Chapter 7: Movement

Question 1

What aspect of brain anatomy facilitates communication between body sensations and body movements?

Answer 1

The motor cortex and the somatosensory cortex are adjacent, and the area of motor cortex devoted to a particular body structure is aligned with the somatosensory cortex area responsive to the same structure

Question 2

What evidence indicates that cortical activity represents the “idea” of the movement and not just the muscle contractions?

Answer 2

Activity in the motor cortex leads to a particular outcome, such as movement of the hand to the mouth, regardless of what muscle contractions are necessary given the hand’s current location.

Question 3

One of the first areas to become active in planning a movement is the….

Answer 3

posterior parietal cortex

Question 4

How does the posterior parietal cortex contribute to movement? The premotor cortex? The supplementary motor cortex? The prefrontal cortex?

Answer 4

The posterior parietal cortex is important for perceiving the location of objects and the position of the body relative to the environment. It is also active for planning of a movement.

The premotor cortex and supplementary motor cortex are also active in preparing a movement shortly before it occurs. The supplementary motor cortex inhibits a habitual action when it is inappropriate.

The prefrontal cortex stores sensory information relevant to a movement and considers possible outcomes of a movement.

Question 5

When expert pianists listen to familiar, well-practiced music, they imagine the finger movements, and the finger area of their motor cortex becomes active, even if they are not moving their fingers (Haueisen & Knösche, 2001). If we regard those neurons as another kind of mirror neuron, what do these results imply about the origin of mirror neurons?

Answer 5

These neurons must have acquired these properties through experience. That is, they did not enable pianists to copy what they hear. They developed as pianists learned to copy what they hear.

Question 6

What kinds of movements does the lateral tract control? The medial tract?

Answer 6

The lateral tract controls detailed movements in the periphery on the contralateral side of the body. For example, the lateral tract from the left hemisphere controls the right side of the body. The medial tract controls trunk movements bilaterally.

Question 7

What kind of perceptual task would be most impaired by damage to the cerebellum?

Answer 7

Damage to the cerebellum impairs perceptual tasks that depend on accurate timing.

Question 8

How are the parallel fibers arranged relative to one another and to the Purkinje cells?

Answer 8

The parallel fibers are parallel to one another and perpendicular to the planes of the Purkinje cells

Question 9

If a larger number of parallel fibers are active, what is the effect on the collective output of the Purkinje cells?

Answer 9

As a larger number of parallel fibers become active, the Purkinje cells increase their duration of response.

Question 10

In general, do the basal ganglia have more effect on responses to a stimulus or on self-initiated movements?

Answer 10

The basal ganglia have more influence on self-initiated movements, which are generally slower

Question 11

Which aspect of movement do the basal ganglia control?

Answer 11

The basal ganglia control the vigor of movements.

Question 12

What kind of learning depends most heavily on the basal ganglia?

Answer 12

The basal ganglia are essential for learning motor habits that are difficult to describe in words.

Question 13

Explain the evidence suggesting that a conscious decision to move does not cause the movement.

Answer 13

Researchers recorded responses in people’s cortex that predicted the upcoming response. Those brain responses occurred earlier than the time people reported as “when they made the decision

Question 14

Why are some researchers skeptical of this evidence?

Answer 14

The studies assume that people accurately report the times of their intentions. However, people’s reports are influenced by events after the movement, and therefore we cannot be confident of their accuracy. Furthermore, a decision to make a voluntary movement is a gradual process that cannot be pinpointed to a single instant.

Question 15

Deadra is holding a complex yoga pose using mainly her abdominal muscles. She is able to maintain this position thanks to her ______ corticospinal tract.
a. medial
b. lateral
c. posterior
d. dorsal

Answer 15

Medial
Correct. The medial corticospinal tract includes axons from many parts of the cerebral cortex and axons from the midbrain tectum, the reticular formation, and the vestibular nucleus. The medial tract controls mainly the muscles of the neck, shoulders, and trunk of the body, which is how Deadra is able to hold her yoga pose.

