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Topics for Consideration in Study 4


So, in this lab what we were interested in was looking at higher order conditioning, specifically second order conditioning. Here's what we did:

First Order: CS+ --- reinforcer
Second Order: CS- (10 sec) ... CS+ (10 sec) --- no reinforcer


Although not required for your study 4 lab write-up (only a methods and results section are necessary) you might want to take a few momments and consider some of the following:

1. In sensory preconditioning, two neutral stimuli are presented prior to any conditioned reinforcement (i.e., they are "preconditioned").

  • Preconditioning: CS1 --- CS2
  • Training: CS1 --- reinforcer
  • Test: CS2 --- ???

If preconditioning worked, then you'd expect a CS2 to produce a CR similar to the one made by CS1.

Consider: what effect would/could sensory preconditioning have had on our protocol? Would you expect results different from the second order conditioning or do you think you would have seen similar results?

2. Consider another possibility. What if, during the second order conditioning you had done another thirty trials? Remember, in the second order phase you give:

  • First Order: CS+ (10 sec) --- reinforcer
  • Second Order: CS- (10 sec) ... CS+ (10 sec) --- no reinforcer

What we (hopefully) found is that the CS- takes on some of the excitatory properties of the CS+. That is, when the CS- is presented the rat shows some food related behaviours. It is as if the rat uses the CS- to anticipate the coming of the CS+. But, what if this kept up? What do you think the rat might come to learn about the times when the CS- preceeds the CS+?

3. Here's another one: What would happen if during Phase II we didn't reinforce the First Order trials? So, what if it looked like this:

  • First Order: CS+ (10 sec) --- no reinforcer
  • Second Order: CS- (10 sec) ... CS+ (10 sec) --- no reinforcer

What behavioural response do you think the rat would make to the second order conditioning? How about the non-reinforced first order conditioning?


Page Created: 18 January 1999 Last updated: 9 February 1999
Michael R. Snyder <msnyder@psych.ualberta.ca>