How to Really Solve the Mind-Body Problem (1)

Abstract: By supporting the idea of a sharp separation between sensation and perception to solve the mind-body problem, Nicholas Humphrey solves some difficult questions but creates others that are insoluble. It thus opens the door to a more complete solution, which retains the need for a dual view of the problem, without making a summary neurological division. Stratium is a solution that, instead of narrowing the mind-matter gap, expands it as a depth of neural processing, joining Giulio Tononi’s Integrated Information Theory and complementing it to make it a true explanation, non-reductive, of the phenomenon of consciousness..


This article is the first in a series whose conclusion will be the complete resolution of the mind-body problem, at least the postponement of its consequences on the general way in which we represent reality including the mind. The articles are ordered as follows:

1) The two-pronged approach of Nicholas Humphrey, who presented the problem in a remarkable way and proposed its solution.

2) The contribution of Humphrey’s critics, gathered following his article in an issue of Journal of Consciousness Studies in 2000.

3) The notion of level of explanation, a level that differs according to the authors. The effort to reduce physicalist and spiritualist looks to each other leads to a dead end. On the contrary, it requires preserving their specificities and making them coincide.

4) What assumptions to keep? We need a reality unified by its relations but which leaves its relational levels owners of their frames. This involves the recognition of a complex dimensional variety. In the vertical axis of this dimension, the systems have a constitutive face and an indissoluble phenomenal face, appearing at what is respectively less complex and more complex. The interface of this “two-sided coin” is discussed elsewhere.

5) The necessity of vertical complexion or emergentism is discussed in relation to its denigration by “flatism”. I show that flatism is in fact a dualistic impasse excluding our mind. The reality of the vertical complexion is readily concealed, in mathematical models, within the sign ‘=’, which often means ‘correlated to’ rather than ‘identical to’.

6) The elevation of complexity within the mind is approached by the example of artificial intelligence and its simulated networks, as well as the example of the hydrocephalic brain, which forms a normal consciousness with 10% of the usual neurons.

7) Stratium is a theory based on the complex dimension of the brain, combining the Global Workspace and Integrated Information. The height of vertical complexion makes the thickness of consciousness. In continuity with the complexity of the neural support, consciousness is anchored in matter before the neuron. The phenomenon of consciousness is inscribed in reality per se. Each individualized entity experiences it in its own way, accessible only to a vertical complexion of the same order. Our consciousness recognizes itself only in itself.

8) Consciousness theories have all received strong criticism. I have taken up the questions and summaries of many authors. How does Stratium respond? Taking the complex dimension into account facilitates the answers. Applications to neuroscientific and psychiatric puzzles are offered.

9) Conclusion summarizing the progress made, with a bonus: Why the errors encountered? A theory of mind, by definition circular, has the additional task of explaining why the mind “self-generates” its errors—errors about its own representation.

The headline refers to Nicholas Humphrey’s 2000 article, How to solve the mind-body problem. After the analysis of Gualtiero Piccinini’s recent Neurocognitive Mechanisms , which approaches the famous problem by privileging the neuroscientific angle, I could not find a better reference than Humphrey for the philosophical approach. His remarkable contribution is complemented by the criticisms of the best contemporary specialists in philosophy of mind. I will focus on pointing out Humphrey’s mistakes, but he has posed the problem so clearly that he is opening a road to the solution. I try this oxymoron: it is the relevance of his mistakes that gives us the key to the problem.


Nicholas Humphrey’s Dual Approach

I borrow from Natika Newton, whose comments we will find later, her excellent summary of Humphrey’s views:

« Humphrey argues that mental and physical stales seem incommensurable because mental states, conceived as sensations, are described as if they are the objects of experience. In fact, however, they are activities: sensings of the true objects: physical stimuli with which the organism is actively engaged. Conceiving of sensations as themselves objects of experience (and then talking, as so many do, of what that experience ‘is like’) leads to a hopeless regress. There is no ‘mental object’ corresponding to ‘experience’, and any proposed candidate for it immediately becomes itself the source of more mysterious ‘objects’: the ‘phenomenal properties of experiences’ which are themselves ‘like something’, ad infinitum.
As long as sensations are conceived of as non-physical objects that can be experienced, they cannot be explained in terms of brain stales, objects of a completely different metaphysical kind. Humphrey’s first move is to distinguish between perception and sensation, and to point out that while perception is indeed ‘of’ external physical objects, sensations are not menial objects of an ‘inner sense’; instead ‘sensory awareness is an activity. We do not have pains, we get to be pained’. Sensory awareness is efferent activity, and the experience it provides is not the experience of a mental object, a sensation, but the experience of the activity itself. In his second move, Humphrey argues that sensory activity has evolved from responses that in the past did carry through into actual behaviour. And the result is that, even today, the experience of sensation retains many of the original characteristics of true bodily action.
Explaining sensory activity in terms of bodily activity allows Humphrey to correlate it with brain activity. Sensation, like bodily action, is characterized by: ownership, bodily location, presentness, qualitative modality, and phenomenal immediacy. Each of these can be understood in terms of brain states, because they are ‘dual currency concepts’, neither purely mental nor purely physical. Humphrey concludes with a plausible evolutionary scenario that would connect the two sides of the mind-body problem. »

