Medical What Are the Key Brain Theories: Gestaltism, Structuralism, and Isomorphism?

[Pythagorean]

And for pythagorean

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

I've just heard about the binding problem and been thinking about it, specifically with respect to how it makes the conscious part of vision a very abstract representation of the real world (highly efficient, dude to it's weighing of importance. By conscious part of vision, I mean that which we interpret which we see. This is opposed to the unconscious part of vision (which can be somewhat isolated in patients with "blind sight"). The patient is aware of kinematic changes in his vision (actually... is he actively aware or does he have to recall it from short-term memory if he chooses to think about it?) but doesn't interpret them "visually" by the standard definition of visual.

So I think the binding problem goes beyond just the binding of senses, but also the binding of some kind of symbolic memory. For instance, you're in a room with a metal worker and a bunch of junk all over, but you're not really paying attention to the junk because you're talking to the metal-worker. It's all formless, even as it's in your field of vision. But as you begin to look at things, you identify the individual pieces of the junk, you know what they are from experience, and as you analyze each piece and identify it, your also relying on your memory to construct the details you can't directly sense. You can imagine how it would smell or feel or taste or sound based on experience.

Langauge itself seems to be a kind of way to reinforce symbolic memory, if it's not in some way directly responsible for it.

 

[Galteeth]

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 learned penumbra of associative response - hearing banana did result in not-black, yes-yellow, etc.

I wonder if the same kind of suppression failure occurs in less specific and localised forms.

It is curious that schizophrenia, which seems to result from a lack of basic sensory filtering, produces a syndrome that makes higher level associations more difficult.

I suppose one is just context suppression failure whereas the other is a more basic suppression failure.