Question 16

Which of the following is not one of the current research findings about the cerebellum?
a. The cerebellum is important for certain aspects of attention.
b. The cerebellum is important for spontaneous, self-initiated behaviors.
c. The cerebellum is important for behaviors with precise timing of short intervals.
d. The cerebellum is active in situations when the individual is not moving.

Answer 16

The cerebellum is important for spontaneous, self-initiated behaviours

Correct. The basal ganglia, not necessarily the cerebellum, are responsible for spontaneous, self-initiated behaviors. The cerebellum has recently been shown to be involved with much more than just balance, including things like precise timing activities and certain aspects of attention.

Question 17

Which of the following is not considered part of the basal ganglia?
a. Globus pallidus
b. Caudate nucleus
c. Putamen
d. Red nucleus

Answer 17

Red nucleus

Correct. The basal ganglia are a group of large, subcortical structures in the forebrain that are responsible for spontaneous, self-initiated behaviors. The parts include the caudate nucleus, putamen, and globus pallidus.

Question 18

How does MPTP exposure influence the likelihood of Parkinson’s disease? What are the effects of cigarette smoking?

Answer 18

Exposure to MPTP can induce symptoms of Parkinson’s disease. Cigarette smoking is correlated with decreased risk of the disease.

Question 19

How does L-dopa relieve the symptoms of Parkinson’s disease?

Answer 19

L-dopa enters the brain, where neurons convert it to dopamine, thus increasing the supply of a depleted neurotransmitter

Question 20

In what ways is L-dopa treatment disappointing?

Answer 20

L-dopa increases dopamine activity in spurts and in all neurons, not steadily and not just in those that need help. It does not stop the loss of neurons. It has unpleasant side effects

Question 21

What procedure has improved the effectiveness of brain grafts for treatment of Parkinson’s disease?

Answer 21

Results improved somewhat after physicians began giving drugs to suppress the immune response.

Question 22

Why does damage to the basal ganglia lead to involuntary movements?

Answer 22

Output from the basal ganglia to the thalamus is inhibitory. After damage to the basal ganglia, the thalamus, and therefore the cortex, receive less inhibition. Thus, they produce unwanted actions.

Question 23

What procedure enables physicians to predict who will or will not get Huntington’s disease and to estimate the age of onset?

Answer 23

Physicians can count the number of consecutive repeats of the combination C-A-G on one gene on chromosome 4. If the number is fewer than 36, the person will not develop Huntington’s disease. For repeats of 36 or more, the larger the number, the more certain the person is to develop the disease and the earlier the probable age of onset.

Question 24

im is 68 years old and has recently started experiencing muscle tremors, slow movements, and difficulty initiating voluntary movements. He is most likely going to be diagnosed with _____.
a. Huntington’s disease
b. Alzheimer’s disease
c. a stroke
d. Parkinson’s disease

Answer 24

Parkinson’s disease

Correct. As a result of losing dopamine neurons in the substantia nigra, Jim has developed Parkinson’s disease. His doctors will likely have him take L-dopa as a treatment.

Question 25

Why is L-dopa given as a treatment for Parkinson's disease and not dopamine? a. So the patient won't become addicted to the dopamine b. Because L-dopa is able to cross the blood–brain barrier c. Because dopamine cannot be made into a pill d. Because L-dopa is cheaper

Answer 25

Because L-dopa is able to cross the blood-brain barrier Correct. Although patients with Parkinson's disease are lacking dopamine, they are usually given a similar drug called L-dopa. L-dopa is able to cross the blood–brain barrier whereas dopamine cannot.

Question 26

The gene that results in Huntington's disease is a(n) ______ gene. a. autosomal dominant b. multisomal dominant c. multisomal recessive d. autosomal recessive

Answer 26

Autosomal dominant Correct. The gene for Huntington's disease is autosomal dominant (that is, it isn't on the X or Y chromosomes). In 1993, it was discovered to be located on chromosome 4.

