Talk:Eigengrau

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An entry from Eigengrau appeared on Wikipedia's Main Page in the Did you know? column on 29 June 2006.

Okay, what else should I add to this? Got a question about eigengrau? Ask it here and I'll add the answer to the article. —Keenan Pepper 02:00, 27 June 2006 (UTC)

I obviously know nothing about this field, but I'll take a shot: what does it mean to say that the sensation is a uniform dark gray? Couldn't the sensation be called "black" in the sense that there one cannot perceive a darker shade? Or would we reserve the word "black" for zero-temperature eigengrau? Or, perhaps, is there an even darker black caused by, say, temporary nerve damage? Melchoir 17:31, 27 June 2006 (UTC)

Good question. You can indeed perceive darker colors than eigengrau. In fact, ordinary black objects are darker than eigengrau, because it's all about contrast. —Keenan Pepper 21:55, 27 June 2006 (UTC)

Very interesting... now, when we say that a black object in a non-black environment is darker than eigengrau, is that a comparison of nerve firing rates, or some kind of perception experiment, or perhaps both? Melchoir 07:09, 29 June 2006 (UTC)

I think it's just a psychological effect, not physiological, but I'm not sure. I'll look it up. —Keenan Pepper 15:42, 29 June 2006 (UTC)

Okay, I found some research that shows that stimulation of one region of the retina inhibits neighboring regions, but the journals (J. Opt. Soc. Am. 53 and 54) are in my library's "remote storage" so I won't have access to them for a few days. —Keenan Pepper 23:07, 29 June 2006 (UTC)

Excellent. Thanks! Melchoir 01:46, 30 June 2006 (UTC)

It's great - love the word - can you tell us who coined it?, who first observed the phenomenon? Adambrowne666 06:57, 29 June 2006 (UTC)

My guess would be Hermann von Helmholtz, just because he's so smart and did all kinds of pioneering work in this field. I'll look it up later today and see if I'm right. —Keenan Pepper 15:42, 29 June 2006 (UTC)

The earliest reference I've been able to find is Hermann Aubert's Physiologie der Nezhaut, 1865, but I can't find it at my library. Is there anyone who has access to this book or can verify that Aubert first observed and named eigengrau? —Keenan Pepper 23:07, 29 June 2006 (UTC)

Fascinating... my only suggestion for improvement would be to rephrase some of the Causes section to make it more accessible for a layperson (someone like myself who might know only basic concepts of the physics of light) to understand. Also, has any of the experimental data come from human patients with damaged retinas? Analogous to the discovery of "language centers" in the brain located in people with speech disorders? -Fsotrain09 16:34, 29 June 2006 (UTC)