Human Sense of Smell Rivals That of Dogs, Says Study (theguardian.com)

One scientific analysis is arguing that the human sense of smell has not only been underestimated over the years, but that it may rival that of dogs and rodents. John McGann, a neuroscientist at Rutgers University in New Jersey and the paper's author, said: "For so long people failed to stop and question this claim, even people who study the sense of smell for a living. The fact is the sense of smell is just as good in humans as in other mammals, like rodents and dogs." McGann has reached this unexpected conclusion after spending 14 years studying the olfactory system. The Guardian reports: McGann identifies a 19th century brain surgeon, Paul Broca, as the primary culprit for introducing the notion of inferior human olfaction into the scientific literature. Broca noted that the olfactory bulb -- the brain region that processes odor detection -- is smaller, relative to total brain volume, in people compared with dogs or rats. The discovery inspired Freud's belief that human sexual repression may be linked to our "usually atrophied" sense of smell. In the latest paper, published in Science, McGann points out that in absolute terms the human olfactory bulb is bigger than in many mammals and a literature search revealed that the absolute number olfactory neurons is remarkably consistent across mammals. McGann goes on to deconstruct other metrics that have been used to support the idea that human smelling abilities are limited. Humans have approximately 1,000 odor receptor genes, for instance, compared to 1,100 in mice, which some had taken as confirmation of mouse superiority. However, other work suggests there is not a tight relationship between the number of olfactory genes and smelling ability. One study found that cows have 2,000 such genes - far more than dogs.

Comments

Drug dogs debunked. Doesn't pass the sniff test

[raymorris]

Talking about the number of genes is a bit silly, agreed. If you want to compare the two, compare them directly. There are humans and dogs trained in smelling things (in the fragrance industry, for example). Run a direct comparison test. Also of course you could directly test having untrained humans and dogs smell for food and other items.

DRUG dogs, specifically, have not fared well in blind in blind tests. While *some* dogs are probably quite good, in testing the typical police dog consistently "alerts" on wherever the handler thinks the drugs are. Tests have been done in which the drugs are in box #1, nothing is in box #2, and the police handler is *told* the drugs are in box #3. A police dog is more likely to alert on #3, where the cop thinks the drugs are, then box #1, where the drugs actually are.

Tigers cannot smell much either

[aberglas]

According to Jim Corbet, 1930s Tiger hunter with a national park named after him (seriously -- he really understood wild tigers).

In his book Corbet warned any readers that wish take up the sport of hunting tigers on foot through thick jungle that tigers do not realize that humans cannot smell. So if you are walking downwind you will be safe from an attack from behind. However, walking upwind can be extremely dangerous if there is a man eater nearby.

Information that I am sure Slash Dot readers will find very useful.

Re:I'm calling horse hockey

[BarbaraHudson]

You thought wrong. Dogs and humans can both smell your stink. The Viet Cong could smell Americans by their soap or tobacco, same as most wild animals can. And a non-smoker can smell the stench of a smoker, even if they haven't smoked all day.