Week 3: Object Recognition Flashcards
Pattern recognition involves processing of specific features and global processing. Which generally precedes the other?
Feature processing generally (but not always) precedes global processing
What did Gestaltists de-emphasise in perceptual organisation that theories based on Bayesian inference acknowledge?
The role of experience and learning
Visual processing typically involves a coarse-to-fine processing sequence.
What is low spatial frequencies and high spatial frequencies in visual input associated with?
Low spatial frequencies = coarse processing
High spatial frequencies = fine processing
Biederman assumed in his recognition-by-components theory that objects consist of what?
Geons (basic shapes)
What does Biderman’s theory de-emphasise
The role of top-down processing
what does the interactive-iterative framework by Baruch et al., 2018 indicate?
Top-down and bottom-up processes interact with top-down processes (e.g., attention) influencing subsequent bottom-up processing
Face processing involves a brain network including what two areas?
The fusiform face and occipital face areas
Areas involved in top-down processing (e.g., left temporal lobe) are more important in ?
Areas involved in bottom-up processing (e.g., early visual cortex) are more important in ?
Top-down = imagery
Bottom-up = perception
What is the Part-Whole effect in face recognition?
It’s easier to recognise a face part when presented in a whole face rather than in isolation.
What is Prosopagnosia?
Face blindness - difficulty recognising faces
What is the Face Inversion Effect?
Faces are harder to recognise upside-down rather than upright
What is Object Agnosia?
An ability to recognise faces but not objects
What brain networks are activated during face processing?
OFA
pSTS-FA and aSTS-FA
temporal FFA
IFG-FA
ATL-FA
OFA = occipital face area;
pSTS-FA and aSTS-FA = posterior and anterior temporal superior sulcus face areas;
temporal FFA = fusiform face area;
IFG-FA = inferior frontal gyrus face area;
ATL-FA = anterior temporal lobe face area
What are the five laws in perceptual organisation?
The Law of Proximity
The Law of Similarity
The Law of Common Fate (moving in the same direction)
The Law of Good Continuation
The Law of Closure
What cues are involved in natural scene perception?
Proximity, similarity, continuation, colour, luminance
What is uniform connectedness?
Any connected region having uniform visual properties (colour, texture etc.) tends to be organised as a single perceptual unit
Describe the difference between Viewpoint-invariance and viewpoint-dependence
Viewpoint-Invariance = categorisation tasks, brain activation mostly similar regardless of object orientation. Occurs only when multiple faces have been presented
Viewpoint-Dependence = identification tasks, greater activation in the inferior temporal cortex when objects not in typical position. Initial face recognition is viewpoint-dependent and becomes more viewpoint-invariant
Describe Figure-ground segmentation
The perceptual organisation of the visual field into a figure (object of central interest) and a ground (less important background)
What is pareidolia?
The tendency to perceive a specific, often meaningful image in a random or ambiguous visual pattern e.g., Rorschach inkblot test
