The humble unicellular slime mold's amazing ability to learn and impart learning even with no brain has been highlighted in a new study. The organism Physarum polycephalum is no plant, animal, or a fungus but a mere gelatinous amoeba.
This creeping, blob-like organism's incredible intelligence was unveiled in a study by researchers at Research Centre on Animal Cognition (CNRS) of Toulouse University in France.
The findings were published in the Dec. 21, issue of the Proceedings of the Royal Society B. The study also also showed Slime Mold's good memory.
"Tantalizing results suggest that the hallmarks for learning can occur at the level of single cells," said the teams' study.
The knowledge imparted by slime molds were "habituated learning," as a response to stimulus play for indicating an irritating obstacle. In the experiment, despite initial repulses, slime mold learns to adjust to the irritation and in the process knowledge, transfer takes place.
The study makes use of slime mold's movement that is peculiar by stretching tendrils to test environment while searching food and an uncanny way to avoid hostile obstacles.
It proves that absence of gray matter is no barrier in slime mold's capacity to learn from experiences and colonies of this amoeba can teach each other. What makes the learning phase special is a unique fusion mode while imparting the knowledge.
Slime Mold Experiment
In the experiments done on cultured slime molds, scientists David Vogel and Audrey Dussutour trained a group of these creatures to move past harmless substances like coffee while reaching for food, and was further trained to also ignore salt. This became the cornerstone of the experiment in assessing the behavior of knowledge transfer to another novice.
After making the habituated slime molds overcome their aversion to salt, they brought in another group of 2,000 slime molds to cross a barrier that had no substance.
Learning Confirmed In Slime Mold
In the second phase, scientists classified slime molds into various groups — habituated, naive, and mixed pairs — and found that slime molds fused when they came into contact with the mixed group.
Later the slime molds from the mixed group was found moving in a speed equaling the habituated creatures while crossing the salt-sprayed barrier and faster than the naive ones, suggesting knowledge transfer that salt is indeed harmless.
It was noticed that no matter how many were fused, one habituated slime mold was enough to do the transfer of information.
To reconfirm whether learning transfer happened, the scientists disengaged slime molds and repeated the experiment. The results showed that naive slime molds that fused with habituated ones ignored the salt while novices were repulsed by it marking the new learning.
In bacterial-farming of slime molds are also unique. The best-known slime mold, Dictyostelium discoideum, spends a substantial part of its life feeding on bacteria from decomposed leaves found on forest floors. When starved for food, thousands of these amoebas fuse into a single entity and crawl off searching for richer pastures.
