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.