Chapter 3: Fundamentals of Perception Flashcards
what is perception?
an experience resulting from a stimulus which provides information for cognition
some perception is_______and some is_____________
personal (ex. pain and beauty)
environmental (gaining accuracy as we gain information) (the bike, wall, sitting picture)
visual cognition is very _________
complex
computers struggle with it more than humans
the 2004 DARPA grand challenge
DARPA created a 150 mile driverless car challenge
the best vehicle made it 7.4 miles before getting stuck on a rock
humans are very good at making sense of ________. Whereas computers can_____________.
complex visual scenes
make look at more things at once, but with less accuracy
why is visual perception so difficult?
-the inverse projection problem
-partial information
-viewpoint variance
what is the inverse projection problem?
-visual sensory information without context is ambiguous, all sensory info looks the same to our retina/a computer
**look at the photo of the soccer balls
ie) a lego soccer ball an inch from your face looks the same to your eye as a 100 ft soccer ball 100 feet away or something like that you get the point
this is why optical illusions work
what does partial information have to do with the difficulty of visual processing
-objects can be partially hidden or blurred which gives us a loss of high frequency information which makes things difficult to decipher without context
what does viewpoint variance have to do with the difficulty of visual processing?
-scenes are constantly changing based on the angle you are looking at them from
what helps make visual processing easier?
experience and processing power
how do humans handle things like visual and auditory processing so well?
utilizing top down and bottom up processing
what type of processing is related to sensation?
bottom up processing
what is bottom up processing
processing that occurs when one does not have previous experience with the stimulus
usually taken from environmental information
ex1. you hear a strange beeping you have never heard before and use your senses to figure out what it is
ex2. the zelda song in class to you
ex3. visual light on the eye or pressure on the eardrum
what type of processing is associated with perception?
top down processing
what is top down processing?
processing that occurs when you have previous knowledge or expectations about the stimulus
ex.1 a song plays that to the normal person may just be a song, but to you it is your ringtone so it makes your skin crawl a little
ex 2 you see a photo of a really specific piece of softball equipment, and a normal person may not know what it is, but you perceive it differently because you have context.
ex 3 the swedish o that looks like a face but actually means island
what are the ways top down processing is used in visual context?
- semantic context:
these are facts that help us process
ex. horses and humans go together, horses and engines do not, therefore the blurry photo must be a person on a horse - spatial configuration:
this is locational context
ex. humans ride on top of horses, horses cannot ride on top of humans or they would crush them. therefore in the blurry photo the human must be sitting on top of the horse - pose
this is directional context
ex. horses and humans typically face the same way when riding. So we will perceive the blurry horse riding photo as being a person facing forward even though they’re actually facing backward
how is top down processing used for speech?
- speech segmentation
-recognizing where one word ends and another begins
how does speech segmentation work?
we use transitional probability, meaning we learn what sounds typically signify the end of a word
ex. -ing, -tion, -ed, -ly
most perception is….
unconscious,, we just do it