What's that you're smelling? Nostril rivalry decides

The title of this article begins with "NOSTRIL RIVALRY," which is intriguing enough, since I'd heard about ocular and two-ear rivalry (both of which this article in Science News explains briefly).

Essentially, when the nostrils take conflicting whiffs of scents, the brain decides which one you will smell.

In an experiment, 12 volunteers were exposed to

two different scents, one in each nostril. One nostril was connected by a tube to a bottle of phenylethyl alcohol, which smells like rose petals. The other was connected to a bottle of n-butanol, which pongs of marker pen. During each whiff, the volunteers breathed in both scents.

Volunteers indicated whether they smelled rose, scented marker, neither or a combination. After each volunteer's 20 trials, spaced out to keep the noses sharp, the researchers found that smell perception alternated, more or less, between rose and markers.

I think it's cool that the smell perception alternated for rose and marker smell, neither of which is really all that bad. Wonder how much alternation there would be if one smell was gross and the other was pleasant? I wonder if the brain would seek to protect us by blocking out the yukky smell in favor of the pleasant one? Most likely there will be further studies to find out!