Tag Archives: perception

Brain Research, Physics, Time

What is ‘Now’?

What is the duration of the present moment? How is it that this present moment is replaced by ‘the next moment’?

Within every organism, sentient or not, there are thousands of chemical processes that occur with their own characteristic time periods, but these time periods start and stop at different times so that there is no synchronized ‘moment’. Elementary atomic collisions that build up molecules take nanoseconds while cell division takes minutes to hours, and tissue cell lifespans vary from 2 days in the stomach lining to 8 years for fat cells (see Cell Biology). None of these jangled timescales collectively or in isolation create the uniform experience we have of now and its future moments. To find the timescale that corresponds to the Now experience we have to look elsewhere.

It’s all in the mind!

A variety of articles over the  years have identified 2 to 3 seconds as the maximum duration of what most people experience as ‘now’, and what researchers call the ‘specious present’. This is the time required by our brain’s neurological mechanisms to combine the information arriving at our senses with our internal, current model of the ‘outside world’. During this time an enormous amount of neural activity has to happen. Not only does the sensory information have to be integrated together for every object in your visual field and cross connected to the other senses, but dozens of specialized brain regions have to be activated or de-activated to update your world model in a consistent way.

In a previous blog I discussed how important this world model is in creating within you a sense of living in a consistent world with a coherent story. But this process is not fixed in stone. Recent studies by Sebastian Sauer and his colleagues at the Ludwig-Maximilians-Universität in Munich show that mindfulness meditators can significantly increase their sense of ‘now’ so that it is prolonged for up to 20 seconds.

In detail, a neuron discharge lasts about 1 millisecond, but it has to be separated from the next one by about 30 milliseconds before a sequence is perceived, and this seems to be true for all senses. When you see a ‘movie’ it is a succession of still images flashed into your visual cortex at intervals less than 30 milliseconds, giving the illusion of a continuous unbroken scene.  (Dainton: Stanford Encyclopedia of Philosophy, 2017).

The knitting together of these ‘nows’ into a smooth flow-of-time is done by our internal model-building system. It works lightning-fast to connect one static collection of sensory inputs to another set and hold these both in our conscious ‘view’ of the world. This gives us a feeling of the passing of one set of conditions smoothly into another set of conditions that now make up the next ‘Now’. To get from one moment to the next, our brain can play fast-and-loose with the data and interpolate what it needs. For example, it our visual world, the fovea in our retina produces a Blind Spot but you never notice it because there are circuits that interpolate across this spot to fill-in the scenery. The same thing happens in the time dimension with the help of our internal model to make our jagged perceptions in time into a smooth movie experience.

Neurological conditions such as strokes, or psychotropic chemicals can disrupt this process and cause dramatic problems. Many schizophrenic patients stop perceiving time as a flow of  linked events.  These defects in time perception may play a part in the hallucinations and delusions experienced by schizophrenic patients according to some studies. There are other milder aberrations that can affect our sense of the flow-of-time.

Research has also suggested the feeling of awe has the ability to expand one’s perceptions of time availability. Fear also produces time-sense distortion. Time seems to slow down when a person skydives or bungee jumps, or when a person suddenly and unexpectedly senses the presence of a potential predator or mate. Research also indicates that the internal clock, used to time durations in the seconds-to-minutes range, is linked to dopamine function in the basal ganglia. Studies in which children with ADHD are given time estimation tasks shows that time passes very slowly for them.

Because the volume of data is enormous, we cannot hold many of these consecutive Now moments in our consciousness with the same clarity, and so earlier Nows either pass into short-term memory if they have been tagged with some emotional or survival attributes, or fade quickly into complete forgetfulness. You will not remember the complete sensory experience of diving into a swimming pool, but if you were pushed, or were injured, you will remember that specific sequence of moments with remarkable clarity years later!

The model-building aspect of our brain is just another tool it has that is equivalent to its pattern-recognition ability in space. It looks for patterns in time to find correlations which it then uses to build up expectations for ‘what comes next’. Amazingly, when this feature yields more certainty than the evidence of our senses, psychologists like Albert Powers at Yale University say that we experience hallucinations (Fan, 2017). In fact, 5-15% of the population experience auditory hallucinations (songs, voices, sounds) at some time in their lives when the brain literally hears a sound that is not there because it was strongly expected on the basis of other clues. One frequent example is that  people claim to hear the Northern Lights as a crackling fire or a swishing sound, because their visual system creates this expectation and the brain obliges.

This, then, presents us with the neurological experience of Now. It is between 30 milliseconds and several minutes in duration. It includes a recollection of the past which fades away for longer intervals in the past, and includes a sense of the immediate future as our model-making facility extrapolates from our immediate past and fabricates an expectation of what comes next.

Living in a perpetual Now is no fun. The famed psychologist Oliver Sacks describes  a patient, Clive Wearing, with a severe form of amnesia, who was unable to form any new memories that lasted longer than 30 seconds, and became convinced every few minutes that he was fully conscious for the first time. “In some ways, he is not anywhere at all; he has dropped out of space and time altogether. He no longer has any inner narrative; he is not leading a life in the sense that the rest of us do….It is not the remembrance of things past, the “once” that Clive yearns for, or can ever achieve. It is the claiming, the filling, of the present, the now, and this is only possible when he is totally immersed in the successive moments of an act. It is the “now” that bridges the abyss.”

Physical ‘Now’.

This monkeying around with brain states, internal model-making and sensory data creates Now as a phenomenon we experience, but the physical world outside our collective brain population does not operate through its own neural systems to create a Cosmic Now. That would only be the case if, for example, we were literally living inside The Matrix….which I believe we are not. So in terms of physics, the idea of Now does not exist. We even know from relativity that there can be no uniform and simultaneous Now spanning large portions of space or the cosmos. This is a problem that has bedeviled many people across the millennia.

Augustine (in the fourth century) wrote, “What is time? If no one asks me, I know; if I wish to explain, I do not know. … My soul yearns to know this most entangled enigma.” Even Einstein himself noted ‘…that there is something essential about the Now which is just outside the realm of science.’ ”

Both of these statements were made before quantum theory became fully developed. Einstein developed relativity, but this was a theory in which spacetime took the place of space and time individually. If you wanted to define ‘now’ by a set of simultaneous conditions, relativity put the kibosh on that idea because due to the relative motions and accelerations of all Observers, there can be no simultaneous ‘now’ that all Observers can experience. Also, there was no ‘flow of time’ because relativity was a theory of worldlines and complete histories of particles from start to finish (called the boundary conditions of worldlines). Quantum theory, however, showed some new possibilities.

