Navigation Links
Sweet smell
Date:9/18/2007

What makes one smell pleasant and another odious? Is there something in the chemistry of a substance that can serve to predict how we will perceive its smell? Scientists at the Weizmann Institute of Science and the University of California at Berkeley have now discovered that there is, indeed, such a link, and knowing the molecular structure of a substance can help predict whether we will find its smell heavenly or malodorous.

In sight and hearing, for instance, our perceptions are determined by the physical properties of waves the length of light waves in sight, and the frequency of sound waves in hearing. But until now, there was no known physical factor that could explain how our brains sense odors. The new study, conducted by Prof. Noam Sobel of the Institutes Neurobiology Department and his colleagues, represents a first step in understanding the physical laws that underlie our perception of smell. Their results appeared last week in the Journal of Neuroscience.

To identify the general principles by which our sense of smell is organized, the researchers began with a database of 160 different odors that had been ranked by 150 perfume and smell experts according to a set of 146 characteristics (sweetish, smoky, musty, etc.). These data were then analyzed with a statistical program that analyzed the variance in perception among the smell experts. The scientists found that the data fell along an axis that describes the 'pleasantness rating' of the odors running from 'sweet' and 'flowery' at one end to 'rancid' and 'sickening' at the other. The same distribution along this axis, they discovered to their surprise, closely describes the variation in chemical and physical properties from one substance to another. From this, the researchers found they could build a model to predict, from the molecular structure of a substance, how pleasing its smell would be perceived.

To double check their model, Sobel and his team tested how experimental subjects assessed 50 odors they had never smelled before for pleasantness. They found that the ratings of their test subjects fit closely with the ranking shown by their model. In other words, they were able to predict the level of pleasantness quite well, even for unfamiliar smells. They noted that, although preferences for smells are commonly supposed to be culturally learned, their study showed that the responses of American subjects, Jewish Israelis and Muslim-Arab Israelis all fit the models predictions to the same extent. Sobel: 'Our findings show that the way we perceive smells is at least partially hard-wired in the brain. Although there is a certain amount of flexibility, and our life experience certainly influences our perception of smell, a large part of our sense of whether an odor is pleasant or unpleasant is due to a real order in the physical world. Thus, we can now use chemistry to predict the perception of the smells of new substances.'


'/>"/>

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

Related biology news :

1. Bad aftertaste? New sensory on/off switch may cure bane of artificial sweetener search
2. A sweet solution for Alzheimers disease?
3. Bitter or sweet? The same taste bud can tell the difference
4. UW-Madison scientists zero in on drugs sweet spots
5. Sweetgum tree could help lessen shortage of bird flu drug
6. Sweet water taste paradoxically predicts sweet taste inhibitors
7. Scientists seek to unwrap the sweet mystery of the sugar coat on bacteria
8. Healing honey: The sweet evidence revealed
9. Attacking cancers sweet tooth is effective strategy against tumors
10. Uncovering DNAs sweet secret
11. A sweet step toward new cancer therapies
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/26/2016)... and LONDON , April 26, ... of EdgeVerve Systems, a product subsidiary of Infosys ... announced a partnership to integrate the Onegini mobile ...      (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) ... customers enhanced security to access and transact across ...
(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:4/15/2016)... Research and Markets has announced ... 2016-2020,"  report to their offering.  , ... global gait biometrics market is expected to grow ... 2016-2020. Gait analysis generates multiple variables ... to compute factors that are not or cannot ...
Breaking Biology News(10 mins):
(Date:5/26/2016)... , ... May 26, 2016 , ... ... company, today announced several positive developments that position the Company for the future. ... of the transaction, Craig F. Kinghorn has been appointed Chairman of the Board, ...
(Date:5/25/2016)... ... May 25, 2016 , ... Founder ... double board-certified in surgery and surgery of the hand by the National Board ... stranger to going above and beyond in his pursuit of providing the most ...
(Date:5/25/2016)... ... May 25, 2016 , ... Biohaven Pharmaceutical Holding ... has granted the company’s orphan drug designation request covering BHV-4157 for the treatment ... by the FDA. , Spinocerebellar ataxia is a rare, debilitating neurodegenerative disorder ...
(Date:5/23/2016)... ... ... for blood donations in South Texas and across the nation is growing. , But according ... donations are on the decline. In fact, donations across the country are at their lowest ... in the last four years alone. , There is no substitute for blood. , “We ...
Breaking Biology Technology: