Placeholder Image

Subtitles section Play video

  • Voiceover: Let's look at the difference between

  • top-down and bottom-up processing.

  • So, what is bottom-up processing?

  • Bottom-up processing basically begins with the stimulus,

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

  • or let's say I'm looking at a banana.

  • The banana is sitting there and

  • it influences what we perceive.

  • 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

  • about what it is I'm looking at.

  • The stimulus basically is influencing my perception.

  • So, for example let's imagine that

  • I'm looking at a cockpit of a plane.

  • I'm not a pilot, so I'm not really

  • too familiar with everything and

  • everything kinda looks fairly confusing.

  • So, basically all the different stimuli,

  • so this stimulus, a bunch of gauges,

  • and this rudder-looking thing,

  • 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.

  • So, this is bottom-up.

  • This is when you start with no preconceived idea

  • of what it is that you're looking at,

  • and allow the stimulus to influence

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

  • So, bottom-up processing is data-driven,

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

  • directs your cognitive awareness of the object.

  • So, in contrast, top-down processing

  • basically uses your background knowledge,

  • so uses your background knowledge

  • to influence perception.

  • 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 are creating this cube.

  • We're basically taking these lines and then

  • putting them together in order to create a cube.

  • Even though the stimulus itself,

  • which is the circles with the lines,

  • actually doesn't draw a cube because

  • there are these black spaces over here,

  • and there is absolutely nothing in the black spaces,

  • but our brains are basically taking this information

  • and using our knowledge of cubes

  • and what they're supposed to look like,

  • we're recreating a cube despite a lack of

  • a cube actually being present in the image.

  • So, that's top-down processing.

  • It's using your background information,

  • your background knowledge, your learning,

  • your expectations, in order to influence

  • what it is that we're perceiving.

  • So, in other words, it's theory-driven.

  • We look at this and we assume that

  • they're trying to represent a cube,

  • even though one's not actually drawn there,

  • and we're using that theory in order to

  • shape our cognitive understanding

  • of what it is that we're looking at.

  • So, our perception, our behavior

  • is influenced by our expectations,

  • which is top-down processing.

  • 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, another good example of top-down

  • processing would be "Where's Waldo?"

  • So, in "Where's Waldo?", we have a

  • mental idea of what we're trying to do,

  • which is to find Waldo amidst this

  • really jumbled mess of a picture.

  • So, if we were using bottom-up processing

  • in order to look at this we would just

  • be seeing a whole bunch of little people,

  • and we wouldn't really be goal-driven,

  • we wouldn't be trying to do anything,

  • but with top-down processing we have a goal,

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

Voiceover: Let's look at the difference between

Subtitles and vocabulary

Operation of videos Adjust the video here to display the subtitles

B1 UK processing stimulus cube perception bottom basically

Bottom-up vs. Top-down processing

  • 43 2
    Bonnie Hui posted on 2016/02/02
Video vocabulary