Lecture Instrumental: Operant Conditioning

L3- Instrumental/ operant conditioning

Thorndike’s learning by trial + error & the law of effect
 Thorndike- interested in animal learning

 He found that learning initially occurs by trial + error

 Law of effect= learning depends on reinforcement. Positive reinforcers (e.g. food)
strengthen the association between stimulus + response. Negative reinforces (e.g.
shocks) weaken it

Skinner’s paradigm of operant conditioning
 An animal in a skinner box has to respond in a particular way to a given stimulus in order
to receive a positive reward

 Operant response= subjects’ response ‘operates’ on the environment to produce a
certain outcome

Instrumental conditioning vs classical conditioning
DS= discriminative stimulus
OR= operant response
RE= reinforcement (reward)

 Differences
- In CC likelihood between CS + US is important BUT in IC likelihood between both DS
+ RE & OR + RE is important
- Less restrictions on OR in IC

 Similarities
- Both IC + CC require the organism to discover likelihoods between certain elements
- Many singularities observed in CC are also found in IC- e.g.:
o Generalisation
o Discrimination
o Blocking
o Second-order conditioning

Reinforcement in instrumental conditioning