Summation of overshadowing and latent inhibition in rats' conditioned taste aversion: scapegoat technique works for familiar meals.

In rats' taste aversion learning, presentation of another taste with a target taste alleviates aversion for the target taste (overshadowing), and exposure of a target taste prior to its conditioning alleviates aversion for that taste (latent inhibition). The present study demonstrated summation of these effects, resulting in the least aversion in the rats that had received both overshadowing and latent inhibition treatments. The finding that overshadowing and latent inhibition summate is contrary to the prediction by the comparator hypothesis that they counteract, as recently reported in conditioned suppression of licking in thirsty rats. The present result supports the employment of the so-called "scapegoat technique" in cancer patients receiving chemotherapy after taking familiar meals.