Memories and the brain

For over a hundred years science has been looking for physical traces of memory in the brain and has, so far, largely failed in such endeavour. Indeed, this video illustrates one of the fundamental difficulties of the postulate that experiences are somehow materially encoded in the brain. Since memories are themselves conscious experiences, many take the inability of science to locate them in the brain as evidence that consciousness is immaterial, as opposed to being merely a result of brain activity. However, recent scientific papers  of which this one is just the most recent example as of the time of writing  have been putting forward new evidence for material memory correlates. We've debated this briefly in this thread of the message board. Nonetheless, in this article, I want to explore in a bit more depth whether this new evidence contradicts, in any way, the hypothesis that consciousness is not a result of brain processes.

There are three hypotheses for the immaterial nature of consciousness, and its relation to the brain, which I find particularly interesting:

  1. The so-called 'transmission' hypothesis, which postulates that consciousness exists in an immaterial realm, protruding into space-time through the brain. The latter is then seen as a kind of transceiver of consciousness, 'SCUBA gear' for consciousness to have a material experience;
  2. The so-called 'filter' hypothesis, which postulates that consciousness is fundamentally non-local and unbound, the brain working as a 'filter' that limits and localizes consciousness to a particular point of space-time. This hypothesis was popularized by Aldous Huxley in the 1950s;
  3. The 'brain as a knot of consciousness' hypothesis that I put forward myself.

These three hypotheses are similar, except in that hypotheses (1) and (2) postulate dualism, while hypothesis (3) entails monism. Nonetheless, hypotheses (1) and (2) can be framed as explanatory metaphors in the context of hypothesis (3), which is exactly what I did in my books Rationalist Spirituality and Dreamed up Reality, respectively. We talked about this 'hosting' of hypotheses (1) and (2) under hypothesis (3) in this thread of our message board. Indeed, for the purposes of this article, all three hypotheses above can be considered equivalent. From this point on, I will refer to them as the 'non-materialist hypotheses.'

The non-materialist hypotheses are consistent with the empirical observation that, ordinarily, subjective states of consciousness correlate fairly well with objective, measurable brain activity. That is why, for instance, your mental state changes when the brain is intoxicated with alcohol; why you get knocked out from physical trauma to the brain; or why you go to sleep under anaesthesia. Indeed, the 'transmission' and 'filter' hypotheses postulate that conscious experience is modulated by physical brain states in much the same way that planetary explorers' perceptions and actions in Mars are modulated by the robotic rovers' sensors and actuators. A similar rationale applies for the 'brain as a knot of consciousness' hypothesis.

Now here is the crucial point I want to make: According to the non-materialist hypotheses, certain brain activity patterns are, in a way, analogous to 'keys' that 'unlock' (not necessarily in a causal, but perhaps a synchronistic manner) the awareness of certain phenomena; phenomena that would otherwise be either unavailable to consciousness ('transmission' hypothesis) or kept out of it ('filter' and 'knot of consciousness' hypotheses). So why should it be different in the case of memories? Why shouldn't access to memories be correlated to 'keying' brain activity (which Rupert Sheldrake would call 'resonant' activity)? If the non-materialist hypotheses are to be internally consistent, that should in fact be the case.  If physical events are found in the brain that correlate with memory access, that in itself would not contradict any of the non-materialist hypotheses, but in fact reinforce their internal consistency. Proponents of the non-materialist hypotheses should look forward to the discovery of clear physical correlates of memory access.

Olin Levi Warner's "Memory" (1896).
Source: Wikipedia.
But one thing must be made clear: The non-materialist hypotheses entail that certain activity in the brain should correlate with memory access; but not necessarily that these physical correlates carry the entire information entailed by the corresponding memory. As Sheldrake explained through a clever metaphor, the 'transmission' hypothesis, for instance, looks upon the brain as a kind of TV tuner. Think of an old analog TV set: The electrical activity in the tuner circuitry causes it to resonate with a broadcast electromagnetic field in the air. It is the latter that carries the information of the TV show one watches, not the tuner. Nonetheless, activity in the tuner correlates well with the programming and, in fact, 'keys' into it. Naturally, trying to crack the TV tuner open to find the information corresponding to last night's show is futile, despite the correlation observed when the show was being watched through the 'keying' action of the tuner.
So when I say that the non-materialist hypotheses should entail physical correlates of memory access in the brain, that does not necessarily mean that the entire information associated with the memories is always in the brain (a TV show is not in the TV set). Therefore, a potential test of the non-materialist hypotheses, insofar as memory is concerned, is to estimate the amount of subjective information contained in a memory and compare that with the amount of information in the activated brain structures that supposedly store the memory. If the latter is lower than the former, the non-materialist hypotheses would be reinforced.

