Object and Face - perception Flashcards
(14 cards)
What are the two main challenges object recognition must overcome?
Intrinsic variations (shape, parts) and extrinsic variations (viewpoint, lighting, occlusion).
Describe Biederman’s Recognition‑by‑Components (RBC) theory.
Decompose objects into geons (basic shapes), classify geon types, and match their configuration to stored representations.
Why are geons view‑invariant?
They rely on nonaccidental properties of contours, robust to changes in viewpoint and occlusion.
What distinguishes view‑dependent theories of object recognition?
They store multiple prototypical views (snapshots) of objects and match new inputs to the nearest stored image.
Name the neural region critical for complex object recognition in primates.
Inferotemporal (IT) cortex.
Define apperceptive agnosia.
Impaired perceptual processing—patients cannot form coherent shape perceptions and fail at matching or copying shapes.
Define associative agnosia.
Intact perception (able to copy shapes) but inability to link perceptual forms to semantic meaning.
What is prosopagnosia?
Selective inability to recognize familiar faces despite preserved object recognition, often due to fusiform damage.
What behavioural effect demonstrates configural processing in face recognition?
The face inversion effect—upright faces are recognized far more accurately than inverted faces.
Where is the Fusiform Face Area (FFA) located, and what is its function?
Ventral temporal surface; shows selective activation to faces versus other object categories.
What is category‑specific agnosia?
Selective impairment in recognizing certain object classes (e.g., living things vs. nonliving things).
How do view‑independent and view‑dependent processes combine during recognition?
The visual system flexibly uses structural (geon‑based) descriptions for broad categories and stored views for fine within‑class discrimination.
What is the Fat‑Face Thin illusion?
A perceptual distortion showing how face configuration influences perceived proportions.
Which brain lesions can lead to visual agnosia?
Lesions in occipito‑temporal areas, particularly IT cortex or fusiform regions.
