I received also two other highly interesting articles, which have helped in the construction of a more detailed model for memory recall in TGD framework. The second link was to a popular article in Science News with title "Ripples race in the brain as memories are recalled" telling about the findings of neuroscientists Vaz et al about memory recall published in Science as article with title "Coupled ripple oscillations between the medial temporal lobe and neocortex retrieve human memory" .
The third link was to a popular article "The human brain works backwards to retrieve memories". The article tells about the work of Linde-Domingo and Wimber et al published in Nature Communications as article titled " Evidence that neural information flow is reversed between object perception and object reconstruction from memory" .
In the sequel I will consider only the first article and mention the important results of the two latter articles only in passing.
1. The experiment
Consider first the experiment described in "Neuroscientists read unconscious brain activity to predict decisions".
- The situation was following. The subject person looked at most T=20 seconds two different pictures, decided to imagine either of them, and pushed immediately the knob. Then she tried to imagine the chosen picture.
Neural activity was detected in brain and it was found that it emerged t=11 second before the decision. From the pattern of activity it was possible to predict the picture. Also the subjectively experienced intensity of imagination also reported by the subject persion can be predicted. One could say that the sensory experience was re-created by imagination in the brain of past.
- The imagination involved could be also regarded as an active memory recall. This interpretation suggests that the time t at which the neural activity appears must be within the T= 20 second interval during which the decision was made.
- The authors leave open whether their finding excludes free will. The first interpretation is that the choice really occurred at unconscious level and for some reason subject person experienced illusion of choise. A real choice combined with illusion about real choice looks rather weird idea, and only shifts the problem of free will to a level unconscious to us. If there is no free will then all experiments involving choice are pseudo experiments: this would throw a large portion of neuroscience to trash bin.
This picture does not say much about what really happens in imagination as active memory recall. To develop this model some background ideas about TGD are needed.
- I have developed a model for motor action as time reversal of sensory perception based on ZEO in an earlier article. This leads also to a model for remory recall as sending a signal to geometric past giving rise to time reflected signal as memory recall Episodal memory as re-experience in the geometric past would correspond to generation of mental image in the geometric past at the opposite boundary of causal diamond (CD) which is basic geometric correlate of conscious entity in ZEO based theory of consciousness provided by TGD.
- There are several words to which one must give meaning: what do "re-experience in geometric past", "time reflection", "imagination as active memory recall" mean? Who is the intentional agent which imagines? The above experiment inspired an attempt to give a more precise meaning for these words.
The idea is to combine the model of memory with a decades old model of living matter as conscious hologram (one more unprecisely defined word!) .
Magnetic body (MB) is the basic notion. MB acts as intentional agent using biological body (BB) as
motor instrument and sensory receptor. In the recent case MB imagines and performs active memory recall by selecting the picture and directing its attention to it (still more words!).
Dark matter hierarchy as hierarchy of phases of ordinary matter (also photons) assignable to the MB and labelled by the value of effective Planck constant heff =n×h0 is a further central element of the general picture. In particular, EEG photons are dark photons with very large value of Planck constant guaranteing that their energies are above thermal threshold. Bio-photons would with energies in visible and UV range would result as dark EEG photons with very large value of heff transform to ordinary photons.
- Brain as a hologram is an old idea originally to Karl Pribram. The formation of hologram involves two waves with the same freqeuency: reference wave and the wave representing the target - typically it reflected from the target. The reference wave is typically simple planewave with some wavelength and thus frequency and defines kind of scale parameter. These waves must interfere so that coherence is required. The interference pattern is stored by the modification of the hologram substrate.
If one illuminates the resulting hologram by reference wave the image of the target is formed. If one illuminates the target with the phase conjugate of the reference wave - its time reversal - the phase conjugate of the image is formed. In ZEO time reversal has precise meaning as also the time reversal of self and mental image.
This requires coherence in the length scale of hot and wet brain and non-standard value of heff makes this possible. The coherence for ordinary photons need not be quantum coherence, but induced by quantum coherence of dark photons transforming to ordinary photons. Quite generally, the coherence of living matter would be induced in this manner from quantum coherence.
- Memory and sensory mental images is generated as MB creates a reference wave in the formation of hologram as interference pattern of incoming ordinary light beam and dark reference beam. This induces the pattern of neural activity. Coherence is not quantum coherence but inherited from quantum coherence of dark photon beam from MB. Also phase conjugate in active memory recall comes from MB. The reported ripples associated with the formation of sensory percept would correspond to the formation of conscious hologram.
- Phase conjugate wave corresponds to time reversal of wave and would be created in ZEO in "big" state function reduction reversing the arrow of time for self involved. The phase conjugate of the reference wave generated by magnetic body (MB) acting as intentional agent trying to imagine would propagate to geometric past and scatter from the brain substrate acting as a hologram and generate the memory mental image in geometric past at the opposite boundary - the "re-experience", which need not be conscious-to-us. The ripples reported to accompany memory recall (see this and this) would correspond to the scattering of the phase conjugate wave from the hologram.
This phase conjugate mental image need not be conscious-to-us: the assumption has indeed been that time reversed mental images are not conscious to us. The assumption will be kept also now.
The next "big" quantum jumps would mean the "death" of the memory mental image and rebirth as a mental image in standard time direction. This would correspond to the "time reflection" generating a signal to the geometric future defining in the recent situation declarative, verbal memory of the mental image. This would be the outcome of imagination experienced by the subject person.
Why these "normal" mental images are not usually genuine sensory mental images at our level of self hierarchy? A good reason for this is that they would interfere with the ordinary sensory perceptions. We can indeed have this kind of mental images during dreaming and hallucinations. During dreaming it is not a threat for survival as it is during hallucinations. I have discussed a detailed model for imagination as almost sensory mental images (see this). They would be created by feedback signals from MB via cortex to a level above sensory organs in the hierarchy so that no actual sensory percepts is obtained. Also imagined motor actions would be similar.
