LPI T5 Flashcards
Contingency
the fact that the CS providesinformation about the US’s arrival
The Rescorla-Wagner equation is:
ΔV = αβ(λ – ΣV)
The Rescorla-Wagner equation is used to predict the
The Rescorla-Wagner model describes the rate of change in associative strength (between stimulusand outcome or response and outcome or stimulus and stimulus) through conditioning.This model focuses on error driven learning.
Assumptions of Rescorla-Wagner error prediction model with regard tothe unconditioned stimulus (US)
The effectiveness of US depends on how different it is from what isexpected The amount of learning on a given trial is a function of the surprisevalue of the US (more surprise then more conditioning)
What does ΔV mean?
change in associative strength (i.e., the strength of the association between the CS and the US)
What does the α value represent
α is the salience of the CS, i.e., how much the CS grabs your attention. E.g., the salience of a brightflashing red light should be higher than the salience of a plain red square. With a strong CS, α shouldapproach 1, but with a weaker stimulus α should tend towards 0.
What does β mean?
β is the salience or motivational value of the US, the outcome, e.g., the motivational value of chocolateas a US might be higher than the motivational value of lettuce as a US. The more we desire an outcome,the more we will learn about it.
What does the λ mean?
λ is the outcome (the US). This is usually only 1 or 0 – 1 when the outcome or US is present, and 0 whenthe outcome or US is absent.
What does ΣV mean?
ΣV is the sum of all the associative strengths of all the stimuli at the beginning of that trial.
What is central to the Rescorla-Wagner prediction
role of surprise
The strength of a Pavlovian conditioned response (CR) depends upon
the strengthof the connection between internal representations of the CS and the US… theassociative strength of the CS.
Cue Competition: the principle of summation
This means that if two cues are trainedin compound, they will compete for associative strength with the pairedoutcome <img></img>
Conditioned Inhibition
A conditioned inhibitor is a stimulus that predicts the absence of an outcome.
How do you learn that a stimulus predicts the absence of an outcome?
This cannot be established simply by pairing a stimulus with no outcome, as that would just result in nolearning.
Extinction Treatment
in a conditioned inhibition paradigm, remove the reward when the stimulus is presented after it’s trained
What are the three strengths of the RW model?
- the equation allows quantitative predictions
- heuristic value for other associative learning theories
- helped with understanding numerous psychological processes
The model provides a good account of many of the facts of compound conditioning, BUT not all the effects associated with blocking and overshadowing are consistent with it. What are the strengths
What are the limitations of the RW model?
- no adequate account for the role of surprise when blocking is considered
- no adequate account of extinction
- inappropriate account for discrimination
- inhibition is conceptualised as negative associative strength
What’s Donald Hebb’s (1949) learning theory
When individual cells are activated at the same time, they establish connecting synapses or strengthen existing onesand thus become a functional unit. These are the structuralbases of memory.
Synapse
specialised junction through which neural signals are transmitted from one neuron (the presynaptic neuron) to another (the postsynaptic neuron)
Hebbian synapse
increase its effectiveness as a result of simultaneous activity in the presynaptic and postsynaptic neurons. Such synapses are essential for many kinds of associative learning.
Long-term potentiation (LTP)
main form of synaptic plasticity reflecting theactivity of synaptic information storage processes, and has been identified as the likelycellular correlate of learning and memory
Explain the principle of LTP
One or more axons connected to a dendrite act as source for stimuli -> sudden and strong stimulation leaves some synapses depolarised/potentiated (more responsive to more stimuli) for varying amount of time
What is associativity in long-term potentiation?
The response to axon 2 is initially weak. Briefly pairing it withrapid stimulation in axon 1 strongly depolarizes the dendrite.Afterward, the response to axon 2 (as well as axon 1) is enhanced.
How does the biological basis relate to Pavlovian Conditioning?
This relates to learning, as previous experience has led to a long-term change inthe behaviour of the synapse, and it can be argued that this is related to surprise asthis is a result of a ‘burst of intense stimulation’ – a difference in what was expected(i.e. a prediction error).
What did Schultz 2007 find on the role of dopamine in learning theory?
dopaminergic neurons exhibitburst activity, also known as ‘phasic activation,’following primary food and liquid rewards and conditioned visual, auditory, and somatosensory reward-predicting stimuli
Does dopamine provides a biological signal for an error prediction, therefore providing a biological indication for surprise?
no dopamine activity to the CS, because lacking association with the reward outcome or US -> dopaminergic neurons shift towards CS after successive trials -> after dopamine reaction only to CS not to outcome/reward or US
Absence of a reward following a blocked stimulus does not induce a neuronal response
When the light, the blocked predictor, was presented with no reward in the test stage, shown asblocking Group A in the table, they saw no dopamine activity Had an association been learnt between the noise and the light, we would expect to see increased dopamineactivity to the presentation of the light, and a depression of dopamine activity when no reward is presented . ➜ That this did not occur supports the findings of the blocking paradigm, as the prior learning about the noise atstage one ‘blocked’ the learning about the light at stage two, and this provides support for the role of dopamine insignalling prediction error.
Neuronal activation following the delivery of a reward after a blocked stimulus
For blocking Group B, when a reward was presented after the light, there was dopamine activity to thereward. Had an association been learnt between the light and the reward, then we would have expected to see increased dopamine activity to the light, not the reward . ➜ That this did not occur supports the findings of the blocking paradigm, as the prior learning about the noise atstage one ‘blocked’ the learning about the light at stage two, and this provides support for the role of dopamine insignalling prediction error.
