Seeing red

[emjay]

 Why is the visual field 2D? 

Because your eyes are incapable of penetrating many objects, you can only see what is presented to your field of vision.  Ie, there are positions in which you cannot see both the front and back of something.

Okay.

You would not be able to detect the right patterns in the pixel information if it was organised in a 1D array... 

We don't need any particular number of "d", because however many "d's" your eyes are capable of perceiving, that isn't fed directly as is to you brain, nor is your brain capable of seeing like an eye as far as we can tell.  

I'm not sure I agree here. I've already said that the final visual perception is the result of many different transformations... lines, shapes, colours etc. In other words the eyes bring in the raw data but it's processed in many different ways, detecting different features of the input, before being 'output' as a perception. So yes, I know it's not a replica of what the eyes detect... it's more like a construction or model created out of the different features of the input that it detects and abstracts. All I meant was that topographically inside the brain it has to retain that map because it needs to use the what I'm calling 'pixel' information relative to other pixels on a 2d map. If it didn't have that map and scattered the output from those cones willy-nilly around the brain it would take some very clever wiring to bring it all together again. So that part has to be essentially 2d, just to allow the next layer of neurons to synapse easily with what represents pixels and their locations relative to each other. But how that applies to visual qualia is just conjecture.

would not be able to detect pixels that were next to each other or diagonal to each other. So it has to be a 2D array and that's how it's physically organised in the brain with this topographical map received from the retina. 

We perceive in 3d, not 2...we can only draw in 2.  I can only see the front of a subaru, but I perceive the rear of the same despite my inability to commit that 3d concept to a 2d page.  I can percieve it, i can even simulate it, I cannot replicate it.  That's a limitation of the surface upon which we impose the image.

My apologies. I was just thinking of it and simplifying it in terms of a flat visual field... because for my thinking I'm only really concerning myself with colour and the fact that that is portrayed like pixels on a screen. But yes I know perception goes a lot deeper than that in so many ways. Just as an aside though, in my own case I believe it is 2D because of my eyesight - I have a lazy eye so everything looks like a cardboard cutout to me and I couldn't catch a ball to save my life. So I don't really know what it's like to perceive in 3D, except for the clues that come from shading, lighting, perspective etc.

And from the brain's perspective it presumably needs to be structured like that so that it can be interconnected correctly retaining that topographical information. So the system is forced to represent the array in a 2D manner because of the constraints of how it will be accessed further down the line... eg for detecting lines etc in needs to know where one pixel sits in relation to another. So all these constraints force it into a specific configuration functionally and structurally. I just wonder if roughly the same thing happens phenomenally, and that therefore colour is the only way to represent/label the 'pixels' in a perception that already looks like it has been forced into being a 2D visual field (well 3D but 2D in terms of how it is in your head), given all the other constraints.

We are forced, as a system, to represent a 3d perception in a 2d manner because the surfaces we use to represent them are limited to 2d.   We, clearly, are not.  The "specific configuration", both structurally and functionally, necessary to differentiate between variables is awfully general.  We label that same phenomena by it's placement in a spectrum described mathematically.  That's just -one- other way to perceive "color", as a number.

Okay I get that. Inside, we create a 3D perception out of a 2D input device (our retinas), but vice versa in the outside world where in art or TV etc we can only represent 3D in 2D because we are limited to 2D surfaces. But you've kind of lost me on the next sentence - what do you mean by 'awfully general'? I know we can describe colour as a number, and that's indeed essentially what it would be in the brain, well a variable at least. But our visual perception doesn't show numbers - we're not like terminators or living in the Matrix looking at 0's and 1's all day. The patterns would be lost in that. Colour allows the right patterns to be detected. But before you jump down my throat about the terminator reference I just want to try and clarify that I don't think anything is happening in perception... that I think all the work is done in the neural networks and that perception just emerges from it as a kind of metaphysical mirror of what's going on neurally. But my theory was that the form it takes is the only one it could be given the different states it has to capture. But it was just a theory There'll be others