Studied by 61 PeopleSensation
Tags & Description
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 experience and expectations)
Selective Attention
the focusing of conscious awareness on a particular stimulus
Inattentional blindness
failing to see visible objects when our attention is directed elsewhere
Change blindness
failing to notice changes in the environment
Transduction
conversion of one form of energy into another
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 necessary 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)
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 - just noticeable difference (jnd)
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 disposition to perceive one thing and not another
Extrasensory Perception (ESP)
the controversial claim that perception can occur apart from sensory input
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
Intensity
the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude
Hue
the dimension of color that is determined by the wavelength of light
Cornea
outer covering of the eye
Pupil
adjustable opening in the center of the eye through which light enters
Iris
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
process by which the eye’s lens changes shape to focus near or far objects in 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; Function in daylight/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 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
Young-Helmholtz trichromatic (three color) theory
the theory that the retina contains three different color receptors (red, green, 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 (some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green)
Gestalt
an organized whole
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; Proximity, Continuity, and Closure
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
Retinal disparity
a binocular cue for perceiving depth, by comparing images from the retinas in the two eyes, the brain computes distance (the greater the disparity between the two images, the closer the object)
Binocular cues
depth cues (ex. retinal disparity) that depend on the use of two eyes
Monocular cues (definition)
depth cues (ex. interposition, linear perspective) available to either eye alone
Monocular cues (examples)
Relative height, Relative size, Interposition, Linear perspective, Relative motion, and Light and shadow
Phi phenomenon
an illusion of movement created when two or more adjacent lights blink on and off in quick succession
Perceptual Constancy
perceiving objects as unchanging (having consistent shapes, size, lightness, and color) even as illumination and retinal images change
Color constancy
perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object