This post is going ask an important question about the field theory of consciousness.
Namely,
What would fields look like that pass though connexions in electrical and chemical synapses?
This question also questions the the readers commitment to whether consciousness is a field. If the reader believes consciousness is a different field, then the question becomes, where else does superpostion happen that is necessary to build up structured information? If the reader believe that consciousness is not a field, but the consequence of action potentials alone, then the question becomes, how does consciousness emerge from action potentials?
If the reader wishes to go down the field route then the question becomes about the geometry of fields within synapses, and not about electrical or chemical descriptions of synapses. A crucial difference between an electrical or chemical description of the brain is that electrical descriptions focus on describing voltages, and chemical descriptions focus on describing molecules, whilst a field description is about describing the geometry of the fields inside the brain cells. If you assume that consciousness is in a large part a field, then it’s necessary to “follow the money” regarding the geometry of fields.
Previous posts have looked at nanohole arrays in both electrical and chemical synapses.
- Are Gap junctions electrical nanohole arrays ?
- Are Dendritic Spines Resonant Cavities ? (i.e post synaptic nano holes)
Electric and chemical synapses are fundamentally different because chemical synapses create a electrical “break” between the pre- and post-synapse. However both electric and chemcial synapses contain nanohole arrays, which are electric channels.
Channel Geometry
The purpose of this blog is to take an objective look at the geometry of fields that pass though these ion channels / nanohole arrays. An important aspect of the geometry of fields through nano hole arrays is what is the geometry of the holes and which of them are open. This is because different open patterns of holes will create different diffraction patterns.
Let’s take a quick look at an array of connexions in an electrical synapse, and to imagine that some of these connexions may be open or closed, and to ask how and why.
The literature shows that only a few nano holes are open in either an electrical or chemical synapse at any point during a synaptic event.
Fukuda (2006) showed that less than 2-5% of channels were open simultaneously in electric synapses in layer 2/3 of area 18 of the visual cortex (i.e. orientation detectors).
Similarly Pereda (2004) found bi-directional gap junctions in Goldfish Mauthner cells were open between 2% or 15-20% of the time.
Highley (2012) also found that less than 5 AMPAR (Ca+2) channels opened during a synaptic event in a chemical synapse.
It is therefore likely that only a few channels are open in electrical and chemcial synapses during an activation event.
Note: It has already been established that electrical synapses form hexagonal arrays of channels. Surprisingly, an aggregate of several hundred connexion channels must be present in an electrical synapse for the first connexion channel to open (Garre 2009) and though the connexion plaque grows in size the number of connexions open remains very small. This could imply that some kind of exact geometrical spacing is required before the connexion channels open.
Note: Unlike electrical synapses the connexions in chemical synapses are not packed together but distributed according to the location of actin fibres in the spine head.
Local Channel Geometry
The next step is to understand what diffraction patterns are produced by fields through small holes. The most famous diffraction pattern was the double slit produced by Young (1804) in 1803.
Diagram illustrating one of the most simple diffraction patterns, known as the double-slit pattern (Feynman 1949).
There are many more diffraction patterns that can be formed and are fairly “limited” in their variety, In fact there is a good source for describing diffraction patterns called, The Atlas of Optical Transforms. This book was originally designed for interpreting X-Ray Crystalogrpahy.
X-Ray Crystalography is a discipline that infers the shape of crystals from their diffraction pattern, The difficulty with this discipline is that diffraction patterns lose their phase information, which make it difficult to guess the structure of the crystal from the diffraction pattern, To overcome this problem a number of techniques have been developed to figure out the structure of the crystal from the diffraction pattern. These techniques may provide some insight into how fields in the brains may be working.
When looking at diffraction patterns it is important to distinguish between Fresnel and Fraunhofer diffraction, Fresnel diffraction is when the holes are close to the source and the curvature of the source field needs to be taken into account. This would happen when the souce is within a wavelength of the holes, in what is known as the near-field region. Fraunhofer differaction is when holes are far from the source and the trajectory of the light is assumed to be parallel. This would happen when the souce is beyond a wavelength of the holes, in what is known as the far-field region. Importantly the near and far field region and not strictly delimited as a single wavelength and are dependent on the behaviour of the source.
