Dreams may often be bizarre – but what was bizarre about this one is I almost never have any dreams. I was walking a dog. I think it was my daughter's dog Kayleigh, somewhere (like most dreams the memories are fragmentary) and then I was taking some post cards out of a box to show someone, and when I came to put them back the box had vanished. A wild search followed, should I call the police, should I tell the university authorities, and where was Kayleigh?
|London Bus with Picture Post Advert|
However the subject of the dream really didn't matter. As a child I had vivid nightmares of a huge monster which prowled the streets and could eat you up. For anyone who lived in London during the war they would have taken the “monster” for granted, but as a 5 year old who had been brought up in rural Somerset I had never seen a double decker bus before – much less one with huge eyes. Perhaps this experience, at a formative stage, “convinced” my brain that dreaming (at least with visual images) was something to be avoided.
So why did I dream last night? It could have been that I took more exercise than usual (a 2 mile walk to the swimming pool (40 lengths) followed immediately by half a mile to the supermarket and half an hour pushing a trolley. Well I was tired but I don't think that was the main cause.
I think it was far more likely to be connected with writing the post The Evolution of Intelligence – from Neural Nets to Language. I have been trying to come up with an acceptable draft for months because that was so much I could say, and so many ways of saying it, and there was no way I could fit everything into one text, especially if I tried to anticipate every question people might have. As a result the post was a compromise and there were many areas which were relevant to the model which I had to leave out, including saying anything about dreaming.
One topic I left out entirely was the subject of dreams – and their role in the development of the brain. Anyone who has seen a sleeping dog's limbs twitch as if it was hunting will think, almost certainly correctly, that it is dreaming. There is good evidence that there are cross connections in the brain between different sections and I started to discuss this in a previous draft in which I was, suggesting that if the brain received a HUNGER signal into the short term memory it would match up statements in the long term memory which would activate the FOOD memode which would look for a FOOD signal. This process could involve memodes associated with sight which might start visually looking for food.
Let us imaging a person or an animal thinking about a tasty meal, either for real or in a dream. How far dies the brain imaging the site, smell or taste of it? And how much does this vary between individuals, of whatever species. Maybe I am exceptional in rarely having any dreams with a visual content. What I do know is that I have problems - compares with some other people about "thinking" colours.
When my daughter Belinda died I was diagnosed with Post Traumatic Stress Disorder and discussions suggested that at the time I aborted the CODIL research and left academic life I was also suffering PTSD following the earlier death of my daughter Lucy. The relevant fact is that I was given counselling and after a few sessions it became clear that the was a problem. The counsellor was expecting me to think "blue" as a colour when all that came to the front of my mind was the word "blue". Definitely I have never dreamed in colour, and I didn't last night.
The important thing to realise is that different brains will model their environments in different ways, and that even when people speech the same language, the internal representations in the brain may differ widely.