This robotic face expresses anger, joy, and other emotions based on the movements of a slime mold. But what does a grinning robot teach us about these remarkable organisms?

Slime molds are single-celled organisms that work together as a larger creature, and that creature has shown some incredible behaviors and abilities, including solving mazes faster than robots do. Ella Gale, who researches neuromorphic and unconventional computers, is currently researching Physarum polycephalum, a common yellow slime mold. One of the ways that she's studying it is with this expressive robot.

Gale placed the slime mold on a series electrodes. As the slime mold moved toward food or away from light, it would produce electrical currents, which Gale translated as sound frequencies. Using the circumplex model of affect, she assigned each reaction an emotion and a relevant facial expression. When she plays the sound frequencies, the robot reacts as in the video above.

The question is, of course, why? Gale is investigating the relationship between the brain and the way that brainless slime molds engage in cellular communication. By assigning something like analogous emotions to the slime mold's movements, perhaps she can get a better sense of how the slime mold learns.

Robot face lets slime mould show its emotional side [New Scientist via Nerdcore]