What kinds of tastes are out there? How can your brain tell them apart?
You will need
A friend
A blindfold
A few different foods (what ever you have, just make sure that they are it's fresh and tasty)
What to do
One person puts on the blindfold and the other person chooses what kind of food they eat.
The blindfolded person needs to guess which of the five basic tastes are in the food.
The five basic tastes are Sour, Sweet, Bitter, Salty, and something else that we have borrowed the Japanese word Umami to describe (meaning a fantastic taste). This taste comes from salts of certain acids like MSG or that savoury meaty taste.
Try with a few different foods.
Now hold your nose and try to taste the foods, what happens?
What's happening?
How are your taste buds linked to your brain? Where does the flavour come from?
Your tongue is covered in tiny bumps called papillae, of which there are four different types. These papillae are covered in tiny taste buds found all over your tongue – the old ‘tongue map' idea, where you tasted sweet at the front and sour at the back, has been thrown out the window.
These 10 000 or so tastebuds are constantly being replaced every one to two weeks. Which is a good thing, as we all know what a tragedy it is to lose tastebuds; like when you burn your tongue. Adults don't have as many tastebuds as children, which is perhaps why they can eat (and like) foods like a smoked mackerel and blue vein cheese sandwich, ugh!
Taste buds are full of taste receptor cells that identify certain chemicals in your saliva from the food, so no saliva means no taste. These cells then send a message to your brain about what kind of chemicals are in your mouth. Your brain then interprets these messages as ‘taste' in parts of the cerebral cortex.
Have a look at your tongue close up in a mirror to see how alien and bizarre the surface is.
When you blocked your nose, did your sense of taste diminish? This shows you how your brain uses its sense of smell to help taste foods. Texture and appearance also help the brain find the taste – you might like to come up with some other experiments to test this.
Did you know that a giraffes tongue can be as long as 74 cm?!
Applications
Taste is ultimately governed by your brain, and some people have gone as far as saying you can link your taste response to whether you are an introvert or an extrovert. It's thought that the amount of saliva you produce after eating something full on, like a lemon, may indicate what sort of personality you have. Sounds juicy – but how? Well, there is a part of your brain called the Reticular Activating System (RAS) that responds to stimulus, be it social or sour.
It is thought introverted people have a high level of activity in this area (these people will produce more saliva) and that their RAS is easily stimulated, which makes them sensitive to stimulus like the lemon juice. These people really prefer a quiet life.
Extroverts on the other hand are thought to have low levels of activity in their Reticular Activating System and when they suck the lemon, they don't produce a lot of saliva. These people need plenty of stimulus to feel alive, and they seek out people and big experiences.
Now what do you think – is there anything to it? How about holding your own experiment, and get a range of people to drop some lemon juice on their tongue to see if it is your quieter friends who start salivating.
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