The Volatility Manifesto

originally posted by Oswaldo Costa:
originally posted by Bill Lundstrom:
i don't know, i always a felt the younger crowd (20's and 30's) identified with natural wine, no matter how volatile or bretty or mousey or whatever, as a way to distance themselves from the more stereotypical "wine snob" crowd. they seem kind of hell bent on convincing themselves and everyone else that cidery , volatile wine is real wine and us old guys don't know what we're missing.
i doubt it had anything to do with sour, sugary candy they enjoyed as kids.

And if you rail against v.a. you become an old fogey who just doesn't "get" natural wines.

As an old fogey, I don't get a lot of things!
 
originally posted by Josh Fontaine:
speaking of which :

Ainsi parle Alice Feiring

Yes, basically the same point O is making ('cept Omnivore needs to hire a copy editor).

And this seems to contain an odd non sequitur "Many are made to a style, murky, leesy and unfinished, one of the reason [sic] for the growing number of glaringly faulty wines, giving natural wine haters, like wine critic Michel Bettane, plenty of arrows for their target." We get the point, I think, except cloudy wines do not necessarily have bacterial flaws (though they might). And what "finishes" a wine? Filtration or settling? Still, that is not the cause.

However, sticking to VA, if you haven't tasted a wide range of classics (fra A til Å - the Norwegian equivalent of from A to Z) how do you even understand what is supposed to be a flaw? You think it is an integral component of natural wines. It ain't.
 
originally posted by mark e:
originally posted by Josh Fontaine:
speaking of which :

Ainsi parle Alice Feiring

Yes, basically the same point O is making ('cept Omnivore needs to hire a copy editor).

And this seems to contain an odd non sequitur "Many are made to a style, murky, leesy and unfinished, one of the reason [sic] for the growing number of glaringly faulty wines, giving natural wine haters, like wine critic Michel Bettane, plenty of arrows for their target." We get the point, I think, except cloudy wines do not necessarily have bacterial flaws (though they might). And what "finishes" a wine? Filtration or settling? Still, that is not the cause.

However, sticking to VA, if you haven't tasted a wide range of classics (fra A til Å - the Norwegian equivalent of from A to Z) how do you even understand what is supposed to be a flaw? You think it is an integral component of natural wines. It ain't.

Flatland comes to mind.
 
originally posted by MLipton:
VA is a lot like Brett: people’s sensitivities differ markedly and in low quantity both can be viewed as positive attributes. At low levels, a little VA can give a wine a “lifted” or “high toned” nose, which some tasters might find appealing.

Mark Lipton

Do we know this? This seems unlikely to me. If you mean sensitivity colloquially, as in people have different levels that they like/find objectionable, then yes. But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced. Everything I know about olfaction makes me think that while there is a lot of variability within individual sensitivity from day to day there isn't that much of a spectrum between individuals. What people like or don't like and also what they can name depends more on social factors than any difference in sensitivity at the physical level.
 
originally posted by mark e:
originally posted by Oswaldo Costa:
originally posted by Bill Lundstrom:
i don't know, i always a felt the younger crowd (20's and 30's) identified with natural wine, no matter how volatile or bretty or mousey or whatever, as a way to distance themselves from the more stereotypical "wine snob" crowd. they seem kind of hell bent on convincing themselves and everyone else that cidery , volatile wine is real wine and us old guys don't know what we're missing.
i doubt it had anything to do with sour, sugary candy they enjoyed as kids.

And if you rail against v.a. you become an old fogey who just doesn't "get" natural wines.

Yup. Especially where I live.

I don't deal with this much in my neck of the woods but it is also not a new phenomenon. I remember Arnaud refusing me a bottle of wine at 360 about 15 years ago. The first bottle was horribly flawed, he said I was wrong. I said bring out another and if they're the same, I'll pay for both. He refused and I got something else (probably Peyra, I often drank Peyra there). Now, there is no telling whether if he had brought out the other bottle of the flawed wine that it would have been any different. Endemic versus episodic flaws or something like that. I miss that place.
 
originally posted by VLM:
originally posted by MLipton:
VA is a lot like Brett: people’s sensitivities differ markedly and in low quantity both can be viewed as positive attributes. At low levels, a little VA can give a wine a “lifted” or “high toned” nose, which some tasters might find appealing.

