Another Space-Time

Another Space-Time? - Pulsars

Ticking and blinking like a cosmic metronome, pulsars keep far better time than the most accurate ordinary clock, and anyone can see the beam of this cosmic lighthouse flash once each rotation of any planet (astronomers wonder how the sky would look from the surface of a planet rotating around a pulsar).

Long-term timing or the radio pulse rate of some pulsars suggests that these objects may have one or more small planetary companions. It is conceivable thus that a planet could survive the evolution of a star into a pulsar. Or a pulsar may have captured a planet at a later time.

If you could somehow survive the gravitational tides and radiation flux trying to land on a pulsar, it is just possible that you might emerge in another part of space-time – somewhere else in space, somewhen else in time. Might gravity tunnels provide a kind of interstellar or intergalactic subway, permitting us to travel to inaccessible places much more rapidly than we could in the ordinary way? Can pulsars serve as time machines, carrying us to the remote past or the distant future? The fact that such ideas are being discussed even semi-seriously shows how surreal the universe may be.

Such worm holes in space, a little like those in an apple, have been suggested by physicists and astronomers, although these phenomena have by no means been proved to exist.

May be, it’s for better, because we must be the most backward technical society in the Galaxy. Any society still more backward would not have radio astronomy at all. If the doleful experiences of cultural conflict on Earth were the galactic standard, it seems we would already have been destroyed, perhaps with some passing admiration expressed for Shakespeare, Bach and Vermeer.

But this has not happened. Perhaps alien intentions are uncompromisingly benign. Or might it be, despite all the pretensions about UFOs and ancient astronauts, that our civilization has not yet been discovered?

On one hand, if even a small fraction of technical civilizations learn to live with themselves and with weapons of mass destruction, there should now be an enormous number of advanced civilizations in the Galaxy. We already have slow interstellar flight, and think fast interstellar flight a possible goal for the human species. On the other hand, there is no credible evidence for the Earth being visited, now or ever. Is this not a contradiction? Pulsars, what role do they play in this? Will we ever know the answer?

Why are they not here, on Earth? May another space-time dimension play a role in this enigma? Image: © Megan Jorgensen.

The Function of Consciousness

The Function of Consciousness: Integrating the Two Worlds

How, without consciousness, would you know how you feel& That is the function consciousness. It is not only intrinsically introspective, it is also evaluative. It imparts value. It tells us whether something is “good” or “bad”; and it does that by making things feel good or bad (or somewhere in between). That is what consciousness, feeling, is for. (And that is why psychiatrists are interested in modifying the chemical outputs of these core brainstem nuclei.)

The evaluative function of our conscious “state” has its roots in the visceral monitoring structures of the core brain. This function of consciousness is therefore intrinsically biological. Its evolutionary survival vale is obvious: How long would we survive if we did not have a way of monitoring the delicate economy of the internal milieu of our bodies? The organ systems of our bodies can only function effectively within a very narrow range of set-points – with respect to temperature, blood-sugar level, and so forth. The most basic function of consciousness, then, is to monitor the state of these homeostatic systems and to report whether they are “contented” or not.

But bodily self-monitoring is only the most basic function consciousness. All our vital inner needs can only be met in the external world. The inner state of consciousness (which tells us, above all, what our current needs are) therefore has to be brought into connection with the current state of the world around us. Although, as we have seen, it is not necessary to be conscious of the external environment in order to perceive it, it is nevertheless useful. It is useful to able to say things like, “I feel like this (hungry), so I want to eat that thing over there,” or, “I feel like this (upset), because thing over there bit me.” In this way, consciousness – that is, value – is imparted to objects, and objects come to be known as “good” or “bad”. Consciousness is not only what you feel, it is what you feel about something.

The similarity between Freud's model and Damasio's is very striking. Photo by Elena.

