[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.70,0:00:03.19,Default,,0000,0000,0000,,Voiceover: Let's look at\Nthe difference between
Dialogue: 0,0:00:03.19,0:00:06.21,Default,,0000,0000,0000,,top-down and bottom-up processing.
Dialogue: 0,0:00:06.44,0:00:10.08,Default,,0000,0000,0000,,So, what is bottom-up processing?
Dialogue: 0,0:00:14.76,0:00:19.38,Default,,0000,0000,0000,,Bottom-up processing basically\Nbegins with the stimulus,
Dialogue: 0,0:00:19.38,0:00:21.91,Default,,0000,0000,0000,,so let's imagine that\Nwe're looking at something,
Dialogue: 0,0:00:21.91,0:00:24.36,Default,,0000,0000,0000,,or let's say I'm looking at a banana.
Dialogue: 0,0:00:24.36,0:00:26.64,Default,,0000,0000,0000,,The banana is sitting there and
Dialogue: 0,0:00:26.64,0:00:29.10,Default,,0000,0000,0000,,it influences what we perceive.
Dialogue: 0,0:00:29.47,0:00:38.21,Default,,0000,0000,0000,,So, stimulus influences what\Nwe perceive, our perception.
Dialogue: 0,0:00:39.56,0:00:43.52,Default,,0000,0000,0000,,So, if I know absolutely\Nnothing about something,
Dialogue: 0,0:00:43.52,0:00:47.30,Default,,0000,0000,0000,,then the stimulus or whatever\Nit is I'm looking at,
Dialogue: 0,0:00:47.30,0:00:49.69,Default,,0000,0000,0000,,yet I don't know anything\Nabout, I've never seen it,
Dialogue: 0,0:00:49.69,0:00:53.45,Default,,0000,0000,0000,,I don't have any preconceived\Ncognitive constructs
Dialogue: 0,0:00:53.45,0:00:55.26,Default,,0000,0000,0000,,about what it is I'm looking at.
Dialogue: 0,0:00:55.26,0:00:59.25,Default,,0000,0000,0000,,The stimulus basically is\Ninfluencing my perception.
Dialogue: 0,0:00:59.25,0:01:02.12,Default,,0000,0000,0000,,So, for example let's imagine that
Dialogue: 0,0:01:02.12,0:01:05.64,Default,,0000,0000,0000,,I'm looking at a cockpit of a plane.
Dialogue: 0,0:01:05.73,0:01:07.23,Default,,0000,0000,0000,,I'm not a pilot, so I'm not really
Dialogue: 0,0:01:07.23,0:01:08.77,Default,,0000,0000,0000,,too familiar with everything and
Dialogue: 0,0:01:08.77,0:01:12.27,Default,,0000,0000,0000,,everything kinda looks fairly confusing.
Dialogue: 0,0:01:12.66,0:01:15.41,Default,,0000,0000,0000,,So, basically all the different stimuli,
Dialogue: 0,0:01:15.41,0:01:18.58,Default,,0000,0000,0000,,so this stimulus, a bunch of gauges,
Dialogue: 0,0:01:18.58,0:01:20.70,Default,,0000,0000,0000,,and this rudder-looking thing,
Dialogue: 0,0:01:20.70,0:01:23.30,Default,,0000,0000,0000,,I'm basically looking at all the different
Dialogue: 0,0:01:23.30,0:01:27.42,Default,,0000,0000,0000,,little parts of something\Nthat is new and novel to me,
Dialogue: 0,0:01:27.42,0:01:31.94,Default,,0000,0000,0000,,and trying to kind of comprehend\Nwhat it is I'm looking at.
Dialogue: 0,0:01:31.94,0:01:32.98,Default,,0000,0000,0000,,So, this is bottom-up.
Dialogue: 0,0:01:32.98,0:01:37.30,Default,,0000,0000,0000,,This is when you start\Nwith no preconceived idea
Dialogue: 0,0:01:37.30,0:01:38.63,Default,,0000,0000,0000,,of what it is that you're looking at,
Dialogue: 0,0:01:38.63,0:01:42.20,Default,,0000,0000,0000,,and allow the stimulus to influence
Dialogue: 0,0:01:42.20,0:01:44.90,Default,,0000,0000,0000,,your perception of what it\Nis that you're looking at.