Mark Lipton

Do we know this? This seems unlikely to me. If you mean sensitivity colloquially, as in people have different levels that they like/find objectionable, then yes. But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced. Everything I know about olfaction makes me think that while there is a lot of variability within individual sensitivity from day to day there isn't that much of a spectrum between individuals. What people like or don't like and also what they can name depends more on social factors than any difference in sensitivity at the physical level.

Actually, I think there is a huge difference between individuals in the ability to detect different volatile components of wine. I'd need to find some studies on ranking of panelists' ability in organoleptic analysis. But suffice to say - and this is anectodal, 'natch - I know for sure that different people cannot detect TCA at the same level.
 
originally posted by VLM:
originally posted by mark e:
originally posted by Oswaldo Costa:
originally posted by Bill Lundstrom:
i don't know, i always a felt the younger crowd (20's and 30's) identified with natural wine, no matter how volatile or bretty or mousey or whatever, as a way to distance themselves from the more stereotypical "wine snob" crowd. they seem kind of hell bent on convincing themselves and everyone else that cidery , volatile wine is real wine and us old guys don't know what we're missing.
i doubt it had anything to do with sour, sugary candy they enjoyed as kids.

And if you rail against v.a. you become an old fogey who just doesn't "get" natural wines.

Yup. Especially where I live.

I don't deal with this much in my neck of the woods but it is also not a new phenomenon. I remember Arnaud refusing me a bottle of wine at 360 about 15 years ago. The first bottle was horribly flawed, he said I was wrong. I said bring out another and if they're the same, I'll pay for both. He refused and I got something else (probably Peyra, I often drank Peyra there). Now, there is no telling whether if he had brought out the other bottle of the flawed wine that it would have been any different. Endemic versus episodic flaws or something like that. I miss that place.

This brings up two things: I, too, miss 360. Great place. Next, I am weary of people in restaurants telling me I'm wrong when I want to send back a corked bottle (most flaws other than that I'll accept it); this has happened so many times I've stopped counting.
 
Mark, I'm not susceptible to TCA. I can surmise that something is wrong with the wine's quality, but I can't sense or identify TCA. Some people can sense TCA seemingly from across the room.

. . . . Pete
 
originally posted by mark e:
originally posted by VLM:
originally posted by MLipton:
VA is a lot like Brett: people’s sensitivities differ markedly and in low quantity both can be viewed as positive attributes. At low levels, a little VA can give a wine a “lifted” or “high toned” nose, which some tasters might find appealing.

Mark Lipton

Do we know this? This seems unlikely to me. If you mean sensitivity colloquially, as in people have different levels that they like/find objectionable, then yes. But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced. Everything I know about olfaction makes me think that while there is a lot of variability within individual sensitivity from day to day there isn't that much of a spectrum between individuals. What people like or don't like and also what they can name depends more on social factors than any difference in sensitivity at the physical level.

Actually, I think there is a huge difference between individuals in the ability to detect different volatile components of wine. I'd need to find some studies on ranking of panelists' ability in organoleptic analysis. But suffice to say - and this is anectodal, 'natch - I know for sure that different people cannot detect TCA at the same level.

Absolutely. The published threshold for TCA is somewhere between 2 and 5 ppt; in my office the threshold is about 0.5, depending on wine type. In my experience showing the same wine to different customers there are very different perceptions of eg acidity and tannin.
 
originally posted by VLM:
originally posted by MLipton:
VA is a lot like Brett: people’s sensitivities differ markedly and in low quantity both can be viewed as positive attributes. At low levels, a little VA can give a wine a “lifted” or “high toned” nose, which some tasters might find appealing.

Mark Lipton

Do we know this? This seems unlikely to me. If you mean sensitivity colloquially, as in people have different levels that they like/find objectionable, then yes. But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced. Everything I know about olfaction makes me think that while there is a lot of variability within individual sensitivity from day to day there isn't that much of a spectrum between individuals. What people like or don't like and also what they can name depends more on social factors than any difference in sensitivity at the physical level.
I've said this before, but I'll say it again. Your knowledge of physiological differences in taste is woefully out of date. And your insistence that differences in what we find pleasing can all be attributed to social factors is just wishful thinking. There is a reason philosophers think that why an individual determines whether a sensation is a pain or a pleasure is finally opaque. So, with regard to VA, some people will perceive it differently and more will disagree on what amounts are a feature or a flaw without even knowing what it is that they are liking or disliking.
 
originally posted by VLM:
...But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced...

