Outline: Recognition
Pattern Recognition - Categorization vs discriminability, naming,
identifying individuals, recognition memory
Invariance of recognition across
Multiple exemplars
Differences in viewpoint, occlusions, lighting, cast shadows, etc.
Category specificity
Faces
Prosopagnosia (face blindness)
Face inversion effects (e.g., the Thatcher illusion)
Face cells in IT
Columnar organization in IT for face viewpoint and for other objects
Fusiform face area
Faces versus expertise (train on greebles and they act like faces: show
inversion effect, light up FFA)
Objects
Object agnosia
Parahippocampal place area
Reading: first and last letters matter
most
Objects: viewpoint dependent (store individual views) versus viewpoint
independent (store object-intrinsic description, e.g., Geons)
Perceptual organization
Segmentation (parts, objects,
figure-ground) versus grouping
Gestalt laws
Proximity
Similarity
Good continuation
Prägnanz: good/simple form
Common fate
Closure
Camouflage
Boundary formation
Texture edges (e.g. Julesz)
Relation to visual search (e.g. Treisman)
Parallel (easy) search (O among X's):
search times independent of number of distractors
Serial (hard) search (T among L's): search times increase with number
of distractors, twice as much for "no" as for "yes" answers
Illusory or subjective contours
What they are
Where are they represented in the brain (probably not in V1, but soon
after)
Figure/Ground problem
Ambiguous Figures (vase/faces as
figure/ground ambiguity)
Scene interpretation
Local interpretations (failure on
Escher figures)