Washington: In the seconds before you "stop and smell the roses", your brain is possibly preparing your olfactory system for that familiar floral smell.

New research from Northwestern University offers strong evidence that the brain sets up a mental expectation of a scent before it hits your nostrils.

This kind of a predictive coding is important because it provides animals, in this case humans, with a behavioural advantage -- they can react more quickly and more accurately to stimuli in the vicinity, the journal Neuron reports.

"If somebody hands you a bottle of milk and asks, 'Is this milk rotten?' there may not be any visual clues to help you accurately determine if the milk has spoiled, so you rely on your sense of smell," said

Christina Zelano, who led the study, according to a Northwestern statement.

"Our study indicated that if your brain can successfully form a template of a rotten milk smell, then you would more accurately determine whether that milk is rotten and therefore you are less likely to get sick. These predictive templates can give us an important advantage," Zelano added.

Researchers used functional MRI techniques and cutting-edge procedures to identify the existence of predictive coding in the olfactory cortex of the brain, where the sense of smell is housed.