Medical EM fields: a plausible correlate of consciousness?

[Q_Goest]

Hi reena. You obviously have a good background for discussing this concept. Please have a gander at the paper under discussion. To summarize very briefly, the cemi field theory suggests that em fields, analogous to TV fields/transmissions, are used by the brain to bind or unify information. These fields are external to the neurons. It has been suggested by many that the em fields within neurons that are passed between gap junctions are insufficient to provide for unity. Such signals are discrete, local, and not integrated.

 

[somasimple]

Hi again,

If all neurons (ie: even nerves) interacted with the cemi field then our legs and fingers would be conscious too, provided they were close enough to interact.

But nerves are neurons!? and are connected to brain by neurons.
Some medical trials say that body stimuli are mandatory to process/create consciousness. So body is an indiscutable part of it (because body is just a way for brain to apprehend world)

See Damasio's books; Looking for Spinoza and the Descartes' Error.

 

[Q_Goest]

Some medical trials say that body stimuli are mandatory to process/create consciousness.

Interesting. Are you saying a "brain in a vat" would result in the brain not being conscious? Are stimuli provided by external means (ie: an electric impulse) not equal to actual stimuli? I can only remember a single bit of research that suggested they were, but that's not my field. I believe the whole point of the 'brain in a vat' thought experiment was to suggest there are no special signals, that any equivalent signal would produce identical reactions and would feel the same to the person. Hence, no loss or change in consciousness despite the brain being disconnected from a human and inside a vat.

 

[somasimple]

Hi,

I wasn't thinking so directly to the "brain in a vat" story. It is perhaps possible to reproduce all incoming "electrical" stimuli with patience and time?

But it will not work if you limit brain, to an electrical "computer" (it is not).
But brain is the first endocrine system of body and hormones/peptides produced are modifying directly the manufacturer.

Consciousness needs a "body state" to create a "reference Self". Brain works with differences comparing a state to a newer one and updating continuously the reference material.

Some medical states as psychosis and phantom limbs problems, for an example show that an impairment/perturbation of incoming stimuli create a distortion and "painful solutions".

It is why I persist to think that a cemi field is an integrated "reflection" of brain activity but it can't directly rely the subtle changes in the brain endocrine system.
Do not forget that a neuron is able to synthetize around... 20,000 peptides.

 

[cotarded]

Wow. The development of this thread has been an immensely pleasant suprise. Thanks to everyone, especially johnjoe - to who I am most grateful for sparing us the time -, q_goest, and somasimple, for putting such effort into what has become a great discourse. I've been humbled into silence thus far, since others have consistently provided a more eloquent and perspicious presentation of whatever questions, confusions, or observations I might have been able to offer. This has been a thoroughly thought-provoking experience, and has impelled me into quite a bit of illuminating research and questioning as well.
But anyway, nobody wants a bunch of praise and gratitude from someone who has nothing to say for themselves. So here's my input:
Somasimple said:

"But it will not work if you limit brain, to an electrical "computer" (it is not). ...
It is why I persist to think that a cemi field is an integrated "reflection" of brain activity but it can't directly rely the subtle changes in the brain endocrine system."

This all seems irrelevant to the cemi field theory, which, though it has claimed that the field has access to all of the information repersented by neural firing, doesn't need complete access to all the biology or chemistry that influences our neural processes. It seems to me that since we've already both accepted that the field is primarily effected ('e' intended) by large, synchronous groups of neurons, and that only a small part of the fields' content even comprises our consciousness, it seems cavilling to try and dismiss the idea on the basis of neglecting to factor a certain type of neural input.
From an evolutionary standpoint, this new system evolved in addition to the old, so it is seems only valid that it integrates less information than the system below it (unnecessary to reproduce the entire existing system - not even productive) to distill meaningful data to be returned to that system.
Somasimple:

"But nerves are neurons!? and are connected to brain by neurons.
Some medical trials say that body stimuli are mandatory to process/create consciousness. So body is an indiscutable part of it (because body is just a way for brain to apprehend world)"

As far as the first sentence, it seems you've forgotten this paper acknowledges a dichotomy between conscious and unconscious neural processing.
In addition, I'm willing to bet that those medical trials didn't induce unconsciousness, but simply disrupted normal functioning. Even someone lost in a fugue is still conscious, though functioning may be disrupted (I'm asserting sentience, which is generally assumed to be a conscious thing). Assuming knocking someone out through sensory deprivation were possible, a loss of sensory input may compromise lower systems in the brain that preceded the conscious, higher level systems evolutionarily, causing a loss of consciousness (as the conscious systems grew taking the others' nominal functioning for granted). A program for which internet access isn't essential, but assumed, can cease to function without an internet connection, because of the assumption, not due to an inherent requirement. This is relevant, because it implies the possibility of using pharmacological intervention to artifically compensate for the lack of afferent arousal and revive consciousness in a discarnate brain.
somasimple:

"Do not forget that a neuron is able to synthetize around... 20,000 peptides."

