How one nostril differs from the other
A study of the intracranial electroencephalogram has revealed that each nostril has its own unique sense of smell.Collaborators from the University of Pennsylvania in Philadelphia and the Barrow Neurological Institute in Phoenix studied the neural processes that underlie odor processing in the human olfactory system and how the brain processes information from different nostrils. The results of the study are published in the journal Current Biology.
Ten subjects participated in the study. They were placed multiple electrodes. The subjects had to identify each of the odors and indicate which nostril picked them up.
During the experiments, the scientists found that odor identity can be deciphered from oscillations in the piriform cortex region of the brain using neural activity recorded using an intracranial electroencephalogram.
The researchers observed that a separate interpretation of the odor occurs through each nostril. Stimulating any nostril with a similar odor elicited similar but still distinct representations during their encoding. This suggests that although each nostril can identify an individual odor as the same, there are subtle differences in how they perceive it.
Studying these processes is necessary for a deeper understanding of how people perceive and identify odors, and may have broader implications for sensory neurobiology and cognitive science.