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Nason Ch 5
Sensation Vocab
Vocab Word | Definition |
---|---|
Sensation | the process by which our sensory receptors and nervous system recieve 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 experience and expecations |
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% of the time |
Signal Detection Theory | a theory predicting how and when we detect the prescence of a faint stimulus ("signal") amid background stimulation ("noise"). Assumes there is no single absolute threshold |
Subliminal | below one's absolute threshold for conscious awareness |
Priming | the activation, often uncosciously, of certain associations, thus predisposing one's perception, memory, or response |
Difference Threshold | the minimum difference between two stimuli required for detection 50% of the time. We experience it as a just noticeable difference (jnd) |
Weber's Law | the principle that, to be perceived as different, two stimuli must differ my 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 brain can interpret |
Wavelength | the distance from the peak of one light or soundwave to the peak of the next |
Hue | the dimension of color that is determined by the wavelength of light; what we know as the color names |
Intensity | the amount of energy in a light or sound wave, which we percieve as brightness or loudness, as determined by the wave's amplitude |
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 |
Accomodation | the process by which the eye's lens changes shape to focus near or far images on the retina |
Retina | the light-sensative inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information |
Acuity | the sharpness of vision |
Nearsightedness | a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina |
Farsightedness | a condition in which far away objects are seen more clearly than near objects because the image of near objects is focused behind the retina |
Rods | retinal receptors that detect black, white, and grey; necessary for peripheral and twilight vision, when cones don't respond |
Cones | retinal receptors that concentrated near the center of the retina and that function in daylight or in well-lit conditions; detect fine details 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 focus 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 several aspects of a problem simultaneously; the brain's natural mode of information processing for many funtions, including vision; contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving |
Young-Helmholtz Trichromatic Theory | the theory that the retina contains three different color receptors- one most sensative to red, one to green, and 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 |
Color Constancy | percieving familiar objects as having consistant color, even if changing illumimation alters the wavelengths reflected by the object |
Audition | the sense or act of hearing |
Frequency | the number of complete wavelengths that pass a point in a given time |
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 Impact | a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea |
Gate-Control Theory | the theory that the spinal cord contains a neurological "gate" that blocks 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, such as when the smell of food influences its taste |
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 |