Operant conditioning

Operant conditioning

1. Learning much more active than in classical conditioning

2. Based on work of Thorndike

3. Learning a behaviour because of its consequences

   • Consequences are rewarding or punishing
     • Make behaviour more or less likely
   • Positive/negative reinforcement
   • Positive/negative punishment

4. Skinner (1904-1990)

   • Radical behaviourism: should only use scientific methods to study human and animal behaviour
     • All behaviour learned from consequences, called this operant conditioning
       • His focus was on effects of emitted behaviour rather than Pavlov's focus on the elicited behaviours themselves
   • 1938, placed pigeon in Skinner box.
     • Pecking at lever would lead to food being delivered
       • Pecked randomly at first and accidentally pecked lever stimulus - S - and received reward - R.
         • Reward was reinforcement, which stamped-in rewarded behaviour
           • Unrewarded behaviour stamped out
             • Behaviour brought under stimulus control
           • Stronger reinforcement = more stamping in
     • If pigeon also learns to get food by pecking at a button when it is lit up it is learning to discriminate between states of illumination (a discriminative simulus)
   • Hungry rat in box: inside box was lever which would dispense food when pressed
     • Rat first had to learn this lever-pressing behaviour, so food dispensed every time it approached the lever at first
       • When rat pressed lever food was dispensed
         • Rat then kept pressing lever to get food (reward
           • Behaviour positively reinforced

5. Skinner described OC in terms of ABC

   • Antecedents: situation beforehand
   • Behaviour: what the animal does
   • Consequences: the probability of a behaviour being repeated depends on strengthening or weakening S-R links

6. Most human behaviour relies not on primary reinforcers (food, water etc.) but on secondary reinforcers (money, tokens, career success, etc.)

   • Secondary reinforcer is neutral stimulus that acquires reinforcing properties because it can be linked with a primary reinforcer (e.g. exchanging money for food)

7. Principles applied to many areas, e.g. education, prisons and psychiatric institutions

   • Used to modify speech in autistic children
     • When a child has under-developed speech, therapist uses a behaviour-shaping technique
       • When child begins to imitate therapist's speech/behaviour, s/he receives praise as a reward - a positive reinforcer
         • Continues until child can use words independently and without prompting