There is no such thing as a 'model patient'. As a statistician, where are your distributions?
 
originally posted by Jonathan Loesberg:
originally posted by VLM:
originally posted by MLipton:
VA is a lot like Brett: people’s sensitivities differ markedly and in low quantity both can be viewed as positive attributes. At low levels, a little VA can give a wine a “lifted” or “high toned” nose, which some tasters might find appealing.

Mark Lipton

Do we know this? This seems unlikely to me. If you mean sensitivity colloquially, as in people have different levels that they like/find objectionable, then yes. But if you mean absolute sensitivity to the physical stimulus, I'd need to be convinced. Everything I know about olfaction makes me think that while there is a lot of variability within individual sensitivity from day to day there isn't that much of a spectrum between individuals. What people like or don't like and also what they can name depends more on social factors than any difference in sensitivity at the physical level.
I've said this before, but I'll say it again. Your knowledge of physiological differences in taste is woefully out of date. And your insistence that differences in what we find pleasing can all be attributed to social factors is just wishful thinking. There is a reason philosophers think that why an individual determines whether a sensation is a pain or a pleasure is finally opaque. So, with regard to VA, some people will perceive it differently and more will disagree on what amounts are a feature or a flaw without even knowing what it is that they are liking or disliking.

OK, citations? Peer reviewed, please.

Like this:
"For example, Tao et al. showed that students exhibited improved aroma discrimination ability after training by Le Nez du Vin [14]. In our previous study, the electronic nose was trained using the 51 aromas from Le Nez du Vin, and was able to discriminate a drip coffee (Colombia coffee) from instant coffee (Colombia-type coffee) based on similarity to seven aromas (coffee, mushroom, pine, honey, strawberry, musk, and caramel) [13]. In the present study, we investigated the applicability of the method to other coffees, and compared the coffees with wine and green tea using an electronic nose trained by Le Nez du Vin."


Which, unfortunately, supports my point and not yours.
 
"Absolute-value smell will help record and compare smells in the development of food and drink products. For example, in the flavour of cheeses and other fermented foods, in addition to consistency and quality, there is a growing consumer demand for a larger diversity [2]. In the wine, Sauvignon Blanc, volatile thiol group are of particular importance to the varietal character, imparting passionfruit, grapefruit, in high concentrations, sweaty or cat's urine aromas [23]. Our methods will help record smells in absolute value. Strong working relationships with tasters or sommeliers may improve the quality of products and create diversity."


None of the stuff I'm running into looks like the Earth has moved much since I was last paying attention.
 
originally posted by VLM:
"Absolute-value smell will help record and compare smells in the development of food and drink products. For example, in the flavour of cheeses and other fermented foods, in addition to consistency and quality, there is a growing consumer demand for a larger diversity [2]. In the wine, Sauvignon Blanc, volatile thiol group are of particular importance to the varietal character, imparting passionfruit, grapefruit, in high concentrations, sweaty or cat's urine aromas [23]. Our methods will help record smells in absolute value. Strong working relationships with tasters or sommeliers may improve the quality of products and create diversity."


None of the stuff I'm running into looks like the Earth has moved much since I was last paying attention.

I'm sure you have seen this:

Genetic variation in taste sensitivity to 6-n-propylthiouracil and its relationship to taste perception and food selection.

Tepper BJ1, White EA, Koelliker Y, Lanzara C, d'Adamo P, Gasparini P.

Abstract

The ability to taste bitter thiourea compounds and related chemicals is a well-known human trait. The majority of individuals perceive these compounds, typified by the bitterness of 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), as moderately-to-extremely bitter. Approximately 30% of the population is taste blind to these substances. It has been hypothesized that PROP/PTC tasters are more sensitive to other bitter tastes, sweet taste, the pungency of chili peppers, the astringency of alcohol, and the texture of fats. Tasters may also show lower preferences for foods with these taste qualities than nontasters who show the opposite set of responses (i.e., lower taste sensitivities and higher preferences for these sensory qualities). This pathway is illustrated in the following model: PROP Sensitivity --> Food Perception -->Preference --> Selection. Robust associations between PROP status and taste perceptions have been well documented. However, subsequent links to food preferences and diet selection have been more difficult to demonstrate. This is not surprising given the complexity of human ingestive behavior that is influenced by numerous factors including health attitudes, personality traits, and cultural norms. Our laboratory has been using PROP screening to investigate individual differences in the selection of bitter foods, especially bitter tasting vegetables and fruits that may have long-term health implications. This chapter will discuss new and recent findings addressing the following issues: 1) whether PROP-related differences in perception of bitter compounds predict the perception and liking of bitter foods; 2) the role of bitter taste modifiers; and 3) the influence of personal characteristics such as food attitudes and cultural background on PROP-related food preferences.
 
