Name: 自下而上與自上而下的處理方式 (Bottom-up vs. Top-down processing)
Uploaded: 2021-01-14T05:57:13.000Z
Duration: 4 min 27 s
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Voiceover: Let's look at the difference between

Bottom-up processing basically begins with the stimulus,

so let's imagine that we're looking at something,

So, stimulus influences what we perceive, our perception.

So, if I know absolutely nothing about something,

then the stimulus or whatever it is I'm looking at,

yet I don't know anything about, I've never seen it,

I don't have any preconceived cognitive constructs

The stimulus basically is influencing my perception.

I'm basically looking at all the different

little parts of something that is new and novel to me,

and trying to kind of comprehend what it is I'm looking at.

This is when you start with no preconceived idea

your perception of what it is that you're looking at.

and your perception of what it is that you're looking at

directs your cognitive awareness of the object.

basically uses your background knowledge,

So, let's look at this example over here.

So, what we're actually seeing are a bunch of circles,

they are just a bunch of circles and then

inside the circle there are a couple of lines drawn.

So, we are looking at this set of circles,

these white circles with lines drawn inside of them.

We're basically taking these lines and then

putting them together in order to create a cube.

and there is absolutely nothing in the black spaces,

but our brains are basically taking this information

we're recreating a cube despite a lack of

a cube actually being present in the image.

your background knowledge, your learning,

even though one's not actually drawn there,

So, we're using what's already in our heads

in order to perceive what it is that we're looking at,

whereas in bottom-up processing we're using

the stimulus itself in order to drive our perception.

So, if we were using bottom-up processing

be seeing a whole bunch of little people,

but with top-down processing we have a goal,

and we're able to look through here to find Waldo.