Understanding the Cortex

If you want to understand the mammalian neocortex, and hence, seemingly, the back-end to most conscious human experience, I believe there are three fundamental areas one must first get to grips with. These are prediction, attention, and the generation and propagation of thought. I won't go into much detail, as I am not entirely clear yet myself.

Prediction is already known to be a fundamental, if not the primary (see Hawkins), function of the neocortex. Having an expectancy of what is to come is essential for learning and for bringing one's attention to important features of the world. Our attention is caught by things new, unexpected, or significantly different from their spatial or temporal surroundings. I get the feeling that these are all essentially the same: simply things that are not accurately predicted in the brain.

I feel that attention, that is the limitation of one's self to focus only on one thing at a time, must be important and must, like prediction, have a physical basis in the structure of the cortex. I believe that attention must be a fundamental function of the cortex. Despite the brain's parallelism, it appears to be almost a necessity that we solve problems by actively thinking about them, which necessarily entails paying attention solely to a specific thought. However, we must not forget that some answers do just spring to mind, so attention is not necessarily required for a solution. But it certainly plays a large role. Consider the following as an example that leads me to believe that attention must have a structural basis. Somehow, despite sound and vision being processed in completely different areas of the cortex, I still cannot pay attention to both simultaneously. Indeed, my attention is automatically drawn away from what I am looking at if I hear an alarming sound.

Thirdly, while we know a lot about how input from our senses is processed, we do not seem to have much of an idea how thoughts originate (if they do) or how they propagate through the cortex. This is very relevant to attention, as we actively think about what we are attending to. I find the reflexivity of thought bares an interesting light on this. The structure of the cortex is similar all over and, as first noted by Vernon Mountcastle in the 1950s, the way in which it works appears to be almost exactly the same throughout. The fact that I can reflect upon any particular thought, that I am aware that I am aware of any particular thought, regardless of what it is (visual, linguistic, auditory etc.) appears to me to be reflected by this repeating cortical structure.

I and others will continue to ponder these issues long into the future. It will be interesting to see whether these three areas do indeed prove to be fundamental, as I expect.

Smelly Memories

It is often said that a smell can bring back a vibrant memory. Indeed, it has been singled out as different from your other senses as different, perhaps more sensitive, in this regard. There appear to be good biological grounds for this statement too, for the brain's olfactory system has close anatomical links with long-term and emotional memory. Yet I dispute this difference. I think that your other senses are just the same in this respect, or at least far more similar than we realise.

Often, I have exactly the same experience with my sense of hearing. This occurs, for example, when I listen to music that I haven't heard for a long time, or that I spent a long time listening to while engaging in a particular activity. When listening again, I suddenly get a vibrant memory of whatever I happened to be doing the last time I listened to the track, album or artist several times over. It is not only smells and sounds that bring back such memories, but every sense.

Furthermore, the majority of smells I experience don't remind me of anything at all, let alone bring back vibrant memories. Of course, I usually forget these - they're just everyday experiences of no significance.

Baring these things in mind, it seems more likely that uncommon experiences with emotional significance or that occurred a lot in a relatively short period, rather than simply your sense of smell, invoke these strong memories. The fact that many smells are uncommon means that your sense of smell brings back more vibrant memories than your others senses. There may be an element of increased sensitivity due to a physical connection with memory in the brain, but I am sure it is not entirely responsible.

The Effect of an Experience

Does every experience you ever have affect you long term? I expect your first day at school has a role to play in who you are at the age of 40, but what effect does waking up for your thousandth school-day have? (Assuming that you wake up in a fairly typical fashion on that day.)

Are there experiences that affect you only in the short term, baring nothing whatsoever on your character at a later time? Watching a film might be an example of this, as might spilling your drink or dropping your toothbrush. These events affect you for a while, but do they have any lasting affect, however small?

Are you affected by experiences of which you have no recollection from the night before while exceedingly intoxicated?

By experience, I mean anything at all you were conscious of - even in a small way. By "conscious of" I do not mean that you thought about it, only that it was for even a moment part of the unity of your conscious mind. This then opens up the possibility that you are then affected by things that you are not conscious of. To these 'things', the same questions apply: does every unconscious experience affect you long term? Are there unconscious experiences that affect you only in the short term? These two questions being very hard to consider I feel it's best we ignore them at least until we've considered at least the conscious cases.

I have no answer to these questions, I ask them because they are interesting and because it would be nice if others pondered them too. One might wonder whether we are only affected long term by only things we remember or perhaps only by critical experiences. What might these 'critical experiences' be? Experiences that are emotional, significant in one's life, or things that affected you over a long period of time could all be candidates.

In my earlier post "Why Don't I Remember Everything?", I said: "generally, we remember what is often used or linked with emotional stimulation (or, I suppose, strongly linked with something else)". According to this, a critical experience is an experience one remembers. However, I strongly expect that the critical experiences for long term memory are different from the critical experiences that affect you long term. I expect that the chance of an experience affecting you is greater than the chance of it becoming a memory. This chance may even be 100%. This is because if you experienced it, your brain processed it. I think that your being affected by an experience depends on whether the act of your brain's processing of it changes how it processes the next data to come through. The question of whether some experiences affect you only for a limited time depends on whether the brain's process is affected only for a limited time. So, discover the process (assuming there is one (that will help us answer this question) and that it can be discovered) and we discover the answers to this question! Although, it can be discussed philosophically with interest without ever thinking about the brain like this.

Why Don't I Remember Everything?

Why don't we remember everything? This an inefficient use of our resources. Our resources being mental capacity, energy and maybe even time.

