GLOSSARY


Perception-

the process of organizing, interpreting, and selectively extracting sensory information.


Innate:-

features or traits that exist from birth.


Perceptual organization:

processes used to group sensory elements together.


Figure-ground perception:

tendency to differentiate target stimuli from back-ground stimuli.


Law of Pragnanz:

the tendency to perceive the simplest form possible; certain stimulus elements just seem to belong together.


Closure:

the tendency to fill in missing information from a perceptual array; to fill in the gaps.


Laws of grouping:

the tendency to perceive similar or proximal stimuli as belonging together.


Binocular disparity:

depth cue based on difference in images as the image reaches each of the two eyes.


Convergence:

depth cue based on the tension of the muscles that control eye movement.


Stereopsis:

comparison of retinal disparity by overlaying images in each eye.


Motion Parallax:

depth cue based on the rate objects move when our head moves.


Elevation:

depth cue based on height in the visual field; typically, objects higher in the field are interpreted as farther away.


Interposition:

nearby objects obscure or block parts of faraway objects.


Linear perspective:

parallel lines appear to converge as they move farther away.


Aerial perspective:

atmospheric haze causes distant objects to appear bluish


Relative brightness:

nearby objects tend to be seen as brighter, even when objects farther away are the same size.


Texture gradient:

depth cue based on the texture gradient provided by regularly sized objects in the environment.


Ecological theory of perception:

Gibson’s theory emphasizing information in the external (distal) stimulus.


Auditory localization:

ability to locate direction and distance of a sound source; usually a result of sound waves reaching each ear at different times.


Size constancy:

perceived size remains constant despite a change in retinal size, so changes in the distance of an object do not alter how large or small we think it is.


Distal stimulus:

the stimulus of an object as it actually exists in the real world.


Proximal stimulus:

the image of a distal stimulus on the retina.


Size-distance invariance hypothesis:

says that size judgments are made by comparing the size of the retinal image with perceived distance.


Shape constancy:

we see shapes as remaining the same despite changes that occur at the retina.


Lightness constancy:

perceived lightness stays the same despite changes in the level of illumination.


Albedo:

the proportion of light reaching a surface that is reflected back to the eye.


Autokinetic effect:

illusory movement of a point of light in a dark environment; a single point of light appears to move.


Stroboscopic movement:

illusory movement produced by the successive presentation of still images; motion pictures are produced through this phenomenon.


Phi phenomenon:

when two successively presented lights are seen as a single moving light.


Pattern Perception:

recognition of familiar forms such as faces, pictures, and objects.


Prototype:

central tendency of a category that contains the essential features of the category.


Prototype-matching theory:

a theory of pattern perception that claims that recognition involves comparison to prototype pattern; the closer the pattern to the prototype, the easier it is to recognize the stimulus.


Feature-analysis theory:

a theory of pattern perception that claims that patterns are represented and recognized by distinctive features.


Recognition by components:

this theory of pattern perception claims that patterns are represented by a relatively small set of simple shapes.


Fourier analysis:

analysis of a stimulus into its component sine waves.


Bottom-up processing:

information processing from receptors (bottom) to higher centers in the brain.


Top-down processing:

information processing from higher perceptual centers to lower centers such as receptor sites.


Set:

an expectancy, preconceived idea, or orientation that influences how a stimulus is processed.


Attention:

a cluster of integrated events and processes that determine which stimuli receive further processing.


Selective attention:

the ability to focus consciousness on a single event in the environment while ignoring other stimuli.


Dichotic listening:

concurrent presentation of two auditory messages.


Stimulus variables:

characteristics of the objects themselves, such as intensity, that can affect attention.


Organismic variables:

processing characteristics of the organism or perceiver that determine which stimuli gain attention.


Divided attention:

ability to monitor two events presented simultaneously.


Automatic processing:

processing that does not require conscious attention.


Controlled processing:

processing that requires conscious attention.


Human factors psychology:

area of psychology that focuses on the human-machine interface and studies ways to make it easier for women and men to work with machines.


Perceptual learning:

improvement in the ability of a person to extract information from the environment and make use of it.


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