Brain Substrates

Question 1

what is the role of the dorsal striatum?

Answer 1

links the stimulus with the response (S-R part)
*linking discriminative sitmuli to behavioral contingencies

Question 2

what is the dorsal striatum comprised of?

Answer 2

caudate and putamen

Question 3

describe the relationship between the dorsal striatum and the motor cortex

Answer 3

dorsal striatum receives highly processed sensory information and projects to motor cortex which produces response

Question 4

what happens if you make a lesion to the dorsal striatum?

Answer 4

*problems of operant conditioning
1. simple S-R relationships are learned correctly (e.g., press lever, get food)
2. no learning with discriminative stimuli (if light is on, then lever press yields food)

Question 5

what role does the orbitofrontal coretx play?

Answer 5

linking responses with outcomes (R-O part)
*learning to predict outcomes of behavior
*receives input from sensory modalities and visceral sensations

Question 6

what does the OPFC control?

Answer 6

social and emotional responses, utilization (goal directed) behavior, evaluates potential consequences

Question 7

what happens in the OPFC during operant conditioning?

Answer 7

1. neurons selectively respond to rewarding or punishing consequences
2. OPFC sends feedback down to DORSAL STRIATUM to help initiate motor response
3. OPFC evaluates potential consequences
4. OPFC helps to choose between actions (based on potential consequences)

Question 8

define hedonistic value

Answer 8

things we like

Question 9

define motivation value

Answer 9

things we will work for

Question 10

what is the VTA (ventral tegmental area)

Answer 10

• found in the brainstem
• one of the wanting pleasure centers
• contains dopamine-producing neurons which project to the frontal cortex

Question 11

when will a reinforcer strengthen the S-R association?

Answer 11

Only when “wanting” and “liking” signals are both present will the arrival of the reinforcer evoke responding and strengthen the S-R association.

Question 12

what is the SNc (substantia nigra pars compacts)?

Answer 12

• one of the pleasure centers
• part of the basal ganglia that contains dopamine-producing neurons that project to the striatum

Question 13

what effect do primary and secondary reinforcers have on dopamine outputs?

Answer 13

increase dopamine output from both VTA and pars compacts

Question 14

what happens if you decrease dopamine output in both VTA and pars compacta?

Answer 14

can still judge how much you like something as well as someone who isn’t impaired, but won’t be motivated to work for it

Question 15

define the incentive salience hypothesis

Answer 15

The hypothesis that dopamine helps provide organisms with the motivation to work for reinforcement.
- increase in DA = increase in wanting or craving
-no DA, no motivation

Question 16

describe the rat experiment for incentive salience hypothesis

Answer 16

*control rats and rats given dopamine antagonist
*both prefer sugar pellets
*control rats willing to work and press lever to get sugar pellets
*IV rats would just eat rat chow to avoid working for food

Question 17

describe Sheffield’s consummatory response theory

Answer 17

it’s the behavior itself that is rewarding, not the food

Question 17

how is liking in the brain registered?

Answer 17

through the opioid system. primary reinforcers increase release of opioids - may be related to satiety as well as please.
*some secondary reinforces and behaviors increase opioid release as well

Question 17

what is the insular cortex (insula)?

Answer 17

• determines IF something is punishing
• important for conscious awareness of our bodies and emotional states
• encodes intensity of pain and negative emotions - hunger, anger, disgust, social rejection

Question 17

describes what occurs when the insula is damaged

Answer 17

damage to insula, can not learn to avoid punishment. However, can still learn reinforcement

Question 18

what is the relation between insulate activity and punishment?

Answer 18

insulate activity is proportionate to punishment. the greater something is perceived as punishing, the greater the insula activity

Question 18

what is the dACC (dorsal anterior cingulate cortex)?

Answer 18

• involved in the motivational value of pain (punishment). how much you learn from it
• it detects unexpected events and suggests an appropriate response