Thus, even if the evolutionary “dawn of consciousness” was purely introspective, in a rudimentary biological sense, it probably quickly generalized, and our external perceptual modalities, too, became imbued with feeling (with consciousness). In this way, our external perception was transformed from being a set of (unconscious) information-processing channels into being the generator of the rich texture of perceptual qualities (conscious sights, sounds, smells, etc.) that we are now able to experience. This is consistent with the anatomical fact that the output of the core brain nuclei in question is broadcast very widely to the forebrain, and with the psychological fat that such “bottom-up” activation is necessary before higher cortical processes can become conscious.

Damasio therefore concluded that consciousness consists of more than mere awareness of our inner states; rather, it consists of fluctuating couplings of the current state of the object world. Each unit of consciousness forges a link between the self and objects. These momentary “units” of conscious time are probably generated by the rhythmical oscillations (the 40-hertz oscillations that characterize visual awareness). The oscillations are generated by pulses of activation of cortex, emanating from deep “reticulate” thalamic nuclei, thereby coupling the two varieties (or sources) of consciousness with one another many times per second. This is how we generate “the feeling of what happens” that provided the title of Damasio's book. Consciousness thus consists of feelings (evaluations) projected onto what is happening around us. Or, to put it the other way round, consciousness consists of awareness of what is happening around us, grounded in a background medium of self-awareness. Note especially that this explanation of consciousness solves both the binding problem and the homuncular problem. The various “channels” of consciousness are bound together by the grounding “state” of consciousness, which is itself the homunculus; the little person in your head is literally a projection of your bodily self.

Damasio calls this coupling mechanism “core consciousness.” Some further complications of consciousness exist.

There are many points of contact between Damasio's neuroscientific theory and those of other psychoanalytic theorists. Photo by Elena.

Limits of Knowledge

The Limits of Our Knowledge about Our Brain

Blindsight

The term blindsight (Weiskrantz, 1986) is applied to patients with damage to the visual cortex of the occipital lobes – the primary visual cortex – which is where most of the nerve fibers from the retinae terminate. Such patients suffer from “cortical blindness”; they are blind because the part of the cortex that generates visual consciousness is no longer working. Blindness, then, means a lack of visual awareness. Thus, if you were to hold an object before these patients' eyes and ask them what they see, they would respond with the obvious: “I don't see anything; I'm blind.” But when they respond in this way, they are actually mistaken. They are erroneously equating “seeing” with “seeing consciously.” The distinction between vision and conscious vision is demonstrated when you ask these same patients to make a “forced choice” between various options (in other words, you encourage them to guess). The results of such experiments reveal that they guess correctly at a level well above chance, which demonstrates that these patients are seeing – are processing visual information – without realizing it (see Weiskrantz, 1986). They are seeing unconsciously. This occurs because some visual information is projected from the retina onto other parts of the cortex (intact in these patients) that do not generate visual consciousness but are, nevertheless, equipped to process the visual information they receive. In other words, these patients – as far as visual information is concerned – act like the “zombies”. Their brains compute visually, but they do not possess visual consciousness.

Implicit Memory

The same thing occurs with respect to other cognitive faculties. It is not all that rare for neurological patients to lose the ability to lay down new memories. This condition is called amnesia. These patients remember (recall consciously) nothing that happens to them after the onset of their brain disease or injury. If you were to read a list of words to such patients, after a few minutes they would not only forget the words, they would even forget the fact that you read them the list. However, as with cases of cortical blindness, such patients can be encouraged to “guess,” using the forced-choice paradigm. When they do so, they “randomly” select of generate words that were on the original list, at a very much higher rate than chance. So, just as we can see unconsciously, we can also remember unconsciously. The technical term for this unconscious type of remembering is implicit memory (conscious remembering is explicit memory).

What is the self in neurobiological terms? Photo by Elena.

Split-Brain Studies

In so-called split-brain patients, to treat otherwise intractable epilepsy the corpus callosum has been severed, thus separating the left (language-dominant) hemisphere of the brain from the right

By briefly flashing an image on a screen to such patients, it is possible to provide the right hemisphere with information that the left hemisphere cannot access. On this basis, it is possible to influence the patient's behavior without him or her being consciously aware of it. In one of Nobel Prize-winning neuroscientist Roger Sperry's famous cases, pornographic pictures were projected and giggled. When Sperry asked her why she why she was embarrassed, she was unable to account for it. This case (described in Galin, 1974, p.573) demonstrates that an entire cerebral hemisphere can process information “unconsciously.”