Man, the complexity of our brains is just unfathomable .
q_goest:

"If all neurons (ie: even nerves) interacted with the cemi field then our legs and fingers would be conscious too, provided they were close enough to interact."

Not conscious, but contributing information to the conscious field. One of the advantages of this theory was it's elegant resolution of the binding problem... we can't simutaneously entertain the idea of delocalized consciousness.
q_goest:

"here are two ways to reduce or eliminate the impact of stray em fields and I believe both are needed for the cemi field theory and both are actually discussed in the papers.
1. Neurons must be reasonably well isolated from stray noise.
2. Neurons must be capable of filtering the noise from the fundamental signal."

It seems to me that these concerns about noise, or a distored signal, are misplaced. Assuming evolution, the whole thing developed with the distortion/noise concurrent. Perhaps I am forgetting that the position of neurons in your brain is far from set in genetic stone. Dismissing genetic evolution, there's the evolution of your conscious system as you develop from a- nebulously conscious -newborn. Your consciousness cohering and becoming "capable of communicating self-generated inrreducibly complex concepts like 'self'," could repersent the slow acquisition of neural configuration that considers the distortion of signal, interference, etc.
lates,
cotarded.

 

[cotarded]

motor neurons: decisive for consciousness?

Again and again, motor neurons are mentioned in this paper and in this thread as what divides the consciousness-relevant bits of the em field from the rest. I propose something that at least to me seems far more reasonable.
After all, what makes consciousness so enigmatic is how private and personal the experience is; I can't reconcile that with a dependency on outward expression (here come the studies that show subvocalisation for our internal speech).

Memory. What is a flash of sentience in the dark? Our consciousness could be what it feels like to be an evolving feedback loop inside short-term memory, with input supplied by the outside world. So maybe there is field consciousness, and all the other sorts described in the paper, but what makes us self-reflective is the fact that we CAN reflect off of ourselves: our stored snapshots in memory. So I opine that the part of our EM field that can affect the memory encoding process is the part that is conscious.

Feedback?

-cotarded.

 

[hypnagogue]

Memory. What is a flash of sentience in the dark? Our consciousness could be what it feels like to be an evolving feedback loop inside short-term memory, with input supplied by the outside world. So maybe there is field consciousness, and all the other sorts described in the paper, but what makes us self-reflective is the fact that we CAN reflect off of ourselves: our stored snapshots in memory. So I opine that the part of our EM field that can affect the memory encoding process is the part that is conscious.

If you read any of Bernard Baars' work, his model of consciousness largely implicates working memory and attention as two of the main cognitive functions associated with consciousness. (Any in-depth further discussion on this is probably better left for another thread.)

In a sense, focusing on motor systems makes sense, since presumably any mental content that is within consciousness can be poised to guide flexible kinds of motor behavior, even if it does not wind up doing so (e.g. as in Ned Block's conception of access consciousness). So a reasonable constraint on any theory of consciousness is that the phenomena in the brain proposed to be correlated/synonymous/whatever with consciousness have the requisite kind of power to affect the brain's motor outputs. Though of course, that will not be the only useful constraint.

 

[Q_Goest]

I feel a bit let down by the 8 predictions provided by the theory. I'm not convinced the predictions, if proven, would thus prove the theory. I'd be glad to hear arguments to the contrary.

However, I think there's a very solid prediction the theory could make. The theory suggests that motor neurons are the ones interacting with the cemi field, but it is acknowledged this field is analogous to a single TV station signal among hundreds of signals which are simply garbage (per McFadden). From the second paper under "Pockett's difficulty 2"