In physics, time is a variable, often represented by the letter t, that is a convenient parameter with which to describe how a system of matter and energy change. The first very puzzling feature of time as a physical variable is that all mathematical representations of physical laws or theories show that time is continuous, smooth and infinitely divisible into smaller intervals. These equations are also ‘timeless’ in that they can be written down on a piece of paper and accurately describe how a system changes from start to finish (based on boundary conditions defined at ‘t=0’) , but the equations show this process as ‘all at once’.

In fact, this perspective is so built into physics that it forms the core of Einstein’s relativity theory in the form of the 4-d spacetime ‘block’. It also appears in quantum mechanics because fundamental equations like Schroedinger’s Equation also offer a timeless view of quantum states.

In all these situations, one endearing feature of our world is actually suppressed and mathematically hidden from view, and that is precisely the feature we call ‘now’.

To describe what things look like Now, you have to dial in to the equations the number t =  t(now). How does nature do that? As discussed by physicist Lee Smolin in his book ‘Time Reborn’, this is the most fundamental experience we have about the physical world as sentient beings, yet it is not represented by any feature in the physical theories we have developed thus far. There is no theory that selects t = t(now) over all the infinite other moments in time.

Perhaps we are looking in the wrong place!

Just as we have seen that what we call ‘space’ is built up like a tapestry from a vast number of quantum events described (we hope!) by quantum gravity, time also seems to be created from a synthesis of elementary events occurring at the quantum scale.   For example, what we call temperature is the result of innumerable collisions among elementary objects such as atoms. Temperature is a measure of the average collision energy of a large collection of particles, but cannot be identified as such at the scale of individual particles. Temperature is a phenomenon that has emerged from the collective properties of thousands or trillions of individual particles.

A system can be described completely by its quantum state – which is a much easier thing to do when you have a dozen atoms than when you have trillions, but the principle is the same. This quantum state describes how the elements of the system are arrayed in 3-d space, but because of Heisenberg’s Uncertainty Principle, the location of a particle at a given speed is spread out rather than localized to a definite position.  But quantum states can also become entangled. For these systems, if you measure one of the particles and detect property P1 then the second particle must have property P2. The crazy thing is that until you measured that property in the first particle, it could have had either property P1 or P2, but after the measurement the distant particle ‘knew’ that it had to have the corresponding property even though this information had to travel faster than light to insure consistency.

An intriguing set of papers by physicist Seth Lloyd at Harvard University in 1984 showed that over time, the quantum states of the member particles become correlated and shared by the larger ensemble. This direction of increasing correlation goes only one way and establishes the ‘Arrow of Time’ on the quantum scale.

One interesting feature of this entanglement idea is that ‘a few minutes ago’, our brain’s quantum state was less correlated with its surroundings and our sensory information than at a later time. This means that the further you go into the past moments, the less correlated they are with the current moment because, for one, the sensory information has to arrive and be processed before it can change our brain’s state. Our sense of Now is the product of how past brain states are correlated with the current state. A big part of this correlating is accomplished, not by sterile quantum entanglement, but by information transmitted through our neural networks and most importantly our internal model of our world – which is a dynamic thing.

If we did not have such an internal model that correlates our sensory information and fabricates an internal story of perception, our sense of Now would be very different because so much of the business of correlating quantum information would not occur very quickly. Instead of a Now measured in seconds, our Now’s would be measured in hours, days or even lifetimes, and be a far more chaotic experience because it would lack a coherent, internal description of our experiences.

This seems to suggest that no two people live in exactly the same Now, but these separate Now experiences can become correlated together as the population of individuals interact with each other and share experiences through the process of correlation. As for the rest of the universe, it exists in an undefined Now state that varies from location to location and is controlled by the speed of light, which is the fastest mode of exchanging information.

Read more:

In my previous blogs, I briefly described how the human brain perceives and models space (Blog 14: Oops one more thing), how Einstein and other physicists dismiss space as an illusion (Blog 10: Relativity and space ), how relativity deals with the concept of space (Blog 12: So what IS space?), what a theory of quantum gravity would have to look like (Blog 13: Quantum Gravity Oh my! ), and along the way why the idea of infinity is not physically real (Blog 11: Is infinity real?) and why space is not nothing (Blog 33: Thinking about Nothing). I even discussed how it is important to ‘think visually’ when trying to model the universe such as the ‘strings’ and ‘loops’ used by physicists as an analog to space ( Blog 34: Thinking Visually)

I also summarized the nature of space in a wrap-up of why something like a quantum theory for gravity is badly needed because the current theories of quantum mechanics and general relativity are incomplete, but also point the way towards a theory that is truly background-independent and relativistic (Blog 36: Quantum Gravity-Again! ). These considerations describe the emergence of the phenomenon we call ‘space’ but also down play its importance because it is an irrelevant and misleading concept.

Astronomy, Brain Research, Physics

Thinking Visually

Look at the two images  for a few minutes and let your mind wander.

What impressions do you get from the patterns of light and dark? If I were to tell you that the one at the top is a dark nebula in the constellation Orion, and the one on the bottom is a nebula in the Pleiades star cluster, would that completely define for you what you are experiencing…or is there something more going on?

Chances are that, in the top image you are seeing what looks like the silhouette of the head and shoulders of some human-like figure being lit from behind by a light. You can’t quite put your finger on it, but the image seems vaguely mysterious and perhaps even a bit frightening the more you stare at it.

The image on the bottom evokes something completely different. Perhaps you are connecting the translucence and delicacy with some image of a shroud or silken cloak floating in a breeze. The image seems almost ghost-like in some respects…spiritual

“But of course this is rather silly” you might say. “These are interstellar clouds, light-years across and all we are doing is letting our imaginations wander which is not a very scientific thing to do if you want to understand the universe.” This rational response then tempts you to reach for your mouse and click to some other page on the web.

What has happened in that split second is that a battle has been fought between one part of your brain and another. The right side of your brain enjoys looking at things and musing over the patterns that it finds there. Alas, it cannot speak because the language centers of the brain live in the left cerebral hemisphere, and it is here that rules of logic and other ‘scientific’ reasoning tools exist. The left side of your brain is vocal, and talking to you right now. It gets rather upset when it is presented with vague patterns because it can’t understand them and stamp them with a definite emotion the way the right hemisphere can. So it argues you into walking away from this challenge of understanding patterns.

If you can suspend this indignation for a moment or two, you will actually find yourself thinking about space in a way that more nearly resembles how a scientist does, though even some scientists don’t spend much time thinking about space. This indifference has begun to change during the last 20 years, and we are now in the midst of a quiet revolution.

