Ivan Pavlov & lab

1. Today we will focus on two basic models of learning, classical and operant conditioning. Specific topics include: • Pavlov's classical conditioning and how it might be implemented in the nervous • system. • Thorndike's law of Effect and its evolution into Skinner's operant conditioning. • A model: How operant conditioning operates together with basic motivations as • an adaptive mechanism. • Uses and abuses of operant conditioning. • If there is time, we will consider the contributions of behaviorism against its • "overclaiming".

2. Ivan Pavlov & lab

5. The CS as a Signal • Evidence suggests that the CS serves as a signal for upcoming events. • Learning is less likely if the CS is simultaneous with the US or follows it. • 0.5 second lead time optimal • Learning occurs only if there is some contingency between the CS and US. • Contiguity isn’t enough

9. Stimulus Generalization

11. Neural Basis of Learning • The neural bases for learning involve diverse mechanisms, such as: • presynaptic facilitation • postsynaptic changes • long-term potentiation (LTP) • creation of new synapses • growth of new dendritic spines

13. Edward Thorndike

16. B. F. Skinner

20. Schedules of Reinforcement • Partial reinforcement: The response is reinforced only some of the time. • schedule of reinforcement • in ratio schedules, reinforcement after a number of responses; the ratio used may be fixed or variable • in interval schedules, reinforcers for the first response made after a given interval since the last reinforcement; this interval can be fixed or variable

25. Extinction under fixed & variable schedules of reinforcement

26. Edward Tolman

28. Variations in Learning: Behavioral Challenges • Observational learning • Biologically biased learning • Belongingness/expectations in learning • “Smart” learning

30. Mirror Neurons

33. Conclusions: Broad Applications Coupled with Severe Limitations of the Behaviorist Viewpoint Next: The Power Law of Practice: Learning just keeps going and going and going….