Friday, May 30, 2008

Science Friday

Good morning! Today's "Science Friday" subject is smell - one of my favorite senses. I will now attempt to bombard you with a bunch of interesting facts about smell and scents, most of which you probably didn't know. Because learning new stuff is fun!

Here goes: Humans have more receptors dedicated to smell than to any other sense except vision, with around 20 million smell receptors. For comparison, a rabbit has 100 million of these olfactory receptors, and a dog 220 million.

The average person can detect more than 10,000 different smells.

Smell plays a powerful role in sexual attraction and genetic diversity. In studies, women prefer the body odor of men whose genes are noticeably different from their own. Well, unless they are on the Pill. The Pill works by hormonally mimicking pregnancy, and scientists say pregnant women may be biologically predisposed to prefer the company and smell of family members.

Scent favorites differ by country and culture. Many Asian countries find the odor of cheese obnoxious, while in Britain the smell of wintergreen is considered off-putting.

Vanilla is thought to be the most universally beloved scent, probably because breast milk contains a similar flavor.

Losing the ability to smell is a condition called anosmia, which can lead to depression. It works both ways, because depression can hamper one's sense of smell too. However, sometimes people who are taking anti-depressant medications find that their sense of smell returns.

On the most fertile days of a woman's menstrual cycle, women have better sense of smell than men. At other times, men and women are equal. But during a woman's period, the ability to distinguish scent is often much worse.

Our sense of smell shuts down while we are asleep.

As you grow older, your sense of smell diminishes. Our smelling ability increases to reach a plateau at about the age of eight, and declines in old age. Some researchers claim that our smell-sensitivity begins to deteriorate long before old age, perhaps even from the early 20s.

Newborn babies and their mothers recognize each other by their scent.

Scent, emotions, and long term memory are directly connected due to the olfactory system's close anatomical ties to the limbic system and hippocampus, areas of the brain that have long been known to be involved in emotion and place memory, respectively.

The human nose is in fact the main organ of taste as well as smell. The so-called taste-buds on our tongues can only distinguish four qualities – sweet, sour, bitter and salt -all other ‘tastes’ are detected by the olfactory receptors high up in our nasal passages.

Lots more information here at The Smell Report. Have a great weekend -