All this said, as a proponent of the 'knot of consciousness' hypothesis, I feel personally encouraged by the recent progress in finding physical correlates of memory access, since my hypothesis somewhat requires them to exist. Indeed, in my book Rationalist Spirituality I talked openly about there being 'symbols' (that is, correlates) of memory circulating in the brain. But I am very cautious about celebrating the progress just yet. If one looks at the different theories being put forward, one notices fairly quickly that they contradict one another; they cannot all be correct, so at least several of the claims recently made are baseless and precipitated (as it seems to happen so often in science these days, given the mad scramble for funding). For instance, this paper proposes that memory formation has to do with protein transcription in the nucleus of the neuron, while this paper states that memories are stored in microtubules. For now, it seems things are all over the place, which doesn't inspire much confidence.

The entire discussion about whether the discovery of material correlates of memory access contradicts or reinforces the non-materialist hypotheses is insignificant in face of the broader problem where it is contained: The problem of explaining consciousness itself in terms of physical metabolism. This broader problem may be unsolvable.

Copyright © 2012 by Bernardo Kastrup. All rights are reserved.


  1. I couldn't help but notice that all of the examples of ''memory'' in the above youtube documentary had to do with either emotional trauma (shocking a mouse, PTSD, etc) or some sort of muscle memory (gill retraction, motor skills, etc). Not really having to do with recall/reliving of past situations past conscious states. It seems they're making an enormous extrapolation from a few rat experiments when in reality there seem to be different types of memories (conscious and unconscious). I have no problem what so ever with the notion that perhaps even ALL unconscious memories (I.E. feeling fear when hearing the preconditioned noise [in the case of the mice]) etc. However conscious recall of past conscious states doesn't seem to really be accounted for at all by any of the contradicting materialist theories. These theories also commit the grave intellectual sin of gross omission of information in order to make what they postulate more likely. For example, what about the experiments with rats where part of the brain were removed yet the mouse still remembered? If the memory were in-coded in a specific set of neurons, as they are claiming, why then would the memory persist? What a convenient overlooking of data, no?


  2. Robbie, I think you raise some good points. Gr, Bernardo.

  3. Excellent post Bernardo. You are right to emphasise the weaknesses of the evidence for a materialist basis for memory. The studies are contradictory, preliminary and over-interpretated in favour of a simplistic physicalist belief system - essentially hyped. However, let's assume for a moment that they have validity, does this contradict the evidence from Lashley who found that rodent learning (and by implication memory in general) was not localised to a given brain region? How can these disparate versions be reconciled?

  4. Thanks Micky. Yes, I avoided going into Lashley and the holonomic brain theory of Pribram and Bohm because that opens up a whole discussion that, I felt, I didn't need to get into in order to defend my point. So I opted to keep it focused. That said, I agree entirely with the point you raise. Gr, Bernardo.

  5. Hello Bernardo and all,
    I've been following for awhile and thought I'd finally jump in.....
    (I'm really enjoying reading Dreamed Up Reality currently BTW..)

    I believe that the new field of 'quantum cognition' could possiby support the non material case for mind and memory.It may not solve 'the hard problem' but I think it could help to build new and useful models.

    In the article linked below,scientists have been able to model the human mental lexicon using the quantum entanglement.I think this is significant for the nonmaterial theory because,as Nicholas Gisen and Antoine Saurez have stated: "There's no story inside of space-time" that explains entanglement.I think the same can be said for qualia and consciousness.

    In regard to memory:Could our minds remain 'entangeled' with prior events in a way analogous to the above article? For instance,could our mental 'images' of a recalled visual memory be 'made of' the same 'light' that was present in the ambient optic array which constituted the original visual input? (If there's an ambient optic array 'out there' ?) Time doesn't exist from the perspective of light as we're told by physics...

    (This would be a sort of quantum version of externalism/direct perception I suppose.)

    Here's reason to think it's possible:


    1. Hi Jeff,
      I will have a look at the link you provided. My current favourite author on the possibility of a relationship between mind and quantum wave function collapse in the brain is Henry Stapp. On the possibility that quantum entanglement could help us understand psi and memories, perhaps... but then again, in my mind, only as a metaphor, for it seems to assume realism, while I subscribe more to the idealist hypothesis (i.e. there is only consciousness, matter existing as an image within consciousness). I don't deny though that the metaphor can be useful, like many other realist metaphors are useful in science today.
      Cheers, Bernardo.

  6. Bernardo, have you seen parapsychologist Stephen Braude critique of Ruperts morphohenic field idea. What did you think?

    1. Hi Mark,
      I haven't and didn't know about him. But now that you mentioned it, I will have a look.
      Gr, Bernardo.