originally posted by mark e:
originally posted by VLM:
"Absolute-value smell will help record and compare smells in the development of food and drink products. For example, in the flavour of cheeses and other fermented foods, in addition to consistency and quality, there is a growing consumer demand for a larger diversity [2]. In the wine, Sauvignon Blanc, volatile thiol group are of particular importance to the varietal character, imparting passionfruit, grapefruit, in high concentrations, sweaty or cat's urine aromas [23]. Our methods will help record smells in absolute value. Strong working relationships with tasters or sommeliers may improve the quality of products and create diversity."


None of the stuff I'm running into looks like the Earth has moved much since I was last paying attention.

I'm sure you have seen this:

Genetic variation in taste sensitivity to 6-n-propylthiouracil and its relationship to taste perception and food selection.

Tepper BJ1, White EA, Koelliker Y, Lanzara C, d'Adamo P, Gasparini P.

Abstract

The ability to taste bitter thiourea compounds and related chemicals is a well-known human trait. The majority of individuals perceive these compounds, typified by the bitterness of 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), as moderately-to-extremely bitter. Approximately 30% of the population is taste blind to these substances. It has been hypothesized that PROP/PTC tasters are more sensitive to other bitter tastes, sweet taste, the pungency of chili peppers, the astringency of alcohol, and the texture of fats. Tasters may also show lower preferences for foods with these taste qualities than nontasters who show the opposite set of responses (i.e., lower taste sensitivities and higher preferences for these sensory qualities). This pathway is illustrated in the following model: PROP Sensitivity --> Food Perception -->Preference --> Selection. Robust associations between PROP status and taste perceptions have been well documented. However, subsequent links to food preferences and diet selection have been more difficult to demonstrate. This is not surprising given the complexity of human ingestive behavior that is influenced by numerous factors including health attitudes, personality traits, and cultural norms. Our laboratory has been using PROP screening to investigate individual differences in the selection of bitter foods, especially bitter tasting vegetables and fruits that may have long-term health implications. This chapter will discuss new and recent findings addressing the following issues: 1) whether PROP-related differences in perception of bitter compounds predict the perception and liking of bitter foods; 2) the role of bitter taste modifiers; and 3) the influence of personal characteristics such as food attitudes and cultural background on PROP-related food preferences.

Taste is a different sense than olfaction with different neural pathways. It's sort of like saying because some people are color blind that individual difference dominate olfaction. Of course there are individual differences but they are very difficult to distinguish from intra-individual differences over repeated measures, IME. People mostly have the same gear and mostly stay within a range.

And then this:

"Previous reports that the sensitivity to the bitter tasting substance 6-n-propylthiouracil (PROP) is related to the sensitivity to other tastes, to chemical irritants, and to fats and oils have led to adoption of PROP as a measure of general oral sensitivity and as a predictor of dietary habits that could impact health. The results, however, have not been consistent."

 
originally posted by VLM:
originally posted by mark e:
originally posted by VLM:
"Absolute-value smell will help record and compare smells in the development of food and drink products. For example, in the flavour of cheeses and other fermented foods, in addition to consistency and quality, there is a growing consumer demand for a larger diversity [2]. In the wine, Sauvignon Blanc, volatile thiol group are of particular importance to the varietal character, imparting passionfruit, grapefruit, in high concentrations, sweaty or cat's urine aromas [23]. Our methods will help record smells in absolute value. Strong working relationships with tasters or sommeliers may improve the quality of products and create diversity."


None of the stuff I'm running into looks like the Earth has moved much since I was last paying attention.

I'm sure you have seen this:

Genetic variation in taste sensitivity to 6-n-propylthiouracil and its relationship to taste perception and food selection.

Tepper BJ1, White EA, Koelliker Y, Lanzara C, d'Adamo P, Gasparini P.

