PSYC 230 UIUC - EXAM 3 QUESTIONS
bottom-up processing
process where physical stimuli influence how they perceive them
top-down processing
process where our existing knowledge of objects influences how they perceive them
recognition
ability to match a presented item with an item and memory
representation
the storage/reconstruction of information when it is not in use
perceptual organization
allows you to recognize/organize objects
(i.e. grouping, segregation)
grouping
organizing into groups (i.e. chairs, lights, plates, etc.)
segregation
making sense of different surfaces in a scene (what is behind, what is in front, etc.)
gestalt psychology
whole is greater than sum of its parts
structuralism
whole = sum of parts
figure-ground organization
distinguishing background vs foreground of a scene (top vs bottom, background vs
foreground)
figure-ground organization rules
symmetry, convexity/concavity
gestalt laws
good continuation, proximity, similarity, common region, connectedness, common fate
receptors used for edge detection
,V1 detectors
role of angles and edges
carry meaning
- "Y'-shaped edge means a corner
- "T"-shaped edge means an occlusion
- angles show good continuation
geon
basic component of an object
recognition by components thoery
(Biederman) objects are recognized by the relation of its geons
viewpoint invariance
recognition of an object is independent of one's viewpoint
problems wit recognition by components
- viewpoint invariance is not foolproof (preferred viewpoint leads to faster recognition)
- many geon combinations can be perceived as multiple things
- faces/letter recognition
template theory
recognition is a point-by-point comparison to a stored "average or ideal" representation
problems with template theory
- multiple stored representations with all possible variations (requires lots of memory
space!)
- separate representations needed for all viewpoints
Where are shapes representations located in the brain?
V4
Where is object recognition located in the brain?
inferotemporal area
fusiform face area (FFA)
- temporal lobe area w/many neurons
- responds to ALREADY KNOWN faces
occipital face area (OFA)
, - occipital lobe area
- responds to face-like images
propagnosia
inability to recognize faces
parahippocampal place area (PPA)
- selective area in temporal lobe
- scene recognition
topographic agnosia
inability to recognize landmarks/spatial layouts
extrastriate body area (EBA)
recognizes body parts
inferotemporal (IT) cortex
part of the cerebral cortex in the lower portion of the temporal lobe, important in object
recognition
- includes PPA, EBA, FFA
capgrass syndrome
- "Label" recognition intact, "emotional" recognition missing
- think people are imposters/fake
criterion for recognizing human face
65% human -> judge to be alive, feeling, having a mind
accidental viewpoints
a viewing position that produces some regularity in the visual image that is not present
in the world
occlusion
one object hides/obstructs the view of a second object
relative height
objects higher on the field of vision (horizon) look more distant
relative size
more distant an object, the smaller the image will be on the retina
familiar size
bottom-up processing
process where physical stimuli influence how they perceive them
top-down processing
process where our existing knowledge of objects influences how they perceive them
recognition
ability to match a presented item with an item and memory
representation
the storage/reconstruction of information when it is not in use
perceptual organization
allows you to recognize/organize objects
(i.e. grouping, segregation)
grouping
organizing into groups (i.e. chairs, lights, plates, etc.)
segregation
making sense of different surfaces in a scene (what is behind, what is in front, etc.)
gestalt psychology
whole is greater than sum of its parts
structuralism
whole = sum of parts
figure-ground organization
distinguishing background vs foreground of a scene (top vs bottom, background vs
foreground)
figure-ground organization rules
symmetry, convexity/concavity
gestalt laws
good continuation, proximity, similarity, common region, connectedness, common fate
receptors used for edge detection
,V1 detectors
role of angles and edges
carry meaning
- "Y'-shaped edge means a corner
- "T"-shaped edge means an occlusion
- angles show good continuation
geon
basic component of an object
recognition by components thoery
(Biederman) objects are recognized by the relation of its geons
viewpoint invariance
recognition of an object is independent of one's viewpoint
problems wit recognition by components
- viewpoint invariance is not foolproof (preferred viewpoint leads to faster recognition)
- many geon combinations can be perceived as multiple things
- faces/letter recognition
template theory
recognition is a point-by-point comparison to a stored "average or ideal" representation
problems with template theory
- multiple stored representations with all possible variations (requires lots of memory
space!)
- separate representations needed for all viewpoints
Where are shapes representations located in the brain?
V4
Where is object recognition located in the brain?
inferotemporal area
fusiform face area (FFA)
- temporal lobe area w/many neurons
- responds to ALREADY KNOWN faces
occipital face area (OFA)
, - occipital lobe area
- responds to face-like images
propagnosia
inability to recognize faces
parahippocampal place area (PPA)
- selective area in temporal lobe
- scene recognition
topographic agnosia
inability to recognize landmarks/spatial layouts
extrastriate body area (EBA)
recognizes body parts
inferotemporal (IT) cortex
part of the cerebral cortex in the lower portion of the temporal lobe, important in object
recognition
- includes PPA, EBA, FFA
capgrass syndrome
- "Label" recognition intact, "emotional" recognition missing
- think people are imposters/fake
criterion for recognizing human face
65% human -> judge to be alive, feeling, having a mind
accidental viewpoints
a viewing position that produces some regularity in the visual image that is not present
in the world
occlusion
one object hides/obstructs the view of a second object
relative height
objects higher on the field of vision (horizon) look more distant
relative size
more distant an object, the smaller the image will be on the retina
familiar size
