Spontaneous Electrical Low-frequency Oscillations (SELFOs)

Phys.org has a great overview of two issues from Royal Society Publishing on the origins of nervous systems. One great thing about the issues is it seems so far at least that almost every article in the two issues seems to be freely and easily available to anyone. The direct links to the issues are here and here.

The Phys.org article by John Hewitt Where did brains come from? focuses especially on the origins of nervous systems with neurotransmitters. “Jékely’s chemical brain hypothesis postulates that neurotransmitters came before synapses and neurites, as opposed to the other way around. In other words, transmitters make nervous systems”. However, the coverage of the two issues is much broader than the Phys.org article suggests. It includes, among others, papers on learning in slime molds, origin of self, and transitions in learning and cognition by Simona Ginsburg and Eva Jablonka.

However, what has more immediately attracted my attention is a paper by Alison Hanson Spontaneous electrical low-frequency oscillations: a possible role in Hydra and all living systems. I would like to quote some major excerpts from it. Here is its abstract. Bolding is mine.

As one of the first model systems in biology, the basal metazoan Hydra has been revealing fundamental features of living systems since it was first discovered by Antonie van Leeuwenhoek in the early eighteenth century. While it has become well-established within cell and developmental biology, this tiny freshwater polyp is only now being re-introduced to modern neuroscience where it has already produced a curious finding: the presence of low-frequency spontaneous neural oscillations at the same frequency as those found in the default mode network in the human brain. Surprisingly, increasing evidence suggests such spontaneous electrical low-frequency oscillations (SELFOs) are found across the wide diversity of life on Earth, from bacteria to humans. This paper reviews the evidence for SELFOs in diverse phyla, beginning with the importance of their discovery in Hydra, and hypothesizes a potential role as electrical organism organizers, which supports a growing literature on the role of bioelectricity as a ‘template’ for developmental memory in organism regeneration.

And here is where the paper points to similarities between oscillations in the Hydra and the Default Mode Network in the human brain.

Sherrington’s still-influential proposal of the nervous system as effectively a ‘reflex organ’ waiting for environmental stimuli to push the organism to behavioural response —the foundational proposition of the input–output view of information processing —cannot account for spontaneous neural activity that seemingly has no effect on behaviour. As we have seen, however, such ‘cryptic’, non-behaviour-inducing spontaneous activity has been recognized in Cnidaria for more than half a century. Although speculated to play a role in coordinating animal behaviour at the time, the function of this activity was left to ‘future work’, which was never done. While poorly understood, findings across diverse Cnidaria were essentially the same: endogenously active nervous systems produced rhythmic, low-frequency pulses even in an unchanging environment and even when organisms were at rest. Why? Why would energetically expensive nervous systems be perpetually active in the absence of a stimulus and in the absence of any discernible behaviour? A clue about the potential role of this low-frequency spontaneous neural activity in comparatively simple organisms comes from an unexpected place: the human brain.

This is tied back to theories by Buszáki.

Another way to think about the potential role of the DMN in human self-construction is as the top layer of the hierarchical predictive coding ‘self-model’ as put forth by Friston. Like Buszáki’s theory, which predicts the need for an ultimate brain integrator or ‘reader’ (i.e. a ‘self’), a hierarchical predictive coding model also implies the need for an ultimate brain integrator or ‘predictor’ (also a ‘self’) at the top of the hierarchy. According to predictive coding brain models, prediction error is passed up the hierarchy from the low-level primary, unimodal sensory areas to the ultimate, multi-modal ‘predictor’ at the top of the hierarchy, which contains a high-level abstract representation (of the ‘self’) that then passes predictions back down to the lower levels. In this way, the DMN, oscillating at the lowest frequency in the brain, might act as the brain’s ultimate information integrator, receiving input from all the lower-level, otherwise isolated units (oscillating at higher frequencies), and passing on one unified ‘self’ prediction back down to generate coherent, adaptive behaviour

In conclusion, the author Hanson conjectures “that SELFOs may be the ultimate organism-wide electrical information integrators and communicators in all biological systems at all levels of scale, making them critical for maintenance of organism unity and coherent, adaptive behaviour”.

McFadden in his EM field theories emphasizes the noticeable synchronous firing of neurons during cognition, however, seems to pay little attention to the so-called “background noise” of the brain. These noticeable firings (frequently shown in red on brain images) are frequently used as proxy representations of consciousness in many cognition studies. I would suggest this might be a mistake. Base consciousness might be found in the EM fields generated by regular, even somewhat non-descript, firings of the DMN whereas the noticeable firings found on MRIs may, in fact, represent the integration of new information into the base consciousness.

Whatever the case may be Hanson provides some interesting thoughts in line with the Cellular Basis of Consciousness theory of Reber..

