Classical conditioning: WACE Year 12 Psychology Unit 3

What this dot point is asking

You must label the five elements in any example, define the four processes, and know each designated study's aim, method, key findings, contribution and limitations. Watson and Rayner (1920) is also a favourite for questions on ethics.

The five elements

• Neutral stimulus (NS): a stimulus that produces no relevant response before conditioning (a tone).
• Unconditioned stimulus (UCS): a stimulus that produces a response automatically, without learning (food).
• Unconditioned response (UCR): the automatic, unlearned response to the UCS (salivation to food).
• Conditioned stimulus (CS): the former NS after it has been paired with the UCS (the tone, after learning).
• Conditioned response (CR): the learned response to the CS alone (salivation to the tone).

Conditioning is usually most effective when the NS comes just before the UCS and the pairing is repeated.

Generalisation, discrimination, extinction and spontaneous recovery

• Stimulus generalisation: the CR is produced by stimuli similar to the CS (a slightly different tone also causes salivation).
• Stimulus discrimination: the CR is produced only by the CS and not by other, different stimuli.
• Extinction: the CR gradually weakens and stops when the CS is repeatedly presented without the UCS.
• Spontaneous recovery: after extinction and a rest period, the CS suddenly produces the CR again (usually weaker), showing the association was suppressed rather than erased.

Designated study: Pavlov's dogs (Pavlov, 1902)

Aim

Ivan Pavlov was a physiologist studying digestion in dogs. When he noticed dogs salivating before food reached them, such as at the sight of the assistant who fed them, he set out to investigate how a stimulus that does not naturally cause salivation could come to do so.

Method

Dogs had a tube surgically placed in the cheek so saliva could be collected and measured. In a controlled laboratory, a neutral stimulus such as a metronome or bell was presented just before food was placed in the dog's mouth. After a number of pairings, the neutral stimulus was presented on its own and salivation was measured.

Key findings

The neutral stimulus alone came to produce salivation: it had become a CS producing a CR. Pavlov's lab also showed extinction (the CR faded when the CS was presented without food), spontaneous recovery, generalisation and discrimination.

Contribution

It was the first systematic, measurable account of learning by association, gave psychology the vocabulary of conditioning, and laid the foundation for behaviourism and for treatments such as systematic desensitisation.

Limitations

The findings come from dogs in a highly controlled laboratory, so generalising to complex human learning is limited. The surgery raises animal ethics questions (today the replacement, reduction and refinement principles apply). The theory also treats the learner as passive and ignores cognition.

Designated study: the 'Little Albert' experiment (Watson and Rayner, 1920)

Aim

John Watson and Rosalie Rayner aimed to show that an emotional response, fear, could be classically conditioned in a human, and to see whether the fear would transfer to similar objects.

Method

Albert, a healthy infant, was tested at about 9 months with a white rat, a rabbit, a dog, masks, cotton wool and other objects, and showed no fear. A loud noise, made by striking a steel bar with a hammer behind his head, did make him startle and cry. At about 11 months, the white rat (NS) was presented and, as Albert reached for it, the bar was struck (UCS), causing fear (UCR). There were seven pairings across two sessions a week apart.

Key findings

The rat alone (now a CS) made Albert cry and crawl away (CR). Albert showed stimulus generalisation to a rabbit, a dog, a fur coat, cotton wool and a Santa Claus mask, and discrimination, because he still played happily with his wooden blocks. The fear was still present, though weaker, a month later.

Contribution

It showed that emotional responses can be learned through classical conditioning in humans, which offered an explanation for how phobias develop and pointed towards ways of treating them.

Limitations

It was a single participant, so the findings cannot be generalised. Fear was judged from the researchers' observations rather than an objective measure. Ethically, the study caused deliberate distress, and Albert left the hospital before any attempt was made to remove the conditioned fear.