Dialogue: 0,0:01:44.90,0:01:47.80,Default,,0000,0000,0000,,So, bottom-up processing is data-driven,
Dialogue: 0,0:01:50.22,0:01:52.41,Default,,0000,0000,0000,,and your perception of what\Nit is that you're looking at
Dialogue: 0,0:01:52.41,0:01:56.91,Default,,0000,0000,0000,,directs your cognitive\Nawareness of the object.
Dialogue: 0,0:01:57.50,0:02:04.36,Default,,0000,0000,0000,,So, in contrast, top-down processing
Dialogue: 0,0:02:05.59,0:02:07.58,Default,,0000,0000,0000,,basically uses your background knowledge,
Dialogue: 0,0:02:07.58,0:02:10.22,Default,,0000,0000,0000,,so uses your background knowledge
Dialogue: 0,0:02:13.90,0:02:18.45,Default,,0000,0000,0000,,to influence perception.
Dialogue: 0,0:02:20.51,0:02:23.16,Default,,0000,0000,0000,,So, let's look at this example over here.
Dialogue: 0,0:02:23.88,0:02:27.92,Default,,0000,0000,0000,,So, what we're actually\Nseeing are a bunch of circles,
Dialogue: 0,0:02:28.39,0:02:29.82,Default,,0000,0000,0000,,they are just a bunch of circles and then
Dialogue: 0,0:02:29.82,0:02:35.99,Default,,0000,0000,0000,,inside the circle there are\Na couple of lines drawn.
Dialogue: 0,0:02:35.99,0:02:39.66,Default,,0000,0000,0000,,So, we are looking at this set of circles,
Dialogue: 0,0:02:39.66,0:02:42.49,Default,,0000,0000,0000,,these white circles with\Nlines drawn inside of them.
Dialogue: 0,0:02:42.49,0:02:45.21,Default,,0000,0000,0000,,We are creating this cube.
Dialogue: 0,0:02:45.21,0:02:47.43,Default,,0000,0000,0000,,We're basically taking\Nthese lines and then
Dialogue: 0,0:02:47.43,0:02:49.45,Default,,0000,0000,0000,,putting them together in\Norder to create a cube.
Dialogue: 0,0:02:49.45,0:02:51.44,Default,,0000,0000,0000,,Even though the stimulus itself,
Dialogue: 0,0:02:51.44,0:02:53.91,Default,,0000,0000,0000,,which is the circles with the lines,
Dialogue: 0,0:02:53.91,0:02:55.90,Default,,0000,0000,0000,,actually doesn't draw a cube because
Dialogue: 0,0:02:55.90,0:02:57.73,Default,,0000,0000,0000,,there are these black spaces over here,
Dialogue: 0,0:02:57.73,0:03:00.59,Default,,0000,0000,0000,,and there is absolutely\Nnothing in the black spaces,
Dialogue: 0,0:03:00.59,0:03:03.41,Default,,0000,0000,0000,,but our brains are basically\Ntaking this information
Dialogue: 0,0:03:03.41,0:03:06.53,Default,,0000,0000,0000,,and using our knowledge of cubes
Dialogue: 0,0:03:06.53,0:03:08.16,Default,,0000,0000,0000,,and what they're supposed to look like,
Dialogue: 0,0:03:08.16,0:03:12.44,Default,,0000,0000,0000,,we're recreating a cube despite a lack of
Dialogue: 0,0:03:12.44,0:03:15.31,Default,,0000,0000,0000,,a cube actually being\Npresent in the image.
Dialogue: 0,0:03:15.31,0:03:16.65,Default,,0000,0000,0000,,So, that's top-down processing.
