Plasmodium Computing

“It’s computing, Jim. But not as we know it.”

If you’ve ever wondered about the origin of intelligence, take a few moments to study a being called Physarum polycephalum. This single-celled organism can find the shortest way through mazes and anticipate periodic events. Now it is learning how to carry out simple computations.

Physarum polycephalum has a complex lifestyle, but in one phase of its existence it forms a single-celled creature called a plasmodium that is visible to the naked eye. When this creature forages for food, it physically surrounds whatever it has settled on for lunch, secretes a few enzymes, and digests it. If it finds several food sources, it sends out numerous tubes that form a kind of digestive network. It is this network that can find its way efficiently through a maze (provided there is food in the middle).

Plasmodium is also remarkably sensitive to light, which it generally avoids. Andrew Adamatzky, of the University of the West of England, Bristol, in the United Kingdom, outlines how it is possible to precisely point, steer, and cleave plasmodium using light and food sources (apparently, they love oat flakes). And since plasmodia always react in the same way to the same stimulus, Adamatzky says they are the “ideal substrate for future and emerging biocomputing devices.”

(Incidentally, we’ve seen Adamatzky before doing other curious kinds of computation.)

Here’s how it works. You “program” this biocomputer by creating a kind of obstacle course for the plasmodium from a pattern of lights and oak flakes. You “run” the program by allowing the creature to tackle this obstacle course and you read out the result by examining the shape of the network that the plasmodium forms. Adamatzky has not yet reported the results of any computations, only the techniques that could be used to carry one out.

While not all may have the patience (or a sufficient quantity of oat flakes) for this kind of programming, plasmodium computing is kinda cool, and you can’t help but admire Adamatzky’s dedication.

Ref:arxiv.org/abs/0908.0850: Steering Plasmodium With Light: Dynamical Programming of Physarum Machine