Editing Classical conditioning (section)

====Comparator theory====
To find out what has been learned, we must somehow measure behavior ("performance") in a test situation. However, as students know all too well, performance in a test situation is not always a good measure of what has been learned. As for conditioning, there is evidence that subjects in a blocking experiment do learn something about the "blocked" CS, but fail to show this learning because of the way that they are usually tested.

"Comparator" theories of conditioning are "performance based", that is, they stress what is going on at the time of the test. In particular, they look at all the stimuli that are present during testing and at how the associations acquired by these stimuli may interact.<ref>{{cite book |vauthors=Gibbon J, Balsam P |date=1981 |chapter=Spreading association in time. |veditors=Locurto CM, Terrace HS, Gibbon J |title=Autoshaping and conditioning theory |pages=219–235 |location=New York |publisher=Academic Press}}</ref><ref>{{cite journal |vauthors=Miller RR, Escobar M |title=Contrasting acquisition-focused and performance-focused models of acquired behavior. |journal=Current Directions in Psychological Science |date=August 2001 |volume=10 |issue=4 |pages=141–5 |doi=10.1111/1467-8721.00135 |s2cid=7159340}}</ref> To oversimplify somewhat, comparator theories assume that during conditioning the subject acquires both CS-US and context-US associations. At the time of the test, these associations are compared, and a response to the CS occurs only if the CS-US association is stronger than the context-US association. After a CS and US are repeatedly paired in simple acquisition, the CS-US association is strong and the context-US association is relatively weak. This means that the CS elicits a strong CR. In "zero contingency" (see above), the conditioned response is weak or absent because the context-US association is about as strong as the CS-US association. Blocking and other more subtle phenomena can also be explained by comparator theories, though, again, they cannot explain everything.<ref name="Bouton_2016"/><ref name="M&E"/>