I, and a lot of other people, find Hoffman's 'theory' to reside in pure speculation concerning a supposed digitized 'informational' interface between ourselves and the world we live in, an interface in which an unreal world is projected by our neurons.
Constance, that's not quite what Hoffman's position is as I understand it. Maybe the following excellent paper will clarify the position for you. (Although Hoffman's position takes a step further than the following.)
The following article is the most lucid that I've encountered at explaining the "brain-centered theory of perception." If one understands the brain-centered theory of perception, it can act as a bridge to understanding the "exotic stimuli" hypothesis of high strange UFO/paranormal phenomena articulated in this thread. Below I will pull out some relevant sections. (
@ufology I would be particularly interested in hearing your thoughts regarding the brain-centered theory of perception.)
The Machine behind the Stage: A Neurobiological Approach toward Theoretical Issues of Sensory Perception
When a neuroscientist considers perception or any other mental process, the starting point is the existence of a biological ‘machine’ (
Ryle, 1949), the brain, the activation of which generates all mental states and events that appear to us as if taking place on the stage of a ‘Cartesian Theater’ in the mind (
Dennett, 1991). There are two main consequences arising from this thesis.
The first one is the fact that the only direct cause of any mental state/event is a given pattern of brain activation: perception is created by a perceptual system, and behind each and every percept there is a certain neuronal activation, fully responsible for causing this percept. What produces the neuronal activation is a separate question: it can be physical objects sending light to the eye, artificial brain stimulation by an electrode, an epileptic seizure, magic mushrooms, auto-activation while dreaming, and many more. All these alternative brain-stimulation events can theoretically have an identical result: a specific brain-activation pattern, leading to the formation of a specific percept. ...
The second consequence of a brain-centered theory of perception is that, since the percept is the creation of a given neuronal system, its characteristics will depend on and directly reflect the properties of this system. [Soupie: Comments from me regarding this to follow. Also,
@Constance, please consider the following closely as it directly applies to your concerns about the interface being abstract and disconnected from nature. Also, the following is very similar to
@Pharoah's HCT, as I have been saying for some time.]
This does not imply that perception is of an esoteric nature and in complete isolation from the physical world. Such isolation would miss the point, since perceptual systems have evolved in order to enable organisms to interact with their environment. In the example of vision, light falling on objects activates the brain by the process of phototransduction, during which photoreceptors at the retina transform electromagnetic energy into electrochemical activation, which in turn sends a neural signal to the rest of the visual brain. This light has specific characteristics which are determined by the properties of the reflecting object (i.e., carries information), and so determines the characteristics of the elicited brain activation. Thus, the characteristics of a percept are dictated by both the perceptual system which creates it and the properties of the physical object we are looking at. In this way we can acquire objective knowledge about the world, albeit in a very subjective manner. Perception is therefore characterized by an objective subjectivity or, to say it perhaps better, a subjective objectivity. Objectivity, since the transformation from the physical to the perceptual world follows certain constant, reliable rules. Subjectivity, since each percept is created by a perceptual system and therefore its characteristics depend on the properties of the latter: the same chair looks different to a human, a cat or a bat, and perhaps looks different even between two humans. Plato has realized that what we perceive are ‘reflexions of reality’ (Plato: The Republic, Book VII). The nature of these reflections depends on the nature of the perceptual system that both creates and perceives them.
[Soupie: Okay, here is the bit that is germane to the "exotic stimuli" hypothesis of High Strange paranormal experiences.]
The characteristics of the percepts created by the brain do not solely depend on the bottom-up processing of incoming sensory information, but are also determined by top-down mechanisms reflecting previous experiences of the subject. Starting from Hermann von Helmholtz more than a century ago (
Helmholtz, 1866), the idea that perception could be seen as an inference process, rather than the intuitive ‘normal-picture scenario,’ has become increasing popular. A percept is the result of such inference process based on the internal representation generated by the brain. Recently, there is some further development of this line of thinking, drawn on the estimation theory and Bayesian inference from the field of statistics, to formulate mathematically rigorous models for perception that can be tested quantitatively against experimental data (for examples see
Knill and Richards, 1996;
Girshick et al., 2011;
Clark, 2013).
This shift is away from the brain as a passive filter of sensations and toward a view of the brain as a statistical organ that generates hypotheses which are tested against sensory evidence. The brain never knows anything about an object for sure but can only make maximum likelihood predictions about what an object is, how it will appear in the future, or how it will interact with different senses based on the sensory information we have at present. Perception is making predictions and thus percepts are reconstructions of the world around us that represent our best guess as to what is out there, based on the statistics of how sensory information impinges on the sense organs. In this way, the ambiguity of sensory information can be dealt with. In 3D vision, for example, the problem of reconstructing a 3D object given two 2D views is inherently under-constrained: given a homographic projection, infinitely many objects of differing size can produce the same image on the retina. It is only through heuristics and tricks based on natural image statistics that the visual system is able to generate a plausible guess at an object’s 3D structure that is correct most of the time (but not always – see
1 for a nice example).
