The 'Fungus Eater' is a testbed for simulation models in emotion psychology proposed by Toda (1962). Thomas Wehrle describes it in New Fungus Eater Experiments:
The Fungus-Eater is a fictitious mining robot that is sent to a planet called Taros to collect uranium ore. It uses wild fungi growing on the surface of the planet as the main energy source for its biochemical engine. Little is known about the distribution of uranium ore and fungi. Every activity of the Fungus-Eater, including the brain-computer operations, consumes some specified amount of fungus-storage. If the Fungus-Eater runs out of fungus-storage it dies. Its mission is to collect as much uranium ore as possible, and there is no reward for the amount of collected fungi (adapted from Toda, 1982). Since uranium ore and fungi are usually not found in the same place there is a conflict in the robot's action selection. We made some further assumptions for the concrete implementation of the Social Fungus-Eaters: They keep a certain distance to each other in order to avoid conflicts at food places and to avoid inefficient mining. On the other hand they also maintain loose contact in this potentially hostile environment, e.g., to help each other in emergency situations. The (emergent) behavior of the Fungus Eater, achieved with our model can be described as follows: As expected, the agents are mostly found around food sources and mines (see Fig. 2). They gently alternate at food places. Agents with similar hunger conditions build circles of 2 to 5 members. The consumption of fungi is more or less equal for each agent in a circle. A circle breaks up when a certain level of energy is reached or when other agents approach the source. Depending on the parameters, agents leave even rich food regions, e.g. to collect ore or to explore the environment. Often these explorers form a couple (but the partner is irrelevant). Sometimes circles may also be found in places without food or ore. These circles collapse when the consumption motive of one or several members becomes stronger. If they do not find enough food in a reasonable time they die. At the food places, very hungry homecomers push less hungry agents aside and clearly misbehave.
Trajectory of a fungus eater society:
