Chapter 8

Question 1

motor pathways organization

Answer 1

hierarchal; Lowest: spinal cord as a point of contact between the nervous system and muscles for simple reflexive movements. Highest: cortical regions translate abstract intentions and goals into movement patterns

Question 2

cerebellum

Answer 2

ipsilateral control of movement; hemispheres connected by medial part called the vermis

Question 3

ataxia

Answer 3

damage to cerebellum resulting in difficulty maintaining balance and producing well-coordinated movements

Question 4

basal ganglia

Answer 4

collection of five nuclei; critical for the selection and initiation of actions

Question 5

nuclei of the basal ganglia

Answer 5

caudate nucleus, putamen, globus pallidus, subthalamic nucleus, substantia nigra

Question 6

primary motor cortex (M1)

Answer 6

somatotopic representation
input: all cortical areas implicated in motor control; basal ganglia and cerebellum
output: corticospinal tract

Question 7

rostral

Answer 7

anterior part of M1; terminates on spinal interneurons, stronger connection with prefrontal regions

Question 8

caudal

Answer 8

posterior part of M1; terminates on interneurons or directly stimulate alpha motor (corticomotor neurons)

Question 9

hemiplegia

Answer 9

loss of voluntary movements on the contralateral side of the body

Question 10

central pattern generator

Answer 10

neurons in spinal cord can produce elementary movement without cortical inputs

Question 11

central representation of movement plans

Answer 11

movements are planned based on the final goal (location endpoint) of the movement

Question 12

neural coding of movement

Answer 12

motor cortex activity is correlated with movement direction that with target location

Question 13

directional tuning anatomy

Answer 13

found in primary motor cortex, premotor, parietal cortex, cerebellum, basal ganglia

Question 14

population vector

Answer 14

sum of individual vectors; shifts before movement is produced suggesting some cells are involved in both planning and executing movements

Question 15

dynamic model

Answer 15

defines the trajectory of neural activity in abstract, multidimensional space

Question 16

SMA (supplementary motor area)

Answer 16

plays a key role in sequential movements or requiring coordinated movement of limbs

Question 17

alien hand syndrome

Answer 17

caused by lesions of the SMA; one limb produce seemingly meaningful action but the person denies responsibility for the action

Question 18

parietal cortex

Answer 18

integrates sensory and visual information with motor signals; conscious awareness of movement

Question 19

premotor cortex

Answer 19

movement execution

Question 20

mirror neurons

Answer 20

network spans frontoparietal cortex, with activation extending into the motor cortex during action observation; essential for comprehending and anticipating actions produced by another

Question 21

basal ganglia (gatekeeper)

Answer 21

crucial role in initiation of actions, completion, and inhibitory signals to keep the motor system in check

Question 22

basal ganglia (learning)

Answer 22

plays a crucial role in reward learning; reinforcement contingency: the consequences of actions affect probability of whether a behavior will be repeated or not

Question 23

Huntington’s disease

Answer 23

hyperkinesia (uncontrollable excessive movement) and abnormal body postures; up to 90% cell loss in the striatum and increased cortical excitation

Question 24

Parkinson’s disease

Answer 24

hypokinesia (reduced ability to initiate voluntary movement); loss of dopamine neurons in the pars compacta of the substantia nigra; reduced cortical excitation

Question 25

error-based learning

Answer 25

essential for the development of coordinated movement

Question 26

sensory prediction error

Answer 26

occurs when the actual feedback doesn't match with predictions

Question 27

forward model

Answer 27

delay between motor command and sensory signals; the expectancy of the sensory consequence of our action. key region: cerebellum