Psychology-Unit 2- Learning

Learning: A relatively permant change in behaviour due to experince.  For learning to occur, there has to be a change in behaviour

Pavlovs Dog:

Pavlov relised that the dog he was studying had learnt to salivate every time a food bucket was brought out. This was a reflex response, a response that naturally occured. 

He set up a bunch of trials to see if he could investigate whether the dog could learn to salivate to other events. Eacch time the dog was fed, a bell was rung for a few times and the amount of a salivar produced was measured.  Then the bell was rung but no food was given, however the same amount of salivar produced was the same as when the bell rung.

Pavlov gave parts of his procedure special names:
Unconditioned is the term used to show that something is unnlearned.                                         Conditioned means that something has been learnt

The procedure of classical conditioning demonstrates a special kind of learning. This is learning  by assocation. During the conditioning trials, two stimuli are associated together. 

Pavlov then tried other procedures to investigate, to see how long the learning would last. He discovered that if he continued to ring the bell but without giving the dog any food, the dog eventually would stop salivating. He called this extinction.Then after a short time, Pavlov rung the bell again and  the dog would immediately salivate again. He called this response spontaneous recovery.

After another series of trials, pavlov found that if he changed the tone of the bell, the dog would still salivate. He said this was generalisation because the dog was widening its learnt repsonse to the conditioned response (CR) to a similar conditioned stimulus (CS) a new bell sound. Pavlov discovered that he could stop generalisation. He rang a nummber of bells of different tones but only presented food at one of them. The dog then only salivated at the sound of the bell which food was presented at. Pavlov called this discrimination because the dog had learnt to narrow its response to particular stimulus.

Key Terms:

Classical conditioning: A procedure during which an  animal or person learns to associate  a reflex response with a new stimulus.

Unconditioned Stimulus (UCS): The stimulus that produces a reflex response, such as the food for Pavlovs dogs.

Unconditioned Response (UCR): The reflex response to an unconditioned stimulus, such as Pavlovs dogs

salivation.Conditioned Stimulus (CS): A new stimulus presented with the UCS, such as the bell in Pavlov experiments.

Conditioned Response (CR): The response that is learnt; it now occurs when the CS is presented, such as Pavlovs dogs salivation.

Extinction: A conditioned response dies out.

Spontaneous recovery: A conditoned  response that has dissapered suddenly appears again.

Generalisation: The conditioned response it produced when a similar stimulus to the orignal condtioned stimulus is presented

Discrimination: (With reference to conditioning) The conditioned response is only produced when a specific stimulus is presented.

Watson and Rayner (1920)

Aim: To see if the emotional response of fear could be conditioned in a human being

Method: Albert was 11 months old. H4e has no fear of white furry objects. A rat was shown to Albert in the trials. Everytime he reached for it, a metal bar was hit very loudly behing his back. This was repearted several times.

Results: After seven times, the rat was presented again. Albert screamed and tried to get away. He did this even though the bar was not hit. He also screamed when shown a santa claus mask and a fur coat.

Conclusion: Fear responses can be learnt and even very young chikldren can learn by classical conditioning.

Evaluation:

• Not ethical for the researchers to do it to a small child
• Only involved one child

Operant conditioning: Learning due to the consequence of behaviour through postive reinforcement or negative reinforcemnet.

Law of effect: Behaviours that are followed by rewards are usually repeated; those that are punished are not normally repeated.

Thorndike designed a puzzle box which a cat would be placed in. The cat had to try and escape. Inside the box there was a loop of string attatched to a latch. When the string was pulled, the latch would lift and the door would open.

When the cat was first placed in the box, it would move around and accidentely pull string so opening the door. This happened each time the cat was placed into the box. However after 20 trials, Thorndike noticed that the cat has began to escape quicker. He suggested the cat had learnt to escape by trial and error. It was the pleasant consuence (escpaing) that would have encouraged the cat to pull the string.

Punishment: A stimulus that vweakens behaviour because it is unpleasant and we try to avoid it

Reinforcement: A consquence of behaviour that encourages or stregthens a behaviour. This might be seen as a reward.

Positive reinforcement: A reward or pleasant consequence that increases the likelihood that a behaviout or action wwill be repeated.

