Plasmodium Computing

The single-celled organism Physarum polycephalum is a power-house of raw animal intelligence. Now researchers are learning how to program it to carry out simple computations.

"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, it can anticipate periodic events and now its 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 remarkable sensitive to light, which it generally avoids. Today, Andrew Adamatzky at the University of the West of England in Bristol, outlines how it is possible to precisely point, steer and cleave plasmodium using light and food sources (they love oat flakes apparently). And since plasmodia always react in the same way to the same stimulus, Adamatzky says they are the "ideal substrate for future and emerging
bio-computing devices".

(Incidentally, we've seen Adamatzky and others before doing other curious kinds of computation)

Here's how it works. You "program" this biocomputer by creating a pattern of lights and oak flakes that make a kind of obstacle course for the plasmodium to negotiate. You then "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 yet to report the results of any computations, only the techniques that could be used to carry out one. And this not the kind of programming that many people will have the patience (or a sufficient quantity of oat flakes) for.

But in a way, plasmodium computing is kinda cool and you can't help but admire Adamatzky's dedication.