Right nostrils provide clues to brain illnesses

People's right nostrils are better at evaluating strange new smells, whether they are pleasant or unpleasant, say Swedish scientists.

People's right nostrils are better at evaluating strange new smells, whether they are pleasant or unpleasant, say Swedish scientists.

While familiar smells appear to be sniffed equally by both nostrils, it is the right that takes the lead when the nose is challenged by a new odour.

The research has implications for the diagnosis of neurological disorders because it suggests that only one side of the brain is involved in processing unfamiliar smells.

By testing patients' reactions to different scents, doctors might be able to diagnose which side of the brain has a problem, the researchers said in "Right Nostril Domination in Discrimination of Unfamiliar Odours", a report in Chemical Senses, a journal published by Oxford University Press.

Brains scans have confirmed that the right cerebral hemisphere is active when smells are being analysed. One theory is that familiar smells can be verbally described more easily and can therefore be more quickly processed by the language and other areas of the left side of the brain.