the process by which our sensory receptors and nervous system receive and represent stimulus energies

the process of organizing and interpreting sensory information,

analysis that begins with the sensory receptors and works up to the brain's integration of information

information processing guided by higher-level mental processes

the focusing of conscious awareness on a particular stimulus

failing to see visible objects when our attention is directed elsewhere

failing to notice changes in the environment

conversion of one form of energy into another

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

the activation, often unconsciously, of certain associations

the minimum difference between two stimuli required for detection 50 percent of the time

the distance from the peak of one light or sound wave to the peak of the next

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

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

the light-sensitive inner surface of the eye, containing the receptor rods and cones

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision

retinal receptor cells that function in daylight or in well-lit conditions.

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

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

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

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement

processing many aspects simultaneously

retina contains three different color receptors which, when stimulated in combination, can produce the perception of any color

the theory that opposing retinal processes enable color vision

emphasize our tendency to integrate pieces of information into meaningful wholes

the ability to see objects in three dimensions

a laboratory device for testing depth perception in infants and young animals

depth cues, such as retinal disparity, that depend on the use of two eyes

an illusion of movement created when two or more adjacent lights blink on and off in quick succession

the sense or act of hearing

the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup)

a coiled, bony, fluid-filled tube in the inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves (nerve deafness.)

hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain

the system for sensing the position and movement of individual body parts.

the sense of body movement and position, including the sense of balance.

Passages in the inner ear associated with maintaining equilibrium

The ability to focus on one auditory message and ignore others

sense of smell

sensory receptors that detect hurtful temperatures, pressure, or chemicals