Minimal amount of energy required to produce any sensation, 50 percent of the time.
Visual messages/cues that require two eyes (retinal disparity, convergence).
Place on the retina out where the optic nerve leaves the eye, no receptors (rods/cones) are located here.
Visual receptor cells; located in retina; works best in bright light; responsible for viewing color; greatest density in the fovea.
Just Noticeable Difference (JND); the smallest change in stimulation that you can detect 50% of the time; differs from one person to the other and from moment to moment.
The focusing of conscious awareness on a particular stimulus, like the cocktail effect (notice your name in a crowd).
The color part of the eye; made of muscle that contracts/relaxes to control the size of the pupil allowing light to enter the eye.
Sense of muscle movement, posture, and strain on muscles/joints; provides information on speed and direction of movement; works with vestibular sense.
Transparent part of the eye behind the iris; focuses light on the retina (accommodation); changes shape to focus on objects.
signal detection theory
States that circumstances, experiences, expectations and motivation level affect our thresholds.
Diminished sensitivity as a consequence of constant stimulation.
Conversion of one form of energy into another. In sensation, the transforming of stimulus energies into neural impulses.
Theory used to explain afterimages; suggest that the retina contains three pairs color receptors or cones-yellow-blue, red-green, black-white; pairs work in opposition (thalamus).
Depth cues, such as interposition and linear perspective, available to either eye alone.
The mental process of sorting, identifying, and arranging raw sensory data into meaningful patterns
Visual receptor cell; located in retina; respond to varying degrees of light and dark; responsible for night vision and peripheral vision.
The raw data of experience; sensory stimulation; ex. eyes only register light energy and ears only register wave energy.
The central focal point in the retina, around which the eye's cones cluster.
conduction hearing loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
sensorineural hearing loss
Hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called nerve deafness.
A device for converting sounds into electrical signals and stimulating the auditory nerve by electrodes threaded into the cochlea.
A coiled, bony, fluid-filled tude in the inner ear through which sound waves trigger nerve impulses.
Young-Helmholtz trichromatic theory
Theory of color vision based on additive color mixing; suggest that the retina contains three types of color receptors, cones: red, green, blue.
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.
The sense of body movement and position, including the sense of balance.
The principle that accounts for how one notices the difference threshold for any change must be proportional.
The spinal cord contains a "gate" that blocks pain signals or allows them to pass on to the brain. It's opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in large fibers or information coming from the brain.
The principle that one sense may influence another, as when the smell of food influences its taste.
Ability to see objects in three dimension although the image that strikes the retina are two-dimensional; allows us to judge distance.
Process by which the eye lens changes shape to focus near or far objects on the retina.