When mice taste something bitter they make a cute pucker expression. Scientists recently found they could make a mouse pucker by stimulating a part of the brain involved in the perception of bitterness.
Check out this short video of a mouse drinking water while getting some brain stim:
In a related experiment, the scientists were able to prevent the pucker face, even when the mouse was tasting something bitter, by zapping the "sweet" part of the brain.
I find this to be an interesting analog of the idea that "pain is in the brain."
Here are several other interesting facts (and some factoids!) about taste that inform my understanding of what causes pain and how to change it.
Taste is not just about the tongue
The sensory information that contributes to a sense of taste does not come solely from the tongue. The nose delivers a lot of information about what we are eating. The appearance of food matters as well - not just in making us want to take a bite, but in determining how that bite actually tastes.
Taste is therefore a great example of multi-sensory integration, which means that seemingly unified perceptions like sight, hearing and touch are built from many different sensory inputs. What we see affects what we hear, what we hear affects what we taste, and what we touch affects what we see.
So everything matters for taste. Bacon tastes better when it sounds crunchy. For me, beer tastes best when sunlight is shining through it, or I just won a soccer game. The finest culinary experience of my life was eating a hamburger after a long day of skiing.
Here’s a cool fact to keep in mind next time you are feeling oppressed by a wine snob: Even top wine experts have trouble telling reds from whites when food coloring is used to change its appearance. Ha! Next time someone tells you they detect the scent of cherries, or chocolate, tell them you detect a slight whiff of bullshit.
To be fair, wine afficionados probably do experience all the subtle qualities of flavor they claim to appreciate. It's just that those flavors don't necessarily come from the wine, but from other inputs, like the look of the label, the lighting in the restaurant, knowledge about the quality of the wine, mood, expectation, and what they just read in the latest edition of the Wine Spectator.
Pain is the same. Bodies don't need the finest quality bones, muscles and joints to feel great. Even the cheap stuff can be delicious under the right circumstances. And any kind of sensory or cognitive input has the potential to change pain for the better - sight, sound, touch, thought, emotion and memory.
Ever get violently sick after drinking too much alcohol? Fun stuff.
You might have developed a strong residual aversion to whatever alcohol you poisoned yourself with. Maybe the very smell of it, or even thought of it made you want to puke.
That’s because you unconsciously formed a Pavlovian style association between the flavor of the drink and the bad experience that resulted from doing ten shots of it.
You probably eventually broke the association through a program of graded exposure. First you looked at the bottle without getting sick. Then smelled it. Then drank a tiny bit. Then some more until the association was extinguished.
You can form associations between pain and movement as well. I think a big part of what we do as movement therapists is find ways to break that association.
Coffee and beer are acquired tastes - they usually don't taste very good on the first try, but eventually taste goooooood. Why is that? Because they contain DRUGS.
It doesn't take long for the brain to associate the taste of coffee with the sweet feeling of not wanting to leave work and crawl back into bed. So now the bitterness of coffee or an IPA is no problemo.
And you don't need drugs to acquire tastes. Kids can acquire a taste for broccoli if you pair it with sugar for a while.
Are there any cool analogies to pain here?
Placebo can work by learned association. If you pair a pain killing drug with an inert treatment for a while, pretty soon the inert treatment will elicit some pain reduction even in the absence of the active ingredient. People who love running are probably runner's high addicts.
Perhaps a similar effect underlies the efficacy of routines or habits people may develop for dealing with common pains or stresses. Part of the benefit of a familiar stretch, yoga class, or massage is attributable to the simple fact that it has worked in the past. Personally I do about 5-10 minutes of light mobility work every day, whether I need it or not. I probably get most of the benefit as soon as I make the decision to get started.
The Purpose Of Taste
Our sense of taste evolved to motivate healthy eating behaviors. Back in the day when our ancestors roamed the African savannah, foods with salt, sugar and fat were usually healthy to eat. So we perceive foods with these qualities as being delicious, which motivates us to chow down on them.
This simple idea can give us some insight into the obesity epidemic. Fast food manufacturers have a LOT of knowledge about how taste affects food consumption, so they pump salt, sugar and fat into almost everything. So we overconsume it. Any good explanation of how people get fat needs to keep this idea in mind.
Similarly, any good explanation for all the surprising phenomena we see with pain must include a clear idea about pain's evolutionary purpose.
Pain evolved to motivate behaviors that protect against perceived threats to the physical integrity of the body. Once you consider that perception isn't reality, and that the best way to protect the body depends on environmental and social context, you have already gone a long way to understanding all the variables that can modify pain.
Want to learn more about pain? Click the articles tab above and find the subsection for articles related to pain.