PSYB51H3 Lecture Notes - Lecture 3: Independent Component Analysis, Visual Acuity, Visual Angle
Document Summary
Psyb51 lec 03: spatial vision: refers to our ability to resolve or discriminate spatially defined features. Gutenberg (1439): invented a printing press w/ movable types to create text: language: sensory (sound) stimulus that can be represented as text. Similarly, visual images can be described represented as compositions of simple and independent elements. Each element can be filtered out separately. Letter represent text/language neurons sensitive to basic visual elements represent visual images of the world. Bell and sejnovski (1996): used independent component analysis (ica) to identify the components of photos of natural images. The components were edges and lines (pieces of gratings) The visual system is plastic (evolution + learning) In our brain, there should be a certain specialization of the visual system for gratings and spatial frequencies. Filters specialized for edges and lines of various orientations: rectangular gratings, sine/sinusoidal wave grating, gabors: piece of sine wave that"s blurred.
