Nostril Fight!

Your nostrils will absolutely not be taking any crap from each other. Scientists have long known about binocular rivalry--a sort-of competition between your eyes. If you control a person's vision so one eye sees one image, and the other eye sees a completely different image, the images won't merge. Instead, the person will experience a tug of war between one scene and the other, with neither eye coming out the winner. Turns out, our noses may be doing something similar. In a small, but interesting, study, researchers presented evidence for what they're calling "binaral rivalry"--competition between the nostrils.

Wen Zhou and Denise Chen presented twelve participants with the smell of rose to one of their nostrils and the smell of a marker pen to their other nostril. After each break in the smells, the participants indicated on a visual scale whether they had detected the scent of rose or of marker pen. Just as with binocular rivalry, the participants' perceptual experience fluctuated back and forth randomly between the two scents.

The researchers believe this nostril rivalry is related in some way to the process of adaptation, both in the receptor cells in the nose and in the part of the brain that processes smells. For example, when repeatedly presented with a balanced mix of both smells, the participants' sensory experience fluctuated between rose and marker pen, presumably because of adaptation in the brain: as central neurons tired of one odour, their response to the other became more dominant and back again. The researchers also showed that adaptation occurs in the nose: swapping the bottles of odour around from one nostril to the other reinstated participants' experience of a given smell after it had previously faded through continuous sniffing.

Via British Psychological Society Research Digest.

Image courtesy Flickr user bazusa, via CC.

Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.

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oxrs

I know this doesn’t have much to do with scent, but how would one scientifically test binocular rivalry? I can show two different images, one each, to each of my eyes, ensuring that neither can see what the other does, and I still see both images at the same time. I’ve never experienced this random switching that has been described and nobody can really show me what they see in this way.

I wouldn’t know how to test smells without precise latex nasal dividers and small amounts of concentrated cents… And that just sounds like more effort than my personal curiosity is worth right at this moment.
Teller

That scientific stuff is great! I used to lay on the floor and look at my dog exactly in this manner so he could smell the hamburger I had the week before. Actually, I don’t what they’re talking about, but I love that photo.
Anonymous

I don’t understand how this is new. Our minds work the same way when dealing with vision, audio, and even tactile sensations(put one hand in cold water and the other in hot). Why couldn’t we just assume that smells wouldn’t be similar.
MadMolecule

@Teller: Yeah, I didn’t get past the dog photo either.
octopod

bless the wikipedia. that http://en.wikipedia.org/wiki/File:Nasal_Ranger.JPG exists is awesome.