When you smell a scent so many times you stop smelling it , but why isnt this the same for sight and hearing ?

Answer 1

Actually this effect does occur to a certain extent. With hearing, you could equate it to "white noise". It will eventually get filtered out by your brain and you'll notice the other sounds that don't fit the pattern.

Likewise for seeing. When you drive the same path everyday, your brain begins to realize the same pattern and will often not store the trip in your short term memory. The only things that are more easy to recall are changes that might have occured. But if there are no significant changes, then you simply won't recall the trip enough to distinguish it from another.

Some people attribute all of these senses getting nullified as an effect that causes older people to feel that time is passing more quickly. As a child, a day seems longer because there are so many new experiences. But as they become more common, your brain shuts off the mundane and time tends to slip past because your brain isn't trying to write stuff to long term memory (or even short term memory).

Great question. Thanks for asking!

Answer 2

Unless the smell changes it is a constant which the brain accepts and ignores. A new smell may mean danger so the brain takes notice. With hearing and vision, the imput is constantly changing, even looking at a still picture the image changes due to subtle light variations, so thats why the brain does not ignore the imput. Mind you, some optical illusions prove that the brain wants constant changes of imput as far as sight is concerned but I can't find any links to a good site at the mo!

Answer 3

Not sure exactly, but I would imagine it's something to do with th basic need to react to sights and sounds. People who work in factories, for example would learn to tune out that particular sound after a while, and then there's that thing going around via email about how the human mind can read english words, as long as the first and last letter are in the right place and it doesn't matter if the rest of the word is mangled up. Maybe we do tune these things out, but just not as often??

Answer 4

The sensory input is constant and your brain will eventually ignore it until a new smell or sensory input is introduced. People who move from the city to the country will miss the constant audio input of sounds.
You can buy white noise generators to help you sleep in those situations.
There was a study where volunteers wore glasses that inverted everything, and they found after a couple of days the brain would " flip" everything to right side up. When the glasses were removed, the volunteers saw everything inverted for a couple days until things flipped again.

Answer 5

Cirric is right (as he is usually, he often time beats me with the perfect answers by just a few seconds).

If you eyes are completely immobilized, then they go blind. You must have done those tricks when you have to stare at a picture for one minute and then look at a blank piece of paper to see a negative of whet you were looking at? Well, that is a limited example of that.

You eyes are always in motion, minute moves that stimulates the sensitive cells of the eye. Likewise, you head is also moving, changing the sound you perceive in small increment. The human brain is best geared to handle, and react to, change. Everything that is constant for too long gets ignored, because this is what is best to ensure survival, and threats are usually things that are new. Of course, that is how snakes and crocodiles catch their prey, by remaining motionless until they are no longer " seen".

Answer 6

But it is the same!

How many times has a car alarm going off in the middle night peed you off, but you haven't noticed when it stopped? And when was the last time you really SAW anything on your trip to work?

The brain just accepts what is constant and you have to pay attention to see, hear or smell it!

Answer 7

It is the same with sight, and a lot of optical illusions depend on this fact.. http://www.panoptikum.net/optischetaeuschungen/opticalillusions.htm

And, as others have pointed out, you 'tune out' sounds that occur all the time. At one point i lived near a railway. At first, the noise of trains woke me every 1/4 hour, through the night...... then, after a day or so, I slept through the nightr and never noticed them

Answer 8

You can habituate to many kinds of sensory stimuli and we tend to notice things more when they change e.g. in intensity, pitch, frequency and so on. For visual stimuli, there is a 'primitive' ('reptilian') part of the brain which will cause us to respond very rapidly to unexpected stimuli e.g. jumping in response to a large spider seen out of the corner of the eye. The thinking part of the brain responds a little later providing us with detail, then you can decide whether you need to take the thing seriously or not.

Answer 9

Do you have a clock that ticks? Do you not hear it unless you think about it? The brain cleverly filters out non essential information unless it thinks you need it. As for sight, there's a thing called "jamais vu" (like deja vu) but literally means "never seen". Ever looked at something you've had for ages and not realised you owned it...?

Answer 10

Hi. It is! Do you hear traffic where you live? Only if you listen for it or a muscle car goes by. Watch a field for a few minutes and your eyes get used to what they are seeing. If something moves, your eyes pick it up quickly.