Classical Conditioning Mechanisms Flashcards
Initial responses to the stimuli
- US effective in eliciting target response from outset
- CS does not elicit conditioned response initially results from association with US
latent inhibition or CS preexposure - new stimuli are more effective than familiar stimuli
- repeated presentation of CS by itself leads to CS preexposure, making CS familiar
US preexposure effect - experiments on US novelty similar to CS- preexposure experiments
- conditioning proceeded faster for novel stimuli than familiar stimuli
intensity and salience
intensity
- more vigourous conditioned repsonding occurs with more intense stimuli
salience
- learning is expedited
- stimulation can be more salient if relevant to biological needs of organism
note:
- stimulus intensity contributes to its noticeability, more attention captivating
- refer to slides 48-49
learning with vs without US
with US
- higher order conditioning; sensory preconditioning
without US
- greatly increases range and instances in classical conditioning
- basis of irrational fears
- sensory preconditioning: associations between stimuli become learned
- CS1 paired illness: if aversion to a flavour develops when later flavour was part of food that induced food poisoning
- those with aversion to CS1 also have aversion to CS2 even though it was never directly paired with US
refer to YouTube video “inhibitory conditioning: learning to predict the absence of a stimulus”
CR determined by US
notion that form of CR was determined by US lead Pavlov to propose:
1. CS-US association turns CS into a surrogate US
2. CS assumed to activate neural circuits previously activated by US
CR determined by US: stimulus-substitution model
emphasizes that the nature of the CR depends substantially on U
CR determined by US: how CS can explain CR
social affiliative response elicited in caged rat; not food responses
CS-US intervals (refer to schema in notebook)
- what responses become conditioned
- short CS-US intervals cause different responses than long
short: - activation appropriate for immediately dealing with US
long - general, time consuming
SS vs SR learning
US devaluation - strategy
phase 1:
- assessment (rats: experimental + control group)
- CS (tone) paired with US (food)
- CS-US formed and assumed to establish representation of US
- conditioning evident with in activity associated with CS
phase 2:
- experimental group given extra food
- evaluated US associated food + US representation of food
- controls did not get the extra food
results: experimental group
- significantly less CR compared to control
- if conditioning established SR connection, Cr would have been elicited
1. irrespective of value/devaluation of food
2. suggests learning conditioning resulted form CS+ representation of US (SS)
modification of response to US: Pavlovian conditioning
standard
- CS comes to elicit new response after being paired with US
learning to response to CS is only useful if it helps cope with US
the UR can be modified
- 2 groups (experimental CS+US) + (control CS, no US)
once CS becomes conditioned to US
- presentation of CS reduces how vigorously subjects blinked (US); conditioned diminution of UR
conditioned reduction of UR
- CS elicits physiological process to counteract effects of US
- Cs can result from paired with aversive US
- release of endorphins can be conditioned to cues associated with aversive US
- CS will then from such aversive cues, stimulate release of endorphins
- refer to slide 59 on drug tolerance example
blocking effect, where two conditioned stimulus are employed…
phase 1
- exp. group receives repeated pairings of one of stimulus A with US; training continues until strong CR = developed with A
- cont. group: stimulus A + US are not paired
phase 2
- stimulus B presented together with stimulus A and is paired with US
- after many trials B = presented alone if it also elicits CR
- very little responding occurs to B
control group results
- more CR to stimulus B than A
- because US was NOT surprising or unexpected
- uncertainty in cont. group where stimulus A is not paired with US resulted in greater learning response
Rescorla-Wagner model
- assumes level of surprise of US depends on how different it is from person’s expectation
- learning will occur if what happens is a surprise
- assumed that expectation of US is related to what has already been learmed
problems with the Rescorla-Wagner model
incorrect analysis of conditioned inhibition
1. model predicts repeated exposure to CS- will lead to loss of conditioned inhibition BUT….
- lots of research has demonstrated repeated non-reinforcement of CS- can increase inhibition
2. model views extinction as reverse acquisition BUT…
- accumulating evidence indicates extinction involves learning a new CS-US relationship
