Comparative Psychology  Classical and Operant Conditioning with respect to Learning

Classical Conditioning - (Pavlovian Conditioning)

A type of learning in which an organism comes to associate different events. Thus a neutral stimulus(NS), after being paired with an unconditioned stimulus(UCS), begins to trigger a response that anticipates and prepares for the unconditioned stimulus(UCS)

Unconditioned Response (UCR) - In classical conditioning,the unlearned, automatic response to the unconditioned stimulus, such as salivation when food is in the mouth.

Unconditioned Stimulus (UCS) - In classical conditioning, a stimulus that naturally and automatically triggers a response without conditioning.

Conditioned Response (CR) - In classical conditioning, the learned response to a conditioned stimulus

Conditioned Stimulus (CS) - In classical conditioning, an originally neutral stimulus that, after association with an unconditioned stimulus (UCS), comes to trigger a conditioned response.

Pavlov's Experiments

 Pavlov completed his classical conditioning experiments with dogs (See separate sheet)

Pavlov eventually distinguished 5 major conditioning processes; 1) Acquisition, 2) Extinction, 3) Spontaneous Recovery, 4) Generalisation and 5) Discrimination

1) Acquisition - The initial stage of learning, during which a response is established and gradually strengthened. In classical conditioning, the phase in which a stimulus comes to evoke a conditioned response.

2) Extinction - In classical conditioning, the diminishing of a response when a conditioned stimulus (cs) is not followed by an unconditioned stimulus (ucs)

3) Spontaneous Recovery - The reappearance, after a rest period, of an extinguished conditioned response.

4) Generalisation - The tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to evoke similar responses.

5) Discrimination - In classical conditioning, the ability to distinguish between a conditioned stimulus and similar but irrelevant stimuli.

Pavlov concluded that classical conditioning is one way that virtually all organisms learn to adapt to their environment.

Classical Conditioning and Behaviourism - Watson(1913)

Watson argued that behaviour could be understood in the term of  conditioned responses.He also argued that learning could be studied by observing behaviour of people, in the same way that rats, cats and dogs were observed. In a famous study 'Little Albert' he demonstrated how specific fears might be conditioned in humans. Their subject was an 11 month old infant named Albert. 'Little Albert' like most infants, feared loud noises, but not white rats. So Watson and Rayner(1920) presented him with a white rat and as he reached out to touch it, struck a hammer against a steel bar just behind his head. After seven repetitions of seeing the rat and hearing the frightening noise, Albert burst into tears at the mere sight of the rat. Also 5 days later Albert showed generalisation of his conditioned response to the rat by reacting with fear when presented with a rabbit and a dog.

Cognitive Learning - Tolman and Honzik(1930)

Tolman studied Cognitive learning in rats, Tolman and Honzick showed that learning can take place without reinforcement by using rats in a maze and demonstrating that some learning had taken place in rats that had run the maze without any reward. According to Tolman these rats had learned a cognitive map of the maze. This concept received dramatic support when the rats had several trials without reward,and were then presented with the opportunity to get food at the end of the maze. Their completion time dropped remarkably. It appeared that their earlier experience of the maze had potentiated their learning for the later very quick runs.

Observational Learning - Social Learning Theory - Bandura et al (1961).

Bandura et al argued that learning takes place via modelling.

 The process of observing and then imitating a specific behaviour is often called modelling. We learn certain specific social behaviours through modelling. A very famous study devised by Bandura et al(1961) used modelling to find out if aggression was socially learnt behaviour. The experiment was conducted as follows ' A nursery school child is at work on a picture. An adult in another part of the room is working with some Tinker Toys. The adult then gets up and for nearly 10 minutes, kicks and throws a large inflated Bobo doll around the room, all the while yelling such remarks as "sock him in the nose...Hit him down.....Kick him."

After observing this outburst, the child is taken to another room where there are many appealing toys. But soon the experimenter interrupts the child's play and explains that she has decided to save these good toys "for the other children." The frustrated child is now taken to an adjacent room containing a few toys including a bobo doll. Left alone what does the child do ? Compared to other children who were not exposed to the adult model, those children who had observed the aggressive outburst were much more likely to lash out at the doll. Apparently, observing the adult model beating up the doll had lowered their inhibitions. But something more than lowered inhibitions was at work, for the children also imitated the very acts, using the identical words, that they had observed.

Gestalt approach - Kohler(1925)

Kohler argues that animals used a higher form of learning called insight, this is basically a higher form of learning where the animal realises that previous behaviour cannot resolve the problem that now confronts them. The problem may then be reflected on and several solutions considered. When the actual solution is found it is acted it is acted upon so quickly so as to resemble a burst of insight. Kohler argued that learning was a matter of perceptual reorganisation and thought .(See problem solving in Chimpanzees for example of Kohlers work) In one study he wanted chimpanzees to obtain food lying out of reach. The food was either outside the bars of their cage or suspended from a hook in the ceiling. The chimpanzees learned to use Bamboo Poles as Rakes and when one was too short, they used 'insight' learning to fit two bamboo poles together to form a longer rake.

Operant Conditioning - A type of learning in which behaviour is strengthened if followed by reinforcement, or diminished if followed by punishment

(See separate sheet)

Operant Conditioning - Skinner(Behaviourist) argues that Operant conditioning is sufficient to explain all learning. Skinner also argued that' behaviour operates on the environment to generate consequences' i.e When a rat presses a lever to obtain a reinforcement it operates on the environment.

Skinner Box - Skinner designed a chamber containing a bar or key that an animal can manipulate to obtain a food or water reinforcer and devices to record the animal's rate of bar pressing or key pecking to be used in operant conditioning research

Shaping - Skinner used a procedure called 'shaping' which started with some existing behaviour and reinforces closer and closer approximations of a desired behaviour

Ethologists - Argue that imprinting is a form of learning that behaviourism cannot explain adequately, since it depends in part upon an innate disposition to a learning process provided by the environment.(Imprinting - Restricted Learning that takes place within a relatively compressed time span , it tends to have a lasting effect on later social behaviour. Classic example is with ducks, a newly hatched duckling will 'imprint' on and follow an object that it is exposed to during a critical period. )

Classical Versus Operant Conditioning

Classical                                                                Operant

Learning through association                                   Learning through reinforcement

Concerned with a reflex or automatic                      Concerned with voluntary behaviour, or any behaviour which

response.                                                                 is naturally produced.

Reinforcement is presented before the CR               Reinforcement occurs after the CR

The reinforcement is not related to anything           The organism is instrumental in obtaining reinforcement

the organism might do.

                            Both involve generalisation, extinction and discrimination.

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