diminished sensitivity as a consequence of constant stimulation
conversion of one form of energy into another; the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
the adjustable opening in the center of the eye through which light enters
the process by which the eye's lens changes shape to focus near or far objects on the retina.
Rods and Cones
retinal receptors that detect black, white and gray, AND color sensations, respectively. The former is necessary for peripheral vision and twilight vision. The latter functions in daylight or in well-lit conditions.
the nerve that carries neural impulses from the eye to the brain
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.
the processing of several aspects of a problem SIMULTANEOUSLY.
Young-Helmholtz trichromatic theory
the theory that the retina contains three different color receptors--one most sensitive to red, one to green, and one to blue--which when stimulated in combination can produce the perception of any color.
the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision.
the sense or act of hearing
a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.
Conduction hearing loss
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 principle that one sense may influence another, as when the smell of food influences its taste.
the system for sensing the position and movement of individual body parts.
the sense of body movement and position, including the sense of balance.
Sensorineural hearing loss
hearing loss caused by damage to the cochlea;s receptor cells or to the auditory nerves (aka "nerve deafness")