3.3 Vision: Sensory and Perceptual Processing

wavelength

the color that you see

cornea

covers the pupil and iris; where the light first enters the eye

pupil

opening in the eye where light passes

iris

forms the colored portion of the eye; controls the size of the pupil

lens

structure behind the pupil that changes shape to help focus images

accommodation

when the lens changes its curvature and thickness

retina

light-sensitive surface of the eye that processes visual information

rods

part of the retina that detect that gray scale and sensitive to the movement

cones

part of the retina that detect fine detail and create color sensations

fovea

central focal point of the retina where the cones cluster; area of greatest visual sharpness

optic nerve

comprised of the axons of the ganglion cells; leaves through the back of the eye and carries neural impulses from the eye to the brain

blind spot

the point where the optic nerve leaves the eye; no receptor cells located there

young-helmholtz trichromatic theory

the theory that the retina contains different types of color receptors (red, green, and blue) that produce the perception of any color

opponent-process theory

the theory that photoreceptors are paired together to enable color vision; activation of one color inhibits the activation of another

feature detectors

in the occipital lobes; respond to something’s edge, lines, angles and movements

parallel processing

thinking about many aspects of a problem simultaneously; the brain’s natural mode of processing information

hue

the dimension of color that is determined by the wavelength of light

intensity

the amount of energy in a light or sound waves that determines what we perceived as bright or loud. amplitude of the wave