AP Psychology Unit 4: Sensation and Perception Key Terms

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

analysis that begins with sensory receptors and works up to the brain’s integration of sensory information

information processing guided by higher-level mental processes, as when we construct perceptions drawings on our experiences and expectations

the focusing of conscious awareness on a particular stimulus

failing to see visible objects when our attention is directed elsewhere

failing to notice changes in the environment

the study of relationships between physical characteristics of stimuli, such as their intensity, and our psychological experience of them

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

a theory predicting how and when we detect the presence of a faint stimuli amid background stimulation (assumes there is no single absolute threshold)

below one’s absolute threshold for conscious awareness

the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response

the minimum difference between two stimuli required for detection 50 percent of the time (a just noticeable difference)

the principle that, to be perceived as different, two stimuli must differ at a constant percentage

diminished sensitivity as a consequence of constant stimulation

conversion of one form of energy into another

the distance from the peak of one sound or light wave to the peak of the next

the dimension of color that is determined by wavelength of light

the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude

the adjustable opening of the eye through which light enters

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

the transparent structure behind the pupil that changes shape to help focus images on the 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

the process of which the eye’s lens changes shape to focus near or far objects on the retina

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond

retina receptor cells that are 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)

the nerve that carries neural impulses from the eye to the brain

the point at which the optic nerve leaves the eye (no receptor cells are located there)

the central focal point in the retina, around which the eye’s cones cluster

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement

the processing of many aspects of a problem simultaneously

the theory that the retina contains three different color receptors-one most sensitive to red, one to green, and one to blue-which when stimulated in combination, can produce the perception of any color

the theory that opposing retinal processes enable color vision

the sense or act of hearing

the number of complete wavelengths that pass a point in a given time

a tone’s experienced highness or lowness; depends on frequency

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

a coild, bony, fluid filled tube in the inner ear through which sound waves trigger nerve impulses

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

in hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated

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

hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves

a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

the system of sensing the position and movement of individual body parts

the sense of body movement and position, including the sense of balance

the theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass onto the brain

the principle that one sense may influence another

an organized whole (emphasizes our tendency to integrate pieces of information into meaningful wholes)

the organization of the visual field into objects that stand out from their surroundings

the perceptual tendency to organize stimuli into coherent groups

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance

a laboratory device for testing depth perception in infants and young animals

depth cues, such as retinal disparity, that depend on the use of two eyes

a binocular cue for perceiving depth by comparing images from the retinas of two eyes, the brain computes distance (the greater the difference between the two images, the closer the object

depth cues, such as interposition and linear perspective, available to either eye alone

an illusion of movement created when two or more adjacent lights blink on and off in quick succession

perceiving objects as unchanging, even as illumination and retinal images change

perceiving similar objects as having consistent color, even if changing illumination alters the wave-lengths reflected by the object

in vision, the ability to adjust to an artificially displaced or even inverted visual field

a mental predisposition to perceive one thing and not another

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition

the study of paranormal phenomena, including ESP, and psychokinesis