College 6: Social Learning (Reinforcement learning)

Question 1

probabilistic outcomes

Answer 1

the same stimulus or action does not always lead to the same outcome

Question 2

R (reward)

Answer 2

reward, also called outcome (positive or negative feedback)

Question 3

V (value)

Answer 3

the expected outcome of a stimulus or action

Question 4

PE Delta

Answer 4

prediction error, the difference between the actual reward and your expected reward R - V

Question 5

alpha

Answer 5

learning rate, the speed of learning

Question 6

dopamine

Answer 6

study of dopamine with monkeys and dogs

pavlovian dog when offered food, dopamine is responsive to expectations rather the actual outcome. Dopamine gets more active when the dog gets unexpected food offered.
When learned, the spike in neurons is active when the bell rings
when it’s not given you see less dopamine

Question 7

pavlovian conditioning

Answer 7

associated more with the ventral striatum

Question 8

operant/instrumental conditioning

Answer 8

associated more with dorsal striatum

Question 9

social reinforcement learning

Answer 9

Study of Jones in which you’re learning from feedback of others (i.e. social feedback)

Question 10

Cohen

Answer 10

is adolescence associated with unique changes in predication errors signals and expected values

probabilistic reinforcement tasks in the brain scanner in which they got abstract stimuli and had to classify this in northern or eastern.

children 8-12
adolescents 14-19
adults 25-30

predictable stimuli (83%)
random stimuli (50%)
with a reward magnitude

striatal prediction error signals peaked in adolescence - more dorsally located

value signals that the mPFC were highest in children

outcome:
- it showed that value and PE show a different developmental trajectory
- larger striatal PE’s might reflect a greater effect of positive outcomes in adolescents
- might suggest taht children learn less efficiently (stronger responses to reward but PE absence)
- Limitation was that they only studies positive prediction errors and not learning speed as well

Question 11

van den Bos

Answer 11

2 stimuli for example an apple and a pear, when you choose the apple (A) you get 80% of the time positive feedback and 20% when you choose the pear.

Stimulus pair AB
A 80%
B 20%

Stimulus pair CD
C 70%
D 30%

the negative learning rate decrease with age which means that children learn faster from negative feedback from both adults and adolescents, and adolescents learn faster than adults

for positive learning rates this is the way around

outcome: VS (prediction error) and mPFC (reward/outcome) was stronger with positive prediction errors than negative.
The strenght became stronger with age

people who learned faster from negative feedback showed less connectivity between VS and mPFC

Question 12

Jones study

Answer 12

social decision making, social status and sensitivity to social cues is changing during adolescence and social reinforcement learning could be important to study during adolescence

participants during 8-25 yo completed a personal survey and peers could either give positive feedback to the participant or to someone else. They manipulated the feedback

children and adults slowed down their responses when the continous peer (100% feedback) suddenly stopped giving notes > higher positive learning rates

adolescents showed more activity putamen and SMA when receiving positive notes receiving positive feedback regardless of their expectations
» adolescents may be more tuned to action-outcome learning
» period of sensitivity towards peer feedback

limitations:
- brain regions has way more functions
- reaction time to the wink in the left or right eye is what they used as learning. But this wasn’t necessarily linked to positive note
- used only positive and not negative
- other forms of social learning weren’t taken into account
- there is a followup study done at the moment

Question 13

ventral striatum

Answer 13

reward magnitude
reward predictive stimulus
greater reactivity when a reward is different than expected
before learning: VS responds at the time of the reward
after learning: VS responds at the time of the predictive stimulus
- pavlovian conditioning
- learning from feedback

Question 14

dorsal striatum

Answer 14

responds to reward but especially early in learning and when there is mapping between actions and outcome

learning from reward

operant/instrumental conditioning

Question 15

OFC (part of mPFC)

Answer 15

associated with outcome value
value signs mPFC higher in children

Question 16

insula

Answer 16

activitity during positive prediction errors