Distortions in perception Flashcards
fabiability
the tendency to make mistakes
is our visual perception perfect
no, it is fallible due to expectations from prior experience or errors can also arise from the stimulus itself or/and from how the sennsory information is processed in the brain
visual illusions
when the perception of a visual stimulus conflicts/differs it is in physical reality/objective reality, most people percieve visual illusions in the same away
is the illusion effecr unavoidable
yes, even when we know we at looking at an illusion our perception is still confused, demostrating its fability
what illusions are we required to know
tthe muller lyer illusion, ames room illusion and spinner dancer illusion
muller lyer illusion
the misinterpretation of two lines of equal length, each with differnt shaped ends (arrowhead/featthertail)
two explanations for muller lyer illusion
biological explanation, social explanation (carpentered-world hypothesis) and apparent distance theory
biological explanation of muller lyer
due to convergence, however this theory is no longer supported
why is the biological explanation of muller lyer not supported
because research has shown that the mullerlyer illusion still persists even if there is no eye movement
how does convergence cause us to view the arrowhead tail as shorter
the arrowheads cause the eyes to turn inwards, creating more tension in the muscles surrounding the eyes, and causing us to percieve tthe line as being closer to us
how does convergence cause us to view the feathertail lines as longer
the feathertail line causes the eye to turn outwards, creating less tension and leading us to percieve the line is further away and therefore longer
carpentered world hypothesis
illusion due to culture, the perception of the two lines is influenced by ones familiarity with modern, western building designs
why does the carpentered world hypothesis make us view tthe feeathertail lines as longer
internal walls have a feathertail shape which are seen as further away and therefore onger
why does the carpentered world hypothesis make us view the arrowhead tail as shorter
external walls have an arrowhead tail shape and are percieved as closer to us so are therefore viewwed as shorterr
how was the carpentered walls hypothesis proved
people who have grown up in cultures in which society is restricted by internal walls are more likely to be tricked those who have grown up in cultures with non-rectunagular designs
apparent distance theory
if two objects cast the same sized retinal image, but one is percieved to be further away, our brain interprets the more distant object as larger
what visual process is used in the apparent disatnce theory
size constancy
how does tha apparent distance theory apply to the muller lyer illusion
our brain uses top-down processing to make sense that the more distant feathertail line can only project the same-sized retinal image as the arrowhead line if it is longer
why are the carpented world theory and apparent distance theory limited in explaing the muller-lyer illusion
because even if the arrowheads/feathertails are replaced with different differntly shaped ends and therefore when turned on their side, would not create percieved depth as a result of familiarity with western building design
what is the ames room illusion
an illusion in which a person views two people in a special ames room through a peephole using only one eye. the person on the left of the room appears much tinnier than the person on the right even though they are both normal sized
how does an ames room work
by using the peephole, it prevents the person from using both eyes and therefore binosular depth cues which is importnat for percieving relative distance of objects
ames room explanation
is often explained with reference to perceptual constancy. the observer has no access to binocular depth cues and therefore cannot perceive that the far left corner of the room is actually further away. This creates the illusion of a standard rectangular room. This shape is maintained by shape constancy, but then must account for the size of the people in the room relative to the height of the walls. This is why we see the people as shrinking or growing as they move around the room
what reinforces the assumption that a room is rectangular in the ames room
by top-down processing where the observer has been raised in a culture in which rooms tend to be rectangular –this is what they expect to see.
what is the spinner dancer illusion
an illusion in which a dancer can be percieved as spinning clockwise or anticlockwise and the same viewer can alternate between percieving a clockwise or anticlockwise spin
