physarum IB-physarum-extended-memory

Physarum uses an EXTERNALIZED spatial memory — avoidance of its own extracellular slime trail — to escape a U-shaped trap: 96% of trials escaped (n=24) versus 33% when the whole arena was pre-coated with slime so the cue was uninformative.

Observed quantities

96% escape (n=24) vs 33% on slime-pre-coated agar

Primary source

Reid et al. 2012, PNAS

Boundary of this block

The stronger reading — that this memory is PURELY external stigmergy with no internal state — was REFUTED; internal (tube) and external (slime) memory coexist.

Connections

Outgoing

relates to Physarum polycephalum encodes the location of a past nutrient stimulus in its tube-diameter hierarchy: tubes toward the food dilate and the diameter pattern persists after the stimulus itself is gone. external slime store operating alongside the internal tube-diameter store

Incoming

relates from Physarum polycephalum encodes the location of a past nutrient stimulus in its tube-diameter hierarchy: tubes toward the food dilate and the diameter pattern persists after the stimulus itself is gone. internal store (tube diameters) alongside an external store (slime trail) in the same organism