Friday, 24 December 2010

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.

Sunday, 12 December 2010

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.

Monday, 6 September 2010

What is Self-consciousness?

In this post I will discuss how one can be aware of one's own consciousness and will, in the process, give a definition and explanation of self-consciousness - what it is to be self-aware.

Let us first consider a creature that is sentient but not self-aware; it is conscious, but does not know it. The experiences of this creature are restricted to sensations from its sensory organs, such as touch and smell, and any internally generated feelings or emotions such as fear and joy. This creature cannot ponder these sensations; indeed, what it lacks is the ability to separate itself from the feeling and think "I feel that".

Humans, and it seems likely to me that in this we are not alone, do have this sense of 'I' and we do distinguish between the sensations we experience. Using the example of happiness: rather than simply feeling happy, you know that you feel happy. One can say "I know that I am aware" however, interestingly, one can also say "I know that I know that I am aware" and indeed "I know that I know that I know that I am aware". This reflexivity could go on forever, yet would not add any more meaning to the base statement "I know that I am aware".

What we see is that to be self-aware is to be aware of one's own thoughts and experiences. One has an experience and is aware of it, this enables one to think specifically about this experience. Furthermore, one is also aware of one's own thought about this experience, which is where the reflexivity comes in. I therefore define 'self-consciousness' as 'to be aware of one's own conscious experience', thus including reflexivity (one's thoughts about one's thoughts).

Sunday, 29 August 2010

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.

Sunday, 25 July 2010

You Think, Therefore You Are?

If an individual says "I know that I think" and is not lying, does this show that they are conscious?

Friday, 4 June 2010

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.

Tuesday, 4 May 2010

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?