Behavioural: L3 - Conditioning (Pavlovian Conditioning (PC) ( (Initially…
Behavioural: L3 - Conditioning
Finding food and drink
Avoiding harm e.g. knowing what/where is dangerous
Being able to make predictions about the world is critical for survival - we do this by learning.
A relatively permanent change in behaviour following manipulation of the environment
– response to a stimulus decreases over time
– response to a stimulus increases overtime Associative learning
The use of a neutral stimulus to signal the imminent delivery of a biologically significant event
This results in a change in the animal’s reaction to the neutral stimulus
Associations form between internal representations of the stimuli
It doesn’t matter what the stimuli are
Initially neutral stimulus which predicts a biologically relevant stimulus is call a
conditioned stimulus (CS)
The biologically relevant stimulus is called an
unconditioned stimulus (US)
The US causes an
unconditioned response (UR)
Following conditioning, the CS causes a
conditioned response (CR)
Lots of different organisms studied e.g. humans, monkeys, rabbits etc
Learning association between a neutral stimulus and a biologically relevant stimulus.
When you pair two stimuli you get learning.
Stimulus becomes associated with a response
Detection of events in the sensory register activates a memory representation of these events
The US also activates a response to produce the UR
Learning can result in CS-R (stimulus response learning) associations or CS-US associations (stimulus/stimulus learning)
Colwill & Motzkin (1994
): Rat subjects
Results are consistent with CS-US account of learning but are difficult to explain with an CS-R account of learning
Associations can form between neutral stimuli
These can only be seen when you look/probe for them
How we study Conditioning?
We present a series of trials to animals:
Each trial consists of presentation of CS and US
Does this change over time? Learning?
Using a change over time on its own is not sufficient (changes in behaviour can just be due to familiarity) so need control conditions to compare against
Animals display tracking when the discrete cue (e.g. light) is present (signals arrival of food)
Animal made ill after eating a flavour will reject that flavour subsequently
conditioning - learning about something that isn't nice.
Conditioning in real life
e.g. anticipatory nausea and vomiting in about 10% cancer patients.
CS = hospital
US = chemotherapy
CR = nausea evoked by hospital
- Emotional Product Differentiation
e.g. Gorn 1982, adverts give emotional response that you associate to that product/makes you want to buy it
Mechanisms of learning are the same, regardless of what is learnt (good or bad)
Associations form between representations of events - Law of equipotentiality
Learning about two CSs simultaneously
Conditioned suppression procedure – effects of conditioning with two stimuli
Rats press lever for food, CS is paired with shock
If they are scared, they stop pressing the lever
Measure the ‘suppression ratio’ – how much the presence of the CS suppresses their lever pressing
Loud noise stopped them learning the association with light and shock. Quire noise didn't. Light and noise competing - more salient element = more learned as has more associative strength
Overshadowing group drank a drink in the experimental context, and received rotation (which induces nausea) US
Control group drank the salient drink at home, and received rotation in the experimental context
Salient drink reduced magnitude of nausea
Effects of prior experience & Surprise
..e.g. Every time you drink beer you get a hangover
One day, you have a whisky - you get a hangover
Cause of hangover? The beer – although you have also had a pairing of whisky and hangover – the learning that beer predicts hangover
learning about the whisky hangover relationship
is the difference between what you expect to happen, and what actually occurs
Learning only happens when there is surprise
Beer leads to hangover = headache
Whisky leads to hangover = nausea
You learn that there is a difference between what you expect and what actually happens.
PC is ubiquitous - happens everywhere, all the time, automatically.