There are three child-like qualities that make for a successful scientist:

Curiosity. This is something that many people seem to outgrow as they get older, or if they maintain it as adults, it is not at the same undiluted strength that it was when they were a child.

Imagination. This is something that also wanes with age but becomes an asset to those that can hang on to even a small vestige of it. It is what ‘Thinking out of the box’ is all about.

Novelty. As a child, everything is new. As an adult we become hopelessly jaded about irrelevant experiences like yet another sunset, yet another meteor shower, yet another eclipse. In some ways we develop an aversion for new experiences preferring the familiarity of the things we have already experienced.

If you wish to understand what space is all about, and explore the patterns hidden in the darker regions of nature, you will have to re-acquaint yourself with that child within you. You will need to pull all the stops out and allow yourself to ‘play’ with nature and the many clues that scientists have uncovered about it. You will need to do more than read books by physicists and astronomers. They speak the language of the left-brain . They can help you to see the logical development of our understanding of space and the Void, but they can not help you internalize this knowledge so that it actually means something to you. For that, you have to engage your right-brain faculties, and this requires that you see the patterns behind the words that physicists and astronomers use. To do that, you will need to think in terms of pictures and other types of images. You will need to bring something to the table to help you make sense of space in a way that you have not been able to before. You will need to expand your internal library of visual imagery to help you find analogues to what physicists and astronomers are trying to describe in words and equations. These visual analogues can be found in many common shapes and patterns, some seen under unusual and evocative circumstances. Here are some evocative images that seem to suggest how space might be put together compliments of  a diatom, the painters Miro and Mondrian, dew on a spider web, and atoms in a tungsten needle tip!

Spider web covered with dew drops

Remember, the right brain uses ALL sensory inputs to search for patterns and to understand them. It even uses imaginary information, dreams, and other free-forms to decode what it is experiencing.  

My book ‘Exploring Quantum Space’ is a guidebook that will give you some of the mental tools you will need to make sense of one of the greatest, and most subtle, discoveries in human history. Space, itself, is far from being ‘nothing’ or merely a container for matter to rattle around within. It is a landscape of hidden patterns and activity that shapes our universe and our destiny. You cannot understand it, or sense the awe and mystery of its existence, by simply reading words and following a logical exposition of ‘ifs and thens’. You also have to experience it through evocative imagery and imagination. Space is such a different medium from anything we have ever had to confront, intellectually, that we need to employ a different strategy if we wish to understand it in a personal way. Once we do this, we will be reconnected with that sense of awe we feel each time we look at the night sky.

My next blog about Nothing introduces some of the other ideas and techniques that scientists use to think about the impossible!

 

Astronomy, Brain Research, Physics

Thinking about Nothing

Looking back at the millennia of model building and deduction that has occurred, not a century has gone by when the prevailing opinion hasn’t been that a perfectly empty vacuum is impossible.

Aristotle’s Aether blends seamlessly into the 19th century Ether. In this century, overlapping quantum waves and virtual particles have finally taken root as the New Ether, though it is now infinitely more ephemeral than anything Aristotle or Maxwell could have imagined. We have also seen how the Atomist School of ancient Greece reached its final vindication in the hands of 19th century scientists such as Boltzman. By the 20th century, the Atomist’s paradigm has even been extended to include not just the graininess of matter, but the possible quantum graininess of the vacuum and space itself. In the virtual particles that animate matter, we finally glimpse the world which Heinrich Hertz warned us about nearly a century ago when he said that we would eventually have to reach some accommodation with “invisible confederates” existing alongside what we can see, to make our whole model of reality more logically self-consistent.

Even by the start of the 21st Century, we have reached this accommodation only by shrugging our shoulders and honestly admitting that there are things going on in the world that seem to defy human intuition. What impresses me most about the evolution of our vision of the vacuum is that the imagery we find so potent today is actually in some sense thousands of years old.

It is difficult to imagine that humans would be drawn to the same understanding of physics and astronomy that we now enjoy if our brains had been wired only slightly differently. Without sight and mobility we could not form the slightest notion of 3-D space and geometry. This is what Kant spoke about, what Henri Poincare described at great length without the benefit of 20th century neuroscience, and what Jacob Bronowski described in his book The Origins of Knowledge and Imagination with the benefit of such knowledge. But the object of science is more than just making sense of our senses. It must also guide us towards a deeper understanding of the physical world. This understanding must be self-consistent, and independent of whether we are sensorially or neurologically handicapped. Mathematics as the premier language of physical model building, seems uniquely suited to providing us with an understanding of the physical world. Mathematics lets us see the world in a way that all of the other human languages do not.

If our mathematical understanding of nature is a product of mental activity, and this activity can be physically affected by the hard-wiring of our brain, how do we arrive at a coherent model of the physical world? Can we see in this process any explanation for why certain ideas in physics appear to be so historically tenacious?

It is commonly believed that in order for mathematics and the underlying logic to exist, at the very least a conscious language must be pre-existent to support it. This is the point of view expressed by Benjamin Whorf. But the thoughtful reflections by individuals such as Einstein, Feynman and Penrose point in a very different direction. Einstein once wrote a note to Jaques Hadamard prompted by Hadamard’s investigation of creative thinking,

“…The words of language, as they are written or spoken, do not seem to play any role in my mechanism of thought. The psychical entities which seem to serve as elements of thought are certain signs ( symbols ) and more or less clear images which can be voluntarily reproduced and combined…The above mentioned elements are, in my case, of visual and some muscular type…”

Roger Penrose echoes some of this same description in his book, The Emperor’s New Mind,

“…Almost all my mathematical thinking is done visually and in terms of non-verbal concepts, although the thoughts are quite often accompanied by inane and almost useless verbal commentary such as ‘that thing goes with that thing and that thing goes with that thing’..”

Freeman Dyson, one of the architects of modern QED had this to say about how Feynman did his calculations,

“…Dick was using his own private quantum mechanics that nobody else could understand. They were getting the same answers whenever they calculated the same problem…The reason Dick’s physics was so hard for ordinary people to grasp was that he did not use equations…Dick just wrote down the solutions out of his head without ever writing down the equations. He had a physical picture of the way things happen, and the pictures gave him the solutions directly with a minimum of calculation…It was no wonder that people who had spent their lives solving equations were baffled by him. Their minds were analytical; his was pictorial…”

In many instances, the conversion of abstract thinking into conventional language is seen as a laborious, almost painful process. Often words are inadequate to encompass the subtleties of the non-verbal, abstract ideas and their interrelationships. According to Penrose,

“I had noticed, on occasion, that if I have been concentrating hard for a while on mathematics and someone would engage me suddenly in conversation, then I would find myself almost unable to speak for several seconds”

In fact, abstract thinking is often argued to be a right-hemisphere function. Visual or pattern-related thinking and artistic talents are frequently coupled to this hemisphere, and since the language centers are in the left-hemisphere, with such a disconnect between language and abstract thinking, there is little wonder that theoreticians and artists find themselves tongue-tied in explaining their ideas, or are inclined to report that their work is non-verbal.

