Navigation Links
The smell of white
Date:11/26/2012

You can see the color white; you can hear white noise. Now, Weizmann Institute researchers show that you can also smell a white odor. Their research findings appear today in the Proceedings of the National Academy of Sciences (PNAS).

The white we see is actually a mixture of light waves of different wavelengths. In a similar manner, the hum we call white noise is made of a combination of assorted sound frequencies. In either case, to be perceived as white, a stimulus must meet two conditions: The mix that produces them must span the range of our perception; and each component must be present at the exact same intensity. Could both of these conditions be met with odors, so as to produce a white smell? That question has remained unanswered, until now, in part due to such technical difficulties as getting the intensities of all the scents to be identical.

A research team in the Neurobiology Department, led by research student Tali Weiss and Dr. Kobi Snitz, both in the group of Prof. Noam Sobel, decided to take up the challenge. They began with 86 different pure scents (each made of a single type of odor molecule) spanning the entire "smell map," diluted them to obtain similar intensities and then created blends. Each blend contained a different mixture of odors from various parts of the smell map. These blends were then presented in pairs to volunteers, who were asked to compare the two scent-blends.

The team discovered that the more odors that were blended together in the paired mixtures, the more the subjects tended to rate them as similar even though the two shared no common components. Blends that each contained 30 different odors or more were thought to be almost identical.

The researchers then created a number of such odor blends, giving them a nonsense name: Laurax. Once the subjects were exposed to one of the Laurax mixes and became accustomed to the smell, they were exposed to new blends mixtures they had not previously smelled. They also called some of these new blends "Laurax," but only if those contained 30 or more odors and these encompassed the range of possible smells. In contrast, mixtures made of 20 scents or fewer were not referred to as Laurax. In other words, Laurax was a white smell. In a follow-up experiment, volunteers described it as being neutral not pleasant, but not unpleasant.

"On the one hand," says Sobel, "The findings expand the concept of 'white' beyond the familiar sight and sound. On the other, they touch on the most basic principles underlying our sense of smell, and these raise some issues with the conventional wisdom on the subject." The most widely accepted view, for instance, describes the sense of smell as a sort of machine that detects odor molecules. But the Weizmann study implies that our smell systems perceive whole scents, rather than the individual odors they comprise.


'/>"/>

Contact: Yivsam Azgad
news@weizmann.ac.il
972-893-43856
Weizmann Institute of Science
Source:Eurekalert

Related biology news :

1. Smell and taste experts to discuss new discoveries
2. A trained palate: Understanding complexities of taste, smell could lead to improved diet
3. Mosquitoes -- how we smell is why they bite, research shows
4. Mice have distinct subsystem to handle smell associated with fear
5. Smell the potassium
6. Cant smell anything? This discovery may give you hope
7. NIH-funded researchers restore sense of smell in mice using genetic technique
8. The birdy smell of a compatible partner
9. The nose knows: Gene therapy restores sense of smell in mice
10. Psychopaths have an impaired sense of smell
11. Ah, that new car smell: NASA technology protects spacecraft from outgassed molecular contaminants
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/22/2016)... 20, 2016  As part of its longstanding mission to ... genetics company, recently released its latest children,s book, titled ... focuses on the topics of inheritance and variation of traits ... taught in elementary school classrooms in the US. ... illustrator Ariana Killoran , whose previous book with 23andMe, ...
(Date:12/16/2016)... MIAMI , Dec. 16, 2016   ... intuitive Identity management products and solutions and a ... announced today that it is offering seamless, integrated ... Edam security entrance products. The solutions provide IdentyTech,s ... to secure their facilities from crime and theft. ...
(Date:12/15/2016)... DUBLIN , Dec 15, 2016 ... Research and Markets has announced ... to their offering. The report forecasts the global military ... 2016-2020. The report has been prepared based on an ... market landscape and its growth prospects over the coming years. The report ...
Breaking Biology News(10 mins):
(Date:1/12/2017)... ... 2017 , ... Huffman Engineering, Inc. , a leader in control systems ... company’s Lincoln office as a chemical engineer. In his new role, Beck will ... the life science manufacturing and water/wastewater industries. , Prior to joining Huffman Engineering, Beck ...
(Date:1/12/2017)... , January 12, 2017 ... the world,s biggest facility for producing mycorrhizae. The Centre ... nutrient tapping potential of mycorrhizae and developed a technology ... ... http://mma.prnewswire.com/media/456932/PRNE_TERI_Logo.jpg) The TERI facility has ...
(Date:1/12/2017)... January 12, 2017 A new report published by Allied Market ... Global Opportunity Analysis and Industry Forecast, 2014-2022," projects that the global in vitro toxicity ... at a CAGR of 15.07% during the forecast period. ... ... ...
(Date:1/12/2017)... ... January 12, 2017 , ... ... enhanced the platform to accommodate increasingly complex and sophisticated deployments, resulting in ... more. In addition to these improvements, the latest release brings enhanced data ...
Breaking Biology Technology: