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Michael Blatt, Geoffrey Pullum, Andreas Draguhn, Barry Bowman, David Robinson, and Lincoln Taiz , "Does electrical activity in fungi function as a language?", Fungal Ecology 2024:

Abstract: All cells generate electrical energy derived from the movements of ions across membranes. In animal neurons, action potentials play an essential role in the central nervous system. Plants utilize a variety of electrical signals to regulate a wide range of physiological processes, including wound responses, mimosa leaf movements, and cell turgor changes, such as those involved in stomatal movements. Although fungal hyphae exhibit electrical fluctuations, their regulatory role(s), if any, is still unknown. In his paper “Language of fungi derived from their electrical spiking activity”, Andrew Adamatzky, based on a quantitative analysis of voltage fluctuations in fungal mycelia, concludes that the patterns of electrical fluctuations he detects can be grouped into “words” analogous to those found in human languages. He goes on to speculate that this “fungal language” is used “to communicate and process information” between different parts of the mycelium. Here we argue on methodological grounds that the presumption of a fungal language is premature and unsupported by the evidence presented, that the voltage fluctuations he detects are likely to originate as nonbiological noise and experimental artifacts, and that the measured electrical patterns show no similarity to any properties of human language.

The cited paper is Andrew Adamatzky, "Language of fungi derived from their electrical spiking activity." Royal Society Open Science 2022:

Abstract: Fungi exhibit oscillations of extracellular electrical potential recorded via differential electrodes inserted into a substrate colonized by mycelium or directly into sporocarps. We analysed electrical activity of ghost fungi (Omphalotus nidiformis), Enoki fungi (Flammulina velutipes), split gill fungi (Schizophyllum commune) and caterpillar fungi (Cordyceps militaris). The spiking characteristics are species specific: a spike duration varies from 1 to 21 h and an amplitude from 0.03 to 2.1 mV. We found that spikes are often clustered into trains. Assuming that spikes of electrical activity are used by fungi to communicate and process information in mycelium networks, we group spikes into words and provide a linguistic and information complexity analysis of the fungal spiking activity. We demonstrate that distributions of fungal word lengths match that of human languages. We also construct algorithmic and Liz-Zempel complexity hierarchies of fungal sentences and show that species S. commune generate the most complex sentences.

The conclusion of Blatt et al.'s critique:

In short, the unexplained electrical activity does not exhibit any of the characteristics of language at all, far less “morphological structure” comparable to that of the European languages that he mentions. Even if the electrophysiological phenomena Adamatzky describes constituted clear and definite groups of pulses well above noise level (which they do not), and were the result of electrochemical activity within the fungus (which has not been demonstrated), the analogy with words could not provide any support for the idea of an underlying syntactic system based on words. Adamatzky provides no support of any kind for the notion that fungi might be using a language.

Among the criticisms:

In the 1970s, polygraph expert Cleve Backster placed electrodes in yogurt and detected large fluctuations in voltage with amplitudes from a few millivolts to several tens of millivolts, which he misinterpreted as bacterial communication (Galston and Slayman 1979). In Adamatzky's experiments with fungi, small vibrations and mechanical drift of the electrode tip within the matrix will have similar effects on the voltage recorded. 

The cited Galston and Slayman paper is worth reading: "The Not-So-Secret Life of Plants: In which the historical and experimental myths about emotional communication between animal and vegetable are put to rest", American Scientist 1979.

It would have been fun — but unnecessary — for Blatt et al. to duplicate Adamatsky's linguistic analysis using voltage fluctuations derived from vibrating yogurt electrodes. You should read their whole take-down anyhow…

To give you an idea of how (not) carefully Adamatzky's paper was written, and how (not) carefully the Royal Society reviewed it, its featured algorithm is rendered as two slightly-different spoonerisms. What the paper refers to as "Liz-Zempel" in the abstract, and "Liv-Zempel" in the body of the article, is actually a confused reference to a set of compression algorithms due to Abraham Lempel and Jacob Ziv, and therefore generally known as "Lempel-Ziv" algorithms, or LZ77 and LZ78.

From Adamatsky's abstract:

And from the body of the paper:

It should not surprise you to learn that mass-media coverage of Adamatzky's claims was less skeptical than Blatt et al. were — e.g. "Mushrooms communicate with each other using up to 50 ‘words’, scientist claims", The Guardian 3/5/2022; "Can mushrooms communicate with each other?", BBC 3/7/2022.

Here's the featured picture in the BBC article — nice to see they're maintaining the tradition:

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We should note that there's good evidence for "communication" at all levels of the Great Chain of Being — for the case of bacteria, see e.g. O'Toole et al., "Biofilm formation as microbial development", Annual Review of Microbiology 2000:

Once the initial colonizers have attached to the surface, cell-cell communication comes into play. In streptococci for example, the growth of the bacteria is relatively slow up to a surface density of ∼2 × 10⁶ cells/mm². However, above this threshold density, the growth rate of the bacteria apparently increases, as measured by 3 H-thymine uptake. This increased growth rate can be stimulated in less dense communities by the addition of supernatants of stationary-phase cultures, suggesting the requirement for an extracellular factor. Preliminary biochemical analysis has shown that this compound, called START, has a molecular weight of <3000 M_r. It is possible that this low-molecular-weight compound acts as a quorum-sensing signaling molecule to accelerate the growth of surface-attached communities.

But that's not a reason to jump into careless fungal anthropomorphizing…

Update– A note from Geoff Pullum, who is a co-author of the debunking paper:

Debunking already published scientific papers is arduous work. We were denied the option of submitting to the journal that published Adamatzky, Royal Society Open Science, because at the point when we asked them we were already outside their very tight time window for replies. We then tried two other mycological journals (with their bug-ridden electronic submission systems and furiously negative pro-fungus referees), getting a lack of interest from one and a rejection from the other, before we finally got an accept-with-revisions from Fungal Ecology. It took much of our spare time for most of a year to get this through the writing, rewriting, multiple refereeing, many revisions, and typesetting.

 

January 9, 2024 @ 10:33 am · Filed by Mark Liberman under Biology of language, Computational linguistics

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