Effect of extra running on running-based taste aversion in rats.

Voluntary running in an activity wheel endowed rats with aversion to a taste solution consumed before the running. This running-based taste aversion was attenuated by extra running opportunities interspersed among the taste-running pairings, but the attenuating effect was reduced by signaling the extra running by another taste cue. These results correspond to the so-called degraded contingency effect and cover-cue effect in the traditional preparations of Pavlovian conditioning.