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45 terms

Unit Three

Includes vision, thesholds ect.
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Sensation
the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
Perception
the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
Bottom-up processing
analysis that begins with the sensory receptors and works up to the brain's integration of sensory information.
Top-down processing
information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experiences and expectations
psychophysics
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.
absolute threshold
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 paint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and level of fatigue.
subliminal
below one's absolute threshold for conscious awareness.
priming
the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (JND)
Weber's Law
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage.
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
transduction
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.
wavelength
the distance from the peak of one light or sound wave to the peak of the next.
hue
the dimension of color that is determined by the wavelength of light.
intensity
the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave's amokutyde
pupil
the adjustable opening in the center of the eye through which light enters.
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.
lens
the transparent structure behind the pupil that changes shape to help focus images on the retina.
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.
accommodation
the process by which they eye's lens changes shape to focus near or far objects on the retina.
rods
retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond.
cones
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.
optic nerve
the nerve that carries neural impulses from the eye to the brain.
blind spot
the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
fovea
the central focal point in the retina, around which the eye's cones cluster.
feature detectors
nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
parallel processing
the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision.
Young-Helmholtz trichromatic 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.
opponent-process theory
the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision.
audtion
the sense or act of hearing.
frequency
the number of complete wavelengths that pass a point in a given time. (ex. per second)
pitch
a tone's experienced highness or lowness; depends on frequency.
middle ear
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.
cochlea
a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.
inner-ear
the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.
place theory
in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.
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.
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.
cochlear implant
a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.
kinesthesis
the system for sensing the position and movement of individual body parts
vestibular sense
the sense of body movement and position, including the sense of balance.
gate-control theory
the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brian. 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.
sensory interaction
the principle that one sense may influence another, as when the smell of food influences its taste.