So the creation of sophisticated physical theories may involve a primarily non-verbal and visual-symbolic thinking processes, often manipulating patterns and only later, with some effort of will, translating this into spoken language or fleshing out the required mathematical details. Could this be why scientists, and artists for that matter have such difficulty in explaining what they are thinking to the rest of the population? Could this be why ancient philosophers managed to land upon archetypes for their Creation legends that seem familiar to us in the 20th century? The symbols that are used appear disembodied, and no amount of word play can capture all of the nuances and motivations that went into a particular interpretive archetypes, and make them seem compelling to the non-mathematician or non-artist. Feynman once wrote about the frustrating process of explaining to the public what goes on in nature,

“…Different people get different reputations for their skill at explaining to the layman in layman’s language these difficult and abstruse subjects. The layman then searches for book after book in the hope that he will avoid the complexities which ultimately set in, even with the best expositor of this type. He finds as he reads a generally increasing confusion, one complicated statement after another,… all apparently disconnected from one another. It becomes obscure, and he hopes that maybe in some other book there is some explanation…but I do not think it is possible, because mathematics is NOT just another language. Mathematics is a language plus reasoning…if you do not appreciate the mathematics, you cannot see, among the great variety of facts, that logic permits you to go from one to the other…”

If this is the mental frame used by some physicists to comprehend physics, it is little wonder that a great chasm exists between the lay person and the physicist in explaining what is going on. The task that even a physicist such as Freeman Dyson had in translating Feynman’s diagrammatic techniques into mathematical symbology, seems even more challenging knowing that Feynman may have had a whole other perspective on visualization via his apparent color-symbol synthesia. The equations below are the current best mathematical expression for the Standard Model in physics, which describes all known particles and fields excepting gravity.

Another feature of thinking that separates scientists and artists from everyone else seems to be the plasticity of the thinking process itself. Scientists flit from one idea to another until they arrive at a model that best explains the available data, although scientists can also get rooted to particular perspectives that are difficult to forget after decades of inculcation. The general adult population prefers a more stable collection of ideas and ‘laws’ which it can refer to over a lifetime.

Where does this all leave us?

The vacuum has been promoted to perhaps the most important clue to our own existence. The difficulty is that we lack a proper Rosetta Stone to translate the various symbolisms we use to describe it. The clues that we do have are scattered among a variety of enigmatic subjects which strain at our best intellectual resources to understand how they are linked together. Could it be that we are lacking an even more potent symbolic metaphor, and an internal non-verbal language, to give it life? Where would such a thing come from?

Spider web covered with dew drops

If we take our clue from how ideas in physics have emerged in the past, the elements of the new way of thinking may be hidden in some unexpected corner of nature. We may find an analogy or a metaphor in our mundane world which, when mixed with mathematical insight, may take us even closer to understanding gravity, spacetime and vacuum. It is no accident that string theory owes much of its success because it asks us to think about quantum fields as ordinary strings operating in an exotic mathematical setting. It is exciting to think that the essential form of the Theory of Everything could be this close to us, perhaps even lurking in a pattern we see, and overlook, in our everyday lives.

Much of this symbolic process may be performed sub-consciously, and only the form of dreams, insights or hunches seem to bring them into consciousness when the circumstances are appropriate. It is, evidently, the non-verbal and unconscious right hemisphere which experiences these ideas. Is there a limit to this process of symbolic thinking? At least a dozen times this century, physicists have had to throw up their hands over what to make of certain features of the world: the collapse of the wave function; quantum indeterminacy; particle/wave dualism; cosmogenesis. Some of these may eventually find their explanation at the next level of model building. Others such as the meaning of quantum indeterminacy and particle/wave dualism, seem to be here to stay.

In working with these contradictions, the human mind prefers the avenue of denial, you can almost hear your inner voice saying “Aw come on, quantum mechanics just can’t be that weird!” or a state of anxiety as the two hemispheres try to fabricate conflicting world models. Little wonder that we have particle/wave duality, the seeming schism between matter and energy, and a whole host of other ‘polar’ ideas in physics, as two separate minds try to resolve the universe into one model or another with the left one preferring time ordered patterns, and the right one, spatial patterns.

It is hard to believe that our brains can control what we experience of the objective world, but we need only realize that the brain actually blindsides us in a variety of subtle ways, from seeing a wider sensory world. The object of science, however, is to discern the shapes of objective laws in a way that gets to the universal elements of nature that are not coupled to a particular kind of brain circuitry. It doesn’t matter if all scientists have anasognosia and see the world differently in some consistent way, what counts is that they must still live by the laws of motion dictated by gravity and quantum mechanics.

Nils Bohr believed atoms are not real in the same sense as trees. The quantum world really does represent a different kind of reality than our apparently naive understanding of macroscopic reality implies. This being the case, we must first ask to what extent fields and the denizens of the quantum vacuum can be represented by any analogy drawn from the macroworld? We already know that the single most important distinguishing characteristic of atomic particles is their spin; far more so than mass or charge. Yet unlike mass and charge, quantum mechanical spin has ABSOLUTELY no analog in the macroscopic world. Moreover, fundamental particles cannot be thought of as tiny spheres of charged matter located at specific points in space. They have no surface, and participate in an infernal wave-like dance of probability, at least when they are not being observed. Yet despite this warning, we feel comfortable that we understand something about what reality is at this scale, in the face of these irreconcilable differences between one set of mental images and what experiments tell us over and over again. What is the true nature of the vacuum? How did the universe begin? I suspect we will not know the answer to these questions in your lifetime or mine, perhaps for the same reason that it took 3000 years for geometers to ‘discover’ non-Euclidean geometry.

At the present time we are faced with what may amount to only a single proof of the parallel-line postulate, unable to see our way through to another way of looking at the proof. There is also the very real worry that some areas of nature may require modalities of symbolic thinking beyond the archetypes that our brains are capable of providing as a consequence of their neural hard-wiring. Today, we have quantum field theory and its tantalizing paradoxes, much as the ancient geometers had their parallel-line postulate. We, like they, scratch the same figures in the sand over and over again, hoping to see the glimmerings of a new world view appearing in the shifting sands. At a precision of one part in a trillion, our quantum theories work too well, and seem to provide few clues to the new direction we must turn to see beyond them.

