Chapter 4: Perceiving and Recognizing Objects Flashcards
(40 cards)
Extrastriate Cortex
The region of cortex bordering the primary visual cortex and containing multiple areas involved in visual processing
Lession
A region of damaged brain, to destroy brain region.
Agnosia
A failure to recognize objects in spite of the ability to see them. Agnosia is typically due to brain damage.
Inferotemporal (IT) cortex
Part of cortex in lower portion of the temporal lobe, important in object recognition
Homologous regions
Brain regions that appear to have the same function in different species.
feed-forward process
a process that carries out a computation one neural step after another, without need for feed-back from a later stage to an earlier stage.
middle vision
a loosley defined stage of visual processing that comes after basic features have been extracted from the image and before object recognition and scene understanding.
Illusory contour
A contour that is perceived even though nothing changes from one side of it to the other in an image.
Structuralism
a school of thought believing that complex objects or perceptions could be understood by analysis of the components.
Gestalt
Perceptual whole could be greater than apparent sum of parts
Gestalt grouping rules
A set of rules describing which elements in an image will appear to group together. The original list was assembles by members of the Gestalt school of thought.
Good Continuation
A Gestalt grouping rule stating that two elements will tend to group together if they seem to lie on the same contour.
texture segmentation
carving an image into regions of common texture properties
similarity
Gestalt rule: tendency of two feature to group together will increase as similarity between them increases
proximity
tendency to group together increases with shortened distance
Parallelsim
a rule for figure-ground assignment stating that parallel contours are likely to belong t the same figure.
symmetry
a rule for figure-ground assignment stating that symmetrical regions are more likely to be seen as figure.
Ambiguous figure
a visual stimulus that gives rise to two or more interpretations of its identity or structure.
Necker cube
an outline that is perceptually bi-stable. Unlike the situation with most stimuli, two interpretations continually battle for perceptual dominance.
accidental viewpoint
A viewing position that produces some regularity in the visual image that is not present in the world
figure-ground assignment
The process of determining that some regions of an image belong to a foreground object (figure) and other regions are part of the background (ground).
Surroundedness
A rule for figure-ground assignment stating that if one region is entirely surrounded by another, it is likely that the surrounded region is the figure.
reliability
The degree to which two line segments appear to be part of the same contour.
heuristic
a mental shortcut