Posted in Consciousness, Electromagnetism, Origin of Life | 10 Comments

Feeling Neurons?

A recent post on panpsychism in relation to a book review and a comment by Travis R. has me thinking about some things.

One thing is whether we are fundamentally conflating two related but somewhat distinct concepts in discussions of consciousness.

The first concept relates to the connection between information and consciousness. The second concept is the feeling of the information.

Since information is physical, there is no reason to believe that matter itself even in its smallest forms might not contain information. An electron, for example, might be conceptualized as an “information field” that is a continually fluctuating wave of calculations about its itself and environment. I am using “information field” in an attempt to suggest something implementation neutral. It might be quantum, electromagnetic, or some other wave-like mechanism not understood at this time. It may be something like a tensegrity structure that I wrote about quite a while ago and that Donald Ingber discussed in a Scientific American piece. While Ingber was primarily talking about living forms towards the end of his discussion he writes:

Finally, more philosophical questions arise: Are these building principles universal? Do they apply to structures that are molded by very large scale forces as well as small-scale ones? We do not know. Snelson, however, has proposed an intriguing model of the atom based on tensegrity that takes off where the French physicist Louis de Broglie left off in 1923. Fuller himself went so far as to imagine the solar system as a structure composed of multiple nondeformable rings of planetary motion held together by continuous gravitational tension. Then, too, the fact that our expanding (tensing) universe contains huge filaments of gravitationally linked galaxies and isolated black holes that experience immense compressive forces locally can only lead us to wonder. Perhaps there is a single underlying theme to nature after all. As suggested by early 20th-century Scottish zoologist D’Arcy W. Thompson, who quoted Galileo, who, in turn, cited Plato: the Book of Nature may indeed be written in the characters of geometry.

The key idea is that there might be similar organizing principles in the small and the large and the principle might involve wrapping information and binding it into structure. The panpsychists then could be correct that consciousness in its information aspect is found throughout the universe in all matter and structures from the smallest to the largest. The complex consciousness that we humans have is but another example of an information structure built on common principles from which all structures in the universe are constructed.

At the same, however, our consciousness seems different, seems to be more than just information. The reason is that it is felt. This might be where the panpsychists, the IIT theorists, and computationalists go wrong when they conflate the feeling of the information with the information itself. Hence, we get absurd statements about electrons feeling things from the panpsychists or the notion that a thermostat might be minimally sentient from an IIT theorist.

Perhaps the prototypical neuron is the sensory neuron – a neuron that senses (feels?) something about its environment. The apparent “feeling” of consciousness is actually neurons sensing the feedback generated by other neurons in its environment. The mind in this feeling aspect is biological and localized to small areas over which neurons are able to be sensed, that is brains. The feedback itself provides an explanation for apparent causal ability of mind without which an evolutionary explanation for its origin is difficult. Consciousness as we know it and feel it represents a sort of wrapped structure, an “information field”, but it belongs to biological matter and is also felt.

Posted in Consciousness, Information, Waves | 7 Comments

Civil Servant With No Brain Explained

Occasionally I have seen various papers, blog posts, and comments referencing the famous 44 year French civil servant who lives a normal life seemingly without a brain. Sometimes the writers demand an explanation from consciousness theories. Other times arguments are made that substantial parts of mental processing must actually be occurring outside the brain (in the ether or mind at large, I suppose). The case was reported in The Lancet originally and was accompanied by this image of a brain scan.

The patient suffers from non-communicating hydrocephalus that likely has developed over the course of many years. The man is not missing a cortex. Rather the cortex has been compressed into a thin sheet.

A paper in 2018 Revisiting Paradoxical Situations Associated with Hydrocephalus explains how people with hydrocephalus can seemingly have normal brain functions.

Presumably, functioning of the neural network of the brain does not depend on the volume of fluid that surrounds its structures provided that certain physical parameters are met. The main requirement is that the behavior of this fluid does not interfere with the function of the brain structures, including the cortical neural network.

If the behavior of cerebrospinal fluid in a hydrocephalic subject meets all three conditions, that is constancy of velocity, normal cerebrocranial pressure, and comparatively low density (in the range of 1.003–1.008 g/mL) of the fluid (or specific weight, which is the same), then the overfilling of the brain with CSF does not limit the efficient functioning of all parts of the brain, including the cortex. This explains the fact that the patients with hydrocephalus who meet these conditions can exist and develop normally.

What cases like this and others tell us is that the brain is very flexible. It can function in a variety of shapes and forms. It can compensate for damages and defects within a fairly wide range. That is amazing but by itself doesn’t present any special paradox to brain and mind theories.

Posted in Brain size, Consciousness, Intelligence | 8 Comments