Meanwhile, a second objection, this one often posed by psychologists in particular, is that this theory was proposed in the 1940s by the gestalt theorist Wolfgang Köhler and disproved experimentally a few years later by Karl Lashley and Roger Sperry. This objection again depends on a lack of understanding about the differences between the fields in Köhler's electric field theory of brain function and those in the modern electromagnetic field theory of consciousness. At the time Köhler was working, almost nothing was known about the details of how the brain works -- even action potentials and synaptic potentials were unknown -- so it was reasonable for him to propose the existence of transcortical rivers of electric current called figure currents to underpin visual perception. Lashley and Sperry individually attempted to test this idea of Köhler's by short-circuiting the hypothetical figure currents with metal pins or strips inserted into the brains of cats and monkeys. After doing this they didn't find any obvious differences in the animals' ability to see, so Lashley proclaimed Köhler's electric field theory dead. (Sperry was a bit more circumspect). In fact by modern standards I don't think either Lashley's or Sperry's experiments were particularly convincing, but the main point here is that with the benefit of nearly 70 years further knowledge of neurophysiology, the modern EM field theory doesn't propose anything like Köhler's figure currents (for which no evidence has since been found in any case). The fields the EM field theory talks about are simply 3-D patterns of local field potentials, which would not be affected at all by Lashley's and Sperry's pins and strips.
There are a number of more idiosyncratic objections advanced and answered in my 2000 book The Nature of Consciousness, but those are the most common ones.
MLU: One advantage of the electromagnetic field theory of consciousness is that it is possible to develop the means to empirically test it. In 2008 I briefly made contact with Russian researchers at the experimental physics department of Ural University of Physics and Technology who reportedly developed the necessary hardware components for an “electromagnetic consciousness” based on the electromagnetic field theory, but I have not heard anything from or about them since. Do you know of any other attempts that have been made to test your theory -- and/or do you have anything in mind yourself?
SP: I have no idea what those Russian guys were talking about, but as I recall they said they were basing their ideas on Johnjoe McFadden's CEMI theory, which is different from mine in a number of respects anyway. No, I don't know of any other experiments that could be construed as tests of my theory -- but yes, I have recently figured out a relatively do-able test which I would very much like to find an opportunity to carry out. Filthy lucre is, of course, again the road-block.
For the aficionado (because to explain it clearly in lay terms would take pages of text and pictures), the basis of this test is to voltage clamp the local field potentials evoked in particular radial layers of particular tangential columns of mammalian neocortex by an external sensory stimulus. The prediction of the theory is that this should prevent the relevant conscious experience. Since the ion channels involved in generating local field potentials are not themselves voltage sensitive, it should be possible to achieve this clamp without affecting the ongoing synaptic processing. Thus this experiment has the major advantage that would not only test the EM field theory, but also unequivocally distinguish between that and the psychoneural identity theory. If it were possible to change a conscious experience by changing the spatial field pattern and not the neural processing that produces it -- in other words to change consciousness by changing the field and only the field -- then Ockham's razor would say pretty unequivocally that consciousness and field are one and the same.