Wine Fans Take Heart: Smells Differ in Nose, Mouth

[KMP]

A piece in All Things Considered by Jon Hamilton (NPR or National Public Radio) talks about new research showing that the brain perceives an odor differently if it arrives through the nose (orthonasal) rather than through the mouth (retronasal). The work is described in an article in the journal Neuron where the authors conclude “The main finding of this experiment is that the same odor may produce differential brain responses depending on whether it is sensed orthonasally and experienced as coming from the nose or retronasally and experienced as coming from the back of the mouth.” (Differential Neural Responses Evoked by Orthonasal versus Retronasal Odorant Perception in Humans. Small DM, Gerber JC, Mak YE, Hummel T. Neuron. 2005, 47:593-605.)

Short review of the concept.

The most fascinating aspect of the study was that the odor of chocolate showed the greatest effect on route of delivery. This suggests that differences in “response to retronasal versus orthonasal perception is influenced by whether an odor represents a food item”. The interpretation is that sensing of odor orthonasally may help indicate the availability of food while retronasal identification may signify receipt of food. However its early days yet because the study only used one food odor (chocolate) compared to three none food odors (lavender, butanol, farnesol). More food odors need to be studied to see if they give the same result as the chocolate odor.

One interesting point from the NPR audio piece is that if you want to increase your ability to detect non-food odors retronasally then you need to ingest something with that odor. Anyone for a drop of cat pee on their tongue?

Mike

[Glen G]

Hi Mike

Very interesting stuff indeed, but on the basics of it, you would think this would be the case anyway.

The one main issue I have of such an experiment is that once the substance is in the mouth, you cannot then interpret it in isolation (as you can orthonasally) ie: the brain is also interpreting other data such as tactility, so it makes for an almost impossible comparison.

Regards
Glen

[TORB]

new research showing that the brain perceives an odor differently if it arrives through the nose (orthonasal) rather than through the mouth (retronasal).

Mike,

Fask....kinating This explains the difference between a case of bad breath and a fart.

[GrahamB]

new research showing that the brain perceives an odor differently if it arrives through the nose (orthonasal) rather than through the mouth (retronasal).

Mike,

Fask....kinating This explains the difference between a case of bad breath and a fart.

CLASSIC Ric!!!!!!!!!!!!!

[KMP]

Hi Mike

Very interesting stuff indeed, but on the basics of it, you would think this would be the case anyway.

The one main issue I have of such an experiment is that once the substance is in the mouth, you cannot then interpret it in isolation (as you can orthonasally) ie: the brain is also interpreting other data such as tactility, so it makes for an almost impossible comparison.

Regards
Glen

Glen

The way the study was done was to deliver the odors via tubes so the retronasal did not involve contact with the tongue or mouth. I have an image up on Shiraz which shows the placement of the cannulae.

Of course for assessing odors in wine you are correct in that the issue is more complicated because retronasal odors are detected after the wine has been in the mouth. But its very early days for this type of analysis and whether it will ever be applied to sensory evaluation of wine is questionable. The point is, farts and bad breath aside, that some very sophisticated and expensive research (in this case MRI) is being done to understand odor detection. That can only help us understand why we detect certain odors in wine, why some people seem to be better than others at it, and why analysis of an individual wine can result in big differences in the description of odors among wine drinkers.

Mike