5.02 Classical and Operant Conditioning

Psychiatry review for the USMLE Step 1 Exam

• Classical Conditioning:

  • Pavlovian conditioning discovered by Ivan Pavlov, a Russian physiologist known for his experiments with dogs.
  • Learning through association.
  • Example: Conditioning dogs to respond to a noise the way they would respond to meat.
  • Involves associating an unconditioned stimulus with a new conditioned stimulus to elicit the same response.

• Process of Classical Conditioning:

  1. Start with a stimulus that produces a response (e.g., smelling pizza makes you hungry).
  2. Pair the stimulus and response with an unconditioned stimulus (e.g., receiving a text indicating pizza delivery).
  3. Eventually, the conditioned stimulus (the text notification) alone elicits the conditioned response (mouth watering).

• Extinction and Spontaneous Recovery in Classical Conditioning:

  • If the conditioned stimulus (text notification) is presented without the unconditioned stimulus (pizza), the conditioned response (mouth watering) will weaken and eventually extinguish.
  • Spontaneous recovery may occur, where the conditioned behavior briefly reappears after a period of extinction.

• Terms in Classical Conditioning:

  • Unconditioned stimulus (US): Triggers a response unconditionally.
  • Unconditioned response (UR): The response elicited by the unconditioned stimulus.
  • Conditioned stimulus (CS): Initially neutral stimulus that becomes associated with the unconditioned stimulus.
  • Conditioned response (CR): The response elicited by the conditioned stimulus.

• Operant Conditioning:

  • Developed by B.F. Skinner.
  • Learning occurs through rewards and punishments for behavior.
  • Three types of responses: neutral operants, reinforcers, and punishers.

• Examples of Operant Conditioning:

  • Positive reinforcement: Giving a child candy for good behavior.
  • Negative reinforcement: Taking away a child's phone until homework is done to increase desired behavior.
  • Positive punishment: Using physical force as punishment (not recommended).
  • Negative punishment: Taking away a child's phone to decrease unwanted behavior.

• Different Schedules of Reinforcement:

  • Continuous Reinforcement: Positive reinforcement every time a specific behavior occurs.
  • Fixed Ratio Reinforcement: Reinforcement after a specified number of correct responses.
  • Fixed Interval Reinforcement: Reinforcement after a fixed time interval with at least one correct response.
  • Variable Ratio Reinforcement: Reinforcement after an unpredictable number of responses.
  • Variable Interval Reinforcement: Reinforcement after an unpredictable amount of time.

• Summary:

  • Classical conditioning involves learning through association of stimuli.
  • Operant conditioning involves learning through rewards and punishments for behavior.