In other words, Humphrey equates sensation with phenomenal consciousness. Experienced consciousness is the simple activity of feeling, of being one’s sensitive body. While perception is the “awareness of”, the interpretation of signals from the outside world and our own behavior, by other neural networks gradually put in place over the course of evolution.

Separating perception and sensation

Let’s give Humphrey the floor directly:

“Sensation has to do with the self, with bodily stimulation, with feelings about what is happening to me now and how I feel about it; Perception, on the contrary, has to do with judgments about the objective facts of the outside world. Things so different in nature must be distinguished. »

How valid is this distinction?

Humphrey insists from the outset, very strongly, on the separation between perception and sensation. Unfortunately these terms are very poorly defined. According to the dictionary: Sensation is the impression directly from the sensory organs. Perception is the act of bringing this sensory information together into a mental image. The separation therefore takes place between the sensory sensors on the one hand, and the central nervous system on the other. Can the study of the mind/body problem be based on a geographical division of the organism?

Dualism and triunism

Philosophically the separation is enriched by a few details: The sensation is immediate, automatic, triggered by an external event. While perception involves attention, interpretation, understanding, memorization. In such a binarism, if we remove the perception of the reasoning human, remains a sensitive plant, oscillating according to the environment. You can guess here the trace of the religious gap between soul and earthly envelope. This outdated dualism, which was also that of the human / the animal, continued with the triune brain, a theory that saw 3 independent brains under our skull, the reptilian dominated by the limbic itself ridden by the cortex. But phylogenetic divisions have not been confirmed by functional divisions. The tasks of the brain are strongly entangled between its regions.

Dualism and triunism introduce a crippling pitfall: Who synthesizes sensations/perceptions, or reptile/mammal/human? Where is this extra brain? The horizontal view of a brain as an assembly of specialized centers was long the norm in neuroscience. Some are still looking for a “center of consciousness.”

The ends of a process

Today the brain appears, under the effect of a more vertical vision, as a deeply hierarchical system. Sensation and perception are best defined as the ends of this integration. As Jean-Pierre Changeux says: “The term sensation’ was used, deliberately, to designate the immediate result of the entry into activity of sensory receptors [and the term ‘perception’] for the final stage which, in the alert and attentive subject, leads to the identification and recognition of the object.” In between: a black box.

Is the gap only the ends of a process? Are sensation and perception phenomena of the same nature? From the point of view of the phenomenon, the sensation seems coarse, pixelated, reinterpreted by perception. Perception adds layers of meaning to the raw data. The phenomenon changes in quality, but in nature? We never experience a sensation of neurons traversed by electrochemical impulses. That would really be a very different kind of phenomenon.


The ancient psychophysical theory of Gustav Fechner in the 19th century linked the intensity of perception to the logarithm of the intensity of sensation. This works well for simple perceptions. We clearly perceive differences in low lighting while glare is the same for all strong lights. But how to apply such a rule when a person crosses our field of vision? Why will it awaken our perception or not? The answer is qualitative, not quantitative. Many criteria add their independent layers until the final perception.

The conscious phenomenon, in the end, includes the basic sensation and many others, which have enriched it. But what happens if the basic sensation does not reach consciousness for lack of intensity or attention? Does this sensation not give rise to any perception? It seems arbitrary to conclude this solely on the ground that she did not access conscious space. Perhaps it has really been perceived by a large part of the intermediate levels? After all, we perceive many vague things, “at the threshold” of consciousness.

Why would some neurons be ‘perceptual’ and others ‘sensory’?