Negative reinforcment: When an unpleasent experience is removed after a behaviour or action has been made. This increases the likelihood of that behaviour or action being repeated.

Behaviour shaping: Changing behaviour in small steps.

B F Skinner

He placed a hungry rat in a box. The rat perfomed actions such as sniffing and exploring, by accident it would press the lever and a pellet of food would immediately drop into the food tray. Every time the lever was pressed, the behaviour of the lever pressing was postively reinforced by a food pellet.Sometimes, Skinner would put and eletric shock through the floor of the box. When the rat pressed the lever, the shock would switch off. This is negative reinforcement.

Phobia: A persistennt and irrational fear of an object. The typical symptoms are intense feelings of fear and anxiety to avoid the object, activity or situation.

To understand how we might treat phobias, it is important to recognise that a phobia is a fear response that has gone wrong.

A child might be afraid of a ballon. Loud noises cause fear. When a child sees a ballon, which then pops hey ar afriad of the loud noise. So seeing the ballon would cause fear.

Systematic Desensitisation

Systematic Desensitisation: A treatment for phobias in which the person is taught to relax and then is gradually exposed to the feared object, activity or event.

Hierachy of fears: A series of feared events ranked from least frightening to most frightening.

• A person with a phobia is taught how to relax themselves. This might involve listening to music and relaxing their muscles.
• The person and therpaist then construct a hierachy of fears that contains the things they are afraid of in order from least frightening (such as the word spider) to the most frightening (such as holding a spider)
• The person relaxes and then gradually works through the hierachy of fears, relaxing after each feared event is presented. The person only moves up the hierachy if they have been relaxed at the previous stage. The final stage is to be relaxed at the most frightening event.

Flooding

Flooding: A treatment for phobias that involves the immediate exposure of the person to the feared object, activity or event until there is no fear response.

The person has to unlearn the connection between the stimulus and the fear response; the CS-CR bond has to be broken. Most people with a phobia avoid or run away from the feared object. However, flooding prevents escape. Instead people learn that their anxiety levels start to drop the more times they are exposed to their fears. Flooding removes the phobia when a person realises they are not in danger and this happens quite quickly.

Ehtical implications: A person loses there right to withdraw; for the treatment to work they have to stay. It can be a very stressful procedure.  This means that the psychologist has o judge exactly how much distress the person should undergo before stopping. It is difficult to avoid harming someone whois being flooded.

Aversion Therapy

Aversion Therapy: A treatment for addictions, such as drug and alcohol dependency which makes the addict have an extemely negative reaction to the addictive substance.

The aim is to get the patient to develop an extremely negative reaction to the drugs or alcohol using the vomiting reflex. It works as the emetic is specially designed so that it only produces the vomiting reflex when the patient drinks alcohol.  A simple everyday emetic could be very slaty water. If you drink lots you will be sick and not able to stop the vomiting. Therefore, the desire for alcohol would decrease and the addiction overcome.

However, ethical issues arise when as it unpleasent for the person experincing this.

Evaluation: Used for individuals who have serious behaviour problems. People can find that their addiction is reduced after time, however when the therapy stops they might go back to the addiction.

Token economy programmes

Primary Reinforcer: A reward such as food or water, that the animal or person needs in order to survive.

Secondary Reinforcer: A reward, such as money or a token, that the animal or person can exchange for a primary reinforcer.

Food is a primary reinforcer as it what the animals needs to survive. If a reinforcer can be exchanged for something that is called a secondary reinforcer. Money is a secondary reinforcer because it can be exchanged for the things we want.Token economy programmes are set up in hospitals and usually in psychiatric wards, to reward socially acceptable behaviour in people who have stopped looking after themselves properly. Everytime a person produces an appropiate behaviour, hospital staff immediately give the person a token. They can then be used to 'pay for' activites like watching a favourite TV programme.

Evaluation: Produces improvements in people who have been in hospital for a long time. Some critics say that the patients focus on the reward rather than on improving their own behaviour.If the behaviour improves in the hosital it doesnt mean it will improve in the outside world. If the reward is not immediate, then assocation between the award and action will be lost.