It would be wonderful to have the ability to perceive danger lurking just around the corner and leave at the right time, which goes beyond being able to smell gas leaks or burnt foods. It seems nature has already gifted us with that strong kind of smell, but we have taken it for granted all this time. In an interesting study by a Swedish institute, researchers found that we can literally smell danger!
The research conducted at Sweden’s Karolinska Institute has suggested that the nerve cells located around the nose can alert the brain within milliseconds when something smells fishy. Study participants were divided into two groups of no-smoking individuals. The first group was asked to smell the perfume of linalool or fruity-smelling ethyl butyrate, then diethyl disulfide which has a garlicky scent, and their brain waves were analyzed. Gamma waves are formed when attention and memory are highly processed. Beta waves are produced when decisions and deliberations are being made.
In the second group of 21 volunteers, unpleasant and pleasant odors were smelt, and their physical reactions were monitored. Scientists noticed that the brain viewed an unpleasant smell as a threat and sent a signal to the motor cortex, causing the brain to take action within 150 milliseconds. The beta and Gamma waves ‘coordinated’ to send a warning signal to the brain. Among the reactions triggered by the signals are jerking the head away from the smell, stopping to breathe, and kindling.
The study published in the journal Proceedings of the National Academy of Sciences concluded that detection and the ability to react to scents are essential for survival for us and other mammals. Furthermore, the study notes that the olfactory organ occupies five percent of the human brain and was able to distinguish between millions of different smells. Most of them were associated with threats to survival. Signals triggered by odors reach the brain within 100 milliseconds of inhalation.