How humans track smells

UC Berkeley researchers report that humans can determine where a smell is coming using just our noses. In Berkeley study study, subjects were presented with essence or rose, cloves, and also odorants that smell like vinegar and banana. Brain scans revealed that the right and left nostrils are tied to separate regions of the primary olfactory cortext. As a result, the brain can locate a smell similarly to the way we localize sound based on input from two ears. From the press release:

"It has been very controversial whether humans can do egocentric localization, that is, keep their head motionless and say where the spatial source of an odor is," said study coauthor Noam Sobel, associate professor of psychology at UC Berkeley and a member of the campus's Helen Wills Neuroscience Institute. "It seems that we have this ability and that, with practice, you could become really good at it."

In future experiments, UC Berkeley biophysics graduate student Jess Porter and Sobel plan to train volunteers to track odors in the field and test the limits of odor localization in humans.

Porter, Sobel and their colleagues reported the results in the August 18 issue of the journal Neuron.

In a review appearing in the same issue of the journal, Jay A. Gottfried of the Department of Neurology at Northwestern University's Feinberg School of Medicine noted that the UC Berkeley findings open numerous avenues for further research. "Finally, what are the implications for the Provençal truffle hunt?" he wrote, only partly tongue-in-cheek. "In the traditional world of the truffle forests, the dog (or pig) is king. The evidence presented here suggests that humans are every bit as well equipped to carry out the search."