Sunday, 18 September 2005

Just a matter of Individual Taste

From the AFP via the ABC :
Taste is in the brain of the beholder and varies, sometimes dramatically, from one person to the next, according to one of the world's leading sensory neurobiologists.

"No two people will ever smell the same thing in the same way," Patrick MacLeod, the president of the Institute of Taste and former director of the sensory neurobiology laboratory at the Ecole Pratique des Hautes Etudes, said.

"When we perceive an odours, the exact nature of the sensation that is produced depends as much on the observer as the object."

Vision, hearing and tactile perception are far more uniform across the species, meaning that human beings see, hear and touch more or less the same things.

But when it comes to odours and taste, one man's wine-of-the-gods can be another man's plonk.

Mr MacLeod says this and other recent findings in sensory neurobiology up-end a lot of received wisdom and a fair amount of established science.

They also carry profound implications for a host of consumer-oriented industries ranging from food and wine to perfumes and household products.

The search for a taste or odours that will please everyone, if Mr MacLeod is right, would seem doomed from the start.

"Almost everything we have done up to now in the study of taste has been called into question. We have to start over," he said.

Several factors account for diversity in the human sense of smell.

The human genome contains 347 olfactory genes - fully 1 per cent of the total - while there are only four, for example, for vision.

At least half of those genes are polymorphous, meaning that "they have a great potential of variation among themselves," Mr MacLeod says.
Mr MacLeod's research is chock-full of counter-intuitive tidbits, beginning with the fact that homo sapiens do have an excellent sense of smell.

"The human sensory system for odours has attained maximum sensitivity," he said.

"A single molecule can provoke a response in a single cell that is then transmitted to the brain.

"As the molecule is the smallest unit possible, there can be no improvement."

Mr MacLeod has also shown that teeth provide the brain nearly half of the information it receives related to taste, and that the nose collects most of the rest - via the mouth.

The tongue is rather useless.
Oh, I don't know about that... I can think of several highly recreational uses for that particular part of the anatomy.

One of the first and most dramatic changes I noticed during my little metabolic odyssey to parts unknown (or at least, unexplored by me), was in my sense of smell.

Suddenly, quite literally overnight, the aromatherapy counter at the local supermarket became, if not exactly a place of pilgramage, a really nice place to be around. Before, I'd often walked past, and unless I noticed the sign saying "armoatherapy products", it might as well have contained cornflakes. Now though, I just have to stop, and gently appreciate it.

On the other hand, the cleaning aisle is best ventured through while wearing a gasmask. It really is that bad.

It was this more than anything else that made me realise that the changes that were happening were not just to my body, but to my brain. Like every other change, there was nothing I could do about it, I just had to accept it. Like every other change, it would have been nice to have had some control over it, or some say in the matter, and really quite terrifying that I didn't. But, like every other change, it was objectively an improvement, one I would have gladly chosen - had I been given the choice.

(Hat Tip - The Evil Pundit of Doom)

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