How many people in my head
How many people are there in my head and in hers?
Jonathan Edwards, Imprint Academic
The author has painstakingly researched and developed his own theory of consciousness. He argues firstly, that consciousness has to exist at the level of the individual neuron, and secondly that this neuron-based consciousness is an electromechanical wave of elasticity in the membrane of the neuron. The wave is classical rather than quantum, which may be felt to leave unanswered the problem of how consciousness would suddenly arise at the complex level, when it does not exist at the fundamental level, especially given that the author is himself dismissive of emergent property theories.
In this book, qualia or subjective experiences are considered to be more than just access to information. The author refers to the philosopher, Bertrand Russell, who pointed out that 19th and early 20th century neuroscience and physics failed to explain subjective experience. Edwards himself remarks that in contrast to its general reputation for scientific development, the 20th century may have been one of the least imaginative periods in history for dealing with some fundamental problems, such as consciousness. He also claims that the more we have discovered about the brain, the more difficult it seems to be to answer questions about consciousness.
In discussing the question of computers and consciousness, the author sees any understanding in the computer as ultimately dependent on an external mind, in contrast to the self-generating nature of the human brain. A computer is likened here to a system that sends out millions of Christmas cards that are either black or white (0 or 1, on or off). An external observer of the computer’s mailings could work out the pattern, but the computer’s own operation is just the end product of lots of on/off switches. Only the designer or an external observer of the mailings has the knowledge of the black and white Christmas card sequence. Some argue that the black and white pattern is the overall property of the system, but Edwards argues that this assumes a knowledge of the extent of the information system, which is also not a property of the on/off chain of the computer.
The working unit of a computer is a logic gate, at which two signals arrive, and one signal leaves. Signals can be either on or off. There are two types of logic gate, an AND gate and an OR gate. For a signal to come out of an AND gate, both incoming signals have to be on. With an OR gate, a signal comes out, if just one incoming signal is on. However, the brain does not work like this. In the computer/brain analogy, the neuron is analogous to a logic gate, but it is something of an open question as to how many and what type of incoming signals are needed to get an outgoing action potential. Edwards sees this process as one of integration. He envisages a short period of time, in which all the elements input into the neuron are present, and the number of these could run into tens-of-thousands. Over a period of a second, the number of elements presented to the neuron could run into millions. The author sees this richness of input as a possible basis for consciousness, in contrast to the relative poverty of the on/off computer system.
Before microscopes were available, it seemed quite reasonable to speculate about a seat for consciousness in the brain, but this is much less plausible now. The more detailed the description of the brain becomes, the less places there are for unexplained properties to hide. The author argues that qualia, such as colour or taste, are not properties of the objects that they are related to, but arise from interactions within the brain. He further points out that these interactions are at the level of individual cells or their synapses, and not on any larger scale.
There is also the binding problem, the problem of how in consciousness, we are aware of qualia from different modalities such as vision, hearing and taste, all at the same time. The author is critical of some mainstream approaches that say that binding is ‘just’ a property of the system, both because it is a cop out, not offering the normal scientific explanation of a mechanism, by which things are done, and because we know that there are connections throughout the brain, which in turn suggests that there is a mechanism there, rather than a magical ‘just so’ arrangement. Edwards criticises the idea of talking about whole systems in relation to consciousness, suggesting that it is just a convenient short-hand way of describing something, rather than a description of a causal process. He looks for a causal process that moves through matter, such as an electromechanical wave, rather than a property that is rather mysteriously possessed by a whole system, for no particular causal reason.
Edwards argues that the individual neuron that can be receiving up to a thousand inputs from other cells has to be the basis of consciousness, because this is the only point at which input enters the brain system. Thus the only way that the author can see, for solving the problem of how millions of cells give the same answer, is for each single neuron to be a point at which the pattern of external information enters the brain. The cell membrane is central to the author’s concept. He thinks it reasonable to assume that waves related to consciousness will operate in or around the cell membrane, because this is already known to be involved with information processing.
