This is the second part of two posts on a paper by Johnjoe McFadden Synchronous Firing and Its Influence on the Brain’s Electromagnetic Field Evidence for an Electromagnetic Field Theory of Consciousness.
The paper provides an overview of McFadden’s EM field theory of consciousness (cemi). In the first post, I focused mainly on eight predictions his theory makes. In this post, I want to focus on the parts of his argument about how EM field theory helps to answer some of the difficult problems in consciousness research.
McFadden begins with a discussion about various ways EM fields might be related to consciousness. McFadden takes what he calls a strong interpretation approach:
I propose here that our thoughts are similarly electromagnetic representations of neuronal information in the brain, and that information is in turn decoded by neurons to generate what we experience as purposeful actions or free will. This circular exchange of information between the neurons and the surrounding em field provides the ‘self-referring loop’ that many cognitive scientists have argued to be an essential feature of consciousness.
A strong interpretation can be contrasted with a weak interpretation that EM fields provide a sort of portal to view the brain’s internal operations or the epiphenomenal view that EM fields are present in the brain but are mostly side-effects of neurons firing that contribute little to consciousness.
McFadden also contrasts his approach also with Susan Pockett’s in his emphasis on informational aspects of EM waves and fields. In this regard he is careful to distinguish between synchrony of firing neurons that transmit information and excessive synchrony that transmits little information, such as the case of epileptic seizures.
Next he tackles five problems of consciousness research that he believes his theory helps to resolve. As before, the selected content below is quoted directly from paper. Highlights in bold are mine. I would especially like to call out his critique of the neural identity theory in the binding problem section.
1. The difference between conscious and unconscious information processing
In the cemi field theory, the neural circuits involved in conscious and unconscious actions are proposed to differ in their sensitivity to the brain’s em field. During unconscious driving, the sensory and motor activity responsible for the driving the car would have been performed by neurons with membrane potentials far from the critical threshold for firing (either positively or negatively) and thereby insensitive to the brain’s em field. When new or unusual stimuli reach the brain (presence of child on road) the consequent synchronous firing of neurons involved in processing that new information would transmit the information to the brain’s em field, allowing it to reach our conscious awareness. This additional sensory input may shift the membrane potential of some of the neurons involved to near the firing threshold and thereby make the whole neuronal pathway sensitive to augmentation by the brain’s em field. Our conscious mind — the cemi field — does indeed take over.
The cemi field theory also provides a natural explanation for how, in the words of Bernard J. Baars (1993), ‘a serial, integrated and very limited stream of consciousness emerge from a nervous system that is mostly unconscious, distributed, parallel and of enormous capacity’.
2. The role of consciousness in memory
If the target neurons for em augmentation are connected by Hebbian synapses then the influence of the brain’s em field will tend to become hard-wired into either increased (long-term potentiation, LTP) or decreased (long-term depression, LTD) neural connectivity. After repeated augmentation by the brain’s em field, conscious motor actions will become increasingly independent of em field influences.
Similarly, in the absence of any motor output, the cemi field may be involved in strengthening synapses to ‘hard-wire’ neurons and thereby lay down long-term memories.
3. The nature of free will
Therefore, whereas in agreement with most modern cognitive theory, the cemi theory views conscious will as a deterministic influence on our actions, in contrast to most cognitive theories it does at least provide a physically active role for ‘will’ in driving our conscious actions. In the cemi field theory, we are not simply automatons that happen to be aware of our actions. Our awareness (the global cemi field) plays a causal role in determining our conscious actions.
4. The nature of qualia
However, awareness per se, without any causal influence on the world, cannot have any scientific meaning since it cannot be the cause of any observable effects. In the cemi field theory, consciousness — the cemi field — is distinct from mere awareness in having a causal influence on the world by virtue of its ability to ‘download’ its informational content into motor neurons. It therefore corresponds quite closely to what Ned Block terms (Block, 1995) ‘access consciousness’. How far animals or inanimate informational systems are conscious will depend on whether they possess complex information fields that are capable of having a causal influence on the world. This may well be amenable to experimental testing.
Since, in the cemi field theory, a conscious being is aware of the information contained within the cemi field, qualia — the subjective feel of particular mind states — must correspond to particular configurations of the cemi field. The qualia for the color red will thereby correspond to the em field perturbations that are generated whenever our neurons are responding to red light in our visual field. However, since at the level of the brain’s em field, sensory information may be combined with neuronal information acquired through learning, the ensuing field modulations would be expected to correlate not with the sensory stimuli alone, but with the meaning of particular stimuli. This was indeed what Freeman discovered in his classic experiments on rabbit olfaction (Freeman, 1991).
5. The binding problem
To illustrate the problem, consider two entirely independent neural networks (either biological or artificial): the first is able to recognize green objects, and the second is able to identify round objects. If an apple is presented to both networks then, in a neural identity theory of consciousness, each network would (if sufficiently complex) experience their own particular qualia for roundness or greenness. But now we add a wire (or neuron) that connects the two networks so that the combined assembly is able to recognize objects that are both round and green. A neural identity theory would then predict that the enlarged network should experience qualia in which roundness and greenness are somehow bound together in a way analogous to our own conscious perception of an apple. Yet the only additional input that either network would have received is a single binary digit travelling down the connecting wire from the adjacent network. Neither ‘roundness’ nor ‘greenness’ could be fully described by a single binary digit. To account for the existence of unified qualia that includes the information coming from both networks, the neural identity theory must propose some overarching reality that connects and unifies the two networks. But no such overarching reality exists — at least at the level of matter
But in the human brain, there is an overarching reality that connects neural networks: the brain’s electromagnetic field. At the field level, and in contrast to the neuronal level, all aspects of the information representing the apple (colour, shape, texture etc.) are physically linked to generate a single physically unified and coherent modulation of cemi field that represents conscious perception.
The cemi field theory is compatible with many contemporary theories of consciousness. The cemi field can be considered to be a global workspace (Baars, 1988) that distributes information to the huge number of parallel unconscious neural processors that form the rest of the brain. Similarly, the brain’s em field may be considered to be the substrate for Dennett’s multiple drafts model (Dennett, 1991) since its informational content will be continually updated by neuronal input until a field configuration is reached that is capable of generating ‘output’ that is downloaded as motor actions or the laying down of memories. The theory also has much in common with quantum models of consciousness (Penrose, 1995) since both propose a field-level description of consciousness. However in contrast to quantum consciousness models that must propose a physically unrealistic level of quantum coherence between neurons or microtubules within neurons, the cemi field theory has no such requirement.