Summary of “Slime Molds Remember”

Research into the behavior of protozoa such as the slime mold Physarum polycephalum suggests that these seemingly simple organisms are capable of complex decision-making and problem-solving within their environments.
Nakagaki and his colleagues have shown, for example, that slime molds are capable of solving maze problems and laying out distribution networks as efficient as ones designed by humans.
Chris Reid and his colleague Simon Garnier, who heads the Swarm Lab at the New Jersey Institute of Technology, are working on the mechanism behind how a slime mold transfers information between all of its parts to act as a kind of collective that mimics the capabilities of a brain full of neurons.
Each tiny part of the slime mold contracts and expands over the course of about one minute, but the contraction rate is linked to the quality of the local environment.
Using computer vision techniques and experiments that might be likened to a slime mold version of an MRI brain scan, the researchers are examining how the slime mold uses this mechanism to transfer information around its giant unicellular body and make complex decisions between conflicting stimuli.
He is not persuaded that Dussutour’s experiment with slime molds staying habituated to salt after extended dormancy shows much.
To Fred Kaijzer, a cognitive scientist at the University of Groningen in the Netherlands, the question of whether these interesting behaviors show that slime molds can learn is similar to the debate over whether Pluto is a planet: The answer depends as much on how the concept of learning is cast as on the empirical evidence.
“Slime mold researchers insist that functionally equivalent behavior observed in the slime mold should use the same descriptive terms as for brained animals, while classical neuroscientists insist that the very definition of learning and intelligence requires a neuron-based architecture,” he said.

The orginal article.