Pockett's second difficulty points out that 'there actually is no one-to-one correspondence between electromagnetic patterns measurable at the scalp or the surface of the brain and the conscious sensations experienced by the "owner" of the brain' (p. 53). However, I would argue that this is only a problem for em field theories that propose an identity between the brain's total em field and conscious experience. Indeed, the issue highlights a difficulty with any identity theory between the brain's em field and consciousness. Since every action potential generates a perturbation in the surrounding em field, the information flow through the brain's em field must be of a similar order of magnitude as the spike rate of cortical neurons, about 10^12 bits per second. But this is far greater than the approximately 40 bits per second that are estimated to be involved in conscious thinking (Norretranders, 1998). Clearly only a tiny component of the information held in the brain's em field can correspond to consciousness so any identity theory must find some means of discarding the excess information. In the cemi field theory this is explained by the requirement for the field information to be downloaded to motor neurons. In my paper, I showed that induced transmembrane voltages are in the range of several microvolts up to about one millivolt. Neurons will thereby only be sensitive to em field effects when they are within a millivolt or less of the firing threshold. Since transmembrane voltages vary across approximately 130 mV, very crudely, we would expect less than one hundredth of neurons to be receptive to information held in the surrounding extracellular field. The corollary of this is that most of the information in the brain's em field will not be downloaded into neurons. Therefore, in the cemi field theory, only a tiny portion of the informational content in EEG or MEG signals would be expected to correlate with consciousness. A one-to-one correspondence between perturbations of the brain's em field and consciousness is not therefore expected in the cemi field theory. Although the failure to make a clearly verifiable prediction of a correlation between the gross structure of the brain's em field and consciousness may be considered to be a weakness of the cemi field theory, the theory does make many alternative predictions as described in my earlier paper, and I describe a direct test in the final section of this paper.

In the final section of the paper, a very unique prediction is provided (Discussion section) but the prediction requires the manufacture of an artificially aware computer. I'd agree this would be a much more solid, even indisputable test of the theory. Unfortunately for us, it is so far off into the future we probably won't see such a test in our lifetimes.

Instead, I would suggest one could make a prediction about the theory which is testable today using current technology.

The theory MUST predict that the portion of the em field in the brain, the cemi field, is somehow different from the rest. If it didn't then the motor neurons would also pick up all the other garbage in the em field and not be able to distinguish, just as a TV signal that had another signal of the same frequency on top of it could not receive the TV signal. Your TV would give you lots of static and garbage because both signals were using the same frequency. The same applies to the cemi field, it has to be different enough (not necessarily frequency, though I'm unsure of this) that the motor neurons can separate it out from the garbage.

Similarly, the cemi field theory must predict that the motor neurons are different than other neurons with respect to certain em fields. One can for example, analyze an antenna and/or a radio and determine what signal frequency it is able to interact with. Conversely, the motor neurons (if they really are picking up this cemi field) must be able to interact with whatever is unique about the cemi field. One should be able to analyze a motor neuron and a neuron in your finger for example, and show that these neurons are capable of interacting with different em fields. This is normally done in engineering using sophisticated finite element or "control volume" concepts. Such tools should be capable of indicating what em fields a neuron is susceptible to and prove one way or another if the cemi field theory is correct or not.

Cotard said: Not conscious, but contributing information to the conscious field.

Yes, exactly. Sensory neurons, per the cemi field theory, must relay information which contributes to the cemi field, but not be sensitive to it (they are not motor neurons in the brain). The only way I can see that being possible is for the sensors (ie: nerves in your hand) to transmit a signal to your brain, and some other neurons in the brain must then convert that information to the cemi field. One has to ask the question, "What neurons create the cemi field?" I don't see that in the paper, but in principal, I believe the answer is that sensory neurons transmit information to the brain which is then converted by other neurons into em vibrations which can be interpreted by the motor neurons or something like that.

I'd also suggest another prediction but I'll hold off on that one for now.

 

[Q_Goest]

Ok, I think I just fell off the deep end and would like to know if there are any sharks in these waters. <grin> I'm looking at a picture of various types of neurons. If I use my imagination, the axon looks a lot like an antenna, and the nodes of Ranvier look like the neuron's way of tuning that antenna. The distance between these nodes might act to selectively transmit/receive specific em frequencies. And I'd think the general shape would have a distinct effect on em field interaction as well (though I suspect that shape is generally straight). This suggests that the length of an axon, and the distance between nodes (and possibly the general shape) will characterize the frequency of response to any em field that the neuron is exposed to. If there is something unique about specific neurons in the brain which might interact with a field, it might be these characteristics of the axon. Can anyone comment on the role of the nodes?

 

[Moonbear]

Ok, I think I just fell off the deep end and would like to know if there are any sharks in these waters. <grin> I'm looking at a picture of various types of neurons. If I use my imagination, the axon looks a lot like an antenna, and the nodes of Ranvier look like the neuron's way of tuning that antenna.

