Perception Flashcards
what is the order of perception
- transduction
- sensation
- perception
- cognition
transduction
process of converting physical energy into neural impulses
sensation
bare awareness resulting from activation of a sense cell
perception
organize and identify stimuli
cognition
process of being aware and thinking about anything
what are the 2 functions of perception
- tell us what stuff does
2. tell us where stuff is
is perception constant
no, it is constantly changing
is perception immediate
no it is the end result of a process
is perception passive
no it is active and it allows us to interact with the world
luminance
amount of light that enters the eye
what 3 things enter the eye
- light source
- reflectance
- shadow
view point invariance
we perceive objects even though we look at them from different angles
size and distance illusion problem
a small image could be a small object or a big object far away
4 methods of dealing with difficult visual illusions
- taking advantage of regularities
- frames of reference
- shadows and shadings
- convergence and retinal display
types of regularities
physical and semantic
physical regularities
we know what objects are likely to be
semantic regularities
we use our knowledge of the world
convergence
brain keeps track of what muscle in the eye are doing
retinal disparity
difference between 2 eyes
visual space
everything that falls on the retina
path from the eye to the brain
optic nerve -> optic chiasm -> LGN and superior colliculus
optic chiasm
point at which left visual field decussates to the right side of the brain
lateral geniculate nucleus
relay station also containing the reticular activating system
reticular activating system
controls sleep-wake cycles
superior colliculs
receives about 10% of information from eyes and controls eye movements
2 visual pathways
dorsal and ventral streams
who came up with the what/where hypothesis
Ungerleider and Mishkin
what pathway
ventral stream specializing in “what” something is
where pathway
dorsal stream specializing in “where” something is
issue with this theory
spatial information is needed to recognize an object. therefore knocking out the where pathway should make objects unrecognizable
who came up with the what/how hypothesis
Goodale and Milner
what stream in what/how pathway
associated with consciousness and awareness
how stream in what/how pathway
gives information on how to interact with objects
visual agnosia
inability to recognize objects
optic ataxia
problem with guiding your hand to grab something
what other evidence supports what/how pathway
fMRI imaging and steepness of hills
synaesthesia
condition in which activation of one sense automatically activates another
where does synaesthesia come from
synaptic pruning does not occur properly in young brains
what allows synaptic pruning to occur
apoptosis
blindsight
ability to visually identify objects even though the visual center has been damaged
what causes blindsight
a damaged “what” pathway with a functioning “how” pathway
bottom-up processing
putting together basic features to form perceptions
template matching theory
templates are copies of shapes in the memory and matching a template = recognizing an object
problem with template matching theory
variation in objects that we can still recognize (eg: fonts)
multiple trace memory model
every time you encounter something you compare it to every instance of seeing something similar
2 steps of multiple trace memory model
- probe
2. echo
probe
see something and compare it to similar things
echo
compare it to the average of every similar thing
who created the pandemonium model and when
Selfridge (1959)
pandemonium model
processes multiple types of information simultaneously to detect features
3 kinds of demons in this model
- feature demons
- cognitive demons
- decision demons
feature demons
detects basic features of objects
cognitive demons
recognize letters
decision demons
make a final decision
what phenomenon does this model explain
tip of the tongue
who created the recognition by components model?
Biederman
recognition by components model
everything is composed of geometric components called geons
geons
geometric icons
evidence for recognition by components model
- we can identify objects without texture, shading or color
- more complex objects recognized faster (more geons)
- intersections in geons are most important information
problems with recognition by components model
- objects change as they move
- we can determine info about people by looking at details in their face
- upside down faces are harder to recognize than upside down objects
who created the ecological theory
Gibson
ecological theory
environment shapes perception
affordance
shape of something determines how we should interact with it
scatter reflection
different textures reflect light in different ways
transformation
change in information entering our eyes as we move
optic flow
change in an object’s position as it moves past us
top-down processing
prior expectations influence perception
gestalt psychology
belief that the mind has to be studied as a whole
6 laws of gestalt
- good contour
- pragnanz
- similarity
- proximity
- closed forms (closure)
- common movement (fate)
pragnanz
similar shapes are grouped together
problems with gestalt
too simplistic and not always true
