Neural Processing in Vision Flashcards
What does the Snellen chart measure?
Foveal acuity - there are no units
What is the framing effect?
Top-down processing can influence even basic visual perception (HDTV vs DVD when both the same)
What is hyperacuity?
Resolution of details of 10’ or less of vernier gratings
May be due to complex neural processing in the visual cortex
What is chromatic aberration?
Different wavelengths focus at different points
What is spherical aberration?
Light rays focus at different points depending on how far from the centre they pass through a lens
What is diffraction?
Light waves ben around obstacles in their path or through a slight; affects different wavelengths to different extents
What is radiance?
Radiant power from a light source
What is illuminance?
Amount of light falling on a surface
What is luminance?
Amount of light reflected from a surface
What is reflectance?
Proportion of light reflected from a surface
What is brightness?
Perceptual impression of intensity of a light source
-psychological counterpart to radiance
What is lightness?
Perceptual impression of surface “greyness”
-psychological counterpart to reflectance
What is spatial frequency?
How a stimulus changes over space (cycles per degree of visual angle)
What is fourier analysis?
Simplified scene description in terms of a set of sine waves
What is contrast sensitivity function?
The ability of a system to preserve contrast and spatial frequency information after it has been encoded
