I am reading the popular 1995 paper "Facing Up to the Problem of Consciousness" by David Chalmers [PDF] as part of my philosophy course. I am only asking about the relevant vision related claims Chalmers makes, so you need not read the full paper.
In the section 7.1 (emphasis my own):
The properties of this [complex three-dimensional] space can be recovered from information-processing considerations: examination of the visual systems shows that waveforms of light are discriminated and analyzed along three different axes, and it is this three-dimensional information that is relevant to later processing. The three-dimensional structure of phenomenal color space therefore corresponds directly to the three dimensional structure of visual awareness. This is precisely what we would expect. After all, every color distinction corresponds to some reportable information, and therefore to a distinction that is represented in the structure of processing. In a more straightforward way, the geometric structure of the visual field is directly reflected in a structure that can be recovered from visual processing.
"Awareness" is defined (earlier in the same section) as:
...the contents of awareness are to be understood as those information contents that are accessible to central systems, and brought to bear in a widespread way in the control of behavior. ... Awareness is a purely functional notion,..
So, I believe visual awareness refers to "how visual signals are processed in the brain".
Chalmers gives vision only for example, as he states that "It is also a central fact that to each of these structural features, there is a corresponding feature in the information-processing structure of awareness." - that is - he generalizes these to all perceptions. However, we can restrict our question to vision for now.
Note the phrases I have emphasized in bold. From what I understand, Chalmers is claiming:
- direct correspondence, in that 3D structures in real world ("three-dimensional structure of phenomenal color space") form 3D structures in our brain ("three dimensional structure of visual awareness").
- the "geometric structure of the visual field" is directly reflected inside our brain in some structure, so that the original geometry can be recovered from this structure.
I wish to ask for biological justification/backing of these claims.
From what I understand, our two eyes receive 2D data, and our brain combines these (slightly offset) 2D images to produce 3D (depth) sensing. Our perceptional ability is severely limited, and it is only because of a lot of "postprocessing" done by the brain that we form our perceptions. This is also the reason why we often perceive motion in changing static images (animation) or are confused by optical illusions (for example, perceing 3d from 2d images on paper, and many more).
My points are similar to the ones raised by Torbjörn Skytt in their paper "The "hard problem" of consciousness is a dead end" (link).
I am not arguing against the claims. But, I am unable to reconcile these claims ("direct reflection" and "direct correspondence") with the day-to-day observations outlined above. Moreover, Chalmers claims that these are "central fact"s, however, I do not find them to be so obvious. If I can get some clear perspective/stand on these claims, it would be helpful.
