Conditioning

Conditioning


Classical conditioning

Classical conditioning is the work of Ivan Pavlov. It is a learning theory that suggests that events which occur together are associated and acquire a similar meaning.

Classical conditioning is different to operant conditioning. In classical conditioning we are looking at responses to stimuli whereas in operant conditioning we are interested in responses to behaviour.

Pavlov demonstrated that innate responses such as a dog salivating (unconditioned response) when it sees food (unconditioned stimulus) can be associated with a neutral stimulus (conditioned stimulus) such as ringing a bell, so that ringing the bell can cause salivation even in the absence of food (conditioned response). 

Important terms used in classical conditioning include:-

TermDescription
ExtinctionIf a conditioned stimulus is repeatedly presented without the unconditioned stimulus then the conditioned response will disappear
Stimulus GeneralisationThis is the extension of the conditioned response from the original conditioned stimulus to other similar stimuli
Higher Order ConditioningThis occurs when a new stimulus becomes a conditioned stimulus when it is paired with an established conditioned stimulus
Spontaneous recoveryIf the conditioned stimulus is not presented at all for sometime after extinction and is then presented again the conditioned response will return to some degree
Forward conditioningIn forward conditioning the conditioned stimulus precedes to unconditioned stimulus. There are two main types:

In delay conditioning the conditioned stimulus proceeds the unconditioned stimulus by a delay. The conditioned stimulus is still active when the unconditioned stimulus begins.

In contrast, trace conditioning involves the presentation of the unconditioned stimulus once the conditioned stimulus has finished
Simultaneous conditioningIn this form of conditioning, the conditioned and unconditioned stimulus are presented at the same time
Backward conditioningHere, the conditioned stimulus follows the unconditioned stimulus
Temporal conditioningHere the unconditioned stimulus is paired to time. The unconditioned stimulus is presented at regular intervals (for example, every 20 minutes). Eventually the unconditioned response will occur shortly prior to the unconditioned stimulus
Aversive conditioningA technique where an unpleasant stimulus is paired with an unwanted behaviour (such as nail-biting, smoking) in order to create an aversion to it
Counter conditioningTeaching a different task or behaviour than the one that was previously occurring in a situation. For example, a dog lunges at the window when the postman walks by. The new task will be sitting quietly
IncubationThis occurs in fear responses. When a person is exposed to a stimulus which causes fear (for example being bitten by a dog), the fear response can increase over time due to brief exposures to the conditioned stimulus (for example to sight of dogs). This explains how fears can grow

Some stimuli are more prone to conditioning than others. This is referred to as stimulus preparedness. This is probably an evolutionary issue. We are more likely to develop fear responses to things such as insects and snakes rather than cars.

Operant conditioning

The theory of operant conditioning (aka instrumental learning) was devised by B F Skinner. It is a theory of learning that's suggests that people learn by operating (interacting) with their environments. 

Reinforcement and punishment

A stimulus/ event that increases the likelihood that a behaviour will be repeated is called a reinforcer. Reinforcement can be either positive or negative. In both positive and negative reinforcement the behaviour is strengthened. Positive reinforcement occurs when a behaviour is strengthened by adding a rewarding stimulus e.g. More likely to come to work if you get paid. Negative reinforcement occurs when a behaviour is strengthened by the removal of an unpleasant stimulus e.g. More likely to put the bins out to put an end to your partner nagging you. 

A stimulus that decreases the likelihood that a behaviour will be repeated is called a punisher. Again there are positive and negative punishers. Positive punishment occurs when a behaviour is reduced in frequency by adding an unpleasant stimulus. An example of positive punishment is if a dog growls at someone who tries to stroke them (an unpleasant stimulus), they will be less inclined to try to stroke them again (reduction in behavioural frequency). An example of negative punishment is a parent taking a child's toys of them (removal of a pleasant stimulus) for throwing their food against the wall, the child should be less inclined to repeat the behaviour. 

Primary and secondary reinforcers

Primary reinforcers are instinctual desires such as food, water, social approval and sex (be careful with social approval as it is considered by some to be a secondary reinforcer).

Secondary reinforcers (aka conditioned reinforcers) are not innately appreciated and people have to learn to like them through classical conditioning or other methods. Secondary reinforcers include things such as money.

Schedules of Reinforcement

Different patterns of reinforcement have different influences on the response. There are five main reinforcement schedules

  • Fixed interval - a reward after a fixed amount of time
  • Variable interval - a reward after a varying amount of time
  • Fixed ratio - a reward occurs after a behavior is repeated x number of times
  • Variable ratio - a reward occurs after a random number of responses
  • Random - no pattern

Variable ratio schedules are most resistant to extinction (gambling works in this way).

Shaping and chaining

Sometimes an exact behaviour cannot be performed and so cannot be rewarded. In this instance it is helpful to reward successive, increasingly accurate approximations to the behaviour. This is called shaping.

Chaining involves breaking a complex task into smaller more manageable sections.

Shaping and chaining are similar but different in two main ways:

  • Shaping always moves forward. Where as it is quite possible to move backward with backward chaining

  • Another difference involves when reinforcers are delivered. In shaping, each new approximation is reinforced. In chaining, reinforcers are usually provided at the end of the chain.

Escape conditioning

This actually involves both classical and operant conditioning.

Escape conditioning refers to a situation whereby an aversive situation is removed after a response. It is a form of negative reinforcement. For example, imagine a rat stood on a raised platform in a pool of water. When an electrical current is applied to the plat from the rat will jump into the water to stop the unpleasant sensation of the electric shock (the shock is removed following the response).

When a person learns to respond to a signal in a way that avoids an aversive stimulus before it arrives this is avoidance conditioning. For example, imagine that in the above example, a buzzer sounded just before the electric shock was applied. Eventually the rats would learn to jump off the platform at the sound of the buzzer rather than wait for the shock.

Habituation

Habituation refers to the phenomenon whereby a there is a decrease in response to a stimulus over time (overtime you pay less attention to repeated sounds in your environment). If the stimulus is removed for a period of time and then reintroduced then the response will reappear at full strength. This is referred to as spontaneous recovery.

Covert sensitisation

This is a technique used whereby someone learns to use mental imagery (hence it's covert) to associate a behaviour with a negative consequence.

For example, a person may be encouraged to use imagery to link smoking a cigarette with the development of lung cancer.