Abstract

The ability to taste bitter thiourea compounds and related chemicals is a well-known human trait. The majority of individuals perceive these compounds, typified by the bitterness of 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), as moderately-to-extremely bitter. Approximately 30% of the population is taste blind to these substances. It has been hypothesized that PROP/PTC tasters are more sensitive to other bitter tastes, sweet taste, the pungency of chili peppers, the astringency of alcohol, and the texture of fats. Tasters may also show lower preferences for foods with these taste qualities than nontasters who show the opposite set of responses (i.e., lower taste sensitivities and higher preferences for these sensory qualities). This pathway is illustrated in the following model: PROP Sensitivity --> Food Perception -->Preference --> Selection. Robust associations between PROP status and taste perceptions have been well documented. However, subsequent links to food preferences and diet selection have been more difficult to demonstrate. This is not surprising given the complexity of human ingestive behavior that is influenced by numerous factors including health attitudes, personality traits, and cultural norms. Our laboratory has been using PROP screening to investigate individual differences in the selection of bitter foods, especially bitter tasting vegetables and fruits that may have long-term health implications. This chapter will discuss new and recent findings addressing the following issues: 1) whether PROP-related differences in perception of bitter compounds predict the perception and liking of bitter foods; 2) the role of bitter taste modifiers; and 3) the influence of personal characteristics such as food attitudes and cultural background on PROP-related food preferences.

Of course there are individual differences but they are very difficult to distinguish from intra-individual differences over repeated measures, IME. People mostly have the same gear and mostly stay within a range.

And you can prove this, right? Since you have a much greater ability to search for peer reviewed studies on tasting panels' olfactory abilities, I suggest that you do that (as generally this involves statistics). See what's in the literature rather than trying to find isolated work that might partially prove your point.
 
One of the reasons I said it was WOEFULLY out of date is that the studies have reached the NYT and even an article in the New Yorker about wine tasting by Anne Fadiman, from a book I think, but the article has the pertinent information. You can also Google genetic variation in taste and get more than you'll know how to deal with. Your response to what Mark cited does not give me hope that you will read with an open mind. First olfactory sensation is a major part of taste. The tongue only perceives five flavors (this is really high school stuff). Second bitterness is one of them. Third, if you reread what you have cited back to Mark, you will see that it takes genetic sensitivity differences in the taste of bitterness as a given. What is in question is the more speculative claims about the consequences of this difference for questions of health.
 
originally posted by Jonathan Loesberg:
One of the reasons I said it was WOEFULLY out of date is that the studies have reached the NYT and even an article in the New Yorker about wine tasting by Anne Fadiman, from a book I think, but the article has the pertinent information. You can also Google genetic variation in taste and get more than you'll know how to deal with. Your response to what Mark cited does not give me hope that you will read with an open mind. First olfactory sensation is a major part of taste. The tongue only perceives five flavors (this is really high school stuff). Second bitterness is one of them. Third, if you reread what you have cited back to Mark, you will see that it takes genetic sensitivity differences in the taste of bitterness as a given. What is in question is the more speculative claims about the consequences of this difference for questions of health.

I really don't care what is in the popular literature. It rarely reflects the facts on the ground in terms of what is happening in the lab or the scientific literature. Books are not part of the scientific literature. To wit, has CRISPR changed your life yet?

Second, you'd have to show me where smell is a big part of taste. The last I saw there was conjecture about how the two systems interacted, but it was mostly that. Perhaps we know a lot more about those interactions now, but my guess is that they would be at a higher processing level. They have very distinct receptor mechanisms, though they are often grouped together as the "chemical senses" and are processed in different parts of the brain. Taste has no equivalent of the olfactory bulb nor the special connection with the amygdala. You would be best off thinking of them as separate systems for your purposes.

I'm a working researcher and do not have a lot of time to do an exhaustive literature review. The examples I posted were from an NCBI (https://www.ncbi.nlm.nih.gov/) search using the keywords human olfaction sensitivity difference. If you have a chance, please fine tune the search and share your results. I don't have skin in the game, this hasn't been my field for a while, but unlike everyone else here, I have done a literature review on the subject at one point in time. You questioning whether I would accept evidence form a well performed, peer-reviewed study questions my very integrity as a scientist and flies in the face of the conduct of my entire career. While I'm sure you are a distinguished scholar in your field, I assure you that I am considered competent in mine.
 
originally posted by mark e:
originally posted by VLM:
originally posted by mark e:
originally posted by VLM:
"Absolute-value smell will help record and compare smells in the development of food and drink products. For example, in the flavour of cheeses and other fermented foods, in addition to consistency and quality, there is a growing consumer demand for a larger diversity [2]. In the wine, Sauvignon Blanc, volatile thiol group are of particular importance to the varietal character, imparting passionfruit, grapefruit, in high concentrations, sweaty or cat's urine aromas [23]. Our methods will help record smells in absolute value. Strong working relationships with tasters or sommeliers may improve the quality of products and create diversity."


