People track scents in same way as dogs
Human reputation for poor sense of smell is down to lack of practice.
If you think only hounds can track a scent trail, think again: people can follow their noses too, a new study says. And they do so in a way very similar to dogs, suggesting we're not so bad at detecting smells — we're just out of practice.
Read the story here.

Comments
It makes sense that two nostrils are better than one, but not because of stereo olfaction. That would require lateralization and humans can only lateralize when there is a trigeminal component. Chocolate shouldn't deliver trigeminal unless very, very strong.
Posted by: Gary Woodward | December 18, 2006 11:54 PM
About 10 years ago I was facing major intestinal surgery which required that I not intake anything other than clear liquids for 5 days prior to the operation. The recovery was difficult and could not eat anything for several days afterwards. The sensation of starvation was upon me and for a time I became a bit delirious. The most unforgettable aspect of the experience was that my sense of smell was elevated to an extremely acute level. On the drive home from the hospital I had the window of the car rolled down and I was picking up a flood of scents. I could smell a cigarette being smoked from a half-block away for instance. Odors jumped out at me like vivid colors on a '60's black-light poster. It was weird and mysterious and fully illustrated to me that humans are definitely not fully utilizing our capabilities in this area. These researchers should study the effects of food deprivation on olfactory function.
Posted by: Bob Selzler | December 20, 2006 07:10 AM
this reminds me of a prank we busted on a friend who fell asleep a few years back in college: we got a tooth pick and smeared a small amount of feces inside his nostril. when he woke up the next day he kept complaining he could smell shit and kept looking at his shoes thinking he had stood in something. however after a few hours he stopped complaining about it and said he couldn't smell it any more.
we all had a good laugh, but the point im making is this: can your nose become immune to a smell after a while of constant exposure to it?
Posted by: marty k | December 20, 2006 08:13 PM