the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events
analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
information processing guided by higher-level mental processes, as when we contruct perceptions drawing on our experience and expectations
the study of relationships between the physical characteristics of stimuli, such as their intensity and our psychological experience of them
the minimum stimulation needed to detect a particular stimulus 50 percent of the time
signal detection theory
a theory predicting how and when we detect the presence of a faint stimulus ("signal") amid background stimulation ("noise"). Assumes there is no 1 single absolute threshold and that detection dependes partly on a person's experience, expectations, motivation, and level of fatigue.
below one's absolute threshold for conscious awareness
the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.
the minimum difference between 2 stimuli required for detecting 50 percent of the time. We experience this as a just noticeable difference. (also called a just noticeable difference or jnd)
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).
diminished sensitivity as a consequence of constant stimulation
conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.
the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from short blips of cosmic rays to the long pulses of radio transmission.
the dimension of color that is determined by a wavelegth of light; what we know as the color names blue, green, and so forth.
the amount of energy in a light or sound wave, which we perceive as brightness of loudness, as determined by the wave's amplitude
the adjustable opening in the center of the eye through which light enters
a ring of muscle tissue that forms the colored portion of the eye around the pupil adn controls the size of the pupil opening
the transparent structure behing the pupil that changes shape to focus near or far objects on the retina
the process by which the eye's lens changes shape to focus near or far objects on the retina
the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
the sharpness of vision
a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina
a condition in whihc far-away objects are seen more clearly than near objects because the inamge of near objects is focused behind the retina
retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond
retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. They detect fine detail and give rise to color sensations
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
the processing of several aspects of a problem simultaneously, the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-steo (serial) processing of most computers and of conscious problem solving
Young-Helmholtz trichromatic(three-color) theory
the theory that the retina contains three different color receptors-one most sensitive to red, one to green, one to blue-which when stimulated in combination can produce the perception fo any color
the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by greena dn inhibited by red; others are stimulated by red and inhibited by green
perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object
the sense of act of hearing
the number of complete wavelengths that pass a point in a given time (for example, per second)
a tone's experienced highness or lowness, depends on frequency.
the 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
a coiled, bony, fluid-filled tube in the inner are through which sound waves trigger nerve impulses
the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs
in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated
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
sensorineural hearing loss
hearing loss caused by damage to the cochlea's receptor cells of to the auditory nerves;also called nerve deafness
a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into 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 "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain
the principle that one sense may influence another, as when the smell fo 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