Single-celled slime molds demonstrate the ability to memorize and anticipate repeated events, a team of Japanese researchers reported in January. The study [pdf] clearly shows “a primitive version of brain function” in an organism with no brain at all.
In their experiment, biophysicist Toshiyuki Nakagaki of Hokkaido University and colleagues manipulated the environment of Physarum slime-mold amoebas (near right). As the cells crawled across an agar plate, the researchers subjected them to cold, dry conditions for the first 10 minutes of every hour. During these cool spells, the cells slowed down their motion. After three cold snaps the scientists stopped changing the temperature and humidity and watched to see whether the amoebas had learned the pattern. Sure enough, many of the cells throttled back right on the hour in anticipation of another bout of cold weather. When conditions stayed stable for a while, the slime-mold amoebas gave up on their ...
