Food-aversion conditioning in Japanese monkeys (Macaca fuscata): a dissociation of feeding in two separate situations

Monkeys were trained in a Skinner box to press keys for soybeans or regular diet pellets on a concurrent fixed-ratio schedule ("key-press session"). Having established a stable response, the monkeys were given "home cage sessions" in which they experienced soybean-poison (100 mg/kg of lithium chloride) pairings in the home cages. They eventually stopped eating soybeans in the home cages, but continued to work for and eat soybeans in the key-press sessions occurring between home cage sessions. Furthermore, avoidance of food in the home cage was specific to soybeans because the monkeys continued to eat diet pellets in this context. The monkeys showed a clear dissociation of feeding in two separate situations following food-poison pairings in one of the situations. These results suggest that, at least in monkeys, exteroceptive contexts have an important role in food-aversion conditioning.