C6: Conditioning

Ivan Pavlov

Ivan Pavlov

Found that dogs learned to pair the sounds in the environment where they were fed with the food that was given to them and begin to salivate simply upon hearing the sounds.

Classical Conditioning

Learning to associate neutral stimuli (e.g. sounds) with stimuli that produces a reflexive, involuntary response (e.g. food) and will learn to respond similarly to the new stimulus as they did to the old one (e.g. salivate)

Unconditioned stimulus (US)

a stimulus that evokes an unconditioned response without any prior conditioning (no learning needed for the response to occur)

Unconditioned response (UR)

an unlearned reaction/response to an unconditioned stimulus that occurs without prior conditioning

Conditioned Stimulus (CS)

a previously neutral stimulus that has, through conditioning, acquired the capacity to evoke a conditioned response

Conditioned Response (CR)

a learned reaction to a conditioned stimulus that occurs because of prior conditioning

Delayed conditioning

CS is presented before the US and it (CS) stays on until the US is presented. Works the best especially if the delay is short.

Trace conditioning

The presentation of the CS, followed by a short break, followed by the presentation of the US.

Simultaneous conditioning

CS and US are presented at the same time

Backward conditioning

US is presented first and is followed by the CS. This method is particularly ineffective.

Extinction

• The process of unlearning a behaviour (taken place when CS no longer elicits the CR)

• Achieved by repeatedly presenting the CS without the US, thus breaking the association between the two.

Spontaneous Recovery

Sometimes, after a conditioned response has been extinguished and no further training of the animals has taken place, the response briefly appears upon presentation of the conditioned stimulus.

Generalization

Often, animals conditioned to respond to a certain stimulus will also respond to similar stimuli, although the response is usually smaller in magnitude.

Discrimination

Training subjects to tell the difference between various stimuli.

John B. Watson and Rosalie Rayner

Conditioned Albert to fear a white rat (aversive conditioning)

John Garcia and Robert Koelling

Performed a famous experiment illustrating how rats more readily learned to make certain associations than others.

Edward Thorndike

Conducted a series of famous experiments using a cat in a puzzle box (law of effect)

Law of Effect

If the consequences of a behaviour are pleasant, the stimulus-response (S-R) connection will be strengthened and the likelihood of the behaviour will decrease.

If the consequences of a behaviour are unpleasant, the S-R connection will weaken and the likelihood of the behaviour will decrease.

B.F. Skinner

Used a Skinner box to research animal learning

Shaping

The production of new forms of operant behaviour by reinforcement of successive approximations to the behaviour

Chaining

Teaching method based on task analysis, where all the smaller units of behaviour comprising a complex skill or task is identified and broken down first and the series of related behaviours is taught in a step-by-step manner.

Primary Reinforcers

Reinforcers that are naturally rewarding (e.g. food, water, rest, etc)

Secondary Reinforcers

Things we have learned to value (e.g. praise, money, etc)

Premack Principle

Whichever of 2 activies is preferred can be used to reinforce the activity that is not preferred

Continuous reinforcement

Rewarding the behaviour each time (best when first teaching it)

Partial-reinforcement effect

Increased resistance to extinction after intermittent reinforcement rather than after continuous reinforcement

Instinctive drift

The tendency for animals to forgo rewards to pursue their typical patterns of behaviour

Fixed-Ratio

Reinforcement is delivered after a set number of responses

Fixed-Interval

Reinforcement is delivered after a behaviour is performed following the passage of a fixed amount of time.

Variable-Ratio

Reinforcement is delivered after a variable number of responses.

Variable-Interval

Reinforcement is delivered after a behaviour is performed following the passage of a variable amount of time.

Contiguity Model (Pavlovian model)

• The more times 2 things are paired, the greater the learning that will take place

  • Contiguity (togetherness) determines the strength of the response

Robert Rescorla

• Revised the contiguity model to take into account a more complex set of circumstances

  • Created contingency model

Contingency model

• A is contingent upon B when A depends upon B and vice versa.

• The predicability of occurence of one stimulus from the presence of another

Modeling

• 2 components: observation and imitation

• Mental representation of the observed behaviour must exist in order to enable the person or animal to imitate it

Albert Bandura

• Studied modeling in the bobo doll experiment

• Demonstrated that children who had watched an adult being violent with a bobo doll were more likely to behave aggressively toward the doll than were children who had watched an adult being nonviolent toward it

Latent learning

Hidden learning that becomes obvious only once a reinforcement is given for demonstrating it.

• Behaviourists asserted that learning is evidenced by gradual changes in behaviour, but Tolman conducted a famous experiment illustrating that sometimes learning occurs but is not immediately evidenced

Edward Tolman

Had 3 groups of rats run through a maze on a series of trials

• Group 1: Got a reward each time it completed the maze; performance improved steadily over the trials

• Group 2: Never got the reward; performance improved only slightly over the trials

• Group 3: Not rewarded in first half, but was rewarded in second; performance improved dramatically and suddenly once it began to be rewarded

Reasoned that these rats must have learned their way around the maze during the first set of trials; performance did not improve because they had no reason to run the maze quickly.

Latent learning is demonstrated → The rats made a mental representation (cognitive map) of the maze during the first half

Abstract Learning

Acquiring knowledge of general or intangible material, such as the meanings of concepts and propositions and the logical and systematic relations between them

Insight Learning

Occurs when one suddenly realizes how to solve a problem.

Wolfgang Köhler

• Argued that learning often happens in this sudden way due to insight rather than because of the gradual strengthening of the S-R connection

• Suspended a banana from a ceiling wall and had several boxes, none of which was high enough to enable the chimpanzees to reach the banana. Köhler found that the chimps spent most of their time unproductively rather than slowly working towards a solution until, all of a sudden, they would pile the boxes on top of each other, climb up, and grab the banana.

• Köhler believed that the solution could not occur until the chimpanzees had a cognitive insight about how to solve the problem