We don't have to do everything

I had been vaguely aware of Scholarpedia, but yesterday, for some reason, I was moved to take a closer look, through reference 1.

It turns out to be built using the same software as Wikipedia, on some of the same principles, but in a rather more conventional, controlled manner, with more organised ownership of articles and review of articles. A sort of bridge between the free and easy – albeit very successful – world of Wikipedia and the straight-laced, hierarchic and regular world of academic publishing. I have no idea yet about how busy Scholarpedia is, but it is organised into nineteen encyclopaedias, as listed at reference 3. A rather eclectic mixture, with a lot of applied mathematics, computation and physics – but also some life science – in particular, that clustered around brains. One encyclopedia on a social science topic – play – and the one of present interest is about touch, and it is to be found at reference 4.

So far, I have looked at the introduction at reference 5, with a little dipping elsewhere, which has prompted the thoughts which follow. I should also say that I found the material offered very helpful.

Quite small animals are touch sensitive, with a variety of touch sensors in their skin, in their integument. But things get more interesting with animals with neurons and nervous systems.

Fish have their lateral line systems which can detect the small changes in water pressure caused by other animals, be they predator or prey, and other obstacles.

While lots of animals have what I might call sensory hairs. Hairs which detect movement in air or water and hairs which detect contact with something. Some of them do vibrations as well as deflections. In the jargon, first order levers and all of them include something at their base for detecting deflection, often according to direction. Sometimes these hairs are on the surface of the body or of the limbs proper, perhaps between the plates of animals with external skeletons and sometimes they are mounted on limb-like structures known as antennae. A lot of mammals have arrays of whiskers arranged around their snouts or muzzles, usually a very important part of how they interact with the world.

Spiders it seems are particularly well endowed with these sensory hairs. Some of which detect contact, some of which detect currents of air – and some of which additionally (and curiously) do smell. There is a massive literature about them, as a few moments with Bing or Google will demonstrate.

What struck me about all this was the huge amount of sensory information coming in. And without worrying here about whether spiders are conscious or not – how much of this information is going to make it to consciousness? How is a one-size-fits-all, visually orientated structure like LWS-N – for which see references 6 and 7 – going to cope with all this?

The answer that I came to was that consciousness was very much a summary, just the highlights or the main points. Lots of stuff is just not there at all. There is lots of stuff going on in the viscera of humans which does make it to the brain but which does not make it to consciousness at all. And even looking at the primary senses of sight and sound, senses of great importance in the life of most mammals, a great deal, most even, of the information collected by the eyes and the ears does not make it to consciousness.

Some of this selectivity might be described as qualitative: this or that sort of information is not sent to consciousness at all. While some of it might be described as quantitative: this sort of information is used to inform consciousness, but what makes it to consciousness is very much a summary. So when looking like a stone covered flat roof, like that illustrated above, the eyes are collecting lots of information about individual stones – but very little of that information makes it to consciousness unless or until one attends to a particular stone or small group of stones. The fact that the roof is covered with grey stone chippings may well have figured in some Bayesian prior involved in the construction of the subjective visual image, but whether that fact itself makes it to consciousness is another matter. One might say something of the same sort about the blades of grass in a field or on a lawn.

Or if we are conscious of something vibrating, we might be conscious of the speed of vibration or its regularity, we might be conscious in a transient way of the individual strokes or strikes of the vibration – but these last are very quickly lost as individuals. We could say nothing about them afterwards. Something of the same sort happens when one watches the sleepers underneath the rails of the railway line next to the one is travelling on, even though it may well be that individual sleepers are, in theory, recoverable from the light signals reaching the retinas. Too much detail expressed in time rather than in space.

Speculating further, I thought about a cat watching a mouse. The cat is probably conscious of looking at a mouse, or at least at a promising prey animal. It knows that it might be a good idea to line itself up so that it is facing the mouse and to pay attention to it, to point in language of hunting dogs. And at some point, it might pounce or make a grab for the mouse. Now in order to do this, the brain needs to know how far away the mouse is. My speculation is that the cat is not conscious of this knowledge: it is enough for the cat to pay attention to the mouse and let the brain go about its business. A cat probably does not have the conscious concepts of distance or direction at all.

And I think that much the same is true of humans. A carpenter needs to pay attention to the chisel and to the piece of wood being cut, but while knowledge of angles and distances is necessary for successful tapping of the mallet, there is no need for that knowledge to be conscious, although one might worry consciously about such things when learning. And this is going to be true of lots of motor tasks which need to be learned – and once they have been learned, conscious knowledge is as likely to hinder as to help.

Another analogy here might be the process by which an important person, perhaps one of Her Majesty’s Secretaries of State, is briefed by his (considerable and clever) staff about something important, but about which he has no prior knowledge. A huge amount of information gets poured into the top of the funnel, but what comes out of the other end has to fit onto the back of a postcard. Given all the pressures on their time – if not their intellects – Secretaries of State cannot cope with any more than this.

Conclusions

All in all, a useful reminder that consciousness is a very selective business. The brain just projects into consciousness what is needed there, in a neat and tidy form – whatever that may be – and leaves everything else out. And if consciousness in this particular sort of brain is not structured to cope with this particular sort of information, tough.

References

Reference 1: http://scholarpedia.org/article/Main_Page.

Reference 2: https://en.wikipedia.org/wiki/Scholarpedia. Scholarpedia according to Wikipedia.

Reference 3: http://scholarpedia.org/article/Scholarpedia:Topics.

Reference 4: http://scholarpedia.org/article/Encyclopedia:Touch.

Reference 5: http://scholarpedia.org/article/The_World_of_Touch.

Reference 6: http://psmv3.blogspot.co.uk/2018/01/an-introduction-to-lws-n.html. A little out of date, but hopefully it will serve here.

Reference 7: https://psmv4.blogspot.com/2019/06/a-further-update-on-seeing-red.html. Inter alia, a list of the other material which has been posted. Also a little out of date.