Conscious Brain’s EM Field
Professor of Molecular Genetics, University of Surrey
Synchronous Firing and its Influence on the the Conscious Brain’s Electromagnetic Field
Journal of Consciousness Studies, 9, No. 4, 2002, pp. 23-50
McFadden starts by stating that synchronous firing in the brain correlates with awareness and perception indicating that disturbances in the brain’s electromagnetic field also correlate with these. This field is a representation of neuronal information and its dynamics could be seen as a correlate of consciousness. McFadden views this field as the physical substrata of consciousness. Popper and Libet (1-4) have both suggested that consciousness might derive from am overarching field that could integrate the processing of neurons, but they did not think that this could be any known physical field. At the same time, there has been considerable interest in synchronous firing of neurons (Eckhorn 1988 & 1994) (Gray et al, 1989)(5-7). Awareness has been shown to correlate with the synchrony of firing in the 40-80Hz range, and this may bind together neurons involved in different aspects of the same visual perception, thus creating the unity of consciousness.
The brain’s electromagnetic field is induced by neuron firing, and also the movement of ions involved in the fluctuation of electrical potential along the cell membrane. The structure of the cortex tends to amplify the induced field. Experiments in the olfactory bulb (Freeman, 1991) (Freeman & Schneider, 1982)(8&9) have demonstrated EEG activity in response to sensory stimuli. Information about the stimuli related to the spatial pattern of the EEG amplitude.
The author concludes that the brain contains a highly structured extracellular electromagnetic field. The field is weak with the transmembrane fields being about 3,000 times stronger (Valberg et al, 1997) (10). It is suggested that neurotransmission through gap junctions may be voltage dependent and therefore sensitive to local fields (Draguhn et al, 1998) (Jefferys, 1995) (11&12). However, McFadden prefers to concentrate on the voltage-gated ion channels in the cell membranes, because their role is better understood.
Synchonous firing is thought to due to a large number of spatially distributed neurons (Lopes da Silva, 1998)(13). It is thought that many millions of neurons could be influenced by such firing. McFadden claims evidence for neuron communication via the electromagnetic field. The medical use of transcranial magnetic stimulation (TMS) is taken to indicate the sensitivity of the brain to weak electromagnetic fields, and as this has impacts on behaviour, it is argued to impact neuronal computation and neuronal function (Chan & Nicholson, 1986) (Jefferys, 1981) (Gluckman et al, 1996) (14-16). Even when fields are weaker than the surrounding noise, they can modulate neurons (Douglas et al, 1993) (17). The brain’s electromagnetic field is argued to hold the same information as the neuron firing patterns. The widespread of the electomagnetic field would help to explain the unity of consciousness.
Clusters of neurons in the visual cortex have been shown to fire in synchrony in response to particular stimuli (Eckhorn, 1988 & 1994)(5&6), (Gray et al, 1989).(7) With insects, destruction of synchronous firing has been shown to reduce the ability to discriminate between stimuli. There is indirect evidence for the correlation between synchronous firing and attention and awareness in humans (Miltner et al, 1999) (Rodriguez et al, 1999) (Srinivasan et al, 1999)(18-20). The olfactory system of rabbits shows that the sensory information is encoded in the spatial pattern of the EEG, and therefore of the electromagnetic field. This correlation also reflected what a particular smell meant to the rabbit, when it had been trained to associate particular things with a smell. This suggested that the shape of the electromagnetic field could be related to perception and meaning. This is taken to suggest that consciousness is related to the electromagnetic field. Where there is habituation with a process and therefore less conscious activity there is a reduction in synchronous firing, so loss of awareness correlates with reduced disturbance in the brain’s electromagnetic field. The theory predicts that only activity that acts on the motor neurons is conscious. This is testable, although there is no direct evidence. The EEG shows that activity increases during creative thinking, declines with sleep but revives with REM dreaming (Molle et al, 1996) (21), so the amount of conscious activity correlates with the amount of electromagnetic activity.
The high conductivity of the cerebral fluid in the brain ventricles makes the brain into a kind of Faraday’s cage, insulating it from external electrical fields. However, it is much easier for magnetic fields to penetrate the brain and other tissues. Moving magnetic fields, such as those used in TMS do produce effects in the brain.
The Function of Consciousness
McFadden sides with those who argue that consciousness must have a function or evolution would not have selected for it. Field effects that had an advantageous effect on the performance of ion channels would have been selected for. Mcfadden thinks that there is information transfer between neurones during synchronous firing. He proposes that the neural circuits involved in conscious and unconscious activity differ in their sensitivity to the electromagnetic field. The conscious will is claimed to be our experience of the electromagnetic field. He thinks that consciousness is not actually the electromagnetic field, but its ability to transmit information to neurones. He also points out the difficulty of trying to perform two conscious tasks or a conscious and unconscious task at the same time. The two interfere with each other, while unconscious multi-tasking is possible.
Consciousness is required for the laying down of long-term memories and for most learning. The cemi field theory conceives that the electromagnetic field in the brain fine tunes the probabilities of neuron firings. The affected neurons may be part of large connected assemblies, and this leads to memory and learning. In simulated networks non-synaptic neuronal interactions via the eelctromagnetic field and also gap junctions enhance learning (Aronsson and Liljenstrom, 2001)(22). Modulation of long term potentiation by electomagnetic fields has also been demonstrated in vitro in rat hippocampal slices (Bawin et al, 1984)(23).
The author claims that free will is the subjective experience of the influence of the cemi field on neurons. However, the influence of the cemi field is seen as entirely deterministic. The fluctuations in the field that are capable of modulating the firing of neurons would all be generated by changing patterns of electrical activity, while the neurons themselves induce the field. The author admits that there might be some element of random quantum fluctuations in the field, but this randomness is unsuitable for producing free will.
The author, in common with others in consciousness studies, tries to have it both ways at this point. The functioning of the brain is claimed to be entirely deterministic, but something called ‘will’ is active in driving our conscious actions. This appears to be a clear a contradiction, since the whole idea of will is an agent which initiates something of its own accord.
The cemi theory might be seen as a near miss in terms of trying to provide a plausible explanation of consciousness. The author could have said that consciousness was a fundamental property of electrical charge, or individual charged particles, or the photons that intermediate it, thus making it a primitive or a brute fact of the universe. But he does not do this. He says that our conscious will is our experience of the influence of the cemi field. This seems to raise a host of questions and contradictions. If the cemi field isn’t conscious itself, who or what is experiencing it’s influence. This suggests a dualistic non-physical entity that experiences the action of the field. Even if we are happy with this concept it is not clear why this particular set of electromagnetic fields should produce this experience for this entity.
Like many before him, Mcfadden suddenly declares by fiat that one particular part of the otherwise ordinary material of the brain produces consciousness. Again, it is reasonable to say that evolution selected for a particular type of field that could fine tune the neurons, but the additional production of a feeling of free will, which is false has no demonstrable value. The author’s apparent need to stay within the deterministic fold appears to rob the theory of all explanatory value.
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