 Hi, and welcome back to this video course biological psychology and in this video video 3.8. We're going to take a look at the perception of balance Now, so what is balance balance is a sensation of which way is down and the movement of the body acceleration of the body and It's also called Equilibrium or vestibular sense right and by this description you can also already tell that balance is kind of a Composite sense right it's not really one sense, but it is a combination of senses that all have to do in one way or another with our sense of balance And most of balance our sense of balance happens through the vestibular organ in the air Which is actually very similar to the to the to our actual inner ear that we use for hearing But then it does something functionally does something very different, but the way that it works is very similar to our sense of hearing So here you see the inner ear right and we've taken a look if you've seen the lecture on the video on hearing You've already seen this part right here, right? So the inner ear that with the hair cells that support hearing now this other part of the inner ear That's where our sense of balance is mostly located So Helen hair cells in these vestibular organs are very similar to the ones that are involved in hearing and they sense Pressure so they can sense that which way is down and movement of the body simply by the fact that They sort of there's a certain pool downwards which allows you to tell which where where down is right? So right now I'm feeling that this way is down that weighs up And that is essentially the pool that is pool on the sensors in my in my vestibular organ That allows me to to have that sense And there are also changes in pressure right the acceleration that happens if you move and That allows you to feel the acceleration of the body Right, and you can see that there are three different kinds of there are three of these canals that are oriented in slightly different ways And these allow us to be sensitive to acceleration and movement in different directions Now balance is certainly not an isolated sense It is a sense that interacts with for example the sensation of limb positions or proprioception, right? So we we feel for example which way is down, but we also feel the position in which our limbs are right? so for example if I would Rotate my head like that of course from my vestibular organs then another direction would be down But because at the same time I know that I've I bent my head backward like that I don't really feel like the world is rotating or anything right because my on the one hand my body knows Okay, I get a different vestibular system on the other hand My body also knows that I've rotated my head and the two together tell me tell tell tell me that actually this the world has Not rotated in any meaningful way Right, so we have there's a strong interaction between our sense of limb position and and balance There's also a very strong interaction between vision and our sense of balance right so Essentially and you can if you are for example in a in an in an airplane where your sense of vision tells you that You're very stable, but your sense of balance tells you that you're actually falling or moving upwards that can be very disturbing right and Conversely for example if you're in a in a driving simulator and your Vision tells you that you're actually moving and you're accelerating and decelerating But your sense of balance is not cooperating that can also be quite nauseating can make you quite sick Right, so in general I would say in this especially in the scent in the case of balance There is a lot of interaction with other senses proprioception our sense of limb position and vision And if there is somehow a mismatch between these different senses that interact that tends to be quite disagreeable Now with that we've arrived at the end of this section on perception. Thank you very much for watching