Liquid cognitive systems

”Understanding the relative computational advantages of liquid versus solid systems is important scientifically, and in the future these understandings are likely to suggest important new ways of thinking about and configuring traditional computations. As computation continues to move off the desktop and into the physical world, we expect that liquid systems characterized by networks of distributed, mobile, and largely autonomous components will become even more important than they are today.” [April 22, 2019]

Liquid cognitive systems, in addition to the ‘solid’ brain model, includes:

“sets of agents that exchange, store and process information but without persistent connections or move relative to each other in physical space. We refer to these networks that lack stable connections and static elements as ‘liquid’ brains, a category that includes ant and termite colonies, immune systems and some microbiomes and slime moulds… The moving hypothesis posits that active exploration of an organism’s spatial environment was a key step in the evolutionary trajectory that produced brains… Predation was likely the most important selective pressure to create learning networks [6]. This powerful evolutionary innovation was not limited to neural networks, and we suggest here that the many kinds of networks of interacting agents that evolved to process information have characteristic similarities and differences.

“Information processing networks can be found in microbial communities, inside cells (as gene regulatory webs), and in immune systems. The diversity of architectures and information-processing strategies of these networks is stunning. Fluid webs of information exchanges among thousands or even millions of ants or termites unfold in most of the biosphere [7,8]. Simple life forms known as slime moulds, made of a single macroscopic (multinucleated) cell, can solve complex problems. Plants seem to occupy a very different region of the space of cognitive networks, lacking neural-like structures and physical movement, yet defining a tremendously successful and ecologically important group. Liquid computers and chemical reactions provide a rather different set of case studies, where computation and informational processes are not clearly defined. In this context, developmental programmes and pattern formation are also considered to be forms of cognition…

“Are there strategies that have been discovered by natural evolution that could lead to new forms of computation, perhaps using synthetic biology? Answering these and other fundamental questions was the goal of a small workshop held at the Santa Fe Institute in December 2017. The meeting convened a group of researchers from diverse fields of science and engineering, including social insect behaviour, microbiology, synthetic biology, developmental and systems biology, neuroscience, computer science and statistical physics. Over several days, the participants took the initial steps towards formulating a theory of liquid versus solid brains with the long-term goal of establishing the basis of a general theory of cognitive networks.

…”nonlinear character requires (in most cases) an appeal to extended views of computation beyond standard definitions [10]. In addition, the collective dynamics exhibited by large populations of agents interacting nonlinearly depends critically on whether or not the basic network components are mobile. We identified two key dimensions to characterize different categories of cognitive networks (figure 1): the physical characteristics of the system, and the presence or absence of neurons.

…”Even before complex neuronal networks evolved, microorganisms discovered collective structures that could respond to stressful environments, especially those that posed threats to individual cells. Survival was thus tied to cooperation, and cooperation required novel forms of communication within collectives. To quote James Shapiro: ‘bacteria are small but not stupid’ [16]. A well-known example of this level of collective behaviour is quorum sensing (QS), a process that involves populations of cells working cooperatively [17]. QS allows groups of bacteria to monitor the presence of other bacteria at a population-wide scale, leading in some cases to the emergence of colony-level coordinated responses. This illustrates how microbial colonies can make collective decisions. In another vein, the collective behaviour of biofilms is illustrated by recent work on long-range electrical communication in bacterial communities [18]. Martinez-Corral et al. [19] investigate how similar chemical signalling might exist in both cortical brain activity and biofilm dynamics.

“Slime moulds Physarum polycephalum are a particularly fascinating example of collective behaviour by aggregates of single cells. Although the organism is single-celled (but including multiple nuclei), in groups it displays highly complex spatial morphological patterns… they also display habituation, i.e. a common adaptive response (displayed by neural organisms) to an unpleasant persistent stimulus. This finding supports the idea that brainless systems can under the right conditions learn from experience to discriminate diverse sources of information.

“The boundaries of cognition space can be delineated by considering the simplest ‘solid’ brains and asking how they do their jobs compared with similarly simple liquid examples [24]. Planarians (flatworms) are a candidate for the first true (i.e. centralized) brains [2,13]. Of particular interest is the tight integration of developmental and cognitive phenomena. As pointed out in [25], remarkable information processing tasks were evolved long before solid brains emerged. Planarians can regenerate every part of their bodies [26] and experimental studies show that memories survive decapitation (see Shomrat & Levin [27] and references therein). These results point to a deep connection between neural-based phenomena and somatic memory. Importantly, many developmental responses to perturbations can be mapped into an attractor diagram that represents morphological end states as attractors. The dynamics leading to these attractor-based responses can be implemented in very different types of non-neural hardware, although we still lack a common theoretical framework for describing these systems, as discussed in [9].

