You Don't See The Blue Tint

Posted by DrDoppio on July 29, 2012 05:45 pm 0

I really enjoy salty food. For years, I’ve been increasing gradually the amount of salt I would add to my food, only to get used to it and think that the food tastes bland again. However, because of the negative health effects of excess dietary salt, I decided to cut down on it.

It wasn’t so easy at first. I had to avoid completely some foods I have been enjoying and others seemed tasteless without the extra salt. Over time though, I started to get used to it. I would less often think that a food needed salt when I first tasted it, and new sensations from my taste buds became more prominent and enjoyable. Eventually, I learned to appreciate certain foods without any addition of salt even more so than before.

I am gradually coming to the point of this post, which is about what is absolute and what is relative in our sensations. There is a well known phenomenon of "transient desensitization" where we stop responding to a stimulus after being exposed to it for a while. We are more adept at detecting change than at estimating the absolute level of sensation. The same goes for our taste buds, sense of smell, hearing, and vision. Thus, I am of the opinion that senses are to a much higher extent relative than absolute.

A few examples to illustrate my claim: (i) musicians use tuning forks to find the absolute frequency of a tone, even though their ears may be trained to distinguish differences in pitch as little as 2Hz; (ii) photographers and film makers use instruments to check the light in their scenes; (iii) doctors use thermometers to take the temperature of patients; etc.

Finally, I would like to point out that I am filled with distrust whenever I read on technical blogs about the tint that a certain type of display has, and how it’s “not natural”. It is true that the colors can be measured objectively; it is also true that two different displays can be juxtaposed and the differences will stand out. What I don’t think is true it that individuals looking at just one of these displays at a time are capable of telling for sure that there is a certain tint or hue. They cannot.

One final example of how our senses are relative can be seen on this web page:
http://www.planetperplex.com/en/item/checker-shadow/