The primary arbiters we have at our disposal to decide between various interpretive schemes, experimental data, are not themselves in unending supply as the abrupt cancellation of the U.S. Superconducting Super Collider program in 1989 showed. It was replaced by the CERN Large Hadron Collider shown above, but even the LHC may not be large enough to access the new physics we need to explore to further our theories and understanding.

Whatever answers we need seem to be hidden, not in the low- energy world accessible to our technology, but at vastly higher energies well beyond any technology we are likely to afford in the next few centuries. It is easy to provide a jet plane with an energy of 100 billion billion billion volts — its energy of motion at a speed of a few hundred miles per hour, but it is beyond understanding how to supply a single proton or electron with the same energy. On the other hand, our internal symbolic thinking seems to lead us to similar interpretative schemes, and unconscious dualities which may only be a reflection of our own neural architecture, which we all share, and which has remained essentially unchanged for millennia. We visualize the vacuum in the same way as the Ancients did because we are still starting from the same limited collection of internal imagery. At least for some general problems, we seem to have hit a glass ceiling for which our current style of theory building seems to lead us to a bipolar and contradictory world populated by various dualities: matter/energy, space/time, wave/particle. When we finally do break through to a new kind of reality in our experiments, would we be able to recognize this event? Will our brains filter out this new world and show us only the ghostly shadows of contradictory archetypes cast upon the cave wall?

We have seen that many schemes have been offered for describing the essential difference between matter and empty space; many have failed. Theoreticians since Einstein have speculated about the geometric features of spacetime, and the structure of electrons and matter for decades. The growing opinion now seems to be that, ultimately, only the properties of space such as its geometry or dimensionality can play a fundamental role in defining what matter really is. In a word, matter may be just another form of space. If the essence of matter is to be found in the geometric properties of ’empty’ space, our current understanding of space will not be sufficient to describe all of matter’s possible aspects.

Brain Research, Physics

Oops…One more thing!

2 Comments

After writing thirteen essays about space, I completely forgot to wrap up the whole discussion with some thoughts about the Big Picture! If you follow the links in this essay you will come to the essay where I explained the idea in more detail!

Why did I start these essays with so much talk about brain research? Well, it is the brain, after all, that tries to create ideas about what you are seeing based on what the senses are telling it. The crazy thing is that what the brain does with sensory information is pretty bizarre when you follow the stimuli all the way to consciousness. In fact, when you look at all the synaptic connections in the brain, only a small number have anything to do with sensory inputs. It’s as though you could literally pluck the brain out of the body and it would hardly realize it needed sensory information to keep it happy. It spends most of its time ‘taking’ to itself.

The whole idea of space really seems to be a means of representing the world to the brain to help it sort out the rules it needs to survive and reproduce. The most important rule is that of cause-and-effect or ‘If A happens then B will follow’. This also forms the hardcore basis of logic and mathematical reasoning!
But scientifically, we know that space and time are not just some illusion because objectively they seem to be the very hard currency through which the universe represents sensory stimuli to us. How we place ourselves in space and time is an interesting issue in itself. We can use our logic and observations to work out the many rules that the universe runs by that involve the free parameters of time and space. But when we take a deep dive into how our brains work and interfaces with the world outside our synapses, we come across something amazing.

The brain needs to keep track of what is inside the body, called the Self, and what is outside the body. If it can’t do this infallibly, it cannot keep track of what factors are controlling its survival, and what factors are solely related to its internal world of thoughts, feelings, and imaginary scenarios. This cannot be just a feature of human brains, but has to also be something that many other creatures also have at some rudimentary level so that they too can function in the external world with its many hazards. In our case, this brain feature is present as an actual physical area in the cerebral cortex. When it is active and stimulated, we have a clear and distinct perception of our body and its relation to space. We can use this to control our muscles, orient ourselves properly in space, walk and perform many other skills that require a keen perception of this outside world. Amazingly, when you remove the activity in this area through drugs or meditation, you can no longer locate yourself in space and this leads to the feeling that your body is ‘one’ with the world, your Self has vanished, and in other cases you experience the complete dislocation of the Self from the body, which you experience as Out of Body travel.

What does this have to do with space in the real world? Well, over millions of years of evolution, we have made up many rules about space and how to operate within it, but then Einstein gave us relativity, and this showed that space and time are much more plastic than any of the rules we internalized over the millennia. But it is the rules and concepts of relativity that make up our external world, not the approximate ‘common sense’ ideas we all carry around with us. Our internal rules about space and time were never designed to give us an accurate internal portrayal of moving near the speed of light, or functioning in regions of the outside world close to large masses that distort space.

But now that we have a scientific way of coming up with even more rules about space and time, we discover that our own logical reasoning wants to paint an even larger picture of what is going on and is happy to do so without bothering too much with actual (sensory) data. We have developed for other reasons a sense of artistry, beauty and aesthetics that, when applied to mathematics and physics, has taken us into the realm of unifying our rules about the outside world so that there are fewer and fewer of them. This passion for simplification and unification has led to many discoveries about the outside world that, miraculously, can be verified to be actual objective facts of this world.

Along this road to simplifying physics, even the foundations of space and time become players in the scenery rather than aloof partners on a stage. This is what we are struggling with today in physics. If you make space and time players in the play, the stage itself vanishes and has to somehow be re-created through the actions of the actors themselves .THAT is what quantum gravity hopes to do, whether you call the mathematics Loop Quantum Gravity or String Theory. This also leads to one of the most challenging concepts in all of physics…and philosophy.

What are we to make of the ingredients that come together to create our sense of space and time in the first place? Are these ingredients, themselves, beyond space and time, just as the parts of a chain mail vest are vastly different than the vest that they create through their linkages? And what is the arena in which these parts connect together to create space and time?

These questions are the ones I have spent my entire adult life trying to comprehend and share with non-scientists, and they lead straight into the arms of the concept of emergent structures: The idea that elements of nature come together in ways that create new objects that have no resemblance to the ingredients, such as evolution emerging from chemistry, or mind emerging from elementary synaptic discharges. Apparently, time and space may emerge from ingredients still more primitive, that may have nothing to do with either time or space!

You have to admit, these ideas certainly make for interesting stories at the campfire!

Check back here on Monday, December 26 for the start of a new series of blogs on diverse topics!

Brain Research, Weird Things

What the…!!!!

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You would think that a scientist lives in a purely rational world, but sometimes even we fall victim to events that are hard to explain at the moment. Here are my two favorite, and involuntary, journeys into the world of altered states!

