Applications and comparisons of learning theories
Classical conditioning as informed by Pavlov: roles of neutral, conditioned, unconditioned stimuli,
unconditioned and conditioned responses
Applications of classical conditioning: graduated exposure, aversion therapy, flooding
The extent to which ethical principles were applied to classic research investigations into learning
including Watson’s ‘Little Albert’ experiment.
Ivan Pavlov, a Russian physiologist, was conducting research on the digestive system in dogs during the early
1900s, when he noted that the dogs salivated before they received the stimulus (meat powder).
 He hypothesised that the dogs had come to associate the laboratory technician with the presence of food and
that this sound had been conditioned to cause the reflex response of salivation.
 Originally, the stimulus (food) produced the response (salivation). Eventually, the sight or sound of the
laboratory technician became the stimulus, which produced salivation. The salivation response, which is
biologically based in the nervous system and occurs involuntarily (i.e. a reflex response), had now been
conditioned to a new stimulus (sight or sound of the technician).
 Pavlov began to experiment by associating various sounds (a bell, a tuning fork and a metronome) with the
food and found that after a few trials the dogs could be conditioned to respond to the sound by salivating.
 As a result of Pavlov's work, clear evidence was provided for a very simple type of learning which was based
on the repetitive association of different stimuli – Classical Conditioning.
Some key terms in classical conditioning
Neutral stimulus (NS) – the name given to the conditioned stimulus before it becomes conditioned.
i.e. it is referred to as a ‘neutral’ stimulus whilst it fails to produce a response.
Unconditioned stimulus (UCS) – any stimulus which consistently produces a particular naturally occurring
automatic response (eg. the food in Pavlov's experiments).
Conditioned stimulus (CS) – the stimulus, which is ‘neutral’ at the start of conditioning. It would not
normally produce the unconditioned response (UCR), but eventually does so because of its association with
the unconditioned stimulus (UCS).
Unconditioned response (UCR) – the response that occurs automatically when the unconditioned stimulus
is presented. The UCR is a reflexive or involuntary response as it is predictably caused by an UCS.
Conditioned response (CR) – the behaviour, which is identical to that of the unconditioned response but is
caused by the conditioned stimulus (CS) after conditioning.
Elements of classical conditioning
Association – the most important part of classical conditioning; the linking of two objects or events so that
they become like ‘linked files’ in long-term memory. It's difficult to think of one without thinking of the other.
Reinforcement – any event that strengthens the likelihood of a particular response occurring over time.
Extinction – when a conditioned response no longer occurs. In classical conditioning, extinction occurs over
a period of time after the unconditioned stimulus (which acts as a reinforcer) is withdrawn.
Spontaneous recovery – extinction is not necessarily permanent. After a rest period from the presentation
of the conditioned stimulus alone, the organism may once again show the conditioned response when the
conditioned stimulus is presented.
Stimulus generalisation – the tendency for familiar stimuli to produce the same response. In classical
conditioning, a response that has been conditioned to a particular CS will often be produced for other stimuli
which resemble it (eg. a bell with a slightly different pitch, volume, or duration).
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Stimulus discrimination – when an organism responds to the conditioned stimulus, but not to any stimulus
which is similar to the conditioned stimulus.
Classical conditioning in practice
Graduated exposure
In treatment of Post-Traumatic Stress Disorder (PTSD), Graduated Exposure is one preferred treatment. In
this treatment, a person is exposed to closer and closer approximations to the fear-provoking stimulus, whilst
the therapist helps them to relax (reduce arousal to a normal level).
Aversion therapy. This is a classically conditioned form of behaviour therapy used to stop unwanted
behaviour by associating it with an unpleasant stimulus. Eg. a nausea-inducing drug might be paired with
alcohol or tobacco consumption so the individual associates the nausea with the alcohol or tobacco. The
alcohol or tobacco becomes the CS (having originally been neutral) after pairing it with the nausea inducing
drug (UCS) which automatically produces the response of feeling ill (UCR).
In this little-used therapy, a patient is immediately exposed to a high level of the fear-provoking stimulus and
the therapist helps them to relax (reduce arousal to a normal level). If it works, this is a very rapid form of
treatment. The first time described, the patient was scared to travel in a car, so the therapist shut her in the
car and drove around for several hours until she had relaxed!
Simple behaviour (conditioned reflexes) Eg. the dimming of the lights in a movie theatre probably meant
nothing on your first visit. It was simply a neutral stimulus (i.e. elicited no response). However, after many
theatre visits, you learnt that dimming the lights is associated with the start of the show. It has therefore
become a conditioned stimulus (CS) which elicits the conditioned response (CR) of silence.
Complex behaviour (eg. Phobias – see Area of Study 2). Phobias are intense, irrational, and persistent
fears of specific objects or situations. For example, a person may develop a bird phobia after being attacked
by a goose in early childhood. Whilst not injured, intense fear was present at the time which becomes heavily
associated with the presence of birds. Birds become a CS which elicit fear as a CR.
The extent to which ethical principles were applied to classic
research investigations into learning including Watson's ‘Little
Albert’ experiment
John B. Watson and his assistant, Rosalie Rayner, set out to test the idea that fear could be acquired through
classical conditioning.
Little Albert, the 8 - month-old son of a female employee at the clinic was the subject (his mother knew nothing of the
 Little Albert was presented with a white laboratory rat to which he initially showed no fear response.
 By associating a loud noise (an UCS which frightened the infant) with the presentation of the rat (which was
initially a neutral stimulus), Little Albert was conditioned to fear the rat
 this response was then generalised to other white fluffy objects including a dog and a sealskin coat.
 slightly less fearful responses were elicited by cotton wool balls and a Santa Clause mask.
Eventually, the infant's mother discovered what was happening and left her job and the city (Baltimore, Maryland).
She was never traced and Little Albert's conditioned emotional response may not have been extinguished.
The ethical issues that were not considered here include:
 causing psychological or physiological harm to the participant
 parental consent
 withdrawal rights
 debriefing of the parent.
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One-trial learning with reference to taste aversion as informed by
John Garcia and Robert A. Koelling (1966)
One-trial learning has a number of similarities and a number of differences to classical conditioning.
 it involves the association of two stimuli with a particular response.
 it occurs as a result of a single (one-off) pairing of two stimuli that produce a response which is particularly
significant for the organism. The conditioned response is extremely difficult to extinguish.
 the time-gap between the stimulus (food) and the response (nausea) is several hours, rather than the very
short gap in classical conditioning.
Taste aversion
Refers to a one-off occurrence in which an individual associates a particular taste with being or feeling ill. It may be
demonstrated that the food was not the cause of the illness but the aversion will usually remain.
Garcia and Koelling’s study (1966):
 Presented rats with sweetened water which they liked to drink, as they drank lights flashed and a clicking
noise was created
 Rats were divided into two groups:
o Group A drank the water (with lights and noise) and were given mild (but unpleasant) electric shocks
o Group B drank the water (with lights and noise) and were exposed to radiation which made them sick
30 minutes later
 Rats were then presented with sweetened water without lights and noise and plain water with the lights and
 Group A rats (lights, noise and shock) would not drink the plain water, but did drink the sweetened water
 Group B rats (radiation and sickness) would not drink the sweetened water, but did drink the plain water.
 Group A had been classically conditioned to associate the lights and noise with the electric shock
 Group B had developed taste aversion (for the sweetened water) as a result of the radiation sickness.
Oxford Psychology Units 3 & 4
ISBN 978 0 19 556717 5 © Oxford University Press Australia