 | Term | Definition |
| |
sensation |
process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment |
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perception |
process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events |
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bottom-up processing |
analysis that begins with the sensory receptors and works up the brain's integration of sensory information |
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top-down processing |
information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations |
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absolute threshold |
minimum stimulus needed to detect a particular stimulus 50 percent of the time |
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signal detection theory |
predicting how and when we detect the presence of a faint stimulus amid background stimulation |
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subliminal |
below one's absolute threshold for conscious awareness |
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priming |
activation, often unconsciously, of certain association, thus predisposing one's perception, memory, or response |
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difference threshold |
minimum difference between two stimuli required for detection 50 percent of the time |
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Weber's law |
principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage |
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sensory adaptation |
diminished sensitivity as a consequence of constant stimulation |
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transduction |
conversion of one form of energy into another. |
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wavelength |
distance from the peak of one light or sound wave to the peak of the next |
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hue |
dimension of color that is determined by the wavelength of light; blue, green, etc. |
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intensity |
amount of energy in a light or sound wave, which we perceive as brightness or loudness |
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pupil |
adjustable opening in the center of the eye through which light enters |
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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 |
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lens |
transparent structure behind the pupil that changes shape to help focus images on the retina |
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accommodation |
process by which the eye's lens change shape to focus near or far objects on the retina |
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retina |
light-sensitive inner surface of the eye, containing the receptor rods and cones |
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acuity |
sharpness of vision |
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nearsightedness |
condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina |
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farsightedness |
condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina |
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rods |
retinal receptors that detect black, white, and gray |
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cones |
retinal receptors that are concentrated near the center of the retina and detect fine detail and give rise to color sensations |
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optic nerve |
nerve that carries neural impulses from the eye to the brain |
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blind spot |
point at which the optic nerve leaves the eye, creating a "blind" spot |
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fovea |
central focal point in the retina, around which the eye's cones cluster |
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parallel processing |
processing of several aspects of a problem simultaneously; contrasts with the step-by-step processing of most problem solving |
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Young-Helmholtz trichromatic (three color) theory |
theory that the retina contains three different color receptors- red, green, and blue |
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opponent-process theory |
theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision |
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color constancy |
perceiving familiar objects as having consisten color, even if changing illumination alters the wavelengths reflected by the object |
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audition |
sense or act of hearing |
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frequency |
number of complete wavelengths that pass a point in a given time |
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pitch |
tone's experienced hightness or lowness; depends on frequency |
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middle ear |
chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window |
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inner ear |
innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs |
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place theory |
in hearing, theory that links the pitch we hear with the place where the cochlea's membrane is stimulated |
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frequency theory |
in hearing, the theory that the rate of impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch |
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conduction hearing loss |
hearing loss caused by the damage to the mechanical system that conducts sound waves to the cochlea |
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sensorineural hearing loss |
hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves |
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cochlear implant |
device for converting sounds into electrical signals and stimulating the auditory nerve |
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gate-control theory |
theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain |
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sensory interaction |
principle that one sense may influence another, as when the smell of food influences its taste |
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kinesthesis |
system for sensing the position and movement of individual body parts |
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vestibular sense |
sense of body movement and position, including the sense of balance |