I have had three experiences that some sufferers of migraine headaches may know all too well. Suddenly from out of nowhere, you may see flashing or shimmering lights, zigzagging lines, or stars. Some people even describe psychedelic images. For me, each one came on suddenly and caused me a bit of consternation before I figured out what was going on!

migraine

Each time, I saw a jagged crescent-shaped light that drifted across my visual field. I did not have a migraine headache either before or after, since I do not suffer from these painful conditions. But the shape and behavior of the image was identical to such migraine auras.

Called scintillating scotomas by opthamologists, in my case the effect occurred in the same part of my visual field no matter where I moved my eyes, so I knew that something was going on way up in my brain to cause it, and not in my retinas, like the experience of having those pesky ‘floaters’. Instead, it is caused by what is termed a ‘cortical spreading depression’. This is literally a physical wave of hyperstimulation followed by neural inhibition, that spreads out from the visual cortex and into the surrounding association areas at a speed of about 5 millimeters per minute. The whole thing lasts less 60 minutes and is quite amazing and slightly painful to watch. If you are driving a car at the time, it is extremely distracting and even dangerous. My events began as a flickering spot that expanded into a nearly ring-like, zig-zag shape about half the size of my visual field before fading away.

You can find simulations of this phenomenon at the Wikipedia page.
https://en.wikipedia.org/wiki/Scintillating_scotoma

The second perceptual event that I have never forgotten was much more complex.

I woke up in the semi-darkness of my bedroom and could see the dim shapes of the furniture around me, but I absolutely could not move so much as an eyelash. My eyes were open, but felt like they were very dry and begging for me to blink to get some tears going to reduce the irritation. But that was not the thing that captured my attention. There, floating at arms-length was a bright visual scene about as big as a dinner plate that had a horse running around in a corral. As I watched, the initially very clear image became less and less distinct until it faded out completely. Within a few minutes, sounds began to flood back and I could again move around in a fully awake state.

I had this experience in my early-50s and it was never to reoccur. Now, I have had quite a few waking dreams in my life, where I woke up in a dream realizing where I was, then waking up a second time to the real world, but this was a completely different experience.I have searched the literature to look for an explanation, and come across discussions of waking dreams and lucid dreaming, but this event seems to be different. Unlike a lucid dream, I was not aware that I was dreaming as I was watching the visual scenery of the horse in the corral. Instead it did not seem like an unusual experience at all. My tendency towards scientifically analyzing my experiences did not kick-in. All I could do was watch and marvel at the event with a feeling of awe, and definitely not fear.The nearest I could find to my experience is the ‘Type 2 false awakening’ where ‘The subject appears to wake up in a realistic manner, but to an atmosphere of suspense.[…] The dreamers surroundings may at first appear normal, and they may gradually become aware of something uncanny in the atmosphere, and perhaps of unwanted [unusual] sounds and movements.’

There is also the phenomenon of sleep paralysis ‘in which an individual briefly experiences an inability to move, speak, or react. It is often accompanied by terrifying hallucinations to which one is unable to react due to paralysis, and physical experiences. These hallucinations often involve a person or supernatural creature suffocating or terrifying the individual, accompanied by a feeling of pressure on one’s chest and difficulty breathing.’

Well, there was nothing terrifying about my experience. In fact, it was extremely pleasurable and awe-inspiring!

In reflecting back on these events, I find myself delighted that I experienced them because sometimes you want to have experiences in life that are extremely unusual and hard to explain just to have something to think about other than the predictable day-to-day world. I’m sure there are detailed medical reasons for each of my apparitions, because they all are related to how my brain works. Our brains are amazing organs that work overtime to make sense of the world, but they are still fallible.The difference between passing a kidney stone and a minor hiccup in the brain, is that our kidneys are not conscious. But, any little innocent tweak to our brain physiology is immediately interpreted as a change in behavior or of our conscious experience of the world.

So the next time you experience something ‘odd’, don’t be too worried about it. Just sit back and try to enjoy the altered experience. In the end, it may only be a completely innocent, though inscrutable, brain hiccup!

In my next blog I will describe how a brain filled with complex associations manages to make sense of it all!

Check back here on Wednesday, December 7 for the next installment!

Ocular migraines:
http://www.healthline.com/health/causes-of-ocular-migraines#Overview1

False awakening:
https://en.wikipedia.org/wiki/False_awakening

Sleep paralysis:
https://en.wikipedia.org/wiki/Sleep_paralysis

Brain Research

What does it mean?

What happens to all this sensory information that gives you a concrete idea about the things that exist in your world?

We saw how the flow of sensory information at any one time is enormous. It starts out as separate streams of information that flow to specific brain regions as their first stop, but then after that the information radiates to many different regions in the brain where it gets mixed with our emotions, and even with other sensory information. This is a process that is called association, and a large volume of the brain is called the Association Cortex for that reason.

association

At first the auditory information called purring, is connected to other sensory information occurring at the same time, for instance, the feeling that something furry is brushing against your leg. These two pieces of information become associated with each other, especially if they are connected to a similar combination you experienced earlier, and which was associated in your language cortex as the sound of the word ‘cat’ or the written word ‘cat’. Communicating this information is then handled by Broca’s Area (speech generation ) and Wernicke’s Area (speech comprehension).

The brain creates meaning by associating sensory information with specific categories of past experience. Nothing can really be understood except through a complex process of being associated with other things you have experienced, or learned. It’s like some enormous, interlinked tapestry of connections, and adding a new bit of information is always about fitting it into what has already been experienced in some way. But if that were all that there is, we would simply be walking encyclopedias.

Most of us have senses that are pretty well-defined. For example, the optic nerve transmits what each eye’s retinas detect and passes this on to the visual cortex at the back of the head after some of this information is first linked by neurons to a small brain region called the suprachiasmatic nucleus and then on to the pineal gland (to detect the day-night cycle). It also connects with the thalamus where it gets associated with other sensory stimuli. The three types of retinal cone cells are tuned to slightly different wavelengths of light and send the usual neural signals along the optic nerve. The outside world actually has no color at all. Everything is decided by the wavelength of light, and this number does not include color information. But by the time the visual cortex and its related association cortex is finished processing the information from the cones, you have a definite internal sense of color being an intimate part of the world. This is, however, very different than seeing the world in black and white, which is actually a better representation of what the world looks like. Our retina also have rod cells that are very sensitive to light intensity at all visual wavelengths, but give you only a sense of a grey world!

By coding light frequency information as well as intensity, our eyes and brains over eons of evolution have ‘decided’ that this extra color information has survival value. It can help classify things in terms of specific frequency fingerprints. For example, a coral snake is deadly and a scarlet king snake is harmless. Their skins have yellow and red bands, and the rhyme ‘Red touch yellow, kills a fellow but red touch black is a friend of Jack’ helps you distinguish between the two. You would be dead if all you could see is black and white. In fact, the complex color selections seen in nature have actually co-evolved with color vision over millions of years. The scarlet king snake adapted a version of the color coding used by coral snakes to fool predators into thinking it was a poisonous snake!

