Theories relating electromagnetic (EM) fields and consciousness date back to the mid-twentieth century. For a high level overview both Scholarpedia and Wikipedia provide good summaries.
There are basically four ways to view the relationship between EM fields and consciousness.
- Consciousness is identical with certain types of electromagnetic fields in the brain.
- Consciousness is produced through a mechanism that allows the brain to perceive its own electromagnetic activity.
- Electromagnetic activity in the brain is involved with but does not directly produce consciousness, possibly by controlling the synchronization of neurons firing.
- Electromagnetic activity in the brain is an epiphenomenon with no direct relationship to consciousness.
Two names recently have become more associated with EMF theories of consciousness: Susan Pockett and Johnjoe McFadden.
Susan Pockett is a neurophysiologist from New Zealand. Her basic thesis is that “consciousness is identical with certain spatiotemporal patterns in the electromagnetic field”. Works by her include:
Pockett, S. (2012) The electromagnetic field theory of consciousness: a testable hypothesis about the characteristics of conscious as opposed to non-conscious fields. Journal of Consciousness Studies 19 (11-12) 191-223. (View a PDF version of the article)
The Nature of Consciousness: A Hypothesis, a book published in 2000.
Johnjoe McFadden is a Professor of Molecular Genetics. Although he has written on quantum mechanical effects in biology, his theories of consciousness do not rely on or require them. An overview of his position can be found on his web site.
McFadden, J. (2002). Synchronous firing and its influence on the brain’s electromagnetic field: Evidence for an electromagnetic field theory of consciousness. Journal of Consciousness Studies 9 (4):23-50.
McFadden, Johnjoe (2006).The CEMI field theory: Seven clues to the nature of consciousness. In J. Tuszynski (ed.), The Emerging Physics of Consciousness. Springer Verlag. pp. 387–406.
There is a great summation of views on the topic with some historical perspective by Mostyn W. Jones: Electromagnetic-Field Theories of Mind.
Some researchers are skeptical that the EM fields produced in the brain by neurons are strong enough to affect other neurons.
McFadden’s take on this:
Neurons are fired by specific structures, known as voltage-gated ion channels that respond to the external em field. Mostly they are gated in such a way that only massive changes to the brain’s em field are likely to influence neuron firing. However, in a busy brain there will be many neurons teetering on the brink of firing and these undecided neurons may be exquisitely sensitive to the em field. The cemi field our consciousness – will come into play when the brain is poised to make delicate decisions.
Much of research on this topic uses the term “ephaptic coupling”. While technically this term can apply to any type of extra synaptic activation, in many cases, the research is exploring EM field effects. This is a difficult topic to research since needs to be done at the cellular level and usually requires insertion of electrodes or other measuring devices which can be intrusive on the effect being studied.
Anastassiou, C., Perin, R., Markram, H. et al. Ephaptic coupling of cortical neurons. Nat Neurosci 14, 217–223 (2011) doi:10.1038/nn.2727
Slow periodic activity in the longitudinal hippocampal slice can self‐propagate non‐synaptically by a mechanism consistent with ephaptic coupling Chia‐Chu Chiang, Rajat S. Shivacharan, Xile Wei, Luis E. Gonzalez‐Reyes, Dominique M. Durand. J Physiol. 2019 Jan 1; 597(1): 249–269. Published online 2018 Nov 10. doi: 10.1113/JP276904 PMCID: PMC6312416
Fröhlich F, McCormick DA.Endogenous electric fields may guide neocortical network activity.Neuron. 2010;67(1):129–143. doi:10.1016/j.neuron.2010.06.005
Zhang M, Ladas TP, Qiu C, Shivacharan RS, Gonzalez-Reyes LE, Durand DM. Propagation of epileptiform activity can be independent of synaptic transmission, gap junctions, or diffusion and is consistent with electrical field transmission. J Neurosci. 2014;34(4):1409–1419. doi:10.1523/JNEUROSCI.3877-13.2014
Scholkmann, Felix. (2015). Two emerging topics regarding long-range physical signaling in neurosystems: Membrane nanotubes and electromagnetic fields. Journal of integrative neuroscience. 14. 1-19. 10.1142/S0219635215300115.
Kyung-SeokHan, ChongGuo, Christopher H.Chen, LaurensWitter, omasOsorno, Wade G.Regehr Ephaptic Coupling Promotes Synchronous Firing of Cerebellar Purkinje Cells, Neuron, Volume 100, Issue 3, 7 November 2018, Pages 564-578.e3