Question 27

Some muscles can damage themselves if too many fibers contract at once; therefore, ____ respond to increases in muscle tension and act as a brake against excessively vigorous contraction. a. muscle spindles b. reflex antagonists c. Golgi tendon organs d. neuromuscular junction sensors

Answer 27

Golgi tendon organs Correct. Golgi tendon organs are also proprioceptors, and they respond to increases in muscle tension. They are located at opposite ends of a muscle and act as a kind of "brake" against excessively vigorous contractions.

Question 28

Central pattern generators are neural mechanisms located in the ____. a. spinal cord b. somatosensory cortex c. cerebellum d. skeletal muscles

Answer 28

spinal cord

Question 29

Terry just yawned with an open-mouth inhalation, a short stretch, and a short exhalation. This fixed sequence of movements is called a ____. a. ballistic pattern b. movement guide c. motor program d. patterned response

Answer 29

Motor program Correct. When Terry yawned, he went through a fixed sequence of movements called a motor program. Once begun, the sequence is fixed from beginning to end. This is why it would be very hard to stop the yawn once Terry started.

Question 30

Sasha is able to perform a number of different movements. Which of the following movements is she most likely to need her cerebral cortex to perform? a. Laughing at a joke b. Writing her name c. Sneezing when she smells pepper d. Crying after cutting her finger

Answer 30

Writing her name Correct. The cerebral cortex is important for complex actions like writing and talking and has less control over actions like laughing, sneezing, crying, and gagging. In this case, Sasha would need the use of her cortex to write her name.

Question 31

The sequence of the ______ cells controls the timing of the output from the cerebellum. a. Purkinje b. parallel c. glial d. nuclei

Answer 31

Purkinje Correct. The Purkinje cells of the cerebellum are activated by the parallel fibers, which run perpendicular to the Purkinje cells. The sequence of Purkinje cells controls the timing of the output, including both its onset and offset.

Question 32

For whom is basal ganglia activity likely to be most important? a. Damon, who is reaching out to keep his toddler son from falling b. Darlene, who is gagging at a nasty odor c. Faye, whose reflexes are being tested by a neurologist d. Kent, who slams on his breaks after a stoplight quickly turns red

Answer 32

Damon, who is reaching out to keep his toddler son from falling Correct. The basal ganglia seem particularly important for self-initiated behaviors (like Damon reaching out to prevent his son from falling) rather than reflexes or stimulus-elicited actions.

Question 33

Who has progressed the furthest in learning a new motor skill? a. Gael, who has rapid but inconsistent firing in her motor cortex b. Zoey, who has moderate but inconsistent firing in her motor cortex c. Joanna, who has consistent patterns of activity in her motor cortex d. Anna, whose motor cortex has extremely low levels of activity

Answer 33

Joanna, who has consistent patterns of activity in her motor cortex Correct. When learning a new skill, movements are slow and irregular at first (as is the firing in the motor cortex). As the skill becomes faster, so does the firing pattern. Once the skill is close to being mastered, the firing rate in the motor cortex would be consistent (as would the skill).

Question 34

Approximately 500 milliseconds before Jane wants to begin running, her motor cortex produces an activity called the ____. a. readiness potential b. conscious decision c. stimulus-triggered movement d. unconscious brain process

Answer 34

readiness potential Correct. Before deciding to run, Jane's motor cortex would produce a kind of activity called a readiness potential. In other words, the brain activity responsible for the movement apparently begins before the person's conscious decision to make that movement.

Question 35

When making a self-initiated movement, activity corresponding to the movement begins 7 to 10 seconds before the response in the ____. a. temporal and occipital cortices b. spinal cord c. frontal and parietal cortices d. cerebellum

Answer 35

frontal and prietal cortices Making a decision to move develops more slowly that we might have guessed, and we are conscious of the decision only toward the end of the process. When making a self-initiated movement, parts of the frontal and parietal cortices show activity before the response. Theoretically, someone monitoring the cortex could predict your behavior before you were aware of making the decision.