    2. I've read it here: I agree with Braude's key criticism that morphic fields cannot be objective, autonomous, mechanistic entities in nature, as proposed by Sheldrake (a criticism Braude repeats in different forms, and justifies in different ways, throughout the paper above). As Braude put it: "Sheldrake seems to take the hard-line Platonist view that morphic units and their associated morphic fields are natural kinds -- i.e. items in an interest-, purpose-, and context-independent set of natural furniture." As Braude, I also disagree with Sheldrake's views here, and wrote about it before: I think the evidence Sheldrake assembles for the hypothesis that nature forms "habits" is indeed compelling, but it is rather evidence of idealism (i.e. nature as essentially mind, since mind forms habits), instead of objective morphic units as autonomous parts of the "furniture of nature." Morphic fields, in my opinion, are still valid as explanatory metaphors, not autonomous ontological entities, and Braude himself seems to agree.
      I do disagree with Braude in his criticism of the resonance model. He claims that resonance doesn't work since similarity is not built into nature but depends on a subjective evaluation by human minds. The latter point is true, but Sheldrake uses the word "similarity" metaphorically. Resonance is a physical phenomenon that does happen between two systems capable of resonating with each other regardless of our opinions regarding their similarities. A famous example of resonance is between wind and a bridge (see, which are hardly similar entities. Therefore, on this point, I depart from Braude and stay with the resonance metaphor, which I think is valid. Braude's argument rests entirely on Sheldrake's use of the word "similarity" and misses the deeper point. Under idealism, you could say that thoughts (oscillations in the medium of mind) can indeed resonate with other thoughts that are amenable to resonance (whether we think these thoughts are similar or not; in fact, we could even _define_ "similar" as "amenable to resonance").

    3. Yes, Rupert Sheldrake's stance has changed more towards process philosophy but now the resonance and similarity metaphors only have a precise definition within physically defined processes or occasions-of-experience. This metaphor needs extending into higher grades of occasions-of-experience.

      Sounds more like a task for psychology, future versions of neuro- or cognitive- sciences, philosophy and so on rather than physics.

  7. Bernardo,

    Do see any relationship between your "knot of consciousness" hypothesis and the "attractors" of chaos theory?

    1. Hhmm... If I had to articulate it explicitly I would say that, no, I don't. But somehow your question invoked an intuition that I want to look into further; perhaps there is a relationship and I am just not seeing it right now. Or perhaps it's just the trickster in action in my mind... :-). I will think about this; I really will. Thanks for bringing this up.

  8. I deal with the natural biophysical substrate of visual perception and visual imagery. The main goal of my research is to prove that intrinsic pictures can be emerged by redox and biophoton processes in retinotopically organized neurons of visual areas during visual imagery, visual hallucination, and REM dream pictures within the brain.

    Kosslyn`s reality simulation principle states that visual mental imagery mimics the corresponding events in the world. However, my concept of intrinsic biophysical visual virtual reality (by bioluminescent photons and iterative processes) in early retinotopic areas may be nothing else than the first possible biophysical basis of the reality simulation principle.

    I hope that my researcher of biophysical picture representation can bring a brand new ways in the brain and cellular researchers, visual prosthesis, and artificial intelligence in the future. I can explain numerous brain related phenomena by biophysical picture representation model in a convergent manner (such as: phosphenes, negative afterimages, saccades, blind sight, visual imagery and perception, REM dream pictures, visual hallucination, autism, savant skill, some color illusions, synaesthesia, etc.

    I do not claim to solve the secret of consciousness, but propose that the evolution in the higher levels of complexity made possible the emergence of intrinsic picture representation of the external visual world by regulated redox and bioluminescent biophotons in the visual system during visual perception and visual imagery.

    1. Hi Bokkon,
      Instead of interpreting the neural correlates of visual perception as a virtual 'copy' of reality inside the brain, I'd rather see them as an image, in mind, of a process of localization of mind, in the same way that a whirlpool is an image, in water, of a process of localization of water. I think that to say that brain activity generates consciousness is as absurd as to say that a whirlpool generates water. Of course, there are correlates between brain activity and first-person conscious perception, because the former is simply a (partial) image of the latter, in the same way that, say, lighting is the partial image of atmospheric electric discharge. Lightning doesn't generate electric discharge, it's simply the way electric discharge looks. I elaborate more on this here:

      Cheers, B.

  9. What do we think of these latest rat experiments:

    On closer inspection, is is overreaching to say they have 'implanted false memories'. What they have in fact is created a false association.

    They appear to have been able to force a recall of a previous environment by activating cells which were active when the rat was in the first box. By stimulating these cells in a second box, they caused the recall of the first box in the mice.

    While this is happening, they applied electric shocks. The mice, unsuprisingly, began to associate the initial recalled box with the shocks, so when they are placed back in the first boxed environment they froze with fear, even although they had never been subject to shocks in the first box.

    It's interesting in that it does appear that the scientists have been able to recall a memory by activating specific cells, but it is a stretch to say that this is 'implanting memories', as the memory already existed - they just confused it by recalling this memory while silmultaniously shocking the creature - wouldnt you learn to fear a particular environment if you associated it with an electric shock?

    We may have found a trigger, or key to a specific memory in these mice, but that does not mean that the activated cells ARE the specific memory, as these researchers, and the media in general, are suggesting. They are hyping that they have found the 'engram of a specific memory'. I think it's reaching to say that at this stage.

    1. I agree completely, Douglas! I posted my thoughts here:


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