PSYA01H3 Lecture 13: Vision
Document Summary
The primary function of the eye is to gather light and change it into action potential. Light travels in waves with varying length and amplitude. Wavelength: the distance between peaks of a wave long waves correspond to our perception of red; short waves blue. Amplitude: the height of a wave; low-amplitude waves are dim colours, high-amplitude waves are bright colours. Colour intensity varies in the following three ways: hue: colour of the spectrum, intensity: brightness, saturation: colourfulness or density. Colour blindness: cones do not contain correct proteins (ex. Red proteins to help see green); generally genetic. Nearsightedness (myopia): slightly elongated eye, causes difficulty seeing distant objects. Farsightedness (hyperopia): slightly shortened eye, image focuses behind retina, causes difficult seeing objects that are close by. The world is a combination of perception (memory systems) and sensation (the raw experience/stimulation: bottom-up: input from the real world, top-down: affects constancies (shape, colour and size) comparisons between our experience and the presence of other objects.