“The solid, aneural region of cognitive space is shared with other groups of living organisms with different organizations, life styles, and life cycles. Plants, in particular, define a limiting case [28,29]. The cognitive potential of plants was recognized as early as Darwin in a monograph [30], where he pointed to the interesting responses displayed by plants to external signals and environmental cues. Plants exhibit responses that suggest interesting computational abilities [28], and the concept of ‘plant intelligence’ [31] has also been developed (with some degree of controversy) in recent decades. Communication at multiple scales, in particular, has been of interest, ranging from networks of stomata in leaves to signals sent through root systems. These examples point to the need for better understanding of information processing in plants [28], including genetic switches and analogue computations that take place within the process of seed dispersal and germination [32]. Intriguingly, these processes involve the ‘movable’ part of the plant’s life cycle.

…”Vining et al. [43] develop liquid cellular automata to demonstrate how liquid systems compute without sophisticated physical network structures. Mobility is shown to increase information flow among moving agents, which encounter and communicate with new agents over time…

…”Understanding the relative computational advantages of liquid versus solid systems is important scientifically, and in the future these understandings are likely to suggest important new ways of thinking about and configuring traditional computations. As computation continues to move off the desktop and into the physical world, we expect that liquid systems characterized by networks of distributed, mobile, and largely autonomous components will become even more important than they are today.”

[same issue: “This article is part of the theme issue ‘Liquid brains, solid brains: How distributed cognitive architectures process information’]…” We hypothesize that a cognitive-level information-processing view of the functions of living systems can complement reductive perspectives, improving efficient top-down control of organism-level outcomes. Exploration of the deep parallels across diverse quantitative paradigms will drive integrative advances in evolutionary biology, regenerative medicine, synthetic bioengineering, cognitive neuroscience and artificial intelligence.”


One of the co-organizers. Melanie Moses at University of NM. Note metabolic tracing in ecology @leo

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While not directly related to fluid computing systems. This remeinds me of Rodger Penrose’s theory of consciousness facilitated through microtubules (the building blocks of the cytoskeleton).

Obviously I dont understand any of this, but when I was seeing if there was anything recent about the theory there was this 2022 paper providing a counter argument to a MIT professor criticism. The whole theory centers around potential quantum coherence in microtubules.

The interesting point is that they assert that (from what I attempted to interpret) ‘incoherent metabolic energy’ contributes to the ordering of water surrounding the microtubules. I haven’t been looking into fourth phase of water type of research lately, but seems like its being integrated.

incoherent metabolic energy supplied to the collective dynamics ordering water in the vicinity of microtubules at a rate exceeding that of decoherence can counter decoherence effects (in the same way that lasers avoid decoherence at room
temperature), and 5) phases of actin gelation may enhance the ordering of water around microtubule bundles, further increasing the decoherence-free zone by an order of magnitude and the decoherence time to 10^ −2 − 10^ −1s. These revisions bring microtubule decoherence into a regime in which quantum gravity can interact with neurophysiology


I agree that water is definitely important in all of this, I just wish I understood it better.

Now that I think of it the use of “liquid” in the title of this conference seems telling.
Reiser emphasized the importance of hydrogen on the universe - also helium.

Looking into H.T. Odum’s involvement with the Atomic Energy Commission on the metabolism of ecosystems processing radioactive material both at Eniwetok Atoll (Operation Ivy) and radiation experiments at El Verde rainforest in Puerto Rico; the fact that he was a meteorologist with the US Army in WWII with an interest in hurricanes; and that his work with global circulation of Strontium was a landmark study - well it just makes me think about the use of engineered weather systems to dose people / life with radiological material and use carbon tracking as a way to keep track of everything. I sense @jenlake has investigated things along those lines. All that work in Florida water systems. Is this some terrible B movie?

The Puerto Rico Rainforest Study was for persistent radioactive fallout, mandated through the Health Physics program of AEC’s Division of Medicine and Biology.

A tropical rain forest : a study of irradiation and ecology at El Verde, Puerto Rico

Title – A tropical rain forest : a study of irradiation and ecology at El Verde, Puerto Rico / Howard T. Odum, editor and project director ; Robert F. Pigeon, associate editor.

Format-- Book

Published-- [Oak Ridge, Tenn.] : Division of Technical Information, U.S. Atomic Energy Commission ; [available from Clearinghouse for Federal Scientific and Technical Information, Springfield, Va.], 1970.

Description-- 1 volume (various pagings) : illustrations (some color), maps ; 29 cm

Other contributors-- Odum, Howard T. (Howard Thomas), 1924-2002. Pigeon, Robert F. U.S. Atomic Energy Commission.

