Mods 16-18 Flashcards
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 visual 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 brains 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 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 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 percent of the time
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 cosmic 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 the color names blue, green, and so forth
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
Cornea
The eyes clear, protective, outer layer, covering the pupil and iris
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; 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. The cones 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
Young-Helmholtz trichromatic (three-color) 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. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green
