classical conditioning

classical conditioning

a form of learning that occurs through the repeated association of two different stimuli

who first decribed classical conditioning

Ivan Pavlov in 1899

3 phases of classical conditioning

• before

• during

• after

Key features of ‘Before Conditioning’ phase

• unconditioned stimulus (UCS)

• unconditioned response (UCR)

• neutral stimulus (NS)

Unconditioned Stimulus (UCS)

stimulus that naturally causes a response (i.e. food)

Unconditioned Response (UCR)

natural, automatic reaction to UCS (i.e. salivation to food)

Neutral Stimulus (NS)

stimulus does not naturally trigger a response (i.e. bell before conditioning)

Key features of ‘During Conditioning’ phase

• NS repeatedly paired with UCS

• subject begins to associate the NS and UCS

• process leads to learning through repeated trials

key features of ‘After conditioning’ phase

• conditioned stimulus (CS)

• conditioned response (CR)

Conditioned Stimulus (CS)

formerly neutral stimulus (bell) that now triggers a learned response (salivation)

Conditioned Response (CR)

learned response (salivation) that occurs when CS (bell) is presented even without the UCS (food)

Influencing Factors of Classical Conditioning

• Nature of the response

• Association of the stimulus

• Timing of the NS and UCS pairing

Nature of the Response in Classical Conditioning

• UCR must be involuntary/ reflexive responses (i.e. salivation, eye-blinking, etc.)

• CRs are often reflexive and involve little coscious thought

Association of Stimuli

• Learning occurs when two stimuli (NS and UCS) are linked together

• Process of continguity refers to how closely in time the 2 stimuli are presented, closer the pairing, stronger the association

Timing of the NS and UCS pairing

• NS should be presented before the UCS for the strongest learning effect

• Ideal interval between the NS and UCS is 0.5 seconds

• Longer time intervals between the NS and UCS reduce effectiveness

Key findings from Pavlov’s Research

• strength of the CR increases rapidly during the acquisition phase and then levels off

• if the UCS (food) is no longer presented with the CS (bell), the CR (salivation) will gradually disappear, process known as extinction

• responses can be spontaneously recovered after extinction after if the CS is presented again after a rest period