PSYB51H3 Chapter Notes - Chapter 3: Visual Acuity, Magnocellular Cell, Visual Cortex
Document Summary
Contrast: the difference in luminance between an object & the background, or between lighter and darker parts of the. Chapter 3- spatial vision: from spots to stripes same object. Acuity: the smallest spatial detail that can be resolved at 100% contrast. Cycle: for a grating, a pair consisting of one dark bar and one bright bar. Visual angle: the angle subtended by an object at the retina. Lines going from top to bottom, or left to right (depending on orientation of stripes) of a cycle on a page. Passes through the centre of the lens, and ends on the retina. To calculate visual angle = size of cycle/viewing distance where you can just barely make out the orientation of the gratings. Then take the arctangent of the ratio. Humans with very good vision can resolve gratings when one cycle subtends an angle of approx. This resolution acuity represents one of the fundamental limits of spatial vision.