The reality we experience is our best guess at how to reconstruct the world based on what most probably generated our sensory inputs. In cases where the brain cannot decide on which of the explanations is most probable, we can have instances of bistable (or multistable) vision (e.g.,
Necker, 1832;
Blake and Logothetis, 2002).
[Okay, this is where things start to get real juicy. We move away from the exotic stimulus hypothesis and into discussion of the nature of consciousness and material relevant to Hoffman's approach to consciousness (mind) and the physical world (matter).]
A good example in order to understand how percepts are psychological entities created by the brain rather than physical entities existing in the physical world is color. The science of color supports the view that phenomenal character is a property of the experience (
Byrne, 2002, p. 9) rather than not (
Tye, 2000), and its phenomenology can be nicely connected with known facts about the anatomy and physiology of the visual system.
Metamers, for example, are stimuli with a different light composition that look exactly the same color, nicely demonstrating that color vision does not necessarily inform us about the precise properties of objects in the real world 4. Instead, the phenomenon is explained by the neurophysiological fact that there are three different cone types with different sensitivities across the visible spectrum. The Trichromatic Theory of Color Vision (see
Blake and Sekuler, 2006, p. 246) can also explain the fact that any triplet of primary
5 colors can give rise to the full gamut of the colors we perceive. Furthermore, the fact that a color cannot be red and green (or blue and yellow) at the same time, together with the fact that we need four (rather than three) names in order to roughly describe all the colors that we perceive, is a direct consequence of the way the cone input combines upstream from the retina to create opponent color-pairs (see
Blake and Sekuler, 2006, p. 258). Finally, the fact that neuronal circuits in the brain compare lights coming from different part of the visual field is responsible for the well-known phenomena of color constancy and color induction
6 (
Land, 1977).
Color vision thus nicely demonstrates that the characteristics of the visual experience are determined by the way in which the perceptual system is constructed. To say it with a philosopher’s words, ‘colors are a feature of the way we process visual information rather than a feature of the objective, mind-independent world’ (
Fish, 2010, p. 145).
The realization that color is not a mind-independent object can generalize to perception as a whole. The old philosophical question of ‘looking red’ vs. ‘being red’ is non-existent for scientists, because there is only ‘looking red’:
red is a psychological property, not a physical one, and therefore it can only exist as a result of the activation of a visual system. When a surface of high reflectance for long-wave light and low reflectance for the rest of the spectrum sends light to a primate retina, the retina transduces this light into neural signal and sends it to the thalamus. From there, the signal reaches the primary visual cortex, areas V2 and V4 and so on, and then, at some unknown point in time [Soupie: !] , the mental event of experiencing redness takes place (see Zeki, 1993 for an excellent review of the visual system). This private mental event is constant for each one of us, but could be different from one person to another. We all refer to this experience as ‘red,’ because we have agreed to give this name to the experience that we have when looking to a surface of such and such a reflectance, whatever this experience might be for each one of us. Thus, when talking about a psychological property PS such as color, nothing is PS but rather some things feel PS. Similarly, when talking about a physical property PH such as reflectance, nothing feels PH but some things are PH.
Failing to realize the distinction between physical and psychological properties is often a cause of confusion in the philosophical literature. For example, color realism (see Byrne and Hilbert, 2003) would claim that a percept is not red, that redness is not a property of this mental event but rather that the mental event is representing red, which is a property of an object in the physical world. This statement is incorrect, as red is indeed nothing more than a mental experience/state. As already mentioned, the presence of this experience might be related to the presence of a physical object that has a certain spectrum reflectance: light from that object falling on the retinae initiates a series of events in our visual system that lead to the creation of a red experience. If one wants to describe this by saying that the particular percept represents the particular reflectance properties of the object, then this is fine but it does not add much to our knowledge of what is going on. Furthermore, if one uses the word ‘red’ to refer to a physical property, namely a high reflectance for long-wave light, then again the problem is mainly a linguistic one. The important thing is to realize that, as physical objects have physical properties, similarly mental events (such as percepts) have psychological properties and that, whatever names one chooses for them, the two should not be confused.
Color is perhaps the most profound example in perplexing the physical with the psychological, but the problem is more generally present. Similar to the distinction between reflectance and color, there is also a distinction between oscillation amplitude and loudness, relative (to the background) energy and brightness, frequency and pitch etc. ...