The images below show Fresenel diffraction patterns in the near-field. These should be constrasted with Franhaufer diffraction patterns shown through the same holes further below
Diagram showing Fresnel Diffraction through small holes.
Diffraction patterns yield several important insights into the relationship between holes and connexions functioning.
Less is more. The fewer holes are open the more definite the pattern. As the images below show, two holes open produce a simple striped pattern.
Diffraction patterns are orthogonal to doublet holes. This means there is a prediction that in the orientation visual cortex that the holes there-abouts are doublets, depending on the algorithm implemented by the neurons.
Hole separation changes the pattern size. The closer the holes are together the larger the wavelength of diffraction pattern that is produced. The further the holes are apart the smaller the wavelength of the diffraction pattern.
The more holes are open more complex patterns are produced. This leads to a prediction that the further down the visual stream the more holes are open.
Hexagonally spaced holes produce a hexagonal pattern that fills the field.
Diagram showing Fraunhofer diffraction through small holes.
Remote Channel Geometry
Importantly, the positioning of synapses in remote locations can contribute to an “understanding” of the relative position and location of distant synapses. The previous images captured a description of local diffraction patterns. The following images capture descriptions of remote diffraction patterns that contains information about the distribution of the remote source. This is important because it could allow neurons to have information about the locations of remote distributed sources and that would allow neurons to make “decisions” about the distributed organisation of neurons that neurons could not infer have from raw action potentials. If the brain does exploit this feature it would be very significant.
The image below the diffraction pattern that is produced by a random distribution of remote hexagon holes. This pattern is essentially the same as the diffraction pattern of a single hexagons, except it is more intense.
The image below shows the diffraction pattern that is produced by a distribution of hexagon holes in aligned pairs. It is predicted that this distribution might happen in the orientation visual cortex, Significantly the orthogonal orientation diffraction pattern and the hexongan local pattern might be at different wavelengths, *Note this “screen” of holes is being interpreted as a transecting through an array of neurons.
The image below show the diffraction that is produced by a distribution of hexagon holes aligned in sets of four. This diffraction pattern could be used by neurons to align remote neurons to remote layouts.
Commentary
If consciousness is, to a large part, a field then techniques from X-Ray crystallography may have a bearing on how the brain implements consciousness.
Pointedly, X-Ray crystallographers are in the same business of brains; trying to understand the 3D structure of the world using 2D information. In the case of X-Ray crystallographers they are trying to reverse diffraction using techniques of deconvolution and Fourier analysis.
I’m not sure if it has been suggested before that brains work on the level of electric-magnetic fields through individual channels, but it does seem an intriguing possibility that the brain operates at the level of the ion channels rather than at the level of the synapse. It is true that synapses do not behave compliantly with Hebbian learning, they are very dynamic and exhibit many odd behaviours when looked at the level of synapses.
Could it be that the brain sets up a number of open holes in nano hole arrays across a number of synapes to detect the best matched patterns, triggered by thresholds, as a form of deconvolution. This would act as an implementation of parallel deconvolution.
You have moved
Finally, one of the first posts entitled You are Here discusses the Theory of Perspectives and Levels. This post captures the underlying philosophy behind the fields of consciousness. Most of the posts on this site have been describing and discussing fields in the brain. These posts have been very much about finding Objective-Signals. That is signals in the brain from an objective perspective,
However to move from these posts to a complete theory of consciousness there will need to be an interpretation based on the Theory of Perspective and Levels.
Significantly the formation of diffraction patterns means the creation of an Objective–Sign from a number of Objective–Signals. This is important because it marks the first time the theory has provided this kinf of break-out, This break-out raises further questions about these levels from this perspective and different perspecives and differen levels.
Fields of Consciousness 