1. Human Learning
Topic 9: Avoidance
CEDP503 Ryan Sain, Ph.D. 1 3/30/2012

2. Discriminated Avoidance
 A warning signal is given
 A response prevents or removes the stimulus
 Escape trials
 Organism makes response to ‘remove’ stimulus
 Happens early in training
 Avoidance trials
 Organism makes response to avoid stimulus

3. Two process theory
 What do you ‘get’ in avoidance?
 Actually nothing
 ‘nothing’ cant cause something
 Two process theory
 Explains most of avoidance behavior
 Is the standard
 Is not perfect

4. More two-process
 Classical conditioning
 CS paired with US  fear
 motivation
 Operant conditioning
 Reduction of fear is a negative reinforcer
 Terminating the CS  reducing fear

5. What is learned?
 Escape from conditioned fear
 This maintains the behavior
 Prevention of shock
 Is the by-product or outcome of the behavior
 This does not control the response

6. Acquired drive
 Experimental paradigm
 Separate CC and OC components
 Produce conditioned fear
 CS  US
 Expose CS and permit termination of it
 Organisms learn to make the response

7. Extinction of avoidance
 Avoiding a stimulus
 Breaking the CS-US connection of fear
 But the response persists dramatically
 How to extinguish?
 Flooding
 Present the CS without the US
 Do not allow the avoidance response
 Response blocking
 Prevent response that terminates the CS
 No CS US pairings
 Failure to make the avoidance response  no shock

8. Free operant avoidance
 No warning signal
 Two process theory does not explain this
 Organisms still learn to make the response
 Humans
 CO2 administrations for 20 seconds
 Pull a plunger prevents this
 No instructions provided