Flashcards in Learning: Challenges For The Behaviourist Approach Deck (25):
Evolution and 'preparedness'
Evolution- survival prospects enhanced by conditioning-prediction
Behaviourists assumed that anything could be taught using principles of conditioning
What is preparedness?
Animals are hard wired to learn certain associations much better than others
I.e. Biological constraints on learning
We have covered nausea becoming associated with food even if the cause was something else (chemotherapy, vodka)
Remember learning was best with a short CS-UCS time interval?
Garcia showed that for 'taste aversion', animals could reliably learn the food- nausea association reliably with up to a 24 hour delay
Garcia and koelling (1966)- rats licking from a drinking tube. Simultaneously exposed to sweet water, light and buzzer. Then irradiated to cause nausea
Would they learn that all 3 stimuli predict nausea and avoid water associated with these?
2nd group of rats were given electric shock rather than radiation
Did they fear all 3 cs's?
In nature, it is good and drink that makes us I'll
It makes sense for a food-illness association to be learned quickly and strongly
Food is rarely encountered alongside physical harm
But changes in light and noise are, so same principle applies
So, friends tend not to make us sick
We associate vomiting with what we've ingested
Broberg and Bernstein (1987)- gave child cancer patients a strange tasting sweet before chemotherapy sessions
Associated this with nausea rather than other foods
With fear, even unconscious presentation of snakes, spiders and angry faces can be easily paired with an electric shock but
Flowers, houses and happy faces give much weaker conditioning (ohman and soares, 1998)
Evolution or learning?
What is instinctive drift?
Some instinctual behaviours are too strong and simply override learning
The role of cognition
Some argued for stimulus-organisms cognitive representation-response (s-o-r)
Kohler's chimps and insight
Tolman and rats in a maze
Trained along 1 path which leads to food, rats are then exposed to many paths. The majority explore a few inches along each and then head for the one which would lead to the same spatial location as the earlier stage
Tolman suggested a cognitive map
Latent learning- Tolman also found that rats could learn these cognitive maps with no reinforcer
After 10 trials with no reinforcer, on the 11th trial, rats performed in the maze to the same degree as those who had already had 10 trials with food reinforcement
With the latent learning experiment
Learning happened but was not evident until there was a reason (food incentive) to navigate quickly through the maze
Expectancy- rescorla (1968)
Rats- bar pressing (for food)
Presented with tone and shock- causes freezing in place(fear response)
Other group also presented with tone and no shock
Group in which tone only predicted shock 50% of the time didn't freeze to later tones
We only condition to stimuli
That consistently act as predictors
Kamin blocking effect
Rats get light and shock
Then get light, noise and shock
Haven't learned noise is a predictor- this association has been blocked by the earlier light- shock association
Kamin blocking effect led to
Strength of association=v
Max value that v could reach=¥
Rate of learning=a (e.g surprise)
See slide for equation
What is latent inhibition?
Pre-exposure to a CS (e.g. A light) causes a weakening of the association between the CS and a later UCS (e.g. A shock)
Rescorla-Wagner predicts this shouldn't happen (effect of latent inhibition)
As the shock is just as surprising whether the CS has been seen before or not
What is latent inhibition?
Habituation to the CS presented on its own
Later, when the CS is paired with UCS, the organism pays less attention to
The CS and so conditioning is weakened
In r-w, if
A=salience then ok