An essential element of the model is that the sensory input is transformed to dark photons beams propagating along flux tubes parallel to axons and being responsible for the communications. The function of nerve pulses would be creation of communication channels by connecting flux tubes associated with axons to longer structures: neural transmitters and various information molecules would do this connecting. Situation would be very much analogous to that in mobile phone communications. It should be noticed that flux tubes also serve as correlates of directed attention.
The notion of re-incarnation is certainly the most controversial aspect of the proposed vision. TGD predicts self hierarchy and sub-selves are identified as mental images so that one can look whether re-incarnation hypothesis makes sense for them. After images appearing periodically would be examples of this kind of mental images: they would be conscious to us and correspond to the level of self hierarchy immediately below us. Since they are typically of different color than the original image, we know that they do not represent a real object. The periods without after image would correspond to the phase conjugates of these mental images and would be un-conscious to us. Essentially a sequence of re-incarnations of mental image would be in question.
- How can subject person (idenfiable as her MB!) actively choose the target of the memory recall? In the experiment considered the two pictures were seen by the subject person for a time not longer than T=20 seconds. Both generate a hologram like structure in visual cortex which in good approximation are disjoint patterns of neural activity - presumably regions of coherence induced by quantum coherence of the dark reference beam.
A conscious choise associated with the memory recall requires that the two areas are labelled by some control parameter which MB can vary. Fixing this parameter directs the attention of MB to
either picture. The frequency of the laser beam is the only parameter available. Incoming beam of light corresponds to the energies of visible light and for the ordinary value of Planck constant one cannot vary the frequency. There is however EEG frequency, which can be varied but its ratio to the frequency of visible light is of order 10-14 for 10 Hz! The energy E= hf of EEG photons is extremely small and EEG photons should have absolutely no effects on brain or correlate with the contents of consciousness. We however know that it does!
In TGD framework this fact was the original motivation for the hierarchy of Planck constants. The choice of the picture to be imagined/attended by MB would mean that the value of heff associated with it changes. The chosen picture naturally corresponds to a larger value of Planck constant since the maximal conscious information content of system increases as heff increase. The increase of heff requires metabolic energy as directed attention certainly indeed does.
- A more refined view about memory recall involves hierarchical structure in which memory recall is built up so that first the "gist" of the pattern is recalled and then come the details. This is the opposite of what happens in sensory perception in which features are identified first and the holistic view emerges later.
TGD predicts self hierarchies labelled by the values of heff and by p-adic length scales. The higher the level of self hierarchy the longger the corresponding length scale. The "gist" corresponds to large values of heff and low EEG frequencies whereas details correspond to smaller values of heff and higher EEG frequencies and smaller wavelengths for ordinary photons. The construction of the memory mental images would correspond to a cascade of state function reductions proceeding from long to short length scales and beginning from largest value of heff involved. The model for what happens in state function reduction in TGD framework assumes this cascade (see this and this).
- This mechanism generalizes to the case of motor action and sensory perception as its time reversal. MB as an intentional agent would be sending reference beams and their phase conjugates at various frequencies f and values of heff serving as control knobs!
- The most general picture is that the "reading" of the sensory percept resp. memory uses reference beam resp. its phase conjugate whereas the formation of sensory percept resp.motor action involve both object beam and reference beam resp. their phase conjugates. Therefore memory recall would involve is re-experiencing in reversed time direction assumed to be unconscious-to-us.
- It is essential that sensory input is transformed to dark photons at sensory organs propagating to the brain: this also makes the processing of sensory information fast and sensory mental images can be built as standardized mental images - pattern recognition - by forth-and-back signalling between brain and sensory organ combining artificial sensory input from brain with genuine sensory input. It is hard to imagine anything simpler!
- Neural activity associated with the neural percept preserves the topography of the visual percept so that the shape of the firing pattern in cortex is same as that of object. This cannot be however used as an objection against holography since it is the reading of the neural hologram which generates the image of the object. The topography of the hologram has nothing to do with the shape of the object.
3. Could one demonstrate experimentally that the standard view about time is wrong?
The prevailing view in neuroscience and physics identifies experienced time with geometric time despite the fact that these two times have very different properties. In TGD framework these times are not identified but are closely correlated. TGD inspired theory of consciousness based on zero energy ontology (ZEO) allows to understand the relationship between the two times and leads to rather dramatic predictions.
TGD interpretation says that in the act of free will MB sends phase conjugate signal to the brain of geometric past or stating it otherwise: replaces the determistic time evolution of brain (and also its past) with a new one (strictly speaking, replaces their quantum superposition with a new one). This should happen also in the choice of which picture is to be imagined.
Could a modification of the experiment replacing imagination with an activity not requiring memory recall allow to demonstrate that the standard interpretation is wrong?
- Consider a thought experiment experiment in which the subject person receives a stimulus and makes a decision to do something - not imagine but something else - during some time interval T after it. Suppose that the decision is found to be preceded by neural activity before the the stimulus appears.
Standard view about time not does allow this since person could have decided about the reaction to the stimulus before it came (precognition would be the only explanation - there is some evidence for this too).
TGD view about the relationship between subjective and geometric time allows this since the decision sends signal to the brain of the past and there is no reason why the moment in past could be before the stimulus.
- The modification of the above experiment in this manner could mean the reduction of T= 20 seconds to - say - 9 seconds. If the neural activity would appear 11 second earlier it would emerge before person has seen the pictures and one would have paradox for standard view about time. However, if the imagined picture relies on memory, this does not happen.
For a summary of earlier postings see Latest progress in TGD.