Ch 7 Action (Exam 2)

Question 1

what is action?

Answer 1

• changes to the environment
• somatic or autonomic

Question 2

somatic

Answer 2

• skeletal muscles

Question 3

autonomic

Answer 3

• smooth muscles
• cardiac muscles
• endocrine glands
• exocrine glands

Question 4

hierarchy in motor control

Answer 4

• starts with a high level goal
• then motor sequence
• then what area of the body is used
• then order of muscles in that area

Question 5

inverse model

Answer 5

• works backwards to determine action needed for goal

Question 6

forward models

Answer 6

• used to evaluate if the movement plan will work as intended

Question 7

feedforward control

Answer 7

• motor commands sent directly to muscle, tell muscle how to act
• faster but less accurate
• used by inverse models

Question 8

feedback control

Answer 8

• motor command sent to muscle
• actual state compared to desired state
• slower, but more accurate
• used by forward models

Question 9

premotor cortex

Answer 9

• involved in selecting goals and planning actions at a conceptual level
• when plans are driven by external stimuli

Question 10

mirror neurons in premotor cortex

Answer 10

• active when performing or observing an action

Question 11

supplementary motor cortex (SMA)

Answer 11

• involved in selecting goals and planning actions at a conceptual level
• when plans involved internally generated sequences of actions

Question 12

damage to SMA

Answer 12

• planing and coordination of sequences of movement disrupted

Question 13

each hemisphere of the cortex controls the ________ side of the body

Answer 13

• contralateral

Question 14

population vector

Answer 14

• the sum of the vector for all active neurons
• accurately represents actual movement direction

Question 15

direct pathway

Answer 15

• basal ganglia
• excitatory
• selection and initiation of action

Question 16

indirect pathway

Answer 16

• basal ganglia
• inhibitory
• inhibition of action (“stop” or “don’t start”)

Question 17

substantia nigra pars compacta

Answer 17

• releases dopamine to basal ganglia

Question 18

2 types of dopamine receptors

Answer 18

1. D1 along direct pathway: excited by dopamine, action is reinforced
2. D2 along indirect pathway: inhibited by dopamine, supressed competing actions

Question 19

unexpected rewards generate a dopamine burst which strengthens the _______ pathway and weakens the ______ pathway

Answer 19

• direct
• indirect

Question 20

disease of basal ganglia

Answer 20

• Huntington’s disease
• Parkinson’s disease

Question 21

gross anatomy of cerebellum

Answer 21

• white matter
• highly folded
• gray matter on outside

Question 22

cytoarchitecture of cerebellum

Answer 22

• cerebellar cortex
• granule cells
• purkinje cells

Question 23

motor coordination and the cerebellum

Answer 23

• uses forward model to predict results of motor commands
• online error correction
• motor learning
• feedback control
• comparison between actual movement and predicted movement

Question 24

Fitts’s Law

Answer 24

• describes the speed/accuracy tradeoff for pointing motions

Question 25

from cortex to spinal cord

Answer 25

- axons from primary cortex synapse directly on lower motor neurons and local circuit neurons - spinal cord circuits can control movements on their own

Question 26

Myasthenia Gravis (MG)

Answer 26

- weakness in voluntary muscles - chronic, waxes and wanes

Question 27

intracellular electrical recordings

Answer 27

- one electrode, directly into cell or near surface

Question 28

extracellular electrical recordings

Answer 28

- recording activity of many neurons - single unit or multi-electrode - field potentials

Question 29

extracellular recordings have great ______ and _____ resolution

Answer 29

- spatial - temporal