Slime mould tactile sensor

Slime mould P. polycephalum is a single cells visible by unaided eye. The cells shows a wide spectrum of intelligent behaviour. By interpreting the behaviour in terms of computation one can make a slime mould based computing device. The Physarum computers are capable to solve a range of tasks of computational geometry, optimisation and logic. Physarum computers designed so far lack of localised inputs. Commonly used inputs --- illumination and chemo-attractants and -repellents --- usually act on extended domains of the slime mould's body. Aiming to design massive-parallel tactile inputs for slime mould computers we analyse a temporal dynamic of P. polycephalum's electrical response to tactile stimulation. In experimental laboratory studies we discover how the Physarum responds to application and removal of a local mechanical pressure with electrical potential impulses and changes in its electrical potential oscillation patterns

Slime mould: The fundamental mechanisms of biological cognition

© 2018 Elsevier B.V. The slime mould Physarum polycephalum has been used in developing unconventional computing devices for in which the slime mould played a role of a sensing, actuating, and computing device. These devices treated the slime mould as an active living substrate, yet it is a self-consistent living creature which evolved over millions of years and occupied most parts of the world, but in any case, that living entity did not own true cognition, just automated biochemical mechanisms. To “rehabilitate” slime mould from the rank of a purely living electronics element to a “creature of thoughts” we are analyzing the cognitive potential of P. polycephalum. We base our theory of minimal cognition of the slime mould on a bottom-up approach, from the biological and biophysical nature of the slime mould and its regulatory systems using frameworks such as Lyon's biogenic cognition, Muller, di Primio-Lengelerś modifiable pathways, Bateson's “patterns that connect” framework, Maturana's autopoietic network, or proto-consciousness and Morgan's Canon

On attraction of slime mould Physarum polycephalum to plants with sedative properties

A plasmodium of acellular slime mould Physarum polycephalum is a large single cell with many nuclei. Presented to a configuration of attracting and repelling stimuli a plasmodium optimizes its growth pattern and spans the attractants, while avoiding repellents, with efficient network of protoplasmic tubes. Such behaviour is interpreted as computation and the plasmodium as an amorphous growing biological computer. Till recently laboratory prototypes of slime mould computing devices (Physarum machines) employed rolled oats and oat powder to represent input data. We explore alternative sources of chemo-attractants, which do not require a sophisticated laboratory synthesis. We show that plasmodium of P. polycephalum prefers sedative herbal tablets and dried plants to oat flakes and honey. In laboratory experiments we develop a hierarchy of slime-mould’s chemo-tactic preferences. We show that Valerian root (Valeriana officinalis) is the strongest chemo-attractant of P. polycephalum outperforming not only most common plants with sedative activities but also some herbal tablets.
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On hybrid circuits exploiting thermistive properties of slime mould

Slime mould Physarum polycephalum is a single cell visible by the unaided eye. Let the slime mould span two electrodes with a single protoplasmic tube: if the tube is heated to approximately ≈40 °C, the electrical resistance of the protoplasmic tube increases from ≈3 Mω to ≈10,000 Mω. The organisms resistance is not proportional nor correlated to the temperature of its environment. Slime mould can therefore not be considered as a thermistor but rather as a thermic switch. We employ the P. polycephalum thermic switch to prototype hybrid electrical analog summator, NAND gates, and cascade the gates into Flip-Flop latch. Computing operations performed on this bio-hybrid computing circuitry feature high repeatability, reproducibility and comparably low propagation delays