Form Perception Flashcards
Gestalt principle
the whole is greats than the sum of its parts
1) figure-ground
ability to distinguish an object from its background
flowers and floral wallpaper
2) proximity
object close together belong together
3) closure
the tendency to lose gabs in to perceive a whole effect
4) similarity
the tendency to group together things that are physically similar
5) continuity
the ability to perceive a simple continuous form rather than a combination of awkward forms
6) common fate
the tendency to group things together that move and change in the same way
bottom-up processing
recognition guided by features of a stimulus
top-down processing
recognition guided by beliefs and expectations
priming effect
processing is more efficient if primed to expect a certain category
bidirectional processing
bottom-up and top-down processing working togehter
geon theory
- we have 36 geons
- using just these we recognize over 150 million objects
template theory
we store many diffrent templates in memory
if unfamiliar object seen, create a new template
prototype theory
we atore typical / ideal exa,lpe in memory, this is more flexible
1) shape constancy
no matter perspective of location
2) location constancy
despite mving on retina pecieved to be stationary (tree while driving by)
3) size constancy
despite sie of retinal image (close vs. far)
4) brightness constancy
despite reflecting more or less light
5) colour constancy
despiteillumination changes
illusions
brain processing ambiguous or partial visual information
Müller - Lyer Illusion
(lines of same length with arrows facing either way)
missapplying size constancy
Ames Room Illusion
(room looks square but is trazoidal so person B looks much closer)
missapplying size constancy
Ponzo Illusion
(two horizontal lines and two converging lines)
missaplying size constancy
parvocellular pathway
retina > axons > optic nerve > LGN > primary visual cortex
magno cells
mainly in the periphery of the retina
detect changes in brightness, motion and depth
parvo cells
throughout retina
detects changes in colour, pattern and form
simple cells
responds based on orientation
opponent fashion
complex cells
respond based on orientation and direction
no “off-zones”
supercomplex cells
respond based on orientation, direction, and length
have very specific inhibitory regions
retinotopic mapping
neighboring objects on the visual field will be processed by neighboring areas in your brain
cortical columns
there are 5 layers of neurons, each layer responding to stimuli that come from the same category
preferential looking method
used to determine that infants prefer the most complex stimuli they can percieve
where do we focus?
under two months: outer contour
over two months: whole shape
can percieve shapes when given only part of shape
3 months
can determine seperate object if move independently
3 months
begin to use colour and texture to differentiate objects
5 months
when do infants begin to develop and understand shape brightness and colour constancies
4 months
some sense of size constancy when?
4-5 months (stared longer at bigger bear))
innate face preferences
4 days: prefer faces
2 months: prefer attractive faces
5 months: can detect emotional expression
just a preference for complex stimuli?
vision development requires
gne and enviroment interaction
visual deprivation for 3-4 days at 1 month old
brain region begins to deteriorate
visual deprivation for 1+ week at 1 month age
visual regions have severe and perminant damage
cataract
distrupt light from passing through lens
PVC damage
like looking through a keyhols, will lose vision in some areas
extrastriate cortex damage
distrupt recognition of objects
object agnosia
cannot detect object by sight but can by touvh
prosopagnosia
inability to recogize faces
fusiform face area is damages
face on mars
people look for meaning in ambiguous stimuli
hollow face illusion
appears like face pops out and rotating opposite way
inverted face
mot as sensitive to changes when faces are upside down
