absolute threshold The lowest level of stimulation that a person can detect accommodation Adapting one's current understandings to incorporate new information. acuity Sharp perception or vision audition The sense or act of hearing blind spot The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
bottom-up processing Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information cochlea A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses color constancy Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object conduction hearing loss Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea cones Cone-shaped visual receptor cells; located in retina; works best in bright light; responsible for viewing color; greatest density in the fovea
difference threshold farsightedness The minimum difference between two stimuli required for detection 50 percent of the time. A condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina feature detectors Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement fovea "Point of central focus". Spot on the back of the retina that has more cones that anywhere else. Helps us see fine detail frequency How many wave peaks pass a certain point per given time
frequency theory 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. gate-control theory The spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. hue A particular shade of a given color inner ear The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs. intensity Brightness
iris kinesthesis A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. the system for sensing the position and movement of individual body parts lens Focuses light onto retina middle ear Air-filled cavity in temporal bone separated from air outside the head by tympanic membran nearsightedness A condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina
opponent-process theory The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. optic nerve Comprised of the axons of retinal ganglion cells, this carries neural impulses from the eye to the brain. parallel processing Processing multiple types of information at the same time perception A person's cognitive (mental) interpretation of events. pitch A tone's experienced highness or lowness; depends on frequency.
place theory In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated psychophysics Methods that measure the strength of a stimulus and the observer's sensitivity to that stimulus pupil retina rods A hole in the center of the iris of the eye that allows light to enter the eyeball. The diameter of pupil is controlled by the iris in response to the brightness of the light. Contains sensory receptors that process visual information and sends it to the brain Located in the periphery of the retina, these are sensory receptors for vision that work best in reduced illumination, and only allow perception of achromatic colors, low sensitivity to detail and are not involved in color vision.
sensation sensorineural hearing loss Process in which the sense organs' receptor cells are stimulated and relay initial information to higher brain centers for further processing. Hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called nerve deafness sensory adaptation Diminished sensitivity as a consequence of constant stimulation sensory interaction The principle that one sense may influence another, as when the smell of food influences its taste signal detection theory A theory predicting how and when we detect the presence of a faint stimulus amid background noise
subliminal Below one's absolute threshold for conscious awareness top-down processing Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations. transduction The process of transfering genetic material from one cell to another by a plasmid or bacteriophage vestibular sense wavelength the sense of body movement and position, including the sense of balance Horizontal distance between the crests or between the troughs of two adjacent waves
Weber's law Principle that, to be perceived as different; two stimuli must differ by a constant minimum percentage(rather than a constant amount). Young-Helmholtz 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 of any color.