What are the arguments against Schultz’s (2007) design supporting the claim that dopamine activity is signalling error prediction?
- no exact replication with punishment or aversive outcome
- Would dopamine still fire in the original experiment
What are the arguments in favour of Schultz’s (2007) design supporting the claim that dopamine activity is signalling error prediction?
- the observed pattern does support the role of dopamine signalling prediction error
- prediction error regards learning in general and is not limited to learning about rewarding outcomes
What key does Siegel 2016 outline in the relation between Pavlovian Conditioning, tolerance and addiction
Conditioned Compensatory Responses
Siegel (2016) The Heroin Overdose Mystery two key points with Classical Conditioning
UR is NOT the effect of the drug, it is the bodily process that addresses the effect of the drug – the body’s RESPONSE CS all stimuli or contextual cues associated with the drug => illicits body’s indirect response
What is the alpha response in the Heroin overdose mystery
a drug is the directresponse that the drug causes, i.e. a rush, depression of respiration.
What’s the beta response in the Heroin overdose mystery
homeostatic counter-response that acts to diminish the direct effects of the drug. These homeostatic counter-responses are the responses that enter into conditioning.
What is Tolerance and how is it accomplished
cues remainconstant prior to the drug arriving intothe body, the conditioned compensatoryresponse (beta response) bothdiminishes the body’s level of reactivity tothe drug – the drug is expected andprocessed more efficiently, thus its effectsare attenuated (less pleasure)
How do you think cues associated with a drug could cause craving, as part of addiction?
- Cues = elicit a conditioned compensatory response.
- For example, cues associated with heroin will elicit the conditioned compensatory responses of “despair,” increased pain sensitivity and increased frequency of breathing (which can make individuals feel anxious).
- The conditioned compensatory responses are all highly aversive.
- In the presence of cues associated with a drug, an individual will experience the negative/aversive-conditioned compensatory responses, and may then be motivated to take the drug simply to alleviate them
Critique of learning theory:
Fails to address the complexity of human behaviour, and too heavily based on animal studies.
What is Behavioural Psychology?
Behaviour is learned• Individual difference in behaviour is the result of differentlearning experiences that people have had and thesituations in which they find themselves
Research definition of learning:
“A long lasting change in behaviour that results fromexperience”
Habituation is the simplest form of learning:
it is –learning NOT to respond to an unimportant event
Explain Pavlovian Conditioning
What does classical conditioning provide us with
a way to learn about cause-effect relations between environmental events
What are two important factors in classical conditioning
Sequence and Timing
Extinction
Present bell with no food following* ➜ reversal of conditioning process* ➜ extinction (association isundone)
Acquisition of new knowledge depends on
Intensity of US -> rapidness of learning Timing -> Optimal: Presentation of the CS occurs shortly before the US
Associative strength
The strength of the connection between internal representationsof the conditioned and unconditioned stimulus which determines the strength ofthe conditioned response (the Rescorla-Wagner model outlines this).
Associability /conditionability
Theease with which the strength of a conditioned response to a stimulus can beincreased by subsequent conditioning.
Error term
Difference betweenwhat you expected to happen and what actually happens
Contiguity
The temporal and spatial(time & space) relationship between events can influence the strength ofassociation. (arriving at the same time)
CS-UScontingency
Thedegree to which the US occurs during the presentation of the CS.
What are positive, negative and zero contingency?
- Positive: US is more likely present than the absent
- Negative: US is more likely absent than the present
- zero: US is equally likely during the presence and the absence of the CS.
Blocking
Kamin’s (1969) blocking effect study demonstrates thatconditioning to a stimulus could be blocked if the stimulus were reinforced incompound with a previously conditioned stimulus. A+, AB+, B+ = blocked conditioning of B
The summation principle
When the associative strength of individual stimuli are presentedtogether, the individual strengths are added together.
Cue competition
If two cues are trained in compound, they will compete for associative strength with the paired outcome, so that if we train AB+, the strength of association that develops between A and the outcome, will be weaker than the association between stimulus and outcome if we trained C+.
Overshadowing
The disruption of conditioning with one stimulus because of the presence of another stimulus. -> stronger conditioned stimulus will overshadow a weaker one
Conditioned compensatory response:
The body usually tries to maintain a state of homeostasis. When people use drugs, the body and brain learn to counteract the effects of the drug upon presentation of conditioned stimuli (cues, e.g. needle) and respond to produce physiological reactions that are opposite to that of the drug (see Siegal paper)
Acquisition
Refers to the initial stage of learning when a response is first established and strengthened through reinforcement or association with a stimulus.. At first, the word can by itself causes no special response. After repeated pairings of the word can and the water, the word by itself gradually becomes more likely to cause a CR.
What are the Clinical applications of Classical Conditioning? (Assumption)
Psychopathology = learned maladaptiveresponse to a situationthat may have generalised to other situations orsimilar stimuli ➜ it could beunlearned (systematic desensitisation, aversion therapy)
How does contingency relate to excitatory or inhibitory learning?
- Positive CS-UScontingency –> excitatory conditioning
- Negative CS-UScontingency –> inhibitory learning.
What was the unconditioned stimulus in Siegel’s (2016) heroin overdose mystery?
heroin
What was the conditioned stimulus in Siegel’s (2016) heroin overdose mystery?
all cues present at the time of heroin consumption
What was the direct response to the heroin in Siegel’s (2016) heroin overdose mystery?
nothing. neither ur nor cr
What was the unconditioned response in Siegel’s (2016) heroin overdose mystery?
the homeostatic counterreaction reducing the effect of the physiological changes brought on by heroin
