Buried in forest litter or sprouting from trees, fungi might give the impression of being silent and relatively self-contained organisms, but a new study suggests they may be champignon communicators.
Mathematical analysis of the electrical signals fungi seemingly send to one another has identified patterns that bear a striking structural similarity to human speech.
Previous research has suggested that fungi conduct electrical impulses through long, underground filamentous structures called hyphae – similar to how nerve cells transmit information in humans.
It has even shown that the firing rate of these impulses increases when the hyphae of wood-digesting fungi come into contact with wooden blocks, raising the possibility that fungi use this electrical “language” to share information about food or injury with distant parts of themselves, or with hyphae-connected partners such as trees.
But do these trains of electrical activity have anything in common with human language?
To investigate, Prof Andrew Adamatzky at the University of the West of England’s unconventional computing laboratory in Bristol analysed the patterns of electrical spikes generated by four species of fungi – enoki, split gill, ghost and caterpillar fungi.
He did this by inserting tiny microelectrodes into substrates colonised by their patchwork of hyphae threads, their mycelia.
“We do not know if there is a direct relationship between spiking patterns in fungi and human speech. Possibly not,” Adamatzky said. “On the other hand, there are many similarities in information processing in living substrates of different classes, families and species. I was just curious to compare.”
The research, published in Royal Society Open Science, found that these spikes often clustered into trains of activity, resembling vocabularies of up to 50 words, and that the distribution of these “fungal word lengths” closely matched those of human languages.
Split gills – which grow on decaying wood, and whose fruiting bodies resemble undulating waves of tightly packed coral – generated the most complex “sentences” of all.
The most likely reasons for these waves of electrical activity are to maintain the fungi’s integrity – analogous to wolves howling to maintain the integrity of the pack – or to report newly discovered sources of attractants and repellants to other parts of their mycelia, Adamtzky suggested.
“There is also another option – they are saying nothing,” he said. “Propagating mycelium tips are electrically charged, and, therefore, when the charged tips pass in a pair of differential electrodes, a spike in the potential difference is recorded.”
Whatever these “spiking events” represent, they do not appear to be random, he added.
Even so, other scientists would like to see more evidence before they are willing to accept them as a form of language. Other types of pulsing behaviour have previously been recorded in fungal networks, such as pulsing nutrient transport – possibly caused by rhythmic growth as fungi forage for food.
“This new paper detects rhythmic patterns in electric signals, of a similar frequency as the nutrient pulses we found,” said Dan Bebber, an associate professor of biosciences at the University of Exeter, and a member of the British Mycological Society’s fungal biology research committee.
“Though interesting, the interpretation as language seems somewhat overenthusiastic, and would require far more research and testing of critical hypotheses before we see ‘Fungus’ on Google Translate.”