Our two nostrils don’t smell in the same way; they each have their own distinct olfactory function. Although it may go unnoticed, our nostrils differ not only in physical appearance but also in their functionality, as revealed by a recent study published in Current Biology. The research, conducted by scientists from the University of Pennsylvania, the Barrow Neurological Institute, and Ohio State University in the United States, involved 10 epileptic patients with electrodes implanted in their brains. These patients were exposed to three different scents, each blown into either one nostril or the other, or both simultaneously. The participants had to identify the odor while indicating which nostril they had used to perceive it. The responses were then compared with the data collected by the electrodes in their brains.
The results were particularly intriguing, showcasing the apparent independence of each nostril, especially when exposed separately to the same fragrance. In such cases, the resulting brain activity was similar but not identical. This independence was confirmed when both nostrils were exposed simultaneously to the same scent, revealing a brief delay before the nostrils synchronized in response to the odor. Drawing on previous studies, including those on rats capable of stereo smelling, the scientists suggest that this difference between the nostrils allows for quicker odor identification. In essence, while having one nostril is good, having two is even better. The separation of smells between the nostrils occurs in the cerebral region known as the piriform cortex, where the sense of smell is processed and interpreted. Although the study’s participant pool is limited, the findings are promising, opening the door to further exploration of our understanding of the human sense of smell.
