Part 5 - The Other Senses - Sensation and Perception

hi everyone this video is part five of the sensation and perception unit this is called the other senses because we will do an overview of the senses that weren't previously covered so in earlier videos we covered vision and audition or hearing and this video will give an overview of the other senses like smell and taste somatosensory which is touch vestibular and proprioception which is also called kinesthetic so we'll go over some of those other senses in an overview so to start with is touch this is your somatosensory sensation and this is picked up and detected by your skin so there are different types of skin sensation or touch we have the feeling of pressure pain temperature there's also variations of those like a tickle and itch and wetness we can all detect those through our skin one theory that you'll have to know that corresponds with your sense of touch is the gate control theory and the gate control theory relates to pain so if you have ever been in a situation where you have felt pain and then you've applied pressure or a cool sensation or something hot sometimes you have this feeling of alleviated pain as if the pain has gone away and the gate control theory attempts to explain why that occurs and the gate control theory is simply that a non-painful input or a non-painful stimulus like pressure or temperature will go first through the nerve to the brain and it's as if it closes the gate to the painful input and so that that pain sensation is slower or blocked from reaching the nervous system so in the diagram you can see how the sharp pain is being blocked because the pressure sensation is going first so there's this little toll gate there to give you a visual of this gate control theory it's as if this non-painful sensation has gone first and blocked the pain from going through that nerve to the brain and so that's the gate control theory the next slide goes over our brain and how our brain is perceiving and processing touch so on the left side you have a brain here at the bottom of this diagram and it is showing you this blue sliver right here which is the somatosensory cortex the somatosensory cortex is on the parietal lobe and here this sliver has been taken out and it's been displayed up here in a larger view so that you can see how all of the different areas of your body where there is skin and there is this feeling of touch or this feeling of pressure or pain it's represented on the somatosensory cortex where it's being processed and you might notice that there are some parts of your body that have more surface area on the brain like your lips for example your lips are taking up more surface area here than like your armpit so we have more sensory receptors than on our lips and it takes up more surface area on our brain than you know our forearm and that just shows you how much more sensitive some of those areas are in your body to touch sensation this is a diagram it's um it's an image on the the right his the name of this is the homunculus man and he is a representation of if our body were proportionate to our sensory receptors then this is what our body would look like and so you can see how the proportions of the hands are much greater and larger than like the shoulder or the elbow because there is more sensitivity to touch in those areas the next section is taste so you can see taste on the left is taken in through the tongue it's also called gustation you can see that there are these pores that are across the tongue and inside of that pour you've got this really large taste bud and this tastes better you can see in a better view on this center picture this picture is a good picture because it talks you through that process how whatever you're taking in whether it's food or drink will come across this poor it will be taken in it will be processed by these receptors and you can see on this right hand side there are different taste receptors sweet umami which is a savory taste a taste that you would find in meat bitter salty and sour and that is receiving and detecting and taking in those tastes and then it's being sent on to the brain the next res or the next sensory the next distance that we will discuss is smell smell is also called olfaction and this is just really brief what you need to know as the chemicals in the air are moving through your nasal passage they are getting caught up here and are being taken up by your olfactory bulb which is where transduction is occurring and then it's sent onto the brain and that is all you need to know for smell the next is your body sensations like your vestibular sense and your kinesthetic sense your vestibular sense is your sense of balance i think that's easy to remember because vestibular has a b in it so vestibular is balance this is detected in your vestibular system or your semicircular canals which are just above your cochlea in your ear these are fluid filled canals that move with your head and body movement and that detection is sent on your brain onto your brain to help you perceive and understand your orientation and if you're upright or if you are offset and that helps you understand your sense of balance your kinesthetic sense is your your awareness of your body and your body parts so i like this image because you can see in this image this person is both taking in visual understanding of where his body is so he can see his hands and he knows where his hands are because he can see them but if he were to close his eyes he would still know where his hands were because of his kinesthetic sense because of just his muscular system the compression of the muscles