Sometimes this process can be flawed. We all know about color blindness, which affects about 8% of men and 0.5% of women. This happens when one of the three cone cell populations in the retina do not work properly. There is no way for the brain to correct for this because the retina has eliminated an important color sense long before the information reaches the optic nerve and the visual cortex.
There is another sensory malady that is even more unusual. Called synesthesia, it is caused by synaptic connections between otherwise separate sensory channels. For instance, you might see letters of the alphabet as having distinct colors on the page, or associate a specific sound with a color, among dozens of other documented possibilities. It is actually much more common than you might suspect. Have you ever felt that numbers have a definite location in space, or that 1980 is ‘farther away’ than 1990? Studies of the brain show that these mixings happen because of cross-wiring of neurons in the brain, either due to genetics or due to training when you were very young.

So, it isn’t even true that everyone perceives the outside world in identical manners. This leads to differences in how each person categorizes events and their internal associations with other things we have experienced. So with all of these variations in exactly what a ‘cat’ is, how do we create models of the world that let us function and survive without having accidents and getting killed all the time?

In my next blog I will describe two very unusual, personal experiences that show how our experience of the world can be temporarily distorted.

Check back here on Monday, December 5 for the next installment!
Seeing Color: http://www.webexhibits.org/causesofcolor/1C.html

Brain Research

A Stroke of Insight

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Once the firehose of sensory information reaches the brain, a bewildering process of making sense of this data begins. The objective is to create an accurate internal model of the world that you can base your next decisions upon. To do this, all of the many bits of data flowing along the sensory neurons have to be knitted together somehow. Thanks to the unfortunate circumstances of minor strokes, brain researchers have been able to track down many of the important steps in this information processing.

brainspecial

You might have heard of the experiences of limb amputees who, for a time, experience the ‘phantom limb’ effect. The neurons having been severed still report back to the brain that their stimulation means the limb still exists, and for a period of time the amputee has to deal with the ghost limb that is not really there. In another bizarre situation, a stroke victim has a perfect understanding that their left arm belongs to them, but insists that their right arm belongs to a relative living 1000 miles away. This malady is called asomatognosia by neurophysiologists.

From many studies of how pinpoint strokes affect brain function, neuroanatomists have identified specific regions of the brain that allow us to integrate our sensory information and create a coherent model of the outside world as it exists in space and time. The first thing the brain has to do is to have a ‘sense’ of its own body and how it is located in space. It also has to identify this ‘self’ as being different from that of other people. If it cannot do this accurately, it cannot decide how to move in space, anticipate the consequences of that movement, or how to anticipate and empathize with the actions of other people. Nearly all of this activity seems to be relegated to a single area in the brain.

The temporoparietal junction (TPJ) takes information from the limbic system (emotional state) and the thalamus (memory) and combines it with information from the visual, hearing and internal body sensory systems to create an integrated internal model of where your body is located in space. The TPJ has left and right ‘lobes’ that control your ability to pay attention (right) and to anticipate other people’s emotions and desires (left). Patients with schizophrenia have abnormal levels of stimulation in the TPJ and cannot discern the intentions of other people. Stimulation of the right TPJ by placing electrodes in unesthetized patients leads to out-of-body experiences, schizophrenic behavior, and the phantom limb effect. The right TPJ tries to create a coherent body image from many different, and sometimes contradictory sensory inputs. When this process breaks down because the contradictory information is too strong to inhibit or ignore, you experience that you actually have two distinct bodies in space. This seems to be the direct, neural basis for out-of-body experiences.

But there is an even stranger brain region whose stimulation leads to an error in deciding where the body and self ends in space, and where the outside world begins.

The posterior cingulate body plays a huge role in self-location and body ownership. What this means is that we experience our body as having a definite location in space, and that this location is where you, the ‘Self’ is located. Strokes in this region cause asomatognosia patients not to recognize a limb as belonging to them. But you don’t have to be a stroke victim to experience this dislocation of body and self.

If you sit at a table facing a barrier that lets you see an artificial, life like right hand but not your real right hand, and you rhythmically stroke the real hand, eventually your brain gets fooled into believing that the artificial right hand is actually yours. If someone suddenly stabs the artificial hand, you will actually jump reflexively as though, for just an instant, the brain got confused about which was your real right hand being attacked!

The Posterior Superior Parietal Lobule gives us a sense of the boundary between our physical body and the rest of the world. When activity in this brain region is reduced, the individual seems to lose a sense of where their body ends and the rest of the world begins. The feeling is one of having ‘merged with the universe’ and your body is in some way infinite. Mindfulness practices such as meditation can modify the stimulation of this region and give the practitioner exactly this dramatic experience.

So you see, once sensory data gets to the brain, it is in for an amazing ride through many brain regions that help us build up the person or self that we feel we are through space and time.

By the way, for a fascinating introduction to these topics, read V.S. Ramachandran and Sandra Blakeslee’s book ‘Phantoms in the Brain: Probing the mysteries of the human mind’

Here is an interesting 2013 research paper in the journal Frontiers in Psychology ‘Alterations in the sense of time, space, and body in the mindfulness-trained brain: a neurophenomenologically-guided MEG study’ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3847819/

The connection between meditation and brain region function and stimulation is covered in this article: Mindfulness Practices and Meditation. https://neurowiki2012.wikispaces.com/Mindfulness+Practices+and+Meditation

But now let’s consider how the brain actually makes its models.

Check back here on Friday, December 2 for the next installment!

Brain Research

Making Sense of the Senses!

If you are trying to understand the world beyond your body, it’s probably a good idea to also understand just how your observations are being made and then interpreted. Our brains process a lot of sensory information, but interpreting it is a lot more fluid and fallible than you might believe!

First of all, there is no ‘person’ inside your head looking through a TV screen into the outside world through your eyes.

Sensory information is received in small bits of impulses traveling along neurons. A visual scene dissolves into clusters of rod and cone cells in the retina that sense edges, colors, and other elemental features of what you are looking at. These qualities are not stored in the visual cortex adjacent to each other like pixels in a picture, but grouped together by thematic features. It is only at the next level of neural connections (called synapses) that associations between areas in the visual cortex are made in order to identify archetypical objects such as cars, houses and, yes, grandmothers! These neurons also make many different synaptic connections along the way to help process the information flow long before you perceive it as an integrated whole. This figure shows, for example, a few of the neural pathways that connect the visual cortex regions ( V1, V2, V3) all the way to the prefrontal cortex (PF).

visualcircuit
What you see is sometimes not always what you get. Your neural networks may actually remove information from your conscious perception of the world. A frog’s retinas only pass information to its brain when something is moving in the visual field. Its brain doesn’t even GET the basic information that things like perfectly edible flies are standing still on a nearby leaf! Only when they move does the retina communicate to the frog’s brain that there is a fly ‘out there’ to go after and eat. You know that ‘blind spot’ in your eye? The brain fills it in with fabricated information so that you do not see a black spot the size of a quarter at arms-length. Our brain is actually lying to our conscious perception of the world!

