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Video transcript

alright so in this video we're going to talk about something known as sensory adaptation so sensory adaptation and as the name implies what a sensory adaptation is is a change in this sensitivity of your perception of a sensation so we're going to look at a couple of different examples of sensory adaptation so the first example the first sense that we're going to look at is hearing your sense of hearing so let's look at hearing so how is it that we're able to go to a rock concert and listen to the entire concert and walk out and still be able to hear things how is it that our eardrums are blown out because of the really really loud sound well one of the ways that you're able to adapt to really loud noises is by a small muscle in your inner ear and what this inner ear muscle does is whenever there's a really loud noise it causes it to contract and when the muscle contracts it actually dampens the vibrations that go into your inner ear and by dampening really loud noises it actually helps protect your eardrums from getting blown it helps protect your inner ear from getting damaged so this actually takes a few seconds for it to kick in so it doesn't work for really really immediate super loud noises such as that of a gunshot or rifle fire because the rifle when it goes off the noise occurs really really quickly and the muscle doesn't have time to contract and protect your ear so you can actually have some kind of damage if you do hear a gunshot close to your ear because this inability to contract very quickly another sense that we're able to that we rely on heavily and that is adaptable is our sense of touch you might have noticed that if you dip your hands in really cold water it's super cold at first but over time the water doesn't feel it's cold and that's because the sensory nerves in your hand that are sensitive to temperature as soon as they go off they become saturated and they stop firing as much and so your sense of touch sense of temperature gets adapted another sense that is adaptable is your sense of smell so we can detect really really low concentrations of chemicals in the air so such as perfumes but I don't know if you've ever actually experienced this or not but if you spray some cologne or some perfume on over time at first you you're able to smell it but over time you forget that you're wearing and that's big again because the sensory receptors in your ear they become desensitized so they become desensitized dyes to the to the molecules and similarly your sense of touch the temperature receptors also get desensitized there are a couple other senses that also get that can also change and adapt to changes in stimulus one of those changes is your sense of proprioception Rio ception so this we talked about in an earlier video but is your sense of balance your sense of self knowing where you are in space and so one experiment they actually did to change someone's sensation of proprioception was they actually put some just goggles so imagine here we have a person and here's eyes so what they actually did was they put goggles on and what these goggles basically did is they skewed everything so they either made everything upside down or they kind of tilted everything at a certain angle but basically the perception of the world basically changed and what they were seeing was no longer what they're used to and over time their brain was actually able to accommodate so if an image was initially upside down over time the image got flipped right side up again so there's this sensory adaptation that can occur for your sense of proprioception as well another sense that undergoes sensory adaptation is your sense of sight and so for all these senses over here we were kind of talking about down-regulation so hearing whenever it's a really loud sound the muscle contracts and your ability to perceive sound is down regulated such as this is the same with touch over time your to feel certain things feel pressure feel temperature gets down regulated said and the same thing goes for smell and proprioception so with sight we can get both down and up regulation so we can get both down and up regulation so one would we get down regulation well imagine that it's really really bright outside so if it's super bright outside you've got lots and lots of light coming in and it enters your eye so if your pupils were really big and dilated so let's imagine that you've got your pupils here and they're really big and dilated a whole bunch of light would enter your pupils and in fact it could even damage your retina so one adaptation that your eyeball has two really bright intensity light is that people actually constrict so the pupil gets smaller so it goes from this size for example to this size and what that effectively does is it allows less light to enter the back of the eye another adaptation to bright light that occurs in your eye is a change in the sensitivity of your rotten cones and we there's an entire playlist on site in which I talk about rods and cones but basically what occurs is your rods and cones that are sitting the red on the back your eye they get desensitized they actually lose sensitivity to light over time and so the combination of pupil constriction and desensitization of the rods and cones in your eyes effectively leads to a down regulation in your ability regulation your ability to sense light so what happens in a dark setting so in a dark setting when there's not a lot of light so there's not very much light we can just kind of draw a little bit alike kind of coming in what you'd want to do is the exact opposite so if your pupils were initially small you'd want to make them big so that we can get more light coming to the back of the eye and in addition what happens in the dark is these rods and cones actually start synthesizing light-sensitive molecules so there's actually more lights instead of molecules and they become more sensitive to light and this effectively leads to a up regulation in sensitivity