If you enter a room that smells like roses or rotting fish, after a while, you usually can’t detect the odor any longer. If you leave the room (or house) for a bit and return, you notice the smell again.
I’m trying to figure out how this could be. It’s not like you just aren’t focusing on the aroma; it just doesn’t seem to be there.
I’m also curious about why this should be. It seems it would be a survival mechanism to notice that an aroma was still there. But since science tends to be better at answering “how” than “why,” I guess I’ll stick with “how.”
And with noises - having lived in a big city for most of my life I barely notice the noise of traffic in the street below or the rumble of subways passing by every 5 minutes.
I suppose sight is also affected to some degree: the human eye picks up movement much better than it does immobile details, and is also more prone to notice changes in familiar scenery.
I would assume there’s some switch or mechanism in the brain that makes new stimuli stick out from the ambient “noise”, then progressively discounts those stimuli if you’ve not acted upon them the first few times. That way the newest or more urgent stimuli (e.g. this bush smells like TIGER!) remain at the top of the information stack while strong yet innocuous ones (e.g. this bush smells like there’s a massive pile of stinking dung in there) are filtered out.
Besides, as Terry Pratchett often writes if we didn’t have the ability to completely ignore 90% of what’s happening right in front of our eyes, we’d never get anything done
Getting away from the gum chewing thingy (gum doesn’t lose it’s taste because of extended chewing, it’s because the flavor is put into the gum during manufacture and eventually gives out), does anyone know whether olfactory fatigue happens in animals who are more dependent on their sense of smell than humans are (say a dog or wolf)?
Your senses are capable of producing more data than you attention can contain, so some attenuation is probably always present. From a survival point of view, change is often more important than a steady state, so new things get fast tracked to the concious mind to review for possible threats, and then maybe less attention is payed to them.
Sight is affected A LOT in this way. If you stabilize the image projected on the retina (something that is, technically ,very difficult to do), it fades from consciousness very quickly, usually in less than a second, and in some circumstances in as little as 80 milliseconds. We don’t usually notice this because normally our eyes are constantly moving and continually moving the image on the retina, or bringing completely new ones onto it.
The same effect occurs with other senses. For example, a continuous background noise becomes less noticeable over time. When something touches your skin you notice it immediately, but after a few minutes you’re not aware of it unless you conciously pay attention to it.
If you stare at a fixed point of a static scene without blinking, everything will seem to disappear after a minute or two. This is hard to do - a slight motion or a single blink will disrupt the effect.
Getting back to the gum chewing thingy, yes, gum does get back some of it’s flavor if you take it out for a while and then re-chew it; however, it is very short-lasting. I conducted some intense studies of this property as an adolescent.
