shape and depth Flashcards
how are shapes recognised in the visual field
visual neurons in v1 respond to specific edges and angles, these combine to create different patterns of activation which code for different objects
which 2 visual streams project from the occipital cortex to other visual areas
ventral stream [identification]
dorsal stream [motion]
what is an illusory conjunction
a perceptual mistake made when features from multiple objects are incorrectly combined
[due to feature integration theory]
feature integration theory
attention binds individual features together to comprise a composite stimulus
which lobe has been implicated in perceptual errors
PARIETAL LOBE; damage results in more illusory conjunctions
how is depth distinguished?
bottom up sensory depth cues
top down predictions
DEPTH CUES
retinal; binocular disparity / monocular, motion parallax, static
extra-retinal; convergence / vertical gaze angle
how is heuristics helpful
helps the brain learn real world irregularities through experience
binocular disparity
each eye has a slightly different perspective; by sensing this disparity the brain can calculate the depth [developing stereoscopic vision]
monocular depth cues
cues available when viewing with only one eye
motion parallax
items in the foreground move much faster than those in the background
static/pictorial cues
info gained from interposition, scene height, order cues, size constancy & scaling
extra-retinal cues
come from the movement of the eyes
CONVERGENCE; eyes turn inwards to close up objects, brain can calculate the angle of convergence
