Our Great Gastronomic (Self) Deception

The unique tastes of butter, pine nuts and vanilla are enjoyed by many cultures around the world.  There is also a clear difference in taste between a strawberry, an apple, or dark chocolate...or so you think!

Let me explain.

Human chemical receptors, commonly referred to the nose and tongue (ok, various papillae on the tongue and the olfactory bulb, above and just behind the nose), are incredibly sensitive.  The brain however, is as bright as it is gullible and is easily confused, either intentionally or unintentionally. Just ask an elite athlete who uses visualization as an integral part of their training to achieve very real benefits, not from actually doing an activity, but by essentially thinking about it, visualizing it with intensity.

With me so far?

Looked at it from a perceptual standpoint, we've all experienced another bit of brain gullibility, or easy confusion, by reaching an incorrect conclusion when we've mixed-up "causality" (something that is the cause of something else), with "correlation" (two things that just happen to occur at the same time, essentially a coincidence).  This mistake sometimes causes some wonderful hockey "rituals", for example, because a player scored one time after they had hummed a tune in the change room before the game (that they never hummed before), so CLEARLY, the tune humming was the contributing "cause" of the goal and not merely a coincidence with it.

An anatomy refresher...

A quick definition of terms will be helpful at this point:

Taste - The perception of certain chemicals by receptors on the tongue, the signalling of such then gets communicated to the brain via electrical impulses.

Smell - Similarly to the perception of substances by the tongue, the nose senses odor molecules in the air. It is thought that humans can differentiate between a trillion different scents.  Keep in mind, the smells we are familiar with are actually a very complex composition of many, many different scent molecules, just like a perfume. The aroma of a baguette crust alone, for example, comprises14 different odor molecules!

Flavour - The combined sensory impression of both taste and smell.

Relatedly, the textural characteristic of a food or drink also impacts your perception.  Think about the different mouth experiences in sampling table syrup vs water, raw oysters vs banana bread, or watermelon vs a sugar apple.

Brain gullibility, taste and smell...

It's very easy to understand how it happens, but the fact remains that people confuse tastes with smells, almost as a rule.  You put a strawberry into your mouth and as soon as you chew, your tongue accurately detects fructose (a sugar found in fruit).  Sugars, after-all, represent one fifth of the "tastes" tongues have evolved to perceive; bitter, salty, sour and umami (savoury) being the other four. However, a fraction of a second after sugar was detected, virtually simultaneously, a wisp of air containing strawberry odor molecules that were floating around in your mouth, gets passed over your olfactory bulb as soon as you breath out your nose, even just a tiny bit, and the perception of the "strawberry scent" is also then transmitted to your brain. 

The result:  our brains confuse causality with correlation, and falsely conclude that because we just put a berry in our mouth, it tastes like a sweet strawberry, when in reality, it tastes sweet and smells like a strawberry.  Because strawberries, apples and dark chocolate have about the same sweetness levels, they "taste" indistinguishably similar...when your nose is pinched.  On the other hand, butter, pine nuts and vanilla, actually have absolutely no taste at all, and have gained their popularity from their scent alone.

The beauty of all this is that you can test it out for yourself at lunch.  In fact, here is a fun experiment to try the next time you are eating.  Simply pay attention to the flavours you are perceiving as you breathe in and out through your nose.  As you breathe in, notice that all that you're getting is sweet, salty, bitter, sour or savoury experiences, but that the moment you breathe out your nose, there is an explosion of different flavours, that previously you assumed were tastes.  Those are the odour molecules joining your flavour party!