Taste (Gustation) – Other Senses (PSY, BIO)

00:01 Now, let’s get on to taste.

00:03 We all love to eat.

00:04 We all love to eat different things.

00:06 And we’re able to actually taste so many different flavors which is also very interesting.

00:12 So the four main flavors that you need to know are our ability to detect bitter, sour, salty, sweet.

00:18 All areas of the tongue can taste all flavors though some areas may be able to detect certain flavors more easily.

00:25 So, you got to think of the main flavors that we have.

00:29 Sweet, which is associated with sugar and you also can taste as well other things like artificial sweeteners and things like that.

00:36 Salty which is sodium or salt, like the name imply.

00:39 Sour, acidic things.

00:40 Bitter, basic.

00:42 We also have something called umami which is quite descriptive for those in the Asian population which is amino acids and nucleotides.

00:49 So it might not be one that kind of commonly comes up.

00:51 So I’ll be more well-versed in the bitter, sour, salty, sweet.

00:55 And depending on the receptors and their localization in the tongue, you start to see detection of that taste.

01:03 So like the figure illustrates here, you can see on the tip of your tongue is the receptors that would detect sweetness.

01:11 Which is why if you were to put something sweet, say, on the back of your mouth, you might not really grasp the full level of sweetness as opposed to if you use the tip of your tongue.

01:20 So remember the next time you’re licking a lollipop to focus on the tip of your tongue as opposed to say sour which is on the sides of your tongue and bitter is near the back of your mouth and everything else is essentially salty.

01:34 Now how does this process work? So as you can see here by the image, we have a cross section of what’s going on at the tongue and we have a receptor.

01:44 And the receptor is based on a -- a structure that’s found within the tongue and it has a small area called a taste pore.

01:52 And in the center, you have these little hairs.

01:56 So taste hairs which detect the food chemicals.

01:59 So taste is actually transmitted by -- is transmitted by the cranial nerve to be processed by the central nervous system, more specifically, the temporal lobe.

02:07 So what’s kind of neat is, when you consume food, is that food goes against your tongue and it’s mixed with saliva and it’s usually an aqueous solution and that bathes your tongue.

02:18 And so molecules that are, say, sweet will activate the -- go within the taste pore, activate the taste receptor cells that are associated with sweet.

02:28 And that is how we’re able to sort of differentiate.

02:30 So again, if you go back to the diagram of the tongue with highlighted areas, those are areas where you’re going to have focus or a higher density of receptors associated for that taste.

02:40 The gustatory cortex is made up of two small substructures that are found in two different lobes of the brain. These substructures are the anterior insula, located on the insular lobe, and the frontal operculum, on the frontal lobe. The insular lobe is found deep within the cerebral cortex, located under the frontal, parietal, and temporal lobes.