American scientists examined the neural processes of odor processing in the human olfactory system and how the brain processes odor information from different nostrils. They found that each of the two nostrils has its own unique sense of smell. The research team noted that this study is crucial for a deeper understanding of how humans perceive and identify odors, and may have broader implications for sensory neuroscience and cognitive science. The relevant paper was published in the latest issue of the journal Current Biology.
The study, conducted by researchers at the University of Pennsylvania in Philadelphia and the Barrow Neurological Institute in Phoenix, asked 10 subjects who had intracranial electrodes implanted to perform an odor identification task. The odors were delivered to the subjects through an olfactory device. of the left nostril, right nostril, or both nostrils. The olfactory device delivers scent via computer control. Subjects had to identify the odor and indicate which nostril the odor came from.
The research team pointed out that compared with the single-nostril condition, subjects performed better in detecting and identifying odors in the dual-nostril condition, but there was no significant efficiency difference between the left nostril and the right nostril.
Researchers were able to decode odor signatures from oscillations in the piriform cortex brain region using neural activity recorded with intracranial electroencephalography. The results showed that odor features were encoded at different times in the dual-nostril condition, suggesting that each nostril interprets the odor in its own way.
Furthermore, the team stimulated either nostril with the same odor and found that different nostrils produced similar but distinguishable performances in encoding these odors. This suggests that while each nostril recognizes the same odor, there are subtle differences in how they perceive it.
(The original title is "Each nostril has a unique sense of smell")