Perceiving Depth, Size, And Illusions Flashcards
Define
Muller-Lyer illusion
a geometric illusion in which two lines of equal length appear unequal depending on whether angular lines forming arrowheads at each end point toward or away from each other
Define
Crossed disparity
An object closer than the horoptor
Definition
stereo pair of images of random dots which when viewed with the aid of a stereoscope, or with the eyes focused on a point in front of or behind the images, produces a sensation of depth, with objects appearing to be in front of or behind the display level
Random-dot stereogram
What is the range of effectiveness for accommodation and convergence?
Near (0-2m)
Definition
a distorted room that creates an optical illusion
Ames room
Define
Accomodation
change in the shape of the lens when we focus on objects at different distances
Define
Horopter
a line or surface containing all those points in space of which images fall on corresponding points of the retinas of the two eyes
Definition
the gradual reappearance of a moving object as it emerges from behind another object
Accretion
Definition
An object closer than the horoptor
Crossed disparity
Define
Disparity-selective cells
cell in the visual cortex that receives inputs from both eyes and responds only when the binocular disparity is within certain predetermined limits, thus providing a basis for stereopsis
Define
Relative height
objects below the horizon that are higher in the field of vision are more distant
Define
Monocular cues
provide depth information when viewing a scene with one eye
Definition
a theory of visual illusions proposed by R. H. Day, which states that our perception of line length depends on an integration of the actual line length and the overall figure length
Conflicting cues theory
What is the range of effectiveness for relative height?
Moderately far to very far (2-30+m)
Define
Relative size
a perceptual clue which allows you to determine how close objects are to an object of known size
Define
Oculomotor cues
cues based on the ability to sense the position of our eyes and the tension in the eye muscles
Definition
one among a number of illusions where a central aspect of a simple line image—e.g. the length, straightness, or parallelism of lines—appears distorted by other aspects of the image—e.g. other background/foreground lines, or other intersecting shapes
Ponzo illusion
Define
Accretion
the gradual reappearance of a moving object as it emerges from behind another object
Definition
the perception of depth produced by the reception in the brain of visual stimuli from both eyes in combination; binocular vision
Stereopsis
What are the issues with the misapplied size-constancy scaling explanation for the Muller-Lyer illusion?
- The “dumbbell” version shows the same perception even though there are no “corners.”
- The illusion also occurs for some 3-D displays that do not implicate depth.
Definition
inward movement of the eyes when we focus on nearby objects
Ocular convergence
What is the range of effectiveness for relative size?
Near - very far
Define
Familiar size
a visual cue used to judge an object’s distance. It is a monocular cue which means it can provide information about depth peception even by using only one eye