Studied by 494 Peoplesensation
Tags & Description
sensation
the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
sensory receptors
sensory nerve endings that respond to stimuli
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 expectations
selective attention
the focusing of conscious awareness on a particular stimulus
inattentional blindness
failure to see visible objects when our attention is directed elsewhere
change blindness
failing to notice changes in the environment; a form of inattentional blindness
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
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 stimulus energy needed to detect a particular stimulus 50% 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 single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness
subliminal
below one's absolute threshold for conscious awareness
difference threshold
the minimum difference between two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference
priming
the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response
Weber's law
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
perceptual set
a mental predisposition to perceive one thing and not another
extrasensory perception (ESP)
the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition
parapsychology
the study of paranormal phenomena, including ESP and psychokinesis
wavelength
the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of gamma rays to the long pulses of radio transmission
hue
the dimension of color that is determined by the wavelength of light; what we know as color names
intensity
the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave's amplitude (height)
cornea
the eye's clear, protective outer layer, covering the pupil and iris
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 the eye's lens changes shape to focus near or far objects on the retina
rods
retinal receptors that detect black ,white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don't respond
cones
retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. 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 focus point in the retina, around which the eye's cones cluster
Young Helmholtz trichromatic (three-color) theory
the theory that the retina contains three different types of 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
theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
feature detectors
nerve cells in the brain's visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement
parallel processing
processing many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision
gestalt
an organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes
figure-ground
the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
grouping
the perceptual tendency to organize stimuli into coherent groups
depth perception
the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance
visual cliff
a laboratory device for testing depth perception in infants and young animals
binocular cue
a depth cue, such as retinal disparity, that depends on the use of two eyes
retinal disparity
a binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance--the greater the disparity (difference) between the two images, the closer the object
monocular cue
a depth cue, such as interposition or linear perspective, available to either eye alone
phi phenomenon
an illusion of movement created when two or more adjacent lights blink on and off in quick successions
perceptual constancy
perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change
color constancy
perceiving familiar objects are having consistent color, even if changing illumination alters the wavelengths reflected by the object