An associative learning experiment using the plasmodium of Physarum polycephalum

The plasmodium of Physarum polycephalum is a unicellular and multinuclear giant amoeba that shows adaptive behaviors. To test the presence of memory and learning ability in the plasmodium, we performed an associative learning experiment using the unicellular organism. The plasmodium in this experiment seemed to acquire a reversed thermotactic property, a new preference for the lower temperature. The result implied a possibility of unicellular learning, though in a preliminary way. We also discuss a possible mechanism of learning by the organism.