A Theory of The Brain

What exactly does he imply by saying "we do not have a theory of the brain"? There's surely a huge amount of research on the brain, but we have to admit that we are very far away from a complete bottom-up description of the brain.

I think it is similar with what's happening with the theory of superconductivity. First came the observations, then phenomenological theories, and then partial success with bottom-up theories...
Still we have no clue about what's happening in high-Tc superconductors.

Brain, of course, is probably much more complicated and really, I don't think there's even a hint of a progress in the bottom-up view of things like Hawkins suggests. It could be a long, long time before the brain riddle is solved, if there's a mystery at all.

But while you fix on what brains (and nervous systems generally) do - anticipate the world - it would also be useful to invest some time in social psychology. Read some Vygotsky in particular. The human mind is scaffolded by its use of language and this is responsible for the "higher powers" we associate with human level consciousness.

And above all, avoid becoming bogged down in phenomenological questions about consciousness - the hard question, qualia, theatres and all that. This has killed mind science again and again.

I especially like Vilayanur Ramachandran's tangent on synethsesia and its connection to creativity... this would be worth investigating to me.

But what's the question exactly?

Under-pruning of synapses would be the standard speculative story on synesthesia. Stuff spills over. And conversely, a well-organised left fusiform gyrus would act as a "module" for orderly cross-modal tieing together (though perhaps more an evolutionary emphasis on language processing that any kind of human creativity module). But anyway, you have two kinds of neural story here - one of overly diffuse connection, the other of focused connectedness.

regarding synethsesia:
blue=colorized black
red=colorized grey
yellow=colorized white

green=blue+yellow
purple=blue+red
orange=red+yellow

are these examples of synethsesia?

regarding synethsesia:
blue=colorized black
red=colorized grey
yellow=colorized white

green=blue+yellow
purple=blue+red
orange=red+yellow

are these examples of synethsesia?

how about these?
sour=sweet+bitter
salty=hot+cold

or these?
sweet=pleasure+taste

No, these wouldn't be examples.

My older daughter is a synesthete and see numbers as colors. A synesthete might "hear" colors. They might "taste" numbers. A flavor might feel "pointed or sharp"

Moreover, my point (yes there was a point) was that maybe these things evolved by first passing through a stage a synethsesia. today we would say that purple is not red or blue but a separate color. yet even now I can kinda see purple as being sorta bluish in a way and at the same time sorta redish in a way.

Moreover, my point (yes there was a point) was that maybe these things evolved by first passing through a stage a synethsesia. today we would say that purple is not red or blue but a separate color. yet even now I can kinda see purple as being sorta bluish in a way and at the same time sorta redish in a way.

Purple is reddish blue, but normally there is no such thing as bluish yellow. So I don't see quite what you're getting at..

What is synesthesia?
Synesthesia is a condition in which one sense (for example, hearing) is simultaneously perceived as if by one or more additional senses such as sight. Another form of synesthesia joins objects such as letters, shapes, numbers or people's names with a sensory perception such as smell, color or flavor. The word synesthesia comes from two Greek words, syn (together) and aisthesis (perception). Therefore, synesthesia literally means "joined perception."

Synesthesia can involve any of the senses. The most common form, colored letters and numbers, occurs when someone always sees a certain color in response to a certain letter of the alphabet or number. For example, a synesthete (a person with synesthesia) might see the word "plane" as mint green or the number "4" as dark brown. There are also synesthetes who hear sounds in response to smell, who smell in response to touch, or who feel something in response to sight. Just about any combination of the senses is possible

The Biological Basis of Synesthesia
Some scientists believe that synesthesia results from "crossed-wiring" in the brain. They hypothesize that in synesthetes, neurons and synapses that are "supposed" to be contained within one sensory system cross to another sensory system. It is unclear why this might happen but some researchers believe that these crossed connections are present in everyone at birth, and only later are the connections refined. In some studies, infants respond to sensory stimuli in a way that researchers think may involve synesthetic perceptions. It is hypothesized by these researchers that many children have crossed connections and later lose them. Adult synesthetes may have simply retained these crossed connections.

It is unclear which parts of the brain are involved in synesthesia. Richard Cytowic's research has led him to believe that the limbic system is primarily responsible for synesthetic experiences. The limbic system includes several brain structures primarily responsible for regulating our emotional responses. Other research, however, has shown significant activity in the cerebral cortex during synesthetic experiences. In fact, studies have shown a particularly interesting effect in the cortex: colored-hearing synesthetes have been shown to display activity in several areas of the visual cortex when they hear certain words. In particular, areas of the visual cortex associated with processing color are activated when the synesthetes hear words. Non-synesthetes do not show activity in these areas, even when asked to imagine colors or to associate certain colors with certain words.

Synesthesia and the Study of Consciousness
Many researchers are interested in synesthesia because it may reveal something about human consciousness. One of the biggest mysteries in the study of consciousness is what is called the "binding problem." No one knows how we bind all of our perceptions together into one complete whole. For example, when you hold a flower, you see the colors, you see its shape, you smell its scent, and you feel its texture. Your brain manages to bind all of these perceptions together into one concept of a flower. Synesthetes might have additional perceptions that add to their concept of a flower. Studying these perceptions may someday help us understand how we perceive our world.

And for pythagorean

http://faculty.washington.edu/chudler/syne.html

Synesthesia as a condition is defined by cross-modal binding of perceptual experiences. But we could generalise the neural lessons to point out how neurons code as much for "not this" as "yes, that". That is, they code with a dichotomous logic.

So a retinal ganglion cell is wired to have an “on/off” receptive field. It compares excitatory input from one type of cone cell, say red, with the inhibitory input from a surround of opponent cells, which would be green. It would then fire strongly when it "saw" red surrounded by not-green. And alternatively, would have its baseline firing rate suppressed, desynchronised, when it saw not-red and surrounding green.

Red and green are of course misleading terms at this level of description as the red cone is broadly tuned - it shows a bell curve response to wavelength that simply peaks at a particular frequency. So will show some response to bright enough "green".

Anyway, a general principle of neural circuitry is that local responses are shaped by global contextual effects. It is all about the cross-wiring. And synthesia is just the cross-wiring being extended too promiscuously across cortical areas. Seeing yellow ought to trigger experiences of not-number and not-shape. Because the yellow object might be actually just a banana or a coloured test card,

And so the cross-wiring should be binding cross-modally to these actual memories - our banana recognition circuitry should be going yes-banana-like and yes-yellow. And so not-cat and not-apple (other objects), and not-blue, not-black (other colours, unless it is a very old banana).

Synthesia is a failure to suppress contextual associations. Note that the reaction is to fairly specific and high-level stimuli - number names and words and musical notes. Quite sharply localised. And from that would seem to be part of the human brain's tinkering to handle language. Evolution had to jiggle with cross-modal connectedness so that words triggered the right learnt penumbra of associative response - hearing banana did result in not-black, yes-yellow, etc.