Perhaps because vision is so dominant among our senses, it intuitively feels as if things in the physical world are exactly as they visually appear to us. It is quite difficult and counter-intuitive to digest the fact that the color of a red tomato shining under the sun does not belong to the tomato per se, but is rather a creation of our own perceptual system7. The physical property of the tomato which contributes to the creation of this color by the brain, i.e., the reflectance of the object for different wavelengths, is not colored at all. Therefore, it is wrong to claim that the properties of our experience belong to the object rather than to the percept. After all, nothing feels like anything unless there is a perceptual system there to feel it. The fallacy is more easily revealed in the case of senses other than vision. Is sweetness the property of a cake? Would a cake be sweet if there was no one to taste it? Couldn’t the same cake taste totally not-sweet to a creature having a different nervous system from the one that we have? Wouldn’t this same cake taste less sweet to the same person, if it is eaten after eating honey or while having the flu (Locke, 1961, p. 124)? Sweetness is as much a property of the cake as color is a property of the tomato. One can still argue that a representation is taking place here, as long as it is clearly understood that there is nothing ‘sweet’ in the properties which are being represented (i.e., the chemical composition of the cake). The latter are neither sweet nor sour, the only property they have is the ability to activate the (particular type of) brain in a way that generates the experience of sweetness. The exact same arguments apply equally well in vision, but the reflexive intuition against them is much stronger in this case.
[And this is where the path gets particularly difficult for the laymen to swallow...]
The usefulness of perception derives from the fact that its characteristics do not only depend on the properties of the perceptual system creating it, but also on the characteristics of the physical objects in the real world. In Plato’s allegory, the shape of the shadows seen by the chained prisoners depends on the shape of the things passing by behind them, in front of a burning fire. Objectivity is further assured by the fact that there is a given deterministic way, a constant ‘algorithm’ which transforms the physical stimulus into neuronal activation and thus to the emergence of a specific percept. For a given perceptual system, a red apple will always look red and a yellow banana will always look yellow, irrespective of what ‘red’ and ‘yellow’ is like for that particular system. Perception can ‘...yield knowledge of an objective world beyond experience, and... put us in a position to think about such a world...’ (Child, 1994, p. 148). In this way our perceptual experiences make sense, helping us to detect constant properties of our environment and gain knowledge about the world in which we exist, thus satisfying the ‘epistemological hat’ of philosophical enquiries (Fish, 2010).
Since percepts are subjective by virtue of the fact that they are created by perceptual systems, could this mean that perception hides from us the ‘truth’ of the real world? ‘If all I ever get is smoke, how do I know what fire is like?’ (Campbell, 2002, p. 6). The problem with this way of thinking is that only a percept is (experientially) like something – the question has no meaning with respect to a physical object. One can complain that the percept of smoke is different to the percept of fire, but it is false to wonder whether a physical object in reality feels different from the experience that it produces. ...
Most scientists would probably agree with naïve realism on the fact that the external world shapes the contours of conscious experiences (Martin, 2004, p. 64), but would disagree on the view that the objects of awareness are actually the mind independent objects that inhabit the world (Fish, 2010, p. 96). The idea that we perceive the world ‘directly’ or ‘as it is’ can be disputed by the fact that what reaches our brains is nothing more than a neuronal signal, the result of sensory transduction at the sensory receptors. Therefore, no light, or pressure, or objects, or anything that exists in the physical world can enter into our neuronal and mental universe. The physical world does not ‘look’ or ‘feel’ like anything, unless there is a perceptual system to look at it or feel it. It follows that our subjective experience of the world is neither correct nor wrong, as the latter does not have a ‘proper’ or ‘true’ experiential quality on its own (unlike the case in Plato’s cave, where objects have true appearances). The definite answer to Berkeley (1910) is that if a tree falls in a forest and there is no one there to hear it, there will be no sound. Similarly, the forest will not look, smell or feel like anything, unless there is a perceptual system there to create the corresponding perceptual experiences. So, to the question of whether we experience the physical world ‘correctly’ (Crane, 1992, p. 139), the answer a scientist would give is that we do not experience the world neither as it is nor as it is not (Fish, 2010, p. 3), since without a perceptual system the world alone has no perceptual quality.
A percept is something that emerges when the brain is activated in a certain way and thus all perceptual experiences (whether veridical, illusory, hallusinatory etc.) have a common cause behind them: a given brain activation pattern. What distinguishes between different cases of perception is what has caused this activation pattern: light coming from a real object, an epileptic seizure, chemicals, artificial stimulation with electrodes implanted in the brain and so on. All of these cases and many others, however, have a factor in common: what causes the emergence of the percept is the fact that the brain is activated in a particular way.
[End article]
So where does Hoffman's thesis enter this story? Well, if "the physical world does not ‘look’ or ‘feel’ like anything, unless there is a perceptual system to look at it or feel it" what is the nature of this perceptual system? The author began this paper with the following statement: "When a neuroscientist considers perception or any other mental process, the starting point is the existence of a biological ‘machine’ (Ryle, 1949), the brain, the activation of which generates all mental states and events that appear to us..."
