Hi, I'm Michael Corayer and this is Psych Exam Review.
This is the first video in our sensation and perception unit so I'd like to start by clarifying what's the difference between sensation
and perception?
So sensation refers specifically to the stimulation of our sensory organs. You might
remember this by noticing that stimulation and sensational both start with S so that can remind you that sensation refers to the stimulation
of your sensory organs.
So what I mean by this is that physical things in the world
stimulate our sensory organs so light hits our retina or sound waves vibrate our eardrum, or things touch our skin, or chemicals go up our
nose or onto our tongue and this stimulates these organs.
Now we have to convert this stimulation because this is a physical signal in the world but it's not something
that our brain can really work with. We need to convert it into the language of the brain
and the language of the brain is neural activity, it's neurons firing.
So we need some process to go from a physical signal like a light wave or a sound wave into neurons firing in
the brain. So for each of our senses we're going to have a process of transduction.
And this refers to the translation into
the language of the brain, into rural activity. So transduction
is the term we use to refer to this conversion
from a physical signal in the world into neurons firing in the brain, into neural activity.
In future videos, for each of our senses, I'll go through and explain how we get
from physical to neural activity. So we'll see the process of transduction for each of our senses.
OK so we have this stimulation it gets converted into brain activity
and now we can start thinking about the process of perception.
so perception is
how we organize and interpret the information that's coming in.
So perception refers to the organization and the interpretation
of the incoming information.
This means that
there's a possibility for learning and experience here. These play a role in perception because
for instance, you can probably tell the difference between the sound of a piano and the sound
of a violin. Each of these instruments stimulates
brain activity slightly differently
and you have learned which of these is playing. You've learned to recognize the sound of a piano vs the sound of a violin. You weren't born
knowing this. You didn't know what a violin sounds like. But through experience and learning you learn how to interpret
this particular pattern of activity. These sound waves from a violin are going to cause a particular pattern of neural activity
and you have learned how to recognize that. The same is true vision. You learn how to see. Even if your sensory organs are
working properly, light is stimulating your eyes, you still have to learn what it is that you're seeing. You have to figure it out.
That's where the role of perception comes in, organization and interpretation of this information. Now when we recognize that
it takes some learning and experience to perceive things we also can realize that we can make mistakes. We can misinterpret things.
We can have a sensation and I can interpret it one way, you can interpret another way. One of my favorite demonstrations of this is a very
simple one and you've probably drawn one of these before.
But perhaps you didn't know what it was called.
This is called a Necker Cube.
This is a very simple demonstration of the idea that
the sensation can be perceived in multiple ways, there's multiple interpretations. So when you look at
this you can choose to see this as the front panel
extending to the right there, or you can choose to see this as the front panel extending off to the left here. Now the stimulation,
the sensation, is not changing. The light pattern hitting your retina is exactly the same in both cases
but the perception is different. How you organize that information changes and you can do this at
will. You can look at it and choose to see this is the front panel or this is the front panel.
So we can consciously change our perception of things.
At least in this case where they're somewhat ambiguous. It's not clear which one is the front panel
and which one is, which direction it's extending.
OK so this idea that we can perceive things in multiple ways
opens up the possibility that we misperceive things. We misinterpret them.
But an important point is that we misinterpret things,
but we misinterpret them in predictable ways. So when you look at this I don't know if
you're seeing this as the front panel or this as the front panel.
But I can be pretty sure that you're not seeing this as the front panel.
So even though I know you might misinterpret it, you're going to misinterpret it in predictable ways. This is really the key to
understanding how illusions work. Illusions are all about causing this to misperceive things but knowing that we're going to misperceive them
in predictable ways. This is not just true of illusions, it's also true of other biases and errors that we're going to see
when we problem solve, when we make decisions
and so understanding this is not just for understanding
sensation and perception it's really for
all sorts of errors that we make.
OK I hope you found this helpful, if so, please like the video and subscribe to the channel for more.
Thanks for watching!