London, U.S. scientists suggest cognition far more than neuron processing in the brain

What if cognition--thinking--is not simply a function of neurons interacting in the brain, but a process involving the entire human organism?

This is the radical suggestion explored in detail by two cognitive scientists, in a preprint posted online on PsyArXiv, Sept. 13. The authors are Anna Ciaunica, a philosopher and cognitive scientist at the Institute of Cognitive Neuroscience, University College London, and Mike Levin, a cognitive scientist and developmental biologist at the Allen Discovery Center, Tufts University in Medford, Massachusetts.

The authors challenge the idea that "only the neuronal cells in the brain have the exclusive ability to `learn' or `cognize.'" Instead, they focus on cellular processing and look at cognition as a "multiscale web of dynamic information processing distributed across a vast array of complex cellular (e.g. neuronal, immune and others) and network systems operating across the entire body, and not just in the brain."

Ciaunica and Levin build their case by reviewing current research that suggests the brain's processes are more flexible and are linked to other systems, such as immune system processing. They look first at the role of cellular processing in general in the self-organization of the human body. 

Second, they present the growing evidence that non-neural cells have the ability to cognize or learn. Third, they discuss the brain as a bodily system that "needs to carefully orchestrate and align its neural processing with a complex network of other types of cellular processing (e.g. immune) to ensure the organism's survival and viable interactions with the world."

Lastly, they suggest the best way to look at cognition is by recognizing it as "multiscale processes" in the whole organism, implemented by bodily systems and cellular networks that are multilevel and intricate.

`Billions to trillions of cells'

The authors bring together much research evidence that the billions to trillions of cells in the bodies of large organisms "need to carefully orchestrate their exchanges with each other and with the external environment to allow the organism to successfully survive and grow." 

They suggest that the roots of sophisticated human cognitive processing can be "traced back to the humble origins of information processing in the metabolic homeostatic mechanisms of ancient cells." The human brain's cognition process is part of a "continuum" with the way simpler forms of life process information, they write. Many organisms, "including aneural ones display proto-cognitive functions such as memory, prediction and learning," 

Interestingly, the authors cite research proposing a "parallel between neurons and bacteria," noting that the molecular infrastructure associated with neural processing actually predated the evolution of neurons.

Signaling to what?

The brain's architecture has a complex network of neural signaling, they write, but this "signaling would be sterile ... if it was not directed at and connected to other non-neuronal cells and network systems subserving the viable functioning of the self-organizing organisms as a whole."

The authors single out the immune system processing as a chief example of this point. "...(T)he immune system is uniquely like the brain. Both brain and immune system develop fully, far beyond their genes, as a result of somatic lifetime experience.... the same way immune cells interact and communicate with each other to deliver adaptive response to incoming signals, the neuronal cells need to interact not only with each other, but also with non-neuronal cells (e.g. immune cells) to coordinate joint responses."

In summary, Ciaunica and Levin emphasize that the boundaries between neuronal and non-neuronal cellular processing are more complex and more flexible than commonly thought. They stress that successful survival of the human organism cannot occur by neural processing alone, without coordination with other body systems. They invite "a nuanced understanding of cognitive processing as cut across multiple levels of bodily systems and cellular processing (e.g. neuronal andimmune)." 

In all the research they compile supports the authors' "radical claim that cognition should not be confined to one system alone, namely the neural system in the brain, no matter how sophisticated the latter notoriously is."

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Anna Ciaunica & Mike Levin. "The Brain is Not Mental! Coupling Neuronal and Immune Cellular Processing in Human Organisms." Preprint, PsyArXiv, Sept. 13. https://doi.org/10.31234/osf.io/fgcy5