Second of all, many of the neurons at the lowest level make connections to the limbic system and are ‘tagged’ with many different emotional states .

The most important of these taggings being the self-preservation, fight-or-flight response. For example, there is very high survival value to quickly tagging a distant shadow as either a predator or a non-predator. Not all shadows will be a lion, but in the grand scheme of evolution even a rule-of-thumb that works only 10% of the time can mean the difference between vital genes being passed on to the next generation or not. This identification has to be made very quickly before you have time to logically consider all the non-threatening possibilities for what the shadow might actually be.

This tendency towards making snap decisions that over-ride time-consuming reasoning has high survival value and is hard-wired into our brains, but it also screws things up as we apply the same data to rationally understanding the world around us. The best case of this is in the eyewitness reporting of crimes. Eyewitnesses are almost always in a highly-emotional state, and great care has to be taken in the courtroom to compare accounts and distill from them the actual facts. Sometimes eyewitness accounts have to be thrown out entirely.

Another big problem with the brain is that it has a nasty habit of using the same neural circuits to handle different tasks. This leads to some extremely crazy situations.

We all like to visually imagine ourselves in different situations as we day dream, read a good novel, or are fast asleep in bed. These visual images and other imagined relationships often use the same circuitry needed for carefully examining the outside world and making sense of it. What this means is that there is actually a neural connection between our imagined world and the hard-rock world we live in. Most people can easily distinguish the difference, but sometimes our imagination, dosed with the limbic system’s associations, can confuse what we are actually seeing or experiencing, not based on an actual experience, but based instead on an imagined one. You can actually improve some elements of sports performance by internally visualizing in detail the actions you want to perform. It seems that imagined activity can train the cerebellum almost as well as the actual act!

Our brain and sensorium have to work together to identify patterns that help us survive, or at least not get injured too badly. There can be some sloppiness in this process that allows a few people to misunderstand gravity and walk out a 35th floor window, but we have evolved so that this is a very rare occurrence. But still, there are many ways in which human perceptions can be misinterpreted or even distorted by the brain as it tries to process billions of bits of information every second against a wash of emotions and other states-of-mind.

In the next blog, I will describe how strokes have helped neuroscientists understand how human brains create consistent models of the world, and how this process can break down with some rather unbelievable results!

Check back here on Sunday, November 27 for the next installment!

Brain Research

Making Sense of the World

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Ask just about anyone how many senses a normal human has and the immediate answer will be five: sight, hearing, taste, smell and touch. By the way, I always manage to forget that last one for some reason!

ebrainsciam

The oldest mention of this particular list goes all the way back to the Hindu Katha Upanashad written in the 6th century BCE. Even Shakespeare mentions them as the ‘five wits’ in King Lear! But a lot has happened since way back when. The entire idea of ‘scientific research’ came into its own, and now there are a whole lot of other human senses that have been added to the classical mix we learn in grade school.

Sense Number Six: You can detect heat and the temperature of any object you touch or are placed close to. Your skin has thousands of little ‘receptors’ that individually detect the attributes of cold and warm.

Sense Number Seven: You can detect whether you are standing upright or lying down through the balance receptors in your inner ear, which are hollow loops filled with liquid. The movement of this liquid in each loop is sensed by neurons and tells the brain your head’s position in 3-dimensions.

Sense Number Eight: Pain is a sense that is not just the overloading of touch or pressure receptors in the skin. In fact we have three different groups of pain receptors that signal internal organ damage, external skin damage, or damage to our bones and joints.

Sense Number Nine: Another overlooked sense is proprioception: the ability for you to sense the orientation of your body and limbs in 3-dimensional space. Without this very important sense, you would not be able to walk, jump, dance, type at your keyboard, or a thousand other activities that make up your life.

Sense Number Ten: Chemoreception is the ability of your body to detect changes in the foods you eat, and signal the body to reject that food if it fails to pass certain internal tests. This sense can cause your stomach to contract, cause you to vomit, and cause changes in your vascular system,: ‘OMG I just ate rotten fish!’

Sense Number Eleven: Although not a specific cellular feature of the nervous system, every normal human has a perception of their place in time. Part of this is our 24-hour circadian rhythm, but through brain activity, we have a timing sense that allows us to sing, dance and play a musical instrument correctly. It also helps us locate ourselves in the present moment within our accumulated memories.

Sense Number Twelve: Outside versus inside. We have a unique sense of where our body ends and where the outside world begins. Without this, we would identify every sensory stimulus as originating within our body, and that our body has grown to encompass the entire physical world ‘outside’. More on this later!

Sense Number Thirteen: Friend versus Foe. Our cells have proteins on their surfaces that identify to our immune systems whether a cell is part of our own body, or is a foreign interloper.

If you think this range of senses covers all of the biological possibilities, there are many more senses that some animals have, and perhaps we also do at some very, very low level.

Sharks and some other fish can detect electrical fields with specialized receptors in their skin. Many animals can detect earth’s magnetic field and use this to navigate. Bees can detect polarized light, which they also use for navigation. The vomeronasal sense allows animals to detect the pheromones of other members of their species and use this to identify a mate in estrus, or members of their own clan. Plants can directly sense gravity and use this to help them grow upwards. Both animals and plants can detect slight changes in air moisture to precisely identify where a source of water is located.

The earliest known senses were developed by single cells to detect changes in various chemical concentrations in water – a potential food source. But by far the oldest sense among complicated organisms is vision. This particular sensory skill has been re-invented literally hundreds of times by evolution across millions of different organisms.

So there you have it. Senses are a brain’s way of detecting an organism’s place and situation in the physical world. Amazingly enough, human brains do not take-in all of the information generated by our senses. If it did, we would be in a near-constant state of epilepsy! So what our brains do is to actively suppress most of the sensory information our receptors generate before it even reaches our consciousness. In fact, if you were to look at the neural activity of the brain, far more neurons are devoted to the brain talking to itself, than checking on what’s happening in the outside world!

So what does the brain do with all of this information?

That will be the topic of my next blog!

Check back here on Friday, November 25 for the next installment!