Generally, we remember what is often used or linked with emotional stimulation (or, I suppose, strongly linked with something else).

The reason you can't remember what you ate for lunch yesterday is the same reason you remember so much about the world.

That Feeling...

You know that sensation you get of something touching you even after it's gone?

Based on the most common form of this, persisting sensations, I came up with the following 'theory'.

My theory is that after the brain has received a given input for an extended period of time it will, if it 'considers' it 'unimportant', stop 'making' you conscious of it. However, when the input is removed, it now 'expects' an input that isn't there. Due to this irregularity your subconscious now 'makes' your conscious aware of this by 'sending' the 'signal' it has not been 'sending' previously. After a time of no input, your brain adapts and stops giving this signal.

I've stuck a load of apostrophes around words there because of the difficulty in describing concepts like this. I believe this description is easier to read this way. However, one can see how this could genuinely occur in the brain.

This 'theory' is possibly thrown off by the fact that these persistent sensations also occasionally occur long after the input has been removed. Any thoughts?

The Consciousness Paradox

I know that I am conscious. This presents me with a problem and a paradox and hence much confusion.

If consciousness is or is a product of the processes in the brain, but does not itself effect the brain, how can I know that I am conscious?

Edit on the 6th of September 2010:

Assuming that consciousness is directly related to the brain in that one's conscious experience is directly related to specific processes occurring within the brain, this 'problem' is solved by allowing that self-conscious beings' brains, or select areas of their brains, have areas that are stimulated by the stimulation of another area in such a way that one is aware specifically of entire thoughts and experiences. Put another way, when an area of one's brain becomes active due to a specific thought or feeling, another area is activated specifically by the activation of the first in a way specific to this original thought or feeling such that (our assumption being that there is a direct relationship between brain activity and consciousness) one can think about said thought or feeling as a definite 'thing'.

Make any sense? Any whatsoever?

A Mental World

After reading this post, I would like you to understand that everything you experience is 'within' your consciousness, and what this entails. That's my aim, anyway.

You accept that the [physical] screen you're looking at isn't in your head and yet you are aware of it. Furthermore, you could tell me the shapes and colours of its components and how it feels to the touch. If it burst into flames you could exclaim: 'it smelt horrible!' and could also let me know what it tasted like, if you really wanted. Is there a monitor really there? If it is, does it really have these properties? Do I experience the monitor in the same way you do?

It's important to note at this point any assumptions I will be making so that you are aware of the limitations of my suggestions. The first assumption I will make is that there is a physical reality and we're not all just brains in vats nor that, for example, there is only consciousness. The second assumption is that consciousness is in some way related to the brain.

There are various other views out there. Take a look at this lecture by Peter Russell and this lecture by Thomas Campbell for some interesting and well presented differing and opposing views to my own. They're quite long, so you'll have to set aside time for them.

So, baring these assumptions in mind, let's examine the experience of looking at an object. Science tells us that before you see the object light travels from it to your eyes where it is focused onto your retina. Here chemical reactions occur to produce electrical pulses that correlate to the intensity of the light at each receptive cell. These pulses are sent, via the optic nerve, to your brain. It is here that things get a little fuzzy. Continuing my physical explanation, I could tell you that neurons fire and synapses spark, but not that you see the object. Yet you do!

No field of science - nor anything at all - understands or explains this phenomenon, hence why I describe it as "fuzzy". So what do we know? Well, although there is disagreement, I would say it's near certain that something in your brain either is the experience of 'seeing' or causes it. If consciousness was unrelated to the brain, how would it be explained that human consciousness is limited to only the inputs (senses and bodily information such as sight, how hot you are and things like headaches) the human brain receives and things it can come up with on its own (memory, dreams etc.)? Further, when conscious decisions take place the body is controlled by sending signals via the nerves from the brain; if consciousness is not related to the brain why would this be the case? Unfortunately, that's about all: we know so much about the brain, but not about its link with consciousness.

It follows that as experience is either consciousness itself or is a consequence of consciousness we can't claim that two people experience the same thing as we don't understand consciousness. Say the object you are looking at is red, if I look too will I see the same colour? If for both of us 'red' makes us happy for some reason, is my feeling of happiness the same as yours?

This leads to an important problem concerning consciousness and the brain. If my experience is the same as yours, as everyone's, why should this be? And if not, why not?

Consciousness provides you with an interpretation of the physical world as well as a window onto a number of other functions of the brain such as memory and the ability to control your breathing. Colour is not the property of an object but the frequencies of light it absorbs and reflects are. You see red but the object isn't fundamentally red; red is your interpretation. This is the same for all your senses, all your experiences. Be careful not to misconstrue this as "red isn't red" or, considering the sense of touch, "cold isn't cold". Something cold is cold (i.e. it has less heat energy than something warm) but it itself does not have the property of the feeling of cold. The feeling of cold is your interpretation or understanding of the physical property, its heat energy.

If you have accepted that consciousness is related to the brain you will also accept that it is therefore only possible to experience, be conscious of, inputs and internally generated information such as memories or thoughts. That our experience is limited by these features entails that it would be possible to experience other things, given more inputs. No one can possibly imagine what these would be like, but we do know that other animals have different or enhanced senses from our own. Dogs have an increased sense of hearing and smell, some creatures 'see' ultraviolet light and single cell creatures experience nothing at all.

Hopefully, by now I have achieved my goal. If successful I have shown you that your experience is somehow linked with your brain and that what you experience is not the world but an interpretation of it limited by your senses and brain wiring. I have more thoughts on this and will expand and extend at a later stage. First though, it's important to understand what I have presented here.