At reference 2, we talked rather loosely of activation, of waves of activation going over, for example, a line. Here we try to expand on that a little.
In the illustration above we have a simple visual scene containing 4 rectangles, of the sort introduced at reference 2, defined using the soft centred patterns introduced at reference 5, in this case a small soft centred pattern, with just three rows and three columns, patterns which might be more legible on click to enlarge. We have used the interior of the patterns to designate the perimeters of the rectangles in black and the various colours of their interiors otherwise – although we have only bothered with the detail of the interior in the rectangle top right. We have not got around to marking the depth, although the effect of this can be seen in the occlusion left.
All of the information in the first illustration is contained within a single layer. In the second illustration, we spend a second layer to fill in the gaps in information about our rectangles caused by occlusion, with the rules about rectangles not sharing the edges and vertices at reference 2 meaning, at least more or less, that there will always be enough of the perimeters left, after the (unavoidable) occlusions caused by crossings, from which to reconstruct all the rectangles.
We can decide at compile time. how much of this additional information in this second illustration, in this second layer, is made available to consciousness. Whether the activation of the first layer, the visible layer, spreads to the second layer, as it were, to the unconscious. Whether or not there is some dim awareness of that part of the rectangle which is not visible.
The elements of our patterns are expressed in terms of the amplitudes of the oscillations of neural activity in a particular frequency band, at grid points, in a particular layer. In the illustrations above, the grid points are shown as cells of an Excel worksheet.
Within our frame of consciousness, we will have one or more rounds of activation, called scans, with each scan covering, at least potentially, the whole field of consciousness, in this case just the visual field, having put aside, for example, any associations or feelings which might be in the air, which might have been held on yet another layer. With this activation being expressed by the amplitude of the oscillations of neural activity in some higher frequency band. And with the units of activation being the elements of the layer objects, the instances of the patterns with which we have made up the scene.
The signal which expresses our data, the contents of our visual scene, our rectangles made of elements of layer objects, is stationary. There are oscillations, but they, or rather their spectral analysis does not change during the frame of consciousness. While the neural activation which makes that data conscious does change, does move about. So, during a scan, that activation moves from one place to another, either a narrow-fronted scan along a perimeter line or a wide-fronted scan across some extent, some interior.
A digression
A digression prompted, in part, by reference 3, a short book mainly about neurons in the superior colliculus of cats which respond to stimuli from more than one sense – in particular both visual and auditory stimuli – with the superior colliculus being particularly concerned with pointing eyes and head towards stimuli of interest, a business which involves issuing a tricky sequence of commands to the various muscles involved – and processing the real-time feedback therefrom.
With, generally speaking, vision being best when looking at something straight ahead. A situation which can be confirmed by any auditory signal there might be, with the two, set-apart ears of mammals, working together, being quite good at direction finding.
Also, prompted by the sense of my eyes moving about as I imagined a rectangle, this morning in March, while waking up but with my eyes still shut. A strong sense that my eyes were scanning the sides of the rectangle, one side after another. With this being how I imagined a rectangle when I did not have one in front of me. A process which seemed to be easier when the rectangle was upright with respect to my face. From which observation, I associate to a memory that when one looks at a rectangle which is not upright in this way, one tends to tilt the head. Maybe because it is much easier for the eyes to scan horizontally or vertically rather than diagonally? The brain does have some sense of its own comfort and convenience?
Also by remembering reading theories of consciousness which talk of the internalisation of efferent impulses, in plain language, action commands. See, for example, reference 4.
All of which is suggestive of the consciousness of a line being related, at least in some way, to the business of the eyes tracking such a line. Not so far from the present activation rolling along the perimeter line, or across the coloured interior.
The story resumed: activation of our rectangles
At reference 1 we talked of random activations along the visible part of the line, whereas now we are thinking of something a bit more directed, a bit more organised. There might be a random element in the choice of rectangle, but after than the action is to scan the visible part (or parts) of its perimeter in a clockwise direction, with the interior on the right and the background (or whatever it is) on the left. With such a traversal being a more plausible generator of a coherent conscious experience than random activation of individual elements of the layer object concerned, let alone individual points on our underlying grid.
Then having scanned the line, a process perhaps taking a tenth or a second or so, the brain scans the interior, taking a wide front, sweeping across the interior in one go, perhaps the dark green area in the example above, a process taking another tenth of a second or so.
The brain then moves onto the next rectangle in the scene, normally one in contact with that just scanned, perhaps the dark blue area in the example above. And so on, until the time allocated to this scan is exhausted and it is time to move on. With the implication being that, in effect, the brain has some of the supervisory systems which, in a computer, are provided by what used to be called the operating system. A system which provides and manages the environment in which processing takes place.
If one could slow all this down, one could watch pulses of activation moving along the lines and across the spaces, perhaps a bit like those animations of the weather you get in television forecasts. But a serial rather than a parallel process; we think that this contrast with the parallel activation which sets the data is a big part of the point of doing the scan. And it is these pulses of activation which we hypothesise to be consciousness. Not the source or cause of consciousness, but to be consciousness. Or, at least, for all the electrical activity generated by all this neural activation to be consciousness.
A bold hypothesis, springing from slender knowledge of the facts on the ground!
Three footnotes
Movement of attention along a line or across a homogenous interior produces very predictable results. Most of the time the prediction that the line continues or that the interior continues will be true. Which will satisfy that large part of the brain which is concerned to know what is about to happen.
Some of the numerical details in the illustration above sometimes seem to vibrate, not to be very stable. I wonder whether this is not the result of brain’s waves getting into something of a muddle as it tries to scan these varying stimuli. Trying to scan at a speed which does not suit the rate of variation of the stimulus? Generating some sort of unfortunate feedback, resulting in an unfortunate, unstable signal to consciousness?
We have made no use of the phase of all these oscillations. An omission which may be turn out to be important as oscillations which are out of phase may cancel out by the time they reach the layers in which we are interested.
Reference 1: http://psmv3.blogspot.co.uk/2017/01/lines.html.
Reference 2: http://psmv3.blogspot.co.uk/2017/03/on-seeing-rectangles.html.
Reference 3: The Merging of the Senses - B.E. Stein, M. Alex Meredith – 1993.
Reference 4: Homing in on Consciousness in the Nervous System: An Action-Based Synthesis - Morsella and others - 2015 – draft.
Reference 5: http://psmv3.blogspot.co.uk/2017/03/soft-centred-patterns.html.
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