Sniffing out dangerMarch 28, 2008CHICAGO -- Each human nose encounters hundreds of thousands of scents in its daily travels perched front and center on our face. Some of these smells are nearly identical, so how do we learn to tell the critical ones apart? Something bad has to happen. Then the nose becomes a very quick learner. New research from Northwestern University's Feinberg School of Medicine shows a single negative experience linked to an odor rapidly teaches us to identify that odor and discriminate it from similar ones. "It's evolutionary," said Wen Li, lead author of the study and a postdoctoral fellow at the Cognitive Neurology and Alzheimer's Disease Center at the Feinberg School. "This helps us to have a very sensitive ability to detect something that is important to our survival from an ocean of environmental information. It warns us that it's dangerous and we have to pay attention to it." The study will be published March 28 in the journal Science. In the study, subjects were exposed to a pair of grassy smells which were nearly identical in their chemical makeup and perceptually indistinguishable. The subjects received an electrical shock when they were exposed to one scent, but not when they were exposed to the other similar one. After being shocked, the subjects learned to discriminate between the two similar smells. This illustrates the tremendous power of the human sense of smell to learn from emotional experience. Odors that once were impossible to tell apart became easy to identify when followed by an aversive event. Li and her colleagues also found specific changes in how odor information is stored in "primitive" olfactory regions of the brain, enhancing perceptual sensitivity for smells that have a high biological relevance. Northwestern University |
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| Related Smell Current Events and Smell News Articles Telling an old book by its smell: Aroma hints at ways of preserving treasured documents Scientists may not be able to tell a good book by its cover, but they now can tell the condition of an old book by its odor. In a report published in the American Chemical Society's Analytical Chemistry, a semi-monthly journal, they describe development of a new test that can measure the degradation of old books and precious historical documents on the basis of their aroma. Weizmann Institute scientists reveal how some aromas are bound up in our memories From Proust's Madeleines to the overbearing food critic in the movie Ratatouille who's transported back to his childhood at the aroma of stew, artists have long been aware that some odors can spontaneously evoke strong memories. Research: Migraine and cardiovascular disease: Systematic review and meta-analysis Migraine with aura (temporary visual or sensory disturbances before or during a migraine headache) is associated with a twofold increased risk of stroke, finds a study published on bmj.com today. UC Davis researchers identify dominant chemical that attracts mosquitoes to humans Scientists at the University of California, Davis, have identified the dominant odor naturally produced in humans and birds that attracts the blood-feeding Culex mosquitoes, which transmit West Nile virus and other life-threatening diseases. Cleanliness IS next to godliness: new research shows clean smells unconsciously promote moral behavior People are unconsciously fairer and more generous when they are in clean-smelling environments, according to a soon-to-be published study led by a Brigham Young University professor. Happy flies look for a place like home A happy youth can influence where a fruit fly chooses to live as an adult, according to new research in the American Naturalist. The study, led by Judy Stamps from the University of California at Davis, provides new insight into how animals choose places to live and raise their young. Study examines treatment for olfactory loss after viral infection Treatment with a glucocorticoid medication, either alone or in combination with Ginkgo biloba, appears to significantly improve the sense of smell in individuals with previous olfactory loss due to upper respiratory infections. Tracking down the human 'odorprint' Each of the 6.7 billion people on Earth has a signature body odor - the chemical counterpart to fingerprints - and scientists are tracking down those odiferous arches, loops, and whorls in the "human odorprint" for purposes ranging from disease diagnosis to crime prevention. How the 100th protein structure solved at Diamond impacts our understanding of how insects smell New research announced today, Wednesday 30th September, by a team of leading scientists working with the UK's national Synchrotron, Diamond Light Source, could have a significant impact on the development and refinement of new eco-friendly pest control methods for worldwide agriculture. Orgasms, sexual health and attitudes about female genitals An Indiana University study published in the September issue of the International Journal of Sexual Health found that women who feel more positively about women's genitals find it easier to orgasm and are more likely to engage in sexual health promoting behaviors, such as having regular gynecological exams or performing vulvar self-examinations. More Smell Current Events and Smell News Articles |
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