The human sense of smell may be better than previously thought, according to a paper in the January issue of Nature Neuroscience. Although humans are often reputed to have a poor sense of smell in comparison to that of other animals, the report shows that people have the ability to track scent trails on the ground.
Noam Sobel and colleagues laid down scent trails in a grassy field, and asked human subjects to find the trail and track it to the end. Subjects were blindfolded and wore thick gloves and earplugs to force them to rely exclusively on smell. The authors found, surprisingly, that the subjects were able to do the task. In addition, they exhibited some of the same tracking strategies observed in other animals, such as dogs.
In subsequent experiments, the authors demonstrated that this ability partially depends on comparisons of odor information in the two nostrils--when subjects have one nostril plugged, their tracking performance is much worse. Although the human subjects in these experiments were much slower at scent tracking than animals like dogs, people improved at scent tracking with time. This raises the intriguing possibility that the sense of smell in humans may be better than is typically believed, and that with training, humans might be capable of tasks previously believed to be the exclusive province of nonhuman animals.
Noam Sobel (University of California Berkeley, CA, USA)
Abstract available online.
(C) Nature Neuroscience press release.
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