None of the stuff I'm running into looks like the Earth has moved much since I was last paying attention.

I'm sure you have seen this:

Genetic variation in taste sensitivity to 6-n-propylthiouracil and its relationship to taste perception and food selection.

Tepper BJ1, White EA, Koelliker Y, Lanzara C, d'Adamo P, Gasparini P.

Abstract

The ability to taste bitter thiourea compounds and related chemicals is a well-known human trait. The majority of individuals perceive these compounds, typified by the bitterness of 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), as moderately-to-extremely bitter. Approximately 30% of the population is taste blind to these substances. It has been hypothesized that PROP/PTC tasters are more sensitive to other bitter tastes, sweet taste, the pungency of chili peppers, the astringency of alcohol, and the texture of fats. Tasters may also show lower preferences for foods with these taste qualities than nontasters who show the opposite set of responses (i.e., lower taste sensitivities and higher preferences for these sensory qualities). This pathway is illustrated in the following model: PROP Sensitivity --> Food Perception -->Preference --> Selection. Robust associations between PROP status and taste perceptions have been well documented. However, subsequent links to food preferences and diet selection have been more difficult to demonstrate. This is not surprising given the complexity of human ingestive behavior that is influenced by numerous factors including health attitudes, personality traits, and cultural norms. Our laboratory has been using PROP screening to investigate individual differences in the selection of bitter foods, especially bitter tasting vegetables and fruits that may have long-term health implications. This chapter will discuss new and recent findings addressing the following issues: 1) whether PROP-related differences in perception of bitter compounds predict the perception and liking of bitter foods; 2) the role of bitter taste modifiers; and 3) the influence of personal characteristics such as food attitudes and cultural background on PROP-related food preferences.

Of course there are individual differences but they are very difficult to distinguish from intra-individual differences over repeated measures, IME. People mostly have the same gear and mostly stay within a range.

And you can prove this, right? Since you have a much greater ability to search for peer reviewed studies on tasting panels' olfactory abilities, I suggest that you do that (as generally this involves statistics). See what's in the literature rather than trying to find isolated work that might partially prove your point.

Mark, those were the results of a quick search and I found it interesting that both made reference to learned differentiation, which is where the literature was years ago. A thorough literature review is beyond my time constraints. If you and Jonathan have the time, I'd be happy to read through what you consider to be important works on common large differences in individual olfactory sensitivity.

Here are the search terms I used: human differences olfactory sensitivity
For NCBI: https://www.ncbi.nlm.nih.gov/

From the first article in the list, this is from the Introduction, which in the sceintific literature includes the literature review and rationale for the current study. This gives a nice description of the physical make-up of the olfactory system:

"Olfactory information, from receptors in the nasal epithelium, is integrated within the (neurochemically-rich) olfactory bulb, passed directly to medial temporal lobe primary olfactory regions (i.e. piriform cortex, amygdala, and entorhinal cortex) necessary for odour detection. These regions then project directly to secondary olfactory cortex, within the ventral (orbital) prefrontal cortex, which underpins odour discrimination and identification10. In the hierarchy of olfactory processing, the ‘peripheral’ ability to detect odours involves olfactory receptors, the olfactory bulb and primary olfactory regions. The ‘higher-order’ ability to discriminate between, identify, and memorise odours, involves the orbitofrontal cortex (OFC)11."

This study is about something else, how cognitive impairment effects olfactory sensitivity, but it is a nice summation. What we call sensitivity is effected by higher order processing, not just what is going on in the epithelium (which, incidentally, regenerates neurons every 30 days or so, AFAIK, the only neurons that do regenerate in adults).

I should note that putting together a comprehensive literature review is a PITA. This search would be a start in a multi-day, maybe multi-week process.
 
Back
Top