AP Psychology - Vocabulary 9

selective attention

the focusing of conscious awareness on a particular stimulus, as in the cocktail party effect

inattentional blindness

failing to see visible objects when our attention is directed elsewhere

visual capture

the tendency for vision to dominate the other senses

gestalt

an organized whole. psychologists emphasized our tendency to integrate pieces of information into meaningful wholes

figure-ground

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

grouping

the perceptual tendency to organize stimuli into coherent schemas

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 cues

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

retinal disparity

a binocular cue for perceiving depth: By comparing images from the two eyeballs, the brain computes distance - the greater the difference between the two images, the closer the object

convergence

a binocular cue for perceiving depth; the extent to which the eyes go inward when looking at an object. The greater the inward strain, the closer the object

monocular cues

depth cues, such as interposition and 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 succession

perceptual constancy

perceiving objects as unchanging (having consistent lightness, color, shape, and size) even as illumination and retinal images change

perceptual adaptation

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

perceptual set

a mental predisposition to perceive one thing and not another

human factors psychology

a branch of psychology that explores how people and machines interact and how machines and physical environments can be made safe and easy to use

extrasensory perception

the controversial claim that perception can occur apart from sensory input. Said to include telepathy, clairvoyance, and precognition

parapsychology

the study of paranormal phenomena, including ESP and psychokinesis

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

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 dtect the presence of a faint stimulus amid background stimulation. Assumes there is no single absolute threshold and detection depends partly on a person's experience, expectations, motivation, and level of fatigue

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. We experience the _____ as a just noticeable difference

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

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

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

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

accommodation

the process by which the eye's lens changes shape to focus near or far objects 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

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 faraway 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 gray; necessary for peripheral and twilight vision.

cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions.

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 blank space 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

olfaction

the sense of smell