Sensation and Perception

       

       Our brain has many different tasks, but the one I will be focusing on is the role it plays in our sensation and perception. What are sensation and perception you may ask? Well when your body receives information from your sensory organs, such as your eyes, ears, skin, or nose, it must process it, this is know as sensation. Perception is the psychological aspect of processing that information from the sensory organs and interpreting, as well as using that information.       
       Now that have a better understanding of sensation and perception, I want to focus on in particular illusions. This can be know as a trick of the mind. However Michael Bach defines them as, "phenomena as highlighting particular good adaptations of our visual system to experience with standard viewing situations. These experiences are based on normal visual

experiences, and thus under unusual contexts can lead to inappropriate interpretations of a visual scene." Which takes away the idea that our 'mind or eyes are playing tricks on us', rather our eyes are adapting to what we experience and see in everyday life and can lead us to seeing something that is not true, or what it appears, when it comes to illusions. This was very true a few years ago when the controversy over whether this dress was 'white and gold' or 'black and blue'. This appears as an illusion because of the way we perceive color. Different colors correspond to different wavelengths. The color we see is decided according to the first burst of light that is made of a specific wavelength hitting your retina, sending that information to our visual cortex, where the brain processes this information.Your brain has the ability to determine what color of light is bouncing off the object that you are looking at, and then subtracts that color from the "real" color of the object. Neuroscientist, Jay Neitz says, "Our visual system is supposed to throw away information about the illuminant and extract information about the actual reflectance." Neitz has been studying individual difference in color for 30 years and said that this one of the dress is "one of the biggest individual differences that I have ever seen." So looking into how this picture of a dress is an illusion to our eyes is because of the daylight that is visible in the photo, for daylight changes color. Bevil Conway, a neuroscientist, explains this by saying, "What's happening here is your visual system is looking at this thing, and you're trying to discount the chromatic bias of the daylight axis. So people either discount the blue side, in which case they end up seeing white and gold, or discount the gold side, in which case they end up with blue and black."
       Another illusion that I looked into is know as 'The Rubber Hand' illusion. How this works is one person sits down at a table placing one of their hands behind a wall, out of sight. It is then replaced with a rubber hand. The point of the illusion is to make the participant feel as if that rubber hand is actually their real hand. Another person who is controlling the illusion, will then begin to stroke both the rubber hand and the real hand at the same time with a

brush. After awhile the participant's brain will soon start to adapt and adopt the rubber hand as its own. At this moment the other person will then hit the rubber hand with a hammer. Even though it is not the participants real hand they will jump with fright, because for a moment they will believe it was theirs. This illusion is great example of how our motor sensory perception can influence how we perceive our own body so that one would believe the rubber hand to be real. This act adapting and adopting of the brain is known as neuroplasticity. This is an idea that says that our brain can change in response to our experience.
       If you are like me and are interested in how illusions work, then I would recommend you go and look at all of the illusions that Michael Bach has gathered together. He goes through dissects and explains the reasoning behind why they work. It is really fascinating how illusions have such an effect on our brain. 

Sources:

http://michaelbach.de/ot/index.html

The Dress: https://www.wired.com/2015/02/science-one-agrees-color-dress/

The Rubber Hand Illusion: https://www.youtube.com/watch?v=sxwn1w7MJvk