The paper titled “Language of fungi derived from electrical spiking activity” by Andrew Adamatzky presents an analysis of the electrical activity for ghost fungi, Enoki fungi, split gill fungi, and caterpillar fungi. Each species shows a peculiar electrical activity, i.e., its characteristic frequency and amplitude of spiking. Assuming that fungi use spikes of electrical activity to communicate and process information in mycelium networks, the author groups spikes into words and provide a linguistic and information complexity analysis of the fungal spiking activity. He demonstrates that distributions of fungal word lengths match that of human languages. He also constructs algorithmic and Liz-Zempel complexity hierarchies of fungal sentences and shows that the species “split gill fungi” generate the most complex sentences.
The paper is well-written. I like the approach proposed by Prof. Adamatzky, who is well-known for his unconventional way of thinking in the field of computing. I invite the author to address the following issues for improving his paper.
1) I suggest introducing the photograph of the electrodes inserted in ghost fungi within Figure 1 and extending the dimensions of the already present pictures.
2) In which physicochemical conditions were the fungi maintained during the recording of their electrical activities? Were they in the same physicochemical environment? Were they constantly under light irradiation or alternate stages of light and darkness? What happens if the fungi are immersed in a “natural” environment and not within the laboratory? Could the author comment on how the surrounding environment might affect their electrical activities?
I pose all these questions because if we want to understand what the fungi communicate, we need to understand the role of the context, i.e., the environment wherein they are embedded.
3) Figure 3 should be improved by making the single graphs larger.
4) Has the author thought of distinguishing between positive and negative spikes? Within a single time trace, there are both positive and negative spikes. They might be signals with well distinct meaning.
5) In the graph of Figure 3a, there are spikes showing a considerable amplitude. It seems up to 10 mV. Is it correct? It seems they are not mentioned within the paper.
6) Figure 10 is not cited within the text, as far as I see.
7) I invite the author to, at least, mention the possibilities of interpreting the electrical activities of fungi as a language by using two alternative approaches to that the author proposes in his paper. The first one is the approach put forward in RSC Adv., 2021, 11, 23151-23160 (https://doi.org/10.1039/D1RA03856G): the authors use a proper integration of the time traces. The second one is based on the theory of Fuzzy sets. Instead of discretizing the peaks in binary forms, the shape of each peak is quite different as shown in Figure 3 of this paper. It might be valuable to characterize each peak by determining its Fuzzy Entropy through the algorithm shown in equation (11) of Molecules 2021, 26(19), 5987; https://doi.org/10.3390/molecules26195987. In this latter way, each peak becomes a word.