The case also reveals something else that is of crucial importance for understanding consciousness. The visual cortex was completely intact in Sperry's patient. This means that the pornographic pictures were perceived by the visual-consciousness generating part of her right hemisphere. Why, then, did she appear not to know what she saw? The answer to this question provides a good illustration of the “functional systems” concept. Although it is true that the primary visual cortex (in either hemisphere) is capable of generation simple visual consciousness, it does not do so in isolation. For someone to reflect consciously on visual experiences, he or she has to recode the visual experiences into words. This capacity is lost when the left (verbal) hemisphere is disconnected from the original visual experience. This shows that a distinction needs to be drawn between two levels or types of consciousness: Simple awareness and reflexive awareness. It also shows that the function of reflexive awareness is intimately connected with the left cerebral hemisphere and therefore with word (or, rather, “inner speech”).

The fact that an entire hemisphere (about half of the forebrain) can, in a sense, function unconsciously raises intriguing questions.

Neuropsychology aims to be entirely objective, and its great power, its advances, com from just this. Illustration by Elena.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

Is Mental Life Conscious?

How Much of Mental Life Is Conscious?

There are various ways of addressing the question of how much of mental life is conscious, each of which leads to slightly different answers. What they all reveal, however, is that consciousness is a very limited part of the mind. For example, if the extent of consciousness is equated with the amount of information that we can “hold in mind” at any one point in time, then readers might be surprised to learn that consciousness is restricted to only seven units of information.

It is no accident that most telephone numbers are roughly seven digits long. Digit span (the capacity to repeat a string of random digits) is a standard clinical test of as aspect of working-memory capacity. (“Working-memory: is synonymous with the ability to consciously “hold things in mind:). If a patient cannot retain roughly seven digits, his or her audiverbal working memory (audioverbal consciousness) information (or “location” information) in mind in a similar way, but this aspect of consciousness is even more restricted: most people can hold only some four units of visuo-spatial information in mind at a time. (This capacity is usually tested by tapping a series of blocks scattered before the patient and asking him or her to hold the sequence of taps in mind.) Considering how many thousands of pieces of information we are processing all the time, this way of measuring the capacity of consciousness reveals that it is very limited indeed. The vast bulk of the information we constantly need to process must be processed in the unconscious part of the mind.

Another way of estimating the “size” of consciousness is to measure the extent of its influence on our behavior. What proportion of our actions is consciously determined? In a review of the scientific evidence pertaining to this question (and related masters). Bargh and Chartrand (1999) concluded that 95% of our actions are unconsciously determined. This way of measuring consciousness therefore suggests that it accounts for only 5% of behavior.

So, regardless of how they measure it, mainstream cognitive scientists today agree with Freud on this point: consciousness is attached to only a very small part of our mental life. Where then, is this consciousness generated in the brain? And how does it become attached to mental processes? And why?

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

What, in neurological terms, might psychotherapists be doing when they treat a disordered “self”?

Materialism and Idealism

Materialism and Idealism

Perhaps the most basic distinction among philosophical approaches to the mind-body problem is the one that divided materialists and idealists. The materialist position is that everything is ultimately reducible to matter. From this standpoint, the thought does not really exist. Its existence is illusory; the mind is really an aspect (or function) of matter.

At the other extreme, the idealist contends that only the mind really exists (for us, at least). For all the apparent substantiality of matter, the “things” we see, touch, and hear are really nothing other than products of our mental processes (i.e., they are actually perceptual images). We can never reach beyond the envelope of conscious awareness and demonstrate the existence of any thing independent of our mind's perceptual images. So, from this standpoint, the concrete thing may not really exist, or at least it, too belongs inside the “thought bubble”.

