Human nose can detect trillion odors

U.S. researchers claim that, contrary to common perception that we are able to distinguish 10,000 different smells - our sense of smell is far more developed and able to distinguish between trillion (thousand billion) different smells - well over 10,000 smells scientists assumed so far that we can detect. The study was published in the journal Science.
How do they check it?

For several decades it was stated in the scientific literature that the human nose can detect approximately 10,000 odors, "says Leslie washell from the  Rockefeller University in New York, co-author of the study." This number was agreed among the experts, but our analysis shows that our ability to detect different smells is much more advanced from that.

washell claim that it was surprising until now that our sense of smell was relatively limited compared to the other senses ,which are advanced much more : the human eye can distinguish up to ten million colors and the ear detects 340,000 tones , for example - and despite the 400 smell sensors that exists in our body, it seemed we identify only ten thousand fragrances . " So far, researchers tested our visual abilities and auditory - but not the smelling potential".

Study involved 26 people who received many mixtures of different fragrances based on 128 different chemicals , herbs , citrus and more. The researchers did not want the fragrances be identified easily , and most mixtures were "odd" , as defined , and included 30 different fragrances.
Subjects smelled every time three compounds - two identical and one different - and asked to identify the unusual compound . They completed a total of 264 such comparisons .
On the basis of these results , the researchers hypothesized how many scents participants were able to identify if they were given all the possible compounds from the 128 basic scents - and reached one trillion odors.


According to the researchers , even this number may be lower then the real figure , because in the real world - outside the research lab - you can create endless combinations of scents.

Our ancestors used a lot more the sense of smell ,says the researchers, and the development of hygiene in the modern world certainly restricts our nose , so we attribute it to feel less important from the Sense of sight or hearing.

However, our sense of smell is closely related to human behavior and the results of the present study may help us understand how our brain processes complex information.