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Bad smells can give you nightmares

By Mark Leyner and Dr. Billy Goldberg

Attention all campers! You no longer have to bother dipping your bunkmate's hand in warm water in an attempt to make him pee in the bed. If you want to know how to terrorize that kid who picked on you on the kickball field, all you have to do is get inside his dreams. Through his nose.

German researchers have found that sleepers exposed to an unpleasant smell will have negative dreams. The opposite is also true. When subjects were exposed to the smell of roses, their dreams were predominantly positive. These olfactory observers used rotten eggs in their study, but we are sure that a stinky gym sock, left perched on the pillow of your enemy, would work just as well. While we're fairly certain that the researchers didn't plan to have their findings used in this manner, there are always unintended (and sometimes dastardly) consequences of scientific breakthroughs.

Image: Body Odd

Because our sense of smell involves such a sensitive and neurologically complex function, and because it's so powerful in its influence on our behavior, it's not surprising at all that so many scientists have studied the effect of different scents on emotion, memory, appetite, energy, and sexual arousal. The sense of smell is known to be closely linked to the same area of the brain which handles memory and behavior, which is why a familiar scent can trigger a vivid memory or feeling about the first time you got a whiff of it. Scientists have also found that our sense of smell intensifies when we sense a dangerous smell — such as a fire — sparking our brain's fight-or-flight response.

It certainly seems logical that there would be a strong connection between smell and stimulation, but you might be shocked to find out what the most sexually "intoxicating" fragrances actually are.

To test the effect a scent has on arousal, Dr. Alan Hirsch, a nationally recognized smell and taste expert and the founder of the Smell & Taste Treatment and Research Foundation in Chicago, chose 30 pleasant odors and hypothesized that these enticing scents would stimulate more than just the nose. He measured penile blood flow while exposing men whose eyes were covered to various scents. The winner, by a nose, was lavender and pumpkin pie, with a 40 percent average increase in blood flow to the penis. The smell of doughnuts and black licorice came in a close second with a 31.5 percent increase in penile blood flow  Cranberry finished dead last, so you may want to leave that off the seduction menu.

Hirsch also studied the effect of odors on women and measured their sexual response. The winners: the combo of Good & Plenty candy and cucumber with a 13 percent increase in vaginal blood flow. Baby powder tied with a lucky 13 percent boost. Pumpkin pie and lavender also seemed to stimulate the ladies, coming in second at 11 percent.

Now, you're probably ready to radically alter your choice of cologne and aftershave, right?  After all, who needs Chanel No. 5 or Boucheron pour Homme, when it's apparently so much more provocative to slather a hunk of pumpkin pie across your neck or daub a melting Twizzler behind your ears? 

It's said that humans are able to distinguish over 10,000 different odor molecules. We do this by simply breathing in. That whiff of air goes up the nostrils and makes its way to the roof of the nasal cavity where it hits a tiny area called the olfactory epithelium. The olfactory epithelium contains millions of olfactory receptor neurons.  On the surface of these neurons are odorant receptors that pass the smell information to the olfactory bulb (just underneath the front of your brain) and then on to the olfactory cortex in the temporal lobe of your brain.

Confused? Well, so are scientists. You see, humans have only about 400 odorant receptors on the surface of those sensory neurons. The otherwise humble mouse has approximately 1,200! Yet we olfactorily challenged humans can still detect thousands of odors.

Because the power of human sense of smell is so greatly underrated, the great and profound enigmas of scratching-and-sniffing remain to be solved.