Download Classical Conditioning Notes by Dr. Ilija Gallego The Simplest Type

Classical Conditioning Notes by Dr. Ilija Gallego
The Simplest Type of Learning: Pavlovian or Respondent Conditioning
Classical conditioning is based on Stimulus > Response
 A stimulus in anything you can pick up on using your senses
 The response is what you do as a result of coming into contact with a stimulus
Responses in Classical Conditioning
 The responses in classical conditioning are all internal, involuntary, automatic,
reflex type responses.
 This is true of the unconditioned response (UR) and the conditioned
response (CR)
Learning by Association
 In classical conditioning the learner learns by association.
 An association is involuntarily made between 2 stimuli.
 The association occurs because we pair a stimulus that always leads to an
involuntary response (an unconditioned stimulus - US), with a stimulus that leads
to no particular response (a neutral stimulus - NS)
EXAMPLES OF UNCONDITIONED REFLEXES
US
UR
Onion juice
Tear up
Food
Salivate
Touching hot object
Pull away
Extreme heat
Sweat
Extreme cold
Shiver
Increase in light
Pupils contract
Puff of air aimed at eye
Blink
Loss
Sadness
Pain
Fear and avoidance
“Formula” for Classical Conditioning
1. Before Conditioning (Learning)
 A neutral stimulus (NS) (one that elicits no response) is chosen.
 An unconditioned stimulus (US) is chosen. This is a stimulus that always leads
to an internal, involuntary, automatic, reflex type response.
 The US elicits an unconditioned response (UR) (an internal, involuntary,
automatic, reflex type response). This is the unconditioned (unlearned)
response.
2. During Conditioning
 The neutral stimulus is paired with the US.
 The US stimulus elicits an UR. The UR is an internal, involuntary, automatic and
INBORN response.
 The pairing of the stimuli is usually done repeatedly.
3. After Conditioning
 The neutral stimulus is presented alone.
 If it elicits a response, then it is no longer neutral. We now call it a conditioned
stimulus (CS).
 The response elicited is internal, involuntary, automatic and reflex like, but it is
not inborn – it is LEARNED. We call this the conditioned (learned) response.
Analysis to Pavlov’s Work
 Before Conditioning
 Bell (Neutral Stimulus) > No response
 Food (US) > Salivation to Food (UR)
 During Conditioning
 Bell (NS) is Paired with the Food (US) > Salivation to Food (UR)
 After Conditioning
 Bell > Salivation to the Bell (CR)
 The bell is no longer a NS, but has become a CS
Extinction
 Pairings of the CS and US lead to conditioning whereas presentation of the CS
only leads to loss of the conditioned response
 Extinction refers to loss of CR due to the CS presented without the US
 Extinction is useful in clinical situations
 Extinction of a phobia can be treated by exposure to the CS only
Spontaneous Recovery
 Sometimes after extinction the CR returns.
 This shows us that the response is gone but not forgotten.
 The learner does not think, “Oh, there is the CS, I’ll make a CR now.” There is
no thinking involved in classical conditioning. Instead the CR is made
involuntarily.
Conditioning of Emotional Responses
 John Watson documented that conditioning of emotional responses in the Little
Albert study
 NS/CS: a white rat
 US: a loud banging sound
 UR: fear/startle response
 Eventually Albert exhibited a learned fear (CR) to the white rat (NS
became the US)
 Other instances of classical learning
 Positive: conditioning of attraction in advertising
 Brand name (CS) + model (US) => positive reaction to product
 Negative: aversion
 Flavor (CS) + illness (US) => flavor aversion
Generalization
 This is when the learner makes a CR to a stimulus that is not the CS, but is
similar to it.
 Examples
 Pavlov’s dogs salivate to a tone that is similar to the bell, but is not the
original bell
 A person becomes afraid of all dogs (or some dogs) after being bitten by
one dog.
 Little Albert became afraid of white furry things
Discrimination
 The learner distinguishes between the CS and other similar stimuli. S/he
responds (makes a CR) only to the CS.
 Examples
 Pavlov’s dogs are taught to salivate to “ding” but not to “dong.”
 A person becomes afraid of only the dog that bit him/her.
4 FACTORS INFLUENCING CLASSICAL CONDITIONING
1. Number of pairings (learning trials) between the US and the CS
More trials leads to stronger CR
2. Intensity of the US
Higher intensity leads to stronger CR and faster learning of CR
3. Consistency of the CS and US pairings
Higher consistency leads to more consistent and stronger CR
4. Temporal relationship (timing) between the CS and the US
4 Subtypes of Classical Conditioning
 Based on the temporal relationship between the CS and the US
 Delayed Conditioning
 Trace Conditioning
 Simultaneous Conditioning
 Backwards Conditioning
1. Delayed Conditioning
 Bell (CS) is rung BEFORE AND DURING the time that the food (US) is given
 Bell (CS) comes BEFORE the food (US)
 Presentation of bell (CS) OVERLAPS with the presentation of the food (US)
2. Trace Conditioning
 Bell (CS) is rung BEFORE BUT NOT DURING the time that the food (US) is
given
 Bell (CS) comes BEFORE the food (US)
 Presentation of bell (CS) DOES NOT OVERLAP with the presentation of the food
(US)
3. Simultaneous Conditioning
 Bell (CS) is rung only DURING the time that the food (US) is given
 Bell (CS) comes with, but NOT BEFORE the food (US)
 Presentation of bell (CS) OVERLAPS with the presentation of the food (US)
4. Backwards Conditioning
 Bell (CS) is rung AFTER the food (US) is given
 Bell (CS) DOES NOT COME BEFORE the food (US)
 Presentation of bell (CS) DOES NOT OVERLAP with the presentation of the food
(US)
Determining the Effectiveness of the Subtypes
1. Does the subtype allow for the learner to passively ANTICIPATE what they
are focused on (the US or food)?
 The CS must come before the US
2. Does the subtype maximize the likelihood that the learner will make a passive
ASSOCIATION between the CS (bell) and the US (food)?
 The CS and US must overlap in time
Evaluating the Effectiveness of the Subtypes
 Delayed: anticipation & association
 Most effective
 Trace: anticipation, but not association
 Somewhat effective
 Simultaneous: association, but not anticipation
 Not very effective
 Backwards: neither anticipation, nor association
 Barely effective or completely ineffective
“Exceptions” to the Rules:
One Trial Learning
 Some CRs can be learned after only one pairing between the NS and the US
 Example: Learning to fear a dog or all dogs from having been bitten once
 Nonetheless, more pairings does lead to stronger learning. How afraid of
dogs would you be if you were repeatedly bitten?
Taste Aversion
 Learning to dislike a food or taste often happens in only one trial.
 Typically it happens in a trace conditioning pattern, but the time between having
a certain food or taste and becoming ill can be as long as 12 hours, and we might
still develop the taste aversion.
Summary of Classical Conditioning
 Learning occurs through pairing 2 stimuli
 Responses, both inborn (UR) and learned (CR) are involuntary, automatic,
internal.
 No thinking is involved.
 Learner is passive
 Learner is focused on the US
 Responses learned include only simple responses such as reflexes, likes and
dislikes, fears and emotional responses