Notes-- “Results of the Atomic Energy Commission Rain Forest Project, 1963-1967.” Includes bibliographical references and index. [with a long list of subprojects/experiments]


D-17. Effect of gamma radiation on chlorophyll A content in bromeliads / F.K.S. Koo, H.T. Odum, and Edith Robles de Irizarry

D-18. Radiation effect on survival and growth of bromeliads / F.K.S. Koo and R.C. Venator

D-19. Vegetative sprouting following irradiation of a tropical rain forest / Carl F. Jordan

E. Animals and the effects of radiation

E-1. Effects of radiation on a population of the Puerto Rican tree snail, Caracolus caracolla / Harold Heatwole [and others]

E-2. Observations of lizards and tree frogs in an irradiated Puerto Rican rain forest / Frederick B. Turner and Clayton S. Gist

F. Microorganisms and the effects of radiation

F-1. Fleshy fungi in relation to irradiation and cutting in the Luquillo Experimental Forest / G.T. Cowley

F-4. Effect of radiation on the microfungal populations of six litter species in the Luquillo Experimental Forest / G.T. Cowley

F-5. Aspects of soil microflora in a gamma-irradiated rain forest / Martin Witkamp

F-6. Response of soil, root, and litter microfungal populations to radiation / James R. Holler and G.T. Cowley

F-10. The survival of actinomycetes in a radiation field / Jerome J. Perry

G. Cytological studies within the irradiated forest

G-2. Inherent and radio-induced cytological abnormalities in Palicourea riparia benth / Robert Venator and F.K.S. Koo

G-3. Fern cytology and the radiation field / Veikko Sorsa

G-4. Karyotype rearrangements and malformation of gonads in the walking-sticks (Phasmatoptera) of the El Verde radiation center / Niilo Virkki

…………etc. A tropical rain forest : a study of irradiation and ecology at El Verde, Puerto Rico | Search Results | IUCAT

Fallout Radioactivity and Epiphytes.

(PDF; 9014537)


  • Authors: Odum, H. T.; Briscoe, George Ann; Briscoe, C. B.
  • Publication Year: 1970
  • Publication Series: Miscellaneous Publication (MISC)
  • Source: A Tropical Rainforest. Rio Piedras, Puerto Rico: Division of Technical Information, US Atomic Energy Commission: H167-H176


After relatively high levels of fallout retention were dicovered in the epiphytic mossy forest of the Luquillo Mountains durin 1962, a survey of the distribution of radioactivity in the rain forest system was made with beta counting of 1500 samples supplemented with gamma spectra. High levels, up to 4138 counts per minute per gram, were found mainly in or on green plant tissue and the derived litter, with as much variability among leaves of the same tree as between trees. The degree of uptake was correlated with epiphytic mode of growth, with algae–moss–liverwort encrustatations highest, massive mosses second, bromeliads third, and rooted plants last. The radioactivity in leaves was found to be in proportion to the epiphytic growth on the leaves and thus was related to their age. Gamma spectra were similar in most material including leaves of many tree species, litter, termite nest, and the roof of algae near San Juan.

  • Citation: Odum, H. T.; Briscoe, George Ann; Briscoe, C. B. 1970. Fallout Radioactivity and Epiphytes. In: Odum, H. T., ed. A Tropical Rainforest. Rio Piedras, Puerto Rico: Division of Technical Information, US Atomic Energy Commission: H167-H176.

“Howard T. Odum spent the late 1940s at Yale Uni-versity. He completed his doctoral dissertation, “The Biogeochemistry of Strontium,” in 1950 under the direction of the famous limnologist and theoretical ecologist G. Evelyn Hutchinson. Without access to notes or personal correspondence, one may only speculate as to why Odum chose to study the global cycle of this trace element. Possibly, Hutchinson suggested the topic: in his own treatise on the biogeochemistry of aluminum and several “lithophilic” trace elements (Hutchinson, 1943), Hutchinson pointed out the uncertainty in the amount of strontium in living terrestrial plants. Strontium was also seen as a means to trace paleoecological processes such as diagenesis of limestones (Odum, 1951a, 1957a, 1957b). Finally, strontium attracted worldwide attention as a notable fission product ( 90 Sr) during the post-World War II years. In the early 1950s, the American public was introduced to the word strontium by extensive media coverage of the discovery that radioactive strontium from nuclear bomb testing had entered food chains and, through biomagnification, made milk sufficiently radioactive to warrant warnings against its consumption…” The Biogeochemistry of Strontium: a review of H.T. Odum’s contributions - ScienceDirect

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I’m listening to this again, and at the beginning of the talk, it does feel like a set up for hormesis. @Stephers