Although these positions both appear logically tenable, the idealist position has fallen out of favor. This seems to be due to the vagaries of intellectual fashion more than anything else. Within cognitive science today, just about everyone is a materialist. But materialists come in different shapes and sizes.

Monism and Dualism

The dichotomy between monism and dualism is perhaps just as fundamental as the one between materialism and idealism, and is easily confused with it. According to the monist position, we are made of only one kind of “stuff”. In other words, mind and matter (which appear to be two things) are really reducible to one and the same thing. This might seem to be identical to the materialist position just described (and the two arguments do normally go together), but the monist position does not actually state that the singular stuff we are made of is matter. A monist could just as well claim that we really consist only of mind (thereby embracing an idealist position) or even that we are actually made of some other kind of stuff, as yet undefined, which is neither mind nor matter. In the monist position, all that counts is that the apparent distinction between mind and matter dissolves into a common something.

The dualist view – closely associated with the name of René Descartes – simply states the opposite: We are divided in our essence and are made of two kinds of stuff. Matter and mind (or body and soul) are quite irreducible to one another. Like idealism, dualism is very unfashionable nowadays. Most cognitive scientists, therefore, are materialist monists: they believe that mind and brain are ultimately reducible to a single kind of stuff, and that that stuff is physical – specifically, some property of neurons (or an aggregate of subset of neurons).

The mind can be regarded as a higher level of organization of neurons, just as water is a higher level of organization of its constituent atoms. Photo by Elena.

Reductionism, Interactionism, Other Strange Things

Materialist monism defines the relationship between two types of stuff. On this view, one type of stuff (brain tissue) is more fundamental, even more real, than the other (conscious awareness). As Dr. Crick said once “you, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will are, in fact, no more than the behavior of a vast assembly of nerve cells” - “you” are reduced to nerve cells. The essence of Crick's reductionism resides in these words: “in fact, no more than.” Reductionism reduces one thing to another (in this case, mind to brain) and thereby explains it away. However, not all materialists are reductive.

Dualists are, by definition, nonreductive. The crux of their position is that mind and brain cannot be reduced to one another. What, then, is the nature of the relationship between two? A dualist's answer to this question determines what kind of dualist he or she is. Most dualists describe the relationship between mind and body in interactionist terms; they assert that physical events have mental effects, and vice versa. The interactionist view, then, is simply that body, and mind interact with each other. This seems perfectly plausible and appears easy to demonstrate empirically: plummeting blood sugar causes loss of consciousness (physical event causes mental event); freely deciding to move your hand causes it to move (mental event causes physical event). But when the logical underpinnings of the dualist position are spelled out, it seems less plausible: the interactionist actually claims that bodily stuff and mental stuff interact with each other. This way of putting it immediately reveals the pitfalls of almost any dualist position. How, exactly, does a thought (which has no physical properties whatever) cause the physical stuff of neurons to start firing? This violates all the known laws of physics.

Other varieties of dualism fare no better. One such well-known variety is called psychophysical parallelism. This position avoids some problems of interactionism by claiming that mental and physical events do not have a causal relationship; the two classes of event simply co-occur – they are correlated with one another. Whenever something specific happens in the brain, something equally specific happens in the mind, and vice versa. The two things occur together, in unison. If the basis of this correlation still seems mysterious, that's because it is. The parallelist does not not feel obliged to explain this linkage.

Emergence

We said above that not all materialists are reductionists. Many cognitive scientists today hold the view that the mind is an emergent property of the brain. According to this view, mind and brain are equally real, but they exist at different levels of complexity. Just as water (wet and flowing, at room temperature) emerges from a particular combination of hydrogen and oxygen and has distinctive properties of its own (properties that do not characterize hydrogen or oxygen alone), so, too, mental phenomena emerge when the neurons of the human brain are connected or activated in a particular way.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

It is possible to find some merit in all of different philosophical positions. It is also possible, with a little effort, to make all of them look ridiculous. Photograph by Elena.