Blindsight and LCD vs E-ink?

[Barcey]

I was reading Scientific American this week and there was an article on "Blindsight" that caught my attention.
http://www.scientificamerican.com/bl...g-i-2010-04-15

The theory is that there is a primitive part of the brain that processes visual information. To demonstrate they have a video of a person who lost use of his primary visual cortex (through strokes) but was still able to navigate obstacles in a hallway.

Other testing has shown that patients are able to recognize emotions expressed by a persons face but not recognize the person or their gender. Other things that can be detected are objects appearing and disappearing, movement, color and orientation of lines.

I wonder if this is related to the fatigue that some people experience from LCD screens. It aligns with my theory that it's more related to the screen refresh then the light, meaning that the screen refresh is fast enough to fool our primary visual cortex into thinking it's seeing a stable image but there is another part of the brain that isn't fooled.

Anyone up for some brain probes to test my theory?

[ardeegee]

I'm no expert in the field, but they seem utterly, utterly unrelated to me.

But here's a free ebook:

http://www.rifters.com/real/Blindsight.htm

[TGS]

Blindsight is a syndrome, which can have a number of organic causes, in which the sufferer has no experience of some aspect of visual perception but whose behaviour is such that it is evident that the visual information has been processed by some area of the brain - the person who can navigate obstacles whilst reporting that they cannot see them for example. However, it is not really an all or nothing kind of thing - we all, all the time, process visual information of which we have no conscious experience of perceiving. I'm not sure what the nature of the link with LCD refresh rates is though

[Kali Yuga]

Originally Posted by Barcey

The theory is that there is a primitive part of the brain that processes visual information.... I wonder if this is related to the fatigue that some people experience from LCD screens.

I'm not an expert, but no.

From what I understand, the areas of the brain that process some visual information, but are not part of the primary visual cortex, are probably a holdover from an ancestor or early evolutionary phase. It's not terribly precise -- e.g. you can't perceive enough features specifically enough to determine gender.

Also keep in mind that there is growing evidence of neural plasticity. It's entirely possible that once the brain "figures out" that the visual cortex is damaged, the brain "recruits" an underutilized region (perhaps one that in earlier evolutionary iterations managed basic visual information, and is no longer in use) to do some rudimentary visual processing. This is just a theory though, I don't know if anyone is actually investigating it yet.

At any rate, it seems highly unlikely that these other areas of the brain will be sophisticated enough to really get involved with language processing, let alone be capable of perceiving information that changes too fast for the primary visual cortex.

Originally Posted by Barcy

It aligns with my theory that it's more related to the screen refresh then the light, meaning that the screen refresh is fast enough to fool our primary visual cortex into thinking it's seeing a stable image but there is another part of the brain that isn't fooled.

LCD's don't really have a "refresh rate," that term applies to CRT's. With LCD's, the pixels are constantly at a specific level of opacity until the next instruction set is received from the video card. LCDs do have a "response time" (how long it takes to change a pixel's opacity), but that doesn't matter except with certain specific high-speed environments, e.g. video games.

There is also "flicker," which is the on/off time of the LCD's backlight. However this is much faster than humans can perceive, consciously or subconsciously.

Furthermore, if your theory was correct, motion pictures would be as difficult for you to watch as LCD's are to read. Movies run at 24 frames per second, which is much slower than CRT's or LCD's refresh.

I do not find reading on LCD's to be particularly pleasant. However I have yet to see any convincing studies that issues with perception and/or enjoyment are due to physical characteristics of the LCD rather than subjective preferences.