Introducing the brain: consciousness as ephaptic fields (Introduction)

by David Turell , Thursday, November 14, 2024, 22:22 (7 days ago) @ David Turell

Latest theory:

https://www.scientificamerican.com/article/consciousness-might-hide-in-our-brains-elect...

"While neuroscientists have long focused on spikes travelling throughout brain cells, “ephaptic” field effects may really be the primary mechanism for consciousness and cognition. These effects, resulting from the electric fields produced by neurons rather than their synaptic firings, may play a leading role in our mind’s workings.

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"Brain researchers have long acknowledged that there are a number of ways other than firing by which neurons could communicate, including the little-known mechanism known as ephaptic coupling. This coupling results from electromagnetic (EM) fields at the medium and large scales of the brain interacting, alongside much smaller scale fields accompanying synaptic spikes (which themselves result from a type of highly localized EM field activity) operating at nanometer scales.

"Retinal neurons, for example, operate without any neural firing. These cells employ a type of electrodiffusion, the diffusion of charged particles without synapses, the connection points between neurons. Electrodiffusion passes along a signal to the optic nerve at very fast rates and with high bandwidth. We couldn’t see without this.

"The “ephaptic” in ephaptic coupling simply means “touching.” Though not well-known, ephaptic field effects result from the textbook electric and magnetic interactions that power our cells. Intriguing experimental results suggest these same forces play a bigger role in the brain than one suspected and perhaps even in consciousness.

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"That lab demonstrated that the mouse cortex was affected without synaptic connections—by definition, ephaptic field interactions. This remarkable effect was found by the Durand team after they cut a slice of mouse hippocampus in half and then measured the voltage potential going up and down the slice. There was almost no change in that measured voltage even after the slice was fully severed, demonstrating a strong influence from ephaptic fields.

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"Another team compared the speed of ephaptic field effects in various tissues, finding that the speed of propagation of ephaptic fields in gray matter is about 5,000 times faster than neural firing.

"This means that what would take normal spike pathways one second to span through the brain, could be traversed 5,000 times during that same time interval with ephaptic effects. If we cube this over the volume of the brain we get an information density up to a staggering 125 billion times more from ephaptic fields than from synaptic firing.

"A key caveat to this statement is to stress that this is potential information density only, and it is not necessarily the case that this potential can actually be reached. More research will need to be done to see how much of this vast ephaptic potential is realized by our brains.

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"Walter Freeman, a legendary now-deceased neuroscientist from the University of California, Berkeley, stated in a 2006 paper that traditional synaptic firing speeds could not explain the speed of cognitive functions he had observed over the years in rabbits and cats.

"Instead the recent spate of ephaptic effects findings suggest a solid mechanism to explain these speeds. Our recent theoretical paper, building on these findings, suggested that ephaptic field effects may in fact be the primary mechanism for consciousness and cognition, rather than neural firing.

"Another recent paper including as authors the University of California, Los Angeles’s Costas Anastassiou and former Caltech neuroscientist Christof Koch, provides strong support for the importance of ephaptic effects. They find that, indeed, ephaptic coupling can explain the “fast coordination” required for consciousness “even in the absence of very fast synapses.”

"This single paper could take the field of ephaptic field science from the fringes of neuroscience to the forefront. Its findings regarding the speed and pervasiveness of ephaptic field effects may presage a fundamentally new understanding of how cognition and consciousness work." (my bold)

Comment: the bold just above expresses my feelings. It is an impressive suggestion. I must admit it comfortably fits my underlying dualism, as a field theory not fully tied to serial synaptic connections but fitting into fields