Behaviour first 4 DO MORE ON CONDITIONING Flashcards
Classical conditioning
predicting what’s going to happen stimulus predicts stimulus whatever animal does
learned CR involuntary – not rational or goal directed - reflects what the animal knows will happen
Instrumental conditioning
controlling what’s going to happen. response only predicts a stimulus if animal responds
response voluntary – rational, goal directed. reflects what animal wants to happen
Omission training
- Keylight CS predicts food but conditioned peck cancels food
Eventually, the bird learned to stop pecking, but note that orientation toward the key continues
evaluative conditioning
- motivational properties of US transfer to CS
- e.g. an unconditioned response for nice food is liking
this transfers to the keylight – also likes the keylight.. will approach the keylight, work to obtain it
Second order conditioning
- Can build long chains of associations
Box -> purple wrapper -> chocolate & toffee -> sweet taste
CS3 -> CS2 -> CS1 -> US - our world is full of things that were once neutral, but we learned to value positively or negatively through associations
sensory preconditioning.
- You have never tried chocolate. But you learned that the purple sweets come in the Quality Street box (even though you never ate them).
- Then one day a friend convinces you to try one. It’s the best thing ever! Now you start to like the purple wrapping and the Quality Street box.
you associated sweets and box, even though neither had value
Conditioned Inhibition
- A conditioned inhibitor signals the absence of the US
- tone -> food tone+light -> no food
- light signals the absence of expected food
tone EXCITES mental representation of food, but light INHIBITS it
Kamin (1969) Blocking
- Same number of light à shock pairings in both groups
- In Group 1 light conditioned with a pretrained noise N
- In Group 2 light conditioned with a novel noise N
- In Group 1 shock not surprising – predicted by pretrained noise.
- In Group 2 shock not predicted, and is surprising.
- Less learning in Group 1, where shock not surprising
- The pretrained noise blocked learning about the light in Group 1
This important observation, that pairings only produce learning when the US is surprising
Rescorla and Wagner (1972) equation
how much association strength increases on each trial (i.e. CS —> US pairing)
- ∆V = ab ( lambhda - EV )
- All the symbols have a psychological meaning
- V is associative strength between CS & US
- ∆V is change in V after each pairing
after one trial V low
a few trials V medium
lots of trials V high
what is a in the equation association strength
a refers to the salience of CS - its intrinsic perceptual intensity
brighter light = more salient a
what is B in the equation for association strength
B refers to salience of US - its intrinsic perceptual intensity
what is lander in the equation for association strength
refers to the size of the US - another physical property
what is EV in the equation for association strength
how much US is predicted
the sum of the associative strengths Vs of everything else that is present on that trial
what is (lander - EV) in the equation for association strength
how surprising the US is
learning stops when… (equation)
EV = lander
Mackintosh 1976
Conditioning two CSs at once
Equal numbers of pairings of light with shock but in overshadowing groups noise presented: quiet n or loud N
Difference between OC and CC
The first event in the association depends on the learner
Making the response is under their control
Law of Effect (Thorndike)
“Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction to the animal will.. be more likely to recur; those which are accompanied or closely followed by discomfort to the animal will… be less likely to occur. The greater the satisfaction or discomfort, the greater the strengthening or weakening of the bond.”
in some ways Thorndike was wrong
- Once the association was formed, the S always elicits the R – but the animal does not know why – it is not responding for a goal.
- If the child got bored of being praised, it would still tidy up
- If rat was full it would still respond
Difference between Thorndike and modern view
Thorndike - US not incorporated in learning, respond because S is there value of US is irrelevant.
A habit
Modern view - US incorporated in learning, respond to get US because it has value
A goal-directed action
Punishment?
- What’s nasty? (punishment)
- getting something nasty (shock) positive
- OR omitting something nice (cancel food) negative
- a response followed by either of these will go DOWN
Reinforcement?
- What’s nice? (reinforcement)
- getting something nice (food) positive
- OR omitting something nasty (cancel shock) negative
a response followed by either of these will go UP
Operant techniques: Escape
- Responses rewarded by removing aversive USs e.g. shock after they’ve begun
- Escape an aversive US e.g. shock after its started
- Escape response rewarded by removing shock