The experiment conducted was a 2x2 within subjects experiment. The 2 cue types were over-expectation and control whereas the 2 independent variables were salience. Subjects were randomly presented varying levels of salient stimuli in the form of food pictures. These pictures were then to be associated with an allergy score between 1 and 9. In the next phase, the subjects were given each cue type 8 times along with some filler cues arranged to some simple rules. The allergy ratings were also to be determined by the subject. The third phase combined the stimuli into a compound CS conditioning and subjects were asked to determine the allergy rating. The test phase involved participants being shown each of the previous foods one at a time. They would then determine the allergic reaction rating. Overall, the results of the experiment used an analysis of variables to show that the likelihood rating for the high salience cues were, on average, lower than those of the lower salience. A significant main effect with cue-type was found, indicating an over-expectation effect, of F(1,271)=25.758, p<0.001. This means that participants rated the compound cues in phase 3 as less allergenic than those that were elementally reinforced in phase 3. While there was no significant difference found between the elementally reinforced stimulus cues I and J (p>0.05), there was found to be a significant difference between the compound cases involving stimulus cues B and F (p<0.05).
With compound CS, the associative strength is now dependant on the combined associative strength of all stimuli present and the total amount of learning. Generally in the Rescorla-Wagner model, conditioning is dependent on how effectively surprising an unconditioned stimulus is. With compound conditioned stimuli, this characterisation of surprise is altered. Instead of just a single CS being linked to a US, it is now the combined effects of...