Edwards is also critical of the idea that the synchronisation of the electrical firing of cells could be the basis of consciousness. He argues that each cell is firing separately and their messages are targeted at particular cells, so there is no explanation here of how the whole system could come together to provide a sensory experience. Edwards thinks it has to be viewed the other way round, with consciousness coming up from the neuron level, and the brain viewed as a colony of conscious neurons. This argument appears sound as far as it goes, but I feel that it does not do justice to the synchronisation question. Some commentators argue that while it is not clear how synchrony could generate consciousness, studies nevertheless suggest that synchronicity is at least correlated with conscious experiences, and in this situation, it appears to be sensible to look for some form of physical connection between consciousness and synchrony.
Edwards views the cell as a good place for grasping a pattern, because a pattern is something that is available all at once, rather than as a string of elements. In common with Penrose, the author remarks on the complex abilities of the single-cell paramecium, suggestive of the possibility that a single cell could be complex enough to support awareness. Edwards accepts that it could be argued that a neuron is not a single place either, because it comprises a complex structure of dendrites and other components. However, he thinks there is an answer to this, in terms of the property of waves, in this case waves in classical rather than quantum physics.
He points out that everything in physics including classical physics comes in waves, so it would not be surprising, if waves were important to neurons, or even that consciousness itself was a wave. Waves are patterns of change in the physical world. Even for the purposes of classical physics, he views waves as not really made of anything, but as a packet of instructions for the likelihood of finding something in a particular place. An x-ray passing through the crystal structure of a protein splits into a complicated pattern that provides information about the molecular structure of the protein. The wave can be viewed as a single thing, but after passing through a crystal lattice, this single thing encodes information about the crystal lattice it has passed through.
The author is particularly interested in phonons which are the quanta or waves of elasticity in matter. His example is the chiming of a bell, where the sound is the product of an elastic pattern of change in the metal of the bell. Thus, the well-ordered structure of the bell has a dominant wave mode. Edwards relates this to a dominant mode of oscillation in the brain. The wave can be clear and dominant, because the domain has a well-ordered structure, and a clear boundary keeping the dominant mode within that particular boundary. The local force of the elastic field is considered suitable, because it is a local property of a defined piece of matter. The author sees this as compatible with the idea that consciousness is closed or private, in that the subjective feel of our own consciousness cannot be directly communicated to others.
The integration of the electrical signals coming into the cell through its dendrites is viewed as being to do with waves. The incoming signals are known as post-synaptic potentials (PSPs). The fine details of how the incoming signals interact in the membrane are still unclear. It is now thought not to be a matter of simply adding up the incoming signals. Other factors are involved. A proportion of the inputs into the cell are inhibitory rather than excitatory, and the position of the incoming signal on the dendritic tree could also influence the outcome. Studies in recent years suggest that the firing of the axon depends not so much on the totalling up of inputs as on their pattern. Edwards makes an analogy between the situation needed to trigger an action potential, and a ‘flush’, or series of cards in poker, as distinct from a simple process of addition.
The author carefully examines the various types of waves that might support the elasticity wave that he envisages as the basis of consciousness. Waves can involve the transduction of one form of energy into another, including transduction into the elasticity of a solid. Andrew Huxley himself did not think that the Hodgkin and Huxley wave that describes both axon potentials and post-synaptic potentials was a suitable candidate for this sort of elasticity wave. In general, these oscillations are not thought to be extensive enough to create the elasticity wave that the author is looking for. The author also discusses the ideas of Herbert Frohlich, who suggested the possibility that cell membranes might support a high-frequency electromechanical oscillation. Frohlich, hypothesised that the voltage difference across the membrane could alter its elastic potential energy. The author’s main reservation concerning the Frohlich scheme is that it has remained largely untested.
Edwards is more attracted to a larger, slower type of electromechanical wave that has been detected in living cells, by Alexander Petrov and others since the late 1990s. Petrov’s form of wave resembles the oscillation of the top of a drum, with molecules on either side of the membrane becoming more tightly or more loosely packed, as a result of the oscillation. This is referred to as piezoelectricity or flexoelectricity. The author thinks it possible that this may prove fundamental to the way in which living cells interact with their environment. It is suggested that the Petrov-type wave is coupled with the Huxley and Hodgkin post-synaptic wave, and that in this form the Pretrov wave could occupy the whole of the dendritic tree of the neuron, and regulate the interaction of the post-synaptic potential.