You're looking at a stylized drawing for the purpose of schematically illustrating the parts of a neuron. It's not what they really look like if you look at them under a microscope. Besides, similarity in shape does not translate into similarity in function.

 

[Moonbear]

[Johnjoe]
But connexion 36 is the major gap junction protein in the mouse brain. Subsequent have confirmed that the KO mice completely lacked ANY functional gap junctions in the brain. See for instance,
De Zeeuw, C. I. et al (2003) Deformation of Network Connectivity in the Inferior Olive of Connexin 36-Deficient Mice Is Compensated by Morphological and Electrophysiological Changes at the Single Neuron Level. The Journal of Neuroscience, June 1, 2003, 23(11):4700-4711
One of the tests the authors performed was to inject Lucifer yellow into olivary neurons. With functional gap junctions [of any kind!] in the wild-type mouse the dye spreads to adjacent neurons but “ in all Cx36-deficient mice, the injections resulted in labeling of single neurons only (n = 16), whereas those in the wild types always provided clusters of multiple neurons (n = 18, with an average of 8 ± 3.8).”
The authors go on to perform electrophysiology measurements that lead them to conclude that “no functional gap junctions exist in the homozygous mutants.”.

Thanks. That article is far more convincing that functional gap junctions are absent than the previously cited ones.

That the mice still demonstrate rhythmic oscillations in the brain is very interesting. The above study found evidence that the mice compensate for loss of gap junctions by making their neuronal membranes more electrically sensitive. This would make them more sensitive to EM fields (although that hasn’t yet been demonstrated) so it may be that EM fields are maintaining synchronicity in these mice.
johnjoe

It seems you've misunderstood what they mean by rhythmicity here. The rhythmic oscillations are detected in single-cell recordings. In the field of circadian rhythms, that individual cells can maintain rhythmicity is well-established, especially in recent years, and the mechanism for this at a molecular level is worked out in great detail (although not complete by any means).

However, what is lacking in these Connexin-36 knock-out mice is the synchronization. In other words, while each cell has a rhythm, those rhythms are not synchronized across cells. This is demonstrated by:
Long MA, Deans MR, Paul DL, Connors BW. 2002 Rhythmicity without synchrony in the electrically uncoupled inferior olive. J Neurosci. 22: 10898-905.

If anything, this seems to demonstrate pretty strongly that gap junctions are required for synchrony (not rhythmicity), and in the absence of gap junctions AND synchrony, behavior (and consciousness) is not grossly affected in these mice (I still haven't come across anything reporting any real battery of behavioral tests in these KO mice to find out if there are any deficits that may be more subtle). That consciousness is not affected by loss of synchrony suggests this synchrony you refer to is not required for consciousness. And, if synchrony can be disrupted by loss of gap junctions, it would also indicate that these CEMI fields are not sufficient for synchrony.

I'm afraid I need to cut this post short though...I forgot my power cord at the office today and my laptop battery is running low.

 

[somasimple]

Hi All,
I took the time to find the thing that ran in my head since I read this piece =>

I showed that induced transmembrane voltages are in the range of several microvolts up to about one millivolt. Neurons will thereby only be sensitive to em field effects when they are within a millivolt or less of the firing threshold. Since transmembrane voltages vary across approximately 130 mV...

Transmembranes voltages during action potential are effectively around 130mV for myelinated axons/soma and "trunks" of pyramidal cells (a very good integrator). That is only true for communication pathways but false for dendritic trees and synaptic trees. The potential is heavily linked to the shape diameter of cell. It is yet a riddle for many "electrical" thinkers about neurons... but it finds its explanation with ions channels, geometry and... Gauss' law.
It is not known how there is an amplification of signals all along these trees since it violates the "orthodox" cable theory.
It remains true that in dendrite and small axons (like C fibres) action potential have only an amplitude of 2 mV and is not measurable on their endings. It means that some axons, with 130 mv APs, travel close to branches where small/non measurable signals are added forming a tree and finally an exploitable AP. The two are existing at the same time and must definitely conclude that noise immunity is enabled at a level that discard the above hypothese. It is well known that in these trees, strong electric stimulations have local effects but it is needed multiple stimuli for an axon firing. That is a protection against stochastic firing and ephactic contamination.
Of course, an EM field may enhance the functionning at this level but it is difficult to understand how a system who share at the same time a collecting of small signal below 1mV (in dendrites and terminals) with an AP of 130 mV which has no effect on the previous, may be perturbed by long distance fields, since close did not.

