Lecture 11 Flashcards
Colour Vision and Visual Processing (17 cards)
What are the three stages of visual processing?
Low-level (shape, colour, contrast), Mid-level (grouping & form), High-level (meaning & attention).
What is low-level visual processing?
Initial processing of edges, motion, and colour in the retina and early visual cortex.
What is mid-level processing?
Organisation of primitives into coherent forms before assigning meaning.
What is high-level processing?
Interpretation using knowledge, expectations, and attention.
What is bottom-up processing?
Processing driven by external stimuli.
What is top-down processing?
Processing guided by goals, expectations, and prior knowledge.
What is visual ‘filling in’?
Top-down process where the brain fills in missing visual info, like the blind spot.
What are Gestalt principles?
Rules that explain how visual elements are grouped into unified wholes.
What is emergence in Gestalt theory?
Seeing the whole before identifying individual parts.
What is reification?
Perceiving shapes or information not explicitly present.
What is multistability?
Seeing multiple stable interpretations in ambiguous images.
What is invariance?
Ability to recognize objects regardless of variation in scale, rotation, etc.
What is Prägnanz?
We tend to perceive the simplest and most stable forms.
What is ensemble coding?
Visual system encodes averages of groups rather than individuals.
What did Ariely (2001) find?
Observers accurately judged the average of a set of circles but not individual sizes.
What is global vs local processing?
Global = seeing the whole, Local = seeing parts.
What did Navon (1977) demonstrate?
Global features interfere with local recognition more than vice versa.