Dialogue: 0,0:03:16.65,0:03:18.79,Default,,0000,0000,0000,,It's using your background information,
Dialogue: 0,0:03:18.79,0:03:20.53,Default,,0000,0000,0000,,your background knowledge, your learning,
Dialogue: 0,0:03:20.53,0:03:22.38,Default,,0000,0000,0000,,your expectations, in order to influence
Dialogue: 0,0:03:22.38,0:03:24.47,Default,,0000,0000,0000,,what it is that we're perceiving.
Dialogue: 0,0:03:24.47,0:03:26.28,Default,,0000,0000,0000,,So, in other words, it's theory-driven.
Dialogue: 0,0:03:26.28,0:03:28.95,Default,,0000,0000,0000,,We look at this and we assume that
Dialogue: 0,0:03:28.95,0:03:30.88,Default,,0000,0000,0000,,they're trying to represent a cube,
Dialogue: 0,0:03:30.88,0:03:33.45,Default,,0000,0000,0000,,even though one's not\Nactually drawn there,
Dialogue: 0,0:03:33.45,0:03:35.95,Default,,0000,0000,0000,,and we're using that theory in order to
Dialogue: 0,0:03:35.95,0:03:37.72,Default,,0000,0000,0000,,shape our cognitive understanding
Dialogue: 0,0:03:37.72,0:03:40.13,Default,,0000,0000,0000,,of what it is that we're looking at.
Dialogue: 0,0:03:41.20,0:03:43.08,Default,,0000,0000,0000,,So, our perception, our behavior
Dialogue: 0,0:03:43.08,0:03:45.03,Default,,0000,0000,0000,,is influenced by our expectations,
Dialogue: 0,0:03:45.03,0:03:46.90,Default,,0000,0000,0000,,which is top-down processing.
Dialogue: 0,0:03:46.90,0:03:49.55,Default,,0000,0000,0000,,So, we're using what's\Nalready in our heads
Dialogue: 0,0:03:49.55,0:03:52.47,Default,,0000,0000,0000,,in order to perceive what\Nit is that we're looking at,
Dialogue: 0,0:03:52.47,0:03:55.12,Default,,0000,0000,0000,,whereas in bottom-up\Nprocessing we're using
Dialogue: 0,0:03:55.12,0:03:58.86,Default,,0000,0000,0000,,the stimulus itself in order\Nto drive our perception.
Dialogue: 0,0:03:58.86,0:04:00.42,Default,,0000,0000,0000,,So, another good example of top-down
Dialogue: 0,0:04:00.42,0:04:02.39,Default,,0000,0000,0000,,processing would be "Where's Waldo?"
Dialogue: 0,0:04:02.39,0:04:03.32,Default,,0000,0000,0000,,So, in "Where's Waldo?", we have a
Dialogue: 0,0:04:03.32,0:04:04.69,Default,,0000,0000,0000,,mental idea of what we're trying to do,
Dialogue: 0,0:04:04.69,0:04:07.19,Default,,0000,0000,0000,,which is to find Waldo amidst this
Dialogue: 0,0:04:07.19,0:04:10.30,Default,,0000,0000,0000,,really jumbled mess of a picture.
Dialogue: 0,0:04:10.30,0:04:12.15,Default,,0000,0000,0000,,So, if we were using bottom-up processing
Dialogue: 0,0:04:12.15,0:04:13.96,Default,,0000,0000,0000,,in order to look at this we would just
Dialogue: 0,0:04:13.96,0:04:15.87,Default,,0000,0000,0000,,be seeing a whole bunch of little people,
Dialogue: 0,0:04:15.87,0:04:18.66,Default,,0000,0000,0000,,and we wouldn't really be goal-driven,
Dialogue: 0,0:04:18.66,0:04:21.31,Default,,0000,0000,0000,,we wouldn't be trying to do anything,
Dialogue: 0,0:04:21.31,0:04:23.76,Default,,0000,0000,0000,,but with top-down\Nprocessing we have a goal,
Dialogue: 0,0:04:23.76,0:04:26.29,Default,,0000,0000,0000,,and we're able to look\Nthrough here to find Waldo.