When the author uses the phrase "perceptual system" I am completely on board with him. However, when the author claims that the physical brain generates all mental states, I have to disagree, strongly. (And no, that has not always been my stance.)
I feel the author's own lucid presentation in this article undercuts his own claim that the physical brain "generates" what he calls "psychological entities," i.e., phenomenal qualities. To be clear, I think the author's presentation is right on the money were he to say that perception is "perceptual-system based" but he undercuts his own argument when he says above: "A good example in order to understand how percepts are psychological entities created by the brain rather than physical entities existing in the physical world is color."
Do you see the problem with that statement? Colors are not physical entities, but rather they are psychological entities created by... the physical brain? If psychological entities such as colors are not physical, how are they created/generated by physical processes in the brain? This by the way is the Hard Problem of consciousness.
Even the author indirectly acknowledges the lack of knowledge regarding this: When a surface of high reflectance for long-wave light and low reflectance for the rest of the spectrum sends light to a primate retina, the retina transduces this light into neural signal and sends it to the thalamus. From there, the signal reaches the primary visual cortex, areas V2 and V4 and so on, and then, at some unknown point in time, the mental event of experiencing redness takes place...
At some unknown point in time. And via some unknown physical process!
The answer is right in front of the author but he misses it despite the excellence and lucidity of his paper. There is indeed a "perceptual system" responsible for generating us, that is, minds. And while this perceptual system is strongly correlated with the physical brain, we must remember that the physical brain is a product of the the perceptual system!
The author said something rather profound early in the paper: "The second consequence of a brain-centered theory of perception is that, since the percept is the creation of a given neuronal system, its characteristics will depend on and directly reflect the properties of this system."
The author was referring to the physical brain in this case. And the paper does explain how properties of the brain directly affect the mind. [I recently encountered a good, simple explanation of how "mind" is distinct from "comsciousness." Will post next.] However, what I believe Hoffman is saying is that we can take this notion deeper. That is, the perceptual system is "behind" all that we experience; the perceptual systems generates everything in experience, including the appearance of brains and neurons. This perceptual system is more fundamental then the reality it presents. The reason scientists must say that consciousness emerges at "some unknown point in time" is because it simply does not emerge at a point in time. It just is. And our perceptual landscape, our experiential mind, is created from it, not the other way around.
Also, the author speaks about truly objective, physical properties such as length and mass. But are these truly objective features of the world? They may be objective in the sense that they represent mind-independent patterns of stimuli in the external world. However we mustn't interpret the authors use of "objective" to mean veridical.
All precepts and concepts about reality are filtered through the human species-specific perceptual system.
The following is one of the best descriptions of what physics can currently tell us about the nature of objective, veridical reality. (For what it is worth, Sean Carrol is highly regarded in physics.)
So, the author above explains lucidly that "without a perceptual system the world alone has no perceptual quality." So what is the world "like" in the absence of perceptual quality?
Space Emerging from Quantum Mechanics
"We human beings, even those who have been studying quantum mechanics for a long time, still think in terms of a classical concepts. Positions, momenta, particles, fields, space itself. Quantum mechanics tells a different story.
The quantum state of the universe is not a collection of things distributed through space, but something called a wave function. The wave function gives us a way of calculating the outcomes of measurements: whenever we measure an observable quantity like the position or momentum or spin of a particle, the wave function has a value for every possible outcome, and the probability of obtaining that outcome is given by the wave function squared. Indeed, that’s typically how we construct wave functions in practice. Start with some classical-sounding notion like “the position of a particle” or “the amplitude of a field,” and to each possible value we attach a complex number. That complex number, squared, gives us the probability of observing the system with that observed value.
Mathematically, wave functions are elements of a mathematical structure called
Hilbert space. That means they are vectors — we can add quantum states together (the origin of
superpositions in quantum mechanics) and calculate the angle (“dot product”) between them. (We’re skipping over some technicalities here, especially regarding complex numbers — see e.g.
The Theoretical Minimum for more.)
The word “space” in “Hilbert space” doesn’t mean the good old three-dimensional space we walk through every day, or even the four-dimensional spacetime of relativity. It’s just math-speak for “a collection of things,” in this case “possible quantum states of the universe.”
Hilbert space is quite an abstract thing, which can seem at times pretty removed from the tangible phenomena of our everyday lives. This leads
some people to wonder whether we need to supplement ordinary quantum mechanics by additional new variables, or alternatively to imagine that wave functions reflect our knowledge of the world, rather than being representations of reality. For purposes of this post I’ll take the
straightforward view that quantum mechanics says that the real world is best described by a wave function, an element of Hilbert space, evolving through time. (Of course time could be emergent too … something for another day.) ..."
Positions, momenta, particles, fields, space itself, these are all concepts humans use that are based on our human species-specific perceptual interface with... the world. Whatever it is.
