Ch.6 Perceptions Flashcards