and joints and his awareness of his body parts is still there through his kinesthetic sense even when his visual input is not there okay so the next slide is about sensory interaction this is when your senses influence one another and influence your perceptual experience so you probably know this with your sense of taste and smell you've probably had this occur if you've ever been congested and you have difficulty smelling sometimes that impacts your ability to taste because usually your eating experience is is actually a combination of smelling and tasting that food and so there's that century sensory interaction of of your sense of smell and your sense of taste there are other situations where your senses influence one another one of those is called the mcgurk effect and i'll let this video explain the mcgurk effect have a look at this what but look what happens when we change the picture bar and yet the sound hasn't changed in every clip you are only ever hearing bar with a b bar it's an illusion known as the mcguck effect take another look concentrate first on the right of the screen now to the left of the screen the illusion occurs because what you are seeing clashes with what you are hearing in the illusion um what we see overrides what we hear so um the mouth movements we see as we look at a face can actually influence what we believe we're hearing if we close our eyes we actually hear the sound as it is if we open our eyes we actually see how the mouth movements can influence what we're hearing it's a bizarre effect remember the only sound you're hearing is ba with a beat what's remarkable about this illusion is even knowing how it's done doesn't seem to make a difference the effect works no matter how much you know about the effect i've been studying the mcgurk effect for 25 years now and i've been the face in the stimuli i've seen stimuli thousands of thousands of times but the effect still works on me i can't help it the speech brain just takes in that information it doesn't care about what outside knowledge you bring to bear ba ba the mcgurk effect shows us that what we hear may not always be the truth okay so that was the mcgirk effect so we have in our next section whenever we are perceiving something without the actual sensation so the first one is the phantom limb sensation and this is where someone is feeling or perceiving that they are having a sensation when they are not because they have had an amputation or a missing limb and this usually occurs between 80 and 100 of people who who are are amputees and so it's very very common but a small percentage of those will have painful experiences and this just occurs because of the after the situation has occurred there's just an adjustment period of these unpredictable different types of sensations that are coming in through the nerves and they're getting mixed and misunderstood signals and so they're having a feeling in that limb even though the limb is not there the next one is tinnitus and this is the perception of noise and it's typically ringing in the ears and when there is no ringing occurring outside of the ears and this is is not a condition itself it's usually a symptom of another condition and it's typically associated with hearing loss the third one is called synesthesia and synesthesia is where there is a stimulation of one sensation and this leads to the perception of another and so this will occur in someone where whenever they see it it could be all kinds of things so maybe they they are having a connection between their hearing and their um site so maybe they hear a note and then they see a color in the sky or maybe they it's their taste and their sight so they taste something and then they see something in their visual field and i know this sounds strange to someone who does not have this occur so i'll show you an example of this but the definition is when there is a stimulation of one sense and at least the perception of another so here's an example of a person with synesthesia to help you kind of get a better idea of how this occurs [Music] my name is caitlin hofa i'm a software engineer neuroscientist and a musician i also have synesthesia synesthesia is a blending of the senses one in 23 people have a form of it for me when i hear specific musical notes i see specific colors and these colors are much brighter at night [Music] what you're seeing in front of me is a lot like what i see when i hear this music [Music] each one of these colored lights corresponds to a particular note and the colors are always the same [Music] i've seen these colors my whole life but i didn't know that was unusual until i was 21 years old it was the final music theory course for my music major at the end of the class my professor mentioned that some people can physically see sounds as colors and to me i thought duh and everyone in the classroom turned to look at me we did tests where they played notes on the piano and i told them what color it was and at that point i knew i had synesthesia [Music] synthesia can manifest itself in so many different ways it can blend together vision taste smell sound it can be almost anything but for me it's always been about the colors okay so hopefully that gave you a little idea into what it's like to have synesthesia so in this video we covered the senses that were not previously covered in the previous videos and we just got a brief overview of those i hope it was a useful experience for you definitely reach out to me if you still have questions

Channel: Joelie McCrary

Views: 76

Rating: 0 out of 5

Keywords:

Id: 8tkVPRSU9gY

Length: 14min 57sec (897 seconds)

Published: Mon Nov 16 2020