All these processes are physiologically identical: some neurons excite others. What is the basis for the elitism of conscious ‘perception’ in relation to the ‘sensation’ of basic neurons? Why are we denying them to “perceive” the stimuli of sensory sensors and their relays? Insoluble questions arise incessantly with dualism, the same ones that have made it “hard” to explain the phenomenon of consciousness.

A redefinition

Paradox of the perception/sensation separation: it is both necessary, and reductive if it is limited to one level. Getting out of the paradox requires redefining the two notions:

1) Separation is necessary: sensation is the experience of the excited neural pattern, identifying itself in sensory data. Perception is the recognition of this state, this identity, by another neural group.

2) Single separation is reductive: perception is also identified in the data of other neurons. That is, all neural groups are both sensory and perceptual. No difference in physiological functioning between them. Each group is simultaneously perceptive of its elements – the stimuli arriving at its neurons – and sensory of the result – the synchronous/integrated state of the group.

Perception and sensation are two facets attached to each neural network that are understandable only in the complex dimension. Suppose a hierarchy of neural networks at 3 levels: the sensations of the N1 networks are the perceptions of the N2 networks; then the sensation experienced by these N2 is in turn the perception of the N3.

Humphrey’s dualism is primarily neurological

Let us return to Humphrey, whose text introduces another dualism, this time of a neurological nature. “Sensation has to do with the self, […] Perception, on the contrary, has to do with [the] outside world.” This passage is misleading. The ‘self’ Humphrey is talking about here is that of sensory afferents and not the psychological self. This is the ‘body to oneself’. While the ‘outside world’ of perception is the mental stage already installed to welcome sensations. It is proactive—it seeks itself in sensations. Humphrey’s dualism is that of an official, identity-based scene, established in one part of the brain, and welcoming the sensory news emitted by another part of the brain.

We will see later the severe criticisms triggered by this too sharp division, contradicting neuroscientific studies that show rather the entanglement between sensation and perception, to the point of hardly differentiating between the two.

A richer stage dualism between Mind-Self and Real

The dualism that Humphrey tries to account for does not lie in different neurological modes. It is a dualism of afferents which leads to a dualism of mental scene. The organism, limited by the skin, is a self in the non-self. Sensory afferents are clearly divided, neurologically, into intrinsic (somesthetic) and extrinsic (vision, hearing, taste, smell). Somesthesia is the main and necessary sensory system. The deprivation of these afferents causes severe psychological disorders, while one can live cut off from the other senses.

The two types of afferents are grouped into two poles of representation in the mind, the body to oneself and the external reality. The body to oneself is a major component of instinctive identity, and therefore of personality. It is completely owned by the individual. This makes me call it ‘Spirit pole’—spirit as individuation in a single organism. While the external reality is more malleable, its abstract perception can be manipulated by countless concepts learned in society. But this pole is also limited by the returns of reality. I call it the ‘Real Pole’ —it can be very whimsical with magical thinking or very structured with scientific thinking.

Both poles are in sensation, as an influx of sensory data, and both are in perception, as an interpretation of images of the body and the world. This stage dualism is not intended to explain consciousness but to understand the conflicts of interest inherent in the functioning of the psychism.

Feel or be the pain, both are possible

Another passage from Humphrey:

« When, for example, I feel pain in my hand, or taste salt on my tongue, or equally when I have a red sensation at my eye, I am not being pained, or being stimulated saltily, or being stimulated redly. In each case I am in fact the active agent. I am not sitting there passively absorbing what comes in from the body surface, I am reflexly reaching out to the body surface with an evaluative response — a response appropriate to the stimulus and the body part affected.
Furthermore, it is this efferent activity that I am aware of. So that what I actually experience as the feeling — the sensation of what is happening to me — is my reading of my own response to it. Hence the quality of the experience, the way it feels, instead of revealing the way something is being done to me, reveals the very way something is being done by me.
• This is how I feel about what’s happening right now at my hand — I’m feeling painily about it!
• This is how I feel about what’s happening right now at this part of the field of my eye — I’m feeling redly about it!
In my book I proposed that we should call the activity of sensing ’sentition’ »

If Humphrey had practiced medicine, he would have met people with contrasting relationships with pain: Some, suffering from fibromyalgia, are entirely, integrally, identitarianly, their pain. They are unable to detach themselves from it, to represent their pain. The doctor discusses with the painful sensation. Other people make pain a sensory backdrop that they pay no attention to, even when necessary. So there are, contrary to Humphrey’s thinking, people who are their suffering, and others who are not. This is only understandable by an intimate entanglement of sensation with perception, which allows all intermediate situations.