 

[somasimple]

Hi guys,

I found unfortunately another failure in the hypothesis.

1/ EM field enhances neuron firing.
2/ neuron firing creates an EM field.

These assertions are components of a divergent system. It functions exactly as a microphone put close to loudspeakers. Good chances to create a Larsen effect.

 

[cotarded]

Hey somasimple, I am not sufficently knowledgeable about transmembrane voltages,etc to do anything but continue my reading to investigate that point.
But as far as this goes:

Hi guys,
I found unfortunately another failure in the hypothesis.
1/ EM field enhances neuron firing.
2/ neuron firing creates an EM field.
These assertions are components of a divergent system. It functions exactly as a microphone put close to loudspeakers. Good chances to create a Larsen effect.

Neuronal firing leads to more firing - so why aren't we in a constant state of seizure? Because there is negative inhibition in the system (there wouldn't need to be much to quell things - the receptive neurons need to be on the knife edge of firing to be so). And it could be the same with this.
Also, just like some neurons are inhibitory, certain bits of the EM field can have an inhibiting effect (perhaps by lack of relative amplitude at that point), or excite inhibitory networks of neurons. And again, we've accepted that only a small contingent of neurons would be responsive to the field - who's to say there's unmitigated feedforward from that region to whatever regions are generating the most field? I'm sure my arguments are swiss cheese, but I'm certain that "there'd be feedback" is far from a theory killer.
If I'm missing something and you can elucidate, please do so. I hope I don't come off as antagonistic.
lates,
cotarded

 

[somasimple]

Cotarded,

I like/love arguing and I do not want to be a theory killer, really.

Maybe I was to quick with my two points and they need a refinement.

1/ Theory says that EM field enhances neuron firing. (hypothese).
2/ neuron firing carries EM field (fact)
3/ AP, EM field and threshold are related to diameter. (fact)
4/ axons have higher diameter than dendrites (fact)
5/ axon transmits information (fact)
6/ dendrites collect/spread information (fact)

If the hypothese is true thus all the following facts are modified accordingly.
It may be normal thus to suppose that it enhances all the components of neuron.
It is of course possible to suppose that soma/axon are enhanced and dendrites inhibited.
You will fall in a divergent system too since you'll get an auto-damped looked loop. The system trends to shut off while EM field is created.

Below is a fine abstract that is saying exactly what you're saying.
Inhibition is coupled with gaps junctions producing a stable system that shows few divergent behaviours.

Neural Comput. 2005 Mar;17(3):633-70.
The combined effects of inhibitory and electrical synapses in synchrony.

Pfeuty B, Mato G, Golomb D, Hansel D.

Neurophysique et Physiologie du Systeme Moteur, Universite Rene Descartes, 75270 Paris Cedex 06, France. bpfeuty@biomedicale.univ-paris5.fr

Recent experimental results have shown that GABAergic interneurons in the central nervous system are frequently connected via electrical synapses. Hence, depending on the area or the subpopulation, interneurons interact via inhibitory synapses or electrical synapses alone or via both types of interactions. The theoretical work presented here addresses the significance of these different modes of interactions for the interneuron networks dynamics. We consider the simplest system in which this issue can be investigated in models or in experiments: a pair of neurons, interacting via electrical synapses, inhibitory synapses, or both, and activated by the injection of a noisy external current. Assuming that the couplings and the noise are weak, we derive an analytical expression relating the cross-correlation (CC) of the activity of the two neurons to the phase response function of the neurons. When electrical and inhibitory interactions are not too strong, they combine their effect in a linear manner. In this regime, the effect of electrical and inhibitory interactions when combined can be deduced knowing the effects of each of the interactions separately. As a consequence, depending on intrinsic neuronal properties, electrical and inhibitory synapses may cooperate, both promoting synchrony, or may compete, with one promoting synchrony while the other impedes it. In contrast, for sufficiently strong couplings, the two types of synapses combine in a nonlinear fashion. Remarkably, we find that in this regime, combining electrical synapses with inhibition amplifies synchrony, whereas electrical synapses alone would desynchronize the activity of the neurons. We apply our theory to predict how the shape of the CC of two neurons changes as a function of ionic channel conductances, focusing on the effect of persistent sodium conductance, of the firing rate of the neurons and the nature and the strength of their interactions. These predictions may be tested using dynamic clamp techniques.

PMID: 15802009 [PubMed - indexed for MEDLINE]