actions from neural activity
D)All of the answer options are correct.

Question 33

Which of the following statements best describes the population vector associated with a reaching movement from left to right?

A)The population vector shifts from right to left only while the arm is actually moving.
B)The population vector shifts from left to right only after the arm has moved and stopped.
C)The population vector shifts from left to right only while the arm is actually moving.
D)The population vector shifts from left to right before the arm begins to move.

Question 34

The _______ seem(s) particularly important in the control and planning of complex motor sequences as opposed to simple movements.

A)primary motor cortex
B)primary somatosensory cortex
C)motor cortex regions in the prefrontal lobes
D)motor cortex regions in the parietal lobes

Question 35

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?

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 36

Single-cell recording studies of the motor control of reaching movements have demonstrated that neurons in the motor cortex are selectively active based on the

A)distance through which a reaching movement must pass.
B)direction in which a reaching movement is generated.
C)speed at which a reaching movement is performed.
D)final arm position achieved once a reaching movement is completed.

Question 37

In the days following her stroke, Patient E cannot refrain from reaching out and grasping nearby objects even when she has been asked not to do so. This syndrome probably is the result of the abnormal dominance of the __________ loop.

A)lateral supplementary motor area
B)lateral premotor
C)medial supplementary motor area
D)medial premotor

Question 38

The concept of endpoint control refers to the observation that voluntary muscle events

A)are programmed to result in the displacement of an effector based on the desired distance from its starting point.
B)are programmed to result in the displacement of an effector based on its desired final location.
C)require sensory feedback that arrives after an effector has been moved to its desired location.
D)require sensory feedback from an effector that arrives during the entire course of its movement.

Question 39

Using single-cell recording, a researcher isolates a neuron in the motor cortex of a monkey that is extremely active when the monkey moves its arm from left to right. In subsequent trials, the animal is required to move its arm from the starting to the ending locations diagrammed here. Which, if any, of these additional trials will also increase activity in this neuron?

A)C only
B)A and B
C)A, B, and D
D)D only

Question 40

Neurons in the spinal cord that can mediate sequences of motor actions even in the absence of external sensory feedback signals are called

A)proximal effectors.
B)central pattern generators.
C)alpha motor neurons.
D)ventral root neurons.

Question 41

In performing a sequence of complex actions, such as playing the piano, each movement is planned primarily in relation to the immediately preceding and subsequent movements.

Question 42

With time, people who experience a hemiplegia typically experience a full recovery.

Question 43

A patient has damage to the basal ganglia, particularly within the striatum, and demonstrates both chorea and hyperkinesia. What is your diagnosis?

A)Parkinson's disease
B)Huntington's disease
C)hypermetria
D)bradykinesia

Question 44

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

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

Question 45

The supplementary motor area (SMA) is particularly active during externally guided movements.

Question 46

Using transgenic mice, Wagner et al.'s 2017 study provided which of the following pieces of evidence that the cerebellum is involved with learning and predictive processes?

A)The cerebellum has more cells than the entire rest of the brain combined.
B)It is possible to perform calcium imaging on transgenic mice whose granule cells had been transfected with genes encoding fluorescent proteins.
C)Not only did the activity of certain cerebellar cells correspond with certain motor activity, but the activity of some cerebellar cells reflected trial outcomes.
D)Cerebellar cells directly affected motor cortex cells in a way that indicates that the cerebellum is involved with learning and predictive processes.

Question 47

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

Question 48

Hyperkinesia is to _______ as hypokinesia is to _______.

A)Parkinson's disease; Huntington's disease
B)Huntington's disease; Parkinson's disease
C)apraxia; hemiballism
D)hemiballism; apraxia

Question 49

Although simple reflexes can occur without sensory input, the generation of rhythmic walking movements requires sensory feedback from the environment.

Question 50

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

Question 51

Which of the following would demonstrate the finding that some aspects of motor learning are independent of the specific effectors used to perform an action?

A)Right-handed pitchers have great difficulty in throwing a baseball accurately with the left hand.
B)Actions such as the backhand stroke in tennis require the coordination of a sequence of separate movements.
C)All cyclists tend to use the same set of effectors in riding, regardless of the specific age at which they learned to ride a bicycle.
D)One's signature looks very similar regardless of whether one uses the left or the right hand to produce it.

Question 52

A diagnosis of apraxia is mainly exclusionary: a person is said to have apraxia if he or she has a coordination problem that can't be linked to a deficit in controlling the muscles themselves.

Question 53

Activity in the premotor cortex reflects not only the trajectory of a movement but also the context in which the movement occurs.

Question 54

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?

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

Question 55

Which of the following is NOT an accurate description of a process related to basal ganglia influence/striatal disinhibition?

A)The striatum receives a dopamine signal that produces different results when dopamine binds D1 as opposed to D2 receptors.
B)Striatal disinhibition can affect a wide range of motor behavior, including eye movements.
C)Neurons in the internal segment of the globus pallidus have a relatively high baseline firing rate, and the direct path of the striatum inhibits them.
D)Inhibition of the internal segment of the globus pallidus dampens cortical activity to decrease motor output.

Question 56

Kawai et al.'s 2015 study used rats to explore how lesions of the motor cortex impact the ability to learn and perform motor sequences. What results regarding the motor cortex did this study yield?

A)Cerebellar activity, but not motor cortex activity, was necessary to learn a new motor sequence.
B)Motor cortex activity was more critical than cerebellar activity in enabling rats to overcome their dislike for reward delay.
C)Once a new motor sequence had been learned, the cerebellum was sufficient to produce that motor sequence, even without motor cortex input.
D)Neither the cerebellum nor motor cortex was necessary to learn a new motor skill.

Question 57

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

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

Question 58

Where are the primary motor cortex, the premotor cortex, and the supplementary motor area located in the brain? What do we know about the different functions of these three areas?

Question 59

One proposed role of dopamine in the context of motor learning via the basal ganglia is that dopamine release

A)from the basal ganglia to motor cortex stimulates motor learning.
B)from the substantia nigra prevents Parkinson's disease by facilitating motor learning.
C)in the basal ganglia results in a combination of stimulatory and inhibitory influences that reinforces particular motor actions.
D)in the basal ganglia produces multiple motor responses simultaneously.

Question 60

One reason that lesions to the cerebellum disrupt the eye blink conditioning response is because

A)the cerebellum regulates the production of acetylcholine in peripheral motor neurons.
B)this structure is involved in timing the activation of different effectors involved in a learned motor sequence.
C)the cerebellum controls the initiation of eye movements.
D)this structure normally inhibits activity in the motor cortex, and when this inhibition is disrupted, motor learning is impaired.

Question 61

Describe the affordance competition hypothesis and explain how single-cell recordings support the model.

Question 62

Compare and contrast the neurological disorders of Parkinson's disease and Huntington's disease. How are they similar, and how do they differ?

Question 63

What does it mean to say that the cerebellum uses a "forward model?" Support your answer with a real-life example and experimental evidence.

Question 64

Why is the basal ganglia structure referred to as a "gatekeeper?" How is inhibition used in its gatekeeping functions?

Question 65

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

Question 66

Describe the neurological condition of apraxia. How does this disorder inform our understanding of how complex movements are represented in the brain?

Question 67

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

Question 68

Argue for or against the future promise of BMI systems. Use examples of successes or limitations in your answer.