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Classical Conditioning • • • • • Summary of Pavlov’s Experiment Key Terms Elements of Classical Conditioning Classical Conditioning in Everyday Life Ethical Issues: The Little Albert Study Pavlov’s Experiment • PAVLOV, a Russian physiologist, was conducting research on the digestive system in dogs during 1920’s, when he noted that the dogs salivated before they received the stimulus (meat powder). • As a result of his research, clear evidence was provided for a very simple type of learning which was based on the repetitive association of different stimuli. Pavlov cont. • 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 (ie a reflex response), had now been conditioned to a new stimulus (sight or sound of technician). Classical Conditioning • Classical conditioning is a simple form of learning that occurs as a result of the repeated association of two stimuli. One of the two stimuli would normally elicit a reflexive, involuntary or automatic response. This is called the unconditioned stimulus (UCS) since it does not need to be conditioned in order to elicit the involuntary response known as the unconditioned response (UCR). Prior to conditioning NS Leads to UCS No relevant response UCR Automatically leads to the • The other stimulus is one that would not normally elicit a response. It is known at this stage as the neutral stimulus because it does nothing. • Of the two stimuli, it is presented first so that the organism comes to anticipate the second stimulus (UCS) that triggers the unconditioned response. During conditioning (Association & Acquisition) CS is associated with UCS UCR Which automatically leads to the • Acquisition of the conditioned response can said to have occurred when the organism continues to respond without the presentation of the unconditioned stimulus. That is, the organism responds to the formally neutral stimulus alone. • This stimulus can now be referred to as the conditioned stimulus (CS) and the response it produces is now called the conditioned response (CR). After conditioning CS CR Leads to a conditioned reflex • A classically conditioned response will rarely last forever in the absence of the unconditioned stimulus. In most cases, the withdrawal of the unconditioned stimulus will eventually lead to the extinction of the conditioned response. Key terms in Classical Conditioning • Neutral Stimulus (NS) – The name given to the conditioned stimulus before it becomes conditioned. – Referred to as ‘neutral’ stimulus whilst it fails to produce a response • Unconditioned Stimulus (UCS) – Any stimulus which consistently produces a particular naturally occurring automatic response. - The food in Pavlov’s Experiment • Conditioned Stimulus (CS) – the stimulus, which is ‘neutral’ at the start of the conditioning. It would not normally produce the unconditioned response (UCR), but does so eventually because of its association with the unconditioned stimulus (UCS). • Unconditioned Response (UCR) – The response which 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 becomes difficult to think of one without thinking of the other. Elements of Classical Conditioning • 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. Elements of Classical Conditioning • 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. Elements of Classical Conditioning • Stimulus Generalisation – 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 higher pitch, duration Elements of Classical Conditioning • Stimulus Discrimination – when an organism responds to the conditioned stimulus, but not any stimulus which is similar to the conditioned stimulus.