1. A comparator view of the overtraining effect Gonzalo P. Urcelay & Ralph. R. Miller. SUNY-Binghamton

2. Is there a relationship between amount of training and conditioned performance? Although counterintuitive, a diminution in conditioned responding is sometimes observed when reinforced training is continued after the CS-US association has reached a peak level.

3. Kamin, 1961, Exp 1

5. The Original Comparator Hypothesis Clicks Directly Activated US Representation Conditioning context Response Comparison Link 1 Link 3 Link 2 Indirectly Activated US Representation

6. Explanations of the overtraining effect US habituation Inhibition of delay Decreased performance due to conditioning of the training context (comparator stimulus)

7. Objectives To demonstrate the basic overtraining effect (Experiment 1) To contrast these divergent explanations of the overtraining effect (Experiment 2)

8. Method Conditioned lick suppression with thirsty rats as subjects. US = footshock; X = click train Dependent variable: latency to resume drinking in the presence of the test stimulus.

9. Experiment 1. Design

10. Experiment 1. Results

11. Conclusions from Exp 1 Other factors being equal, increasing the number of X  US pairings decreased conditioned responding to X. We observed an overtraining effect.

12. Experiment 2 Test divergent explanations of the overtraining effect

13. The Original Comparator Hypothesis Clicks Directly Activated US Representation Conditioning context Response Comparison Link 1 Link 3 Link 2 Indirectly Activated US Representation

15. Experiment 2. Results

16. Conclusions from Exp 2 Similar to Experiment 1, without any posttraining manipulation we observed an overtraining effect (Condition Control) When the training context was massively extinguished, conditioned responding increased after 5 (not significantly) and 50 training trials As indicated by the interaction, the increase was much larger in groups trained with 50 trials.

17. Overall conclusions With the present parameters, we saw a diminution in conditioned responding after extended reinforced training When the training context was extinguished, responding after 50 trials recovered, suggesting that this is a performance effect rather than habituation to the US.

18. Questions?