Visual Perception 2 Flashcards
which area in the visual filed of view are more likely to be perceived as figures rather than background
areas lower in the vf more likely to be figures than background
- areas in the upper visual field we see the sky/ceiling and the objects are usually lower
ex. cows against sky
is there a right or left preference for determing figure from background
no
figures are more likely to be perceived on the ___ side of the borders
convex
borders that bulge out
when we isolate or limit the objects in the image, the likelihood that the convex borders will appear as figures is …
decreased, meaning that segregation takes into account a wider scene
what is the border-color effect
the direction that the color is spreading defines the object
the grouping principles overpower what?
think of M and W example
past experience
gestalt psychologists thought that _____ is one of the first htings to happen in the perceptual process
-what did they argue
figure-ground
-they argued that figure must stand out from the ground in order to be recognized (and categrozied)
what experiment disproved gestalt psych saying figure-ground is one of the first things to happen
experiments by gibson and peterson (1994) showed that figure-ground perception can be influenced by the meaningfulness of the figure
ex. lady turned upside down cant tell background anymore
meaningfulness can influence the perception of a figure against a background which means that…
the process of recognition must occur at the same time or as right before the process of segregation (segregating the figure from the ground)
ex. either we segregate figure from the background at the same time as we recognize that its a lady or we recognize it as a lady and then segretate
in scene perceptions, the figure-ground segregation finds _______ in the perception of a scene
real-world applications
what does a scene contain
a background and multiple objects on the foreground that are organized in a meaningful way
objects in a scene are compact and are acted ___ while scenes are extended in space and are acted ____
acted upon
acted within
what are global image featuers
feathers w/in a scene that help us to perceive the gist of the scene
despite the complexity of a scene we can give a general description of the type of the scene. what is this known as
the gist of the scene
how fast can the gist of a scene be perceived w/in
w/in a fractin of a second (~250 ms)
what are the global image features
degree of naturalness degree of openness degree of expansion degree of roughness color
man-made scenes are dominated to be horiz and vert lines while natural scenes have texture and undulating contours. what is this known as
degree of naturalness
open scenes have a visible horizon line and contain few _____ .
what is this known as
objects
degree of openness
ex. ocean
rough scenes contain many _____ and are more complex
-what is this known as
objects
degree of roughness
ex. the forest and city have high degree bc many objects
scenes w/ parallel lines that _____ show a high degree of expansion
-what is this known as
converge
degree of expansion
ex. city scene has high degree of exp
-no 2 lines in the forest/ocean converge to a single point
some scenes have a predominant characteristic color, what is this known as
scene perception-color
ex. ocean blue and forest green
these global image features are holistic-must be applied to the _______ image, and rapidly perceived and do not contribute in perceiving ___and recognizing ___
whole
details, objects
global image features also demonstrate that _____ influences the perception of a scene
past experience
ex. we know the ocean is blue and therefore we get the gist of a scene w/ only this knowledge
other info we use for perceiving scenes are the ….
this happens….
regularities of the environment
-happens unconsciously
what are the 2 types of regularities
- physical regularities
2. semantic regularities
what are physical regularities
the physical properties that occur in the environment
ex. trees and flowers grow in upright position
we are more sensitive to perceiving horizontal and vertical lines (vert grating) we are not as good as perceiving oblique objects. this is known as the..
oblique effect
a physicla regularity is that objects in the environment have _____ colors (pinciple of similiarity) and can be described by a single color.
homogenous
our experience says that light is coming from above, whether the light comes from the sun or from artificial lighting. waht is this known as
what asssumption can we use in this
shape from shading
-we can make assumpitions using this physicla regularity called light from above assumpiton
what are the characteristics assotiated w/ the functions carried out in different types of scenes
semantic regularities
-the meaning of a scene
ex. cooking/eating happens in the kitchen
dancing happens in the club
-we have knowledge of things happneing in certain scenes and we are using it for perception
we use our knowledge for physical regularities and semantic regularities to actually infer what is in a ____
scene
what is the theory of unconscious inference
-when did hemholtz introduce this
some of our perceptions are the result of unconscious assumptions we make about the environment
-hemholtz introduced this is the late 19th century
what is object and scene perception based on
-based on what principles
both object and scene perception are based on assumpitons we make about the environment and the object, based on grouping and segregation principles and based on experience for regularities in our world
do object and scene perception involve action from the observer?
no. all unconscious process
what is the process of focusing on a specific object and ignoring others called
attention
we can’t pay attention to all the objects in a scene
the perceptual system has a limited capacity for ____
processing info in a scene
the perceptual system withdrwas from some things in order to deal more ……
effectively w/ others
wehre do we attend? do we attend to what interests us?
yes, but not just that
we look at a whole scene in addition to the object of iinterest
what is it called when we move our fixation from object to object until we find the one that interests us
visual scanning
-one mech for selecting certain things in a scene
how do we find justin beiber? we fixate on each face and decide whether or not it is him, if not we move to another face until we find him. how do we acheive this
saccadic eye movements
-fast jerky eye movements from one object to anotehr
how often does scanning happen
not happening only when consciously looking for an object but happens continuously
how many saccades per sec do we make when we are freely viewing a scene (w/o looking for something in particular)
3 saccades per second
how can companies use our perceptual system to know where to put advertisements and hwat color they should be
eye gaze tracking. the person begins to scan a webpage
by using eye saccades, he was able to scan the whole website page to look for something tha tinterested him
what 2 types of attnetion does visual scanning involve
- overt attention
2. covert attention
what is overt attention
when we consciouly fixate at objects and direct our attention to them
what is covert attention
when we don’t fixate on an object but our attention is directed towards it
ex. basketball player img-the players are not looking at each other but their attention is on the other one to gauge their next move
attention can be directed by _____ processes (stimuli that stand out) and by _____ processes (goals and intentions or cognitive factors)
involuntary
voluntary
involuntary processes are directed by ____
stimulus salience (salience=importance)
what does stimulus salience refer to
physical properties of the stimulus like color, contrast movement and orientation that makes this stimulus to stand out from the rest of the objects
what are the different types of stimulus salience
- color salience
- contranst salience
- orientation salience
- movement salience
what is it called when our attention is directed by stimulus salience
attention capture
bc its something that captures our attention
why can attention capture be really important
serves as a warning
ex. animal on the highwya
what usually influence the way we attend a scene
experience and knowledge
top-down processing
in addition to experience and knowledge, the direction of attention can also be influenced by…
personal preference
ex. architect will look at architecture of the building and geologist will be more attentive to the rocks in the scene
