Perception Flashcards
Define perception
integration of stimulation from the senses in active process; involves inferences and involves top-down processes.
how is perception different to sensation
more psychological and occurs later; sensation is more biological
what are top down processes
the involvement of memory, expectations, mood, current context and beliefs on the interpretation of information from the senses.
what does perception allow
sensation to become perception
give 2 examples of inference in perception
perceptual constancy
brightness contrast
what is perceptual constancy
despite variation in the “raw data” received by the brain from the senses, our perception of the world remains remarkably constant.
what 4 perceptions remain the same despite perceptual constancy
size
shape
colour
brightness
define brightness contrast
perception of brightness depends on the absolute amount of light reflected from surface of an object and on amount of light reflected from other objects in the vicinity.
what is brightness contrast in contrast to
brightness constancy
what is a top down process; give 3 examples
Filling in the gaps
phonemic restoration, illusory contours, degraded figures
define perceptual set
readiness to interpret stimuli in certain way depending on expectations, experience, psychological state.
what are perceptually ambiguous figures
figures that can be perceived in 2 different ways.
same “raw material” from the senses different
“interpretations”
can bias interpretation of figure by manipulating perceptual set
what is the proposed argument for perception and reality
that we may have adjusted well to a distorted perception of reality and thus are not experiencing objective reality
give an example of research into perception and reality
Stratton and his inverted world goggles
what examples are there for arguing we impose our own reality
Descartes Malevolent Demon
VR
how do we locate an object with visual perception
depth perception
define depth perception and what it encompasses
ability to judge distance; encompasses absolute and relative distance
what are binocular depth cues
need 2 eyes; for examples convergence or retinal disparity
what are monocular depth cues
only need one eye; for example motion parallax or linear relative size
what is convergence
eyes move together as object gets closer
muscle tension is a cue to how far away object is
what is retinal/ binocular disparity
slightly different views of world presented to each eye interpreted by brain to give depth information.
The further object is, the less the disparity btwn the images projected on the retinas of the 2 eyes
what is motion parallax
objects closer to observer appear to move faster
what is relative size
size of an object relative to others around it.
must have prior knowledge of size of object
attribute difference in size of retinal image to distance rather than size.
give an example of relative size
moon illusion where moon on horizon seems larger so assume objects on horizon are farther away
automatically scale size according to distance
what is linear perspective
Apparent convergence of parallel lines on the horizon. Converge at vanishing point.
what is texture gradient
distant objects are denser, less detailed, closer together
what is aerial perceptive
distant objects fuzzy due to moisture and particles in the air
what is occlusion
objects occlude others perceived to be closer
what are visual illusions; give 3 examples
when we are fooled by top down processes
Muller Lyon effec; Ponzo illusion; Ames room
what is the Muller Lyon effect
depth cues suggest it is closer, the principle of size constancy causes us to see same size retina image as larger
2 lines
similar to moon illusion
what is the Ponzo illusion effect
linear perspective suggests object is further away; perceptual system makes same size retinal image
seem larger
size constancy
bread on train tracks
what is the Ames room illusion
all depth cues suggest these people in room are the same distance from the observer; actually they are not
what is absolute distance
distance btwn observer and object
what is relative distance
distance btwn objects
what are the 3 steps in locating objects using auditory perception
Difference in the intensity of sound at the two ears
Overall intensity of sound; if louder: closer
Difference in the time it takes sound to reach different ears
what is evidence for the innate nature of auditory perception
newborns will turn head to face sound
what happens when we do no perceive motion; e.g. stable objects and move our eyes; we see a stable image despite retinal image change
Perceptual system compensates for voluntary eye movements.
If move eyes with something other than eye muscles then perceptual system can’t compensate; see object as moving
what happens when we do perceive motion e.g. need to distinguish btwn object or observer movement
Notice how the background changes relative to object. Moving object occludes objects as it moves; if we are moving then objects appears more stable relative to background.
how do the ears help in motion perception during perceived motion
discrepancy in sound intensity to each ear gives information about movement
what is an example of an illusion of motion
apparent motion
what is the Phi-phenomenon
apparent motion produced by succession of flashing lights
what is induced motion
if objects near a stationary one are moving, the stationary one appears also to be moving.
what is the motion after effect
after moving forward for some time and then stop; scenery outside seems like moving backward slightly.
what is apparent motion; give 2 examples
perceptual system fills in gaps on successive, motionless images
e.g. motion pictures; animation
what are the 2 ways we perceive form and are they top down/bottom up processes
Gestalt - top down
Feature analysis - bottom up
what is the Gestalt process and what does it use
can’t understand perception by looking at the whole built up from the parts; must perceive the object as a whole first then analyse the parts
use of perceptually ambiguous figures and filling in the gaps
define filling in the gaps
the perceptual system wants to make a holistic interpretation; if pieces are missing, fills them in using memory
what are perceptually ambiguous figures in Gestalt
the Gestalt/organisation can “flip” on you and suddenly a brand new interpretation is obtained
how are Gestalts formed
Organising Principles
what are the 2 organising principles of Gestalt
figure/ground principle and grouping principles
what is the figure/ground principle
the distinction btwn that which stands out (figure) and that which is back(ground)
what are the 3 grouping principles
proximity
good continuation
closure
why can’t you see both Gestalts at once
because gestalts “flip back and forth” from one organisation to the next
how do Gestalt principles help problem solving, especially with AHA! type problems
AHA! type problems organised into a particular Gestalt,
but suddenly “flip” for new interpretation necessary to solve the problem.
from prior experience, fixate on one organisation of problem
Solving the problem involves new Gestalt accompanied by a feeling of eureka or an AHA! experience.
give 2 pieces of evidence for the nature explanation of perceptual organisation
At 6 months, not go to beckoning mother if there is a visual cliff- shows that infants respond to depth cues
Newborns show preference for shapes resembling
human faces
give 2 pieces of evidence fro the nurture explanation of perceptual organisation
Feature detectors cells
Perceptual adaptation and Differentiation adaptation
what is perceptual adaptation; give an example
refers to the ability to adapt to an environment by filtering out distractions
e.g. filter out train sound to sleep at night
what is perceptual differentiation; give an example
when experience refines perception
e.g. trained musicians can hear subtleties in harmony that others would miss
why are feature detection cells evidence for the nature explanation of perceptual organisation
because can be trained to be sensitive to particular orientations
