Effects of context on responding during a compound stimulus.

In 4 experiments, the authors used rats to examine the strength of responding during a clicker-tone compound in the presence of a light, after the auditory stimuli had individually been paired with food in the presence of the same light. Experiment 1 demonstrated a higher rate of responding during the compound when the duration of the light was short rather than long. In Experiments 2, 3, and 4, the long duration light was used as a signal for food in a conditional discrimination involving the tone and the clicker. Responding on test trials with the clicker-tone compound during the light was enhanced by this treatment and resulted in a level of performance that was no different from that observed when the duration of the light was short. The results are more compatible with a configural than an elemental theory of associative learning.