AP Psychology Vision

Prospagnosia

inability to recognize faces

Transduction

conversion of one form of energy into another. In sensation, the transforming of physical energy, such as sights, sounds, and smells, into neural impulses the brain can interpret.

cornea

the eye's clear, protective outer layer, covering the pupil and iris.

pupil

the adjustable opening in the center of the eye through which light enters.

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina.

retina

the light-sensitive back inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

accomodation

(1) in sensation and perception, the process by which the eye's lens changes shape to focus images of near or far objects on the retina. (2) in developmental psychology, adapting our current schemas (understandings) to incorporate new information.

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don't respond.

cones

retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and give rise to color sensations.

optic nerve

the nerve that carries neural impulses from the eye to the brain.

blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.

Fovea

the central focal point in the retina, around which the eye's cones cluster.

Young-Helmholtz trichromatic theory

the theory that the retina contains three different types of color receptors — one most sensitive to red, one to green, one to blue — which, when stimulated in combination, can produce the perception of any color.

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

Feature dectors

nerve cells in the brain's visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement.

parrelel processing

processing multiple aspects of a stimulus or problem simultaneously.

Fusiform Face Area

Part of brain that recognizes faces.