Humphrey is here poorly influenced by a neuroscience already outdated in his time. Identifying different neurological pathways for sensation and perception may make them different mental functions , but does not show the reversal between sensation and perception. Nor does it explain the transition from stimulus to phenomenon. Why does this phenomenon become so special by engaging in a neural processing loop, if it is only a longer loop?

Complexity that progresses rather than separate paths

Unfortunately that Humphrey did not verticalize his thinking. Because he is moving on the right track for the rest. The opposition between sensation and perception allows him to understand how the mind emancipates itself from sensory data, seeks itself in these data to evaluate them. He is perfectly in tune this time with contemporary neuroscience, and his evolutionary perspective is excellent. He makes only one mistake, but one of importance: emancipation is achieved by increasing the depth of neural processing and not by separate neurological pathways. To be convinced, let us remember that an infant has an embryonic perceptual consciousness, very little freed from sensations, while the same neurological pathways as the adult are in place. It is dendritic pruning that sets up symbolic patterns and increases the complexity of perception.

Consciousness is not a self that perceives a non-self. It is a merger that perceives the previous merger it was, revised and augmented with new conceptual organizations. Consciousness has an essential temporal dimension, which Humphrey’s version does not render. I am an observation of what I have been (in my relationship with the world). This is very easy to explain with a hierarchical organization that is also a temporal sequence, but not with two functions recreating the world and oneself.

Humphrey finds better examples in elementary sensory processing. Neurological disorders and the effect of drugs are indeed a good demonstration of the dissociation between perception and sensation of color. But these are adjacent levels of neural depth. These examples show the importance of keeping the concept of dissociation in the hierarchy of schemas. This does not make them different neurological functions. Sensation is not a function but a phenomenon. It is the recognition of a sensation that becomes a function. This recognition is itself a perception; of a higher order, but a perception. A neural group receives and interprets; It is both perception and representation.

The authentic solution must be enlightening

Humphrey will be obliged, in a counter-argument after the criticisms, to insist peremptorily on the sensation/perception division, which is the basis of his theory. No, no, if a solution to the mind-body problem is to gather all the votes, it must appear enlightening as well as rational to our intuition. It can surprise, disorient, leave you speechless, because it is too foreign to existing solutions. But it cannot be a new mixture of the same ingredients from which we have already drawn all the recipes, each of us preferring one without being able to impose it.

Let’s predict that the right solution will collect some “Yes but it remains to be proven” and as many “Where is the experimentation that can validate?”, but few “It is in contradiction with this or that fact”. Just theory reinserts all facts into a monistic coherence. It does not oppose existing concepts but encompasses them. Knowledge also has its complex dimension. We colloquially say that we have “changed the level of consciousness” when a theory suddenly merges the universe fragmented by the previous ones. Our neurons, which experienced consciousness in a certain way, now perceive themselves as holders of this ancient consciousness, and experience themselves differently.


How to solve the mind-body problem, Nicholas Humphrey, Journal of Consciousness Studies 7 (4):5-20 (2000)


2 thoughts on “How to Really Solve the Mind-Body Problem (1)”

  1. Thanks for the message Jp. Your approach certainly looks interesting, though I confess gto not properly understanding much of your terminology. My main comment is on the importance you give to Nick Humphrey’s ideas. His views on consciousness are very much in the ‘neuro-emergentist’ camp which is now generally regarded as incomplete at best. He tries to give them added plausibility by regarding phenomenality as an ‘internalisation’ of environmental impacts on cell surfaces; an argument which can seem no better than tautologous. I wonder if you need to deal with this difficulty head on – maybe you have and I haven’t understood you!
    Chris Nunn

    • The interesting side of the neuro-emergentism approach is precisely to start from its insufficiencies to show that neuroscience fails to explain the consciousness phenomenon, and that behind it, it is science that globally lacks a dimension to explain the phenomena which it attends, and which is seduced by illusionism. This lack serves to introduce the complex dimension, used as a backdrop by science without being the subject of any modelling. Since I proposed such modeling in my main work, Surimposium, I do indeed use a particular terminology. It is truly a new philosophical method capable of regaining control of scientific discourse. It is in no way opposed to current terminology; it encompasses it with this complex dimension. I encourage you to go into more detail in the dedicated articles to find answers… and certainly raise points that are still contentious. Thanks for your interest, Chris.


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