Chapter 5

Question 1

anosognosia

Answer 1

Lack of awareness of one’s own disability.

Question 2

Apraxia

Answer 2

a loss of the ability to execute learned voluntary movements, especially
complex sequences of movements, despite the motivation and physical capability to perform the actions

Question 3

Ideational apraxia

Answer 3

the inability to carry out sequential tasks involving the use of tools or objects in the proper order

Question 4

verbal apraxia

Answer 4

Results in difficulty
producing speech. Verbal apraxia can afflict both adults and children, the latter
having potentially devastating consequences for learning and socialization.

Question 5

basal ganglia

Answer 5

A group of nuclei lying deep in the subcortical white matter of the frontal lobes that organize motor behavior. The caudate, putamen, and globus pallidus are major components of the basal ganglia; the subthalamic nucleus and substantia nigra are often included.

Question 6

cerebellum

Answer 6

The prominent hindbrain structure that is concerned with motor coordination, posture, balance, and some cognitive processes; composed of a three-layered cortex and deep nuclei, and attached to the brainstem by the cerebellar peduncles.

Question 7

choreiform movement

Answer 7

Uncontrollable, dancelike (“choreiform”) writhing or twisting associated with damage to the basal ganglia, as occurs in disorders such as Huntington’s disease.

Question 8

frontal eye fields

Answer 8

A region of the prefrontal cortex in human and non-human primates, often associated with area 8a, that plays a key role in voluntary visual orienting movements.

Question 9

gating

Answer 9

Allowing or permitting. The basal ganglia, for example, gate movement initiation. Channels through the neuronal membrane are often gated, allowing the access of certain ions under certain conditions.

Question 10

hemiballismus

Answer 10

A neurological disorder resulting from unilateral damage to the basal ganglia; manifested by flinging movements of the limbs contralateral to the lesion.

Question 11

Huntington’s disease

Answer 11

An autosomal dominant genetic disorder in which a single gene mutation results in damage to the basal ganglia that causes personality changes, progressive loss of the control of voluntary movement, and eventually death.

Question 12

intention tremor

Answer 12

A tremor that occurs during performance of a voluntary motor act. Characteristic of cerebellar pathology.

Question 13

local circuit neuron

Answer 13

Also called interneuron. A neuron whose local connections contribute to processing circuitry

Question 14

lower motor neuron

Answer 14

Also called primary motor neuron. A motor neuron that directly innervates muscle.

Question 15

medullary pyramids

Answer 15

Longitudinal bulges on the ventral aspect of the medulla that signify the corticospinal tracts at this level of the nervous system.

Question 16

motor program

Answer 16

The plan to produce a particular motor action, such as writing one’s name, that occurs independently of the effectors used to carry out the movement.

Question 17

optic ataxia

Answer 17

A neurological condition associated with damage to the dorsal parietal cortex and characterized by deficits in visually guided reaching.

Question 18

Parkinson’s disease

Answer 18

A neurodegenerative process affecting the substantia nigra that results in a characteristic tremor at rest and a general paucity of movement.

Question 19

premotor cortex

Answer 19

Part of the prefrontal cortex lying just anterior to the primary motor cortex; involved in planning movement.

Question 20

premotor cortical areas

Answer 20

Cortical areas, including the premotor cortex, supplementary motor cortex, and parts of the parietal cortex, that provide motor programming signals to the primary motor cortex.

Question 21

primary motor cortex

Answer 21

A major source of descending projections to motor neurons in the spinal cord and cranial nerve nuclei; located in the precentral gyrus (area 4) and essential for the voluntary control of movement.

Question 22

readiness potential

Answer 22

An electrical potential, recorded from the motor and premotor cortices with EEG electrodes, that signals the intention to initiate a voluntary movement well in advance of actual production of the movement.

Question 23

reward value

Answer 23

The likelihood that a particular movement will yield a reward, multiplied by the amount of reward expected.

Question 24

saccade

Answer 24

A ballistic eye movement that changes the point of binocular visual fixation; normally occur at a rate of about three to four per second.

Question 25

striatum

Answer 25

The input nuclei of the basal ganglia, consisting of the caudate and the putamen. So called because of the striped appearance of these structures in brain sections.

Question 26

substantia nigra pars reticulata (SNr)

Answer 26

A component of the midbrain substantia nigra nucleus that plays a key role in the suppression and initiation of saccadic eye movements.

Question 27

superior colliculi (sing. superior colliculus)

Answer 27

Paired structures that form part of the roof of the midbrain; important in orienting movements of the head and eyes.

Question 28

supplementary motor cortex

Answer 28

Also called supplementary motor area or area 6. A premotor area, lying anterior to the primary motor cortex on the medial surface of the cerebral hemisphere, that plays an important role in movement planning.

Question 29

upper motor neuron

Answer 29

A neuron that gives rise to a descending projection that controls the activity of lower motor neurons in the brainstem and spinal cord.