Thursday, November 3, 2011

Taste, Wine, and Not Understanding Permutations

Jonah Lehrer wrote an article on Wired discussing the limited sense of taste and how taste can be easily fooled. But he's wrong on nearly all fronts. Here's his opening:
Let's be blunt: The tongue is really dumb. Unlike the rest of our sensory organs, which are exquisitely sensitive, that lump of exposed muscle sitting in the mouth is a crude perceptual device, able to only detect five different taste sensations... [but], we are convinced that the tongue is remarkably sensitive, able to perceive all sorts of subtle flavors. That's why we rhapsodize about the taste of our favorite foods and drinks... 

Obviously Lehrer doesn't understand the mathematics of permutations. Sure, the tongue is capable of only sensing five separate tastes: salty, sour, bitter, sweet and umami (the brothy, mouthwatery taste of meat is considered umami) but that doesn't mean taste isn't infinitely complex. In fact, proving that taste is infinitely complex is inestimably easy:

Let's mix only two of each of the five basic tastes together in perfect, 50/50 harmony. Doing that gets us up to 20 different tastes right away. To make this point in a visual manner, I've listed the combinations below (and keep in mind that Salty, Salty is definitely different than Salty, Nothing... for instance, if I pour a whole cup of salt into your mouth, it will taste a lot more like Salty, Salty, than if I put one grain of salt on your tongue, which will taste more like Salty, Nothing). Anyway, here are the 20 different tastes:

Salty, Nothing
Salty, Salty
Salty, Sour
Salty, Bitter
Salty, Sweet
Salty, Umami
Sour, Nothing
Sour, Sour
Sour, Bitter
Sour, Sweet
Sour, Umami
Bitter, Nothing
Bitter, Bitter
Bitter, Sweet
Bitter, Umami
Sweet, Nothing
Sweet, Sweet
Sweet, Umami
Umami, Nothing
Umami, Umami

As we can see, just from the "limited" five tastes we have a combination of 20 very distinct tastes the tongue can appreciate. At minimum.

But what if we take this a step further, and mix all five tastes together perfectly so that each 'taste' in any individual piece of food represents EXACTLY 16.67% of the food being eaten? Suddenly we get to 462 different tastes that our "dumb" tongues can sense. Below are four of the possible combinations:

Salty, Salty, Sour, Bitter, Sweet
Salty, Sweet, Sour, Bitter, Nothing
Salty, Sweet, Sweet, Bitter, Nothing
Sweet, Sweet, Bitter, Umami, Umami

You get the idea. But again, these 462 different combinations are still operating on a binary scale of taste (either it's salty or not salty, there is no in-between). But anyone who's eaten anything knows that we don't have a binary sense of taste. There are subtle and not-so-subtle degrees of taste.

As I mentioned before, if I drop one grain of salt in your mouth, it will taste different than if I ask you to swallow a teaspoon of salt. And if I pour an entire salt-shaker into your mouth you'll probably gag and ask for a gallon of water to wash it down and it will certainly taste different than the teaspoon of salt I gave you earlier. But to assume that we only have 462 different tastes means we have to assume only six degrees of possible salt combinations. Which basically means that this particular combination...

Salt, Salt, Salt, Salt, Salt, Salt

... tastes exactly the same to every single person on the planet. Which I'm not sure is true. And that means that the five "tastes" have to have more than six degrees to them, which raises the possibility that our "dumb" tongues can sense nearly infinite possibilities.

However, for the sake of argument, I'll assume that all tastes are all exactly the same and that "Salt, Salt, Salt, Salt, Salt, Salt" tastes exactly the same to every single person on the planet (hey, it might). If that's true then yes, there are only 462 different combinations of taste in any single piece of food. But wait, that still doesn't account for texture does it? No, of course not, how stupid of me!

How many textures should I add in? Um... hard, medium and soft with no further degrees or differences (but is there a difference in texture between the "hardest" and "softest" cheeses and "hardest" and "softest" breads? Of course there is, but for this experiment only one degree of hard, medium and soft will suffice). So if I add hard, medium and soft into the permutation formula suddenly we have 24,310 different possible tastes. And Lehrer's "dumb" tongue statement starts falling apart rather quickly.

But now we need to go further and add spiciness and temperature to the foods we're eating (and, by the way, there is an absolute CERTAINTY that temperature isn't a binary experience). Once we add those two into our formula now we're up to 352,716 different possible tastes that our "dumb" tongues can appreciate (and this number was arrived at using assumptions designed to limit it to the lowest possible integer).

In short, you don't have to be some egg-head scientist to understand all of this, all you need to understand is basic math. And any egghead scientist (or person who wrote a book titled "How We Decide") ought to understand basic math. If they did, then writing about the tongue only being able to sense five different tastes would be either misleading or stupid on their parts.

Are there are million different taste to red wine? No. Can wine reviewers be fooled, and does cheap wine often taste better than expensive wine? Absolutely. But that doesn't mean Lehrer's article makes any sense. No. And for proof, look at the last few paragraphs he offers:
A new study led by Adrian North of Heriot-Watt University adds to the indictment [of the tongue]... [He] has shown that when people drink wine to the accompaniment of music, they perceive the wine to have taste characteristics that reflect the nature of that concurrent music... Some of the participants sampled their glass to the tune of music identified... as powerful and heavy; others drank their wine to music rated earlier as subtle and refined; others to the tune of zingy and refreshing music; and lastly, the remaining participants drank their wine with mellow and soft music in the background....

After they'd savored their wine for five minutes, the participants were asked to rate how much they felt the wine was powerful and heavy; subtle and refined; mellow and soft; and zingy and refreshing. The results showed that the music had a consistent effect on the participants' perception of the wine. They tended to think their wine had the qualities of the music they were listening to.
He's gone off the rails here, because he's now delved into the world of Neuro-Linguistic Programming and doesn't realize it (and neither do the creators of the experiments, apparently). Humans are highly suggestible creatures. In fact, stupid things like not shaking hands with someone can be enough to disrupt their routine and put them into a suggestible trance. If the general atmosphere of a place, its music, or the specific words a waitress (or experimenter) says, are being used to validate something OTHER than NLP, then that study is inherently flawed.

But this is old news. Or, at minimum, this should be old news to someone who, again, wrote a book called "How We Decide". For Lehrer not to understand NLP is dumb, and for him to think that NLP actively negates a person's sense of taste is even dumber (and now I'm wondering if How We Decide is worth reading).

People can be influenced to say and do all sorts of things using NLP. If a test subject eats dog crap wrapped in a burrito and the experimenter uses the right NLP techniques afterward (certain auditory or visual cues), then the subject will probably repeat whatever the tester wants him to (i.e. that the dog crap burrito tasted like powdered sugar). This doesn't prove that the subject's taste buds are "dumb", it only proves that NLP is a much more powerful influencer than taste.

Is it a big surprise that we're more influenced by visual and auditory cues than olfactory or gustatory ones? Again, to someone like Lehrer this shouldn't be a surprise, and certainly shouldn't be something worth writing about. But the last few lines in his column contain a whole concoction of ways NLP affects people when  they're dining out and it's worth reading for that alone (even if Lehrer doesn't know it):
[T]his is why the ambience of a restaurant matters... For instance, when we eat a meal in a fancy place, full of elaborate place settings, fine porcelain and waiters wearing tuxedos, the food is going to taste different than if we ate the same food in a cheap diner.... [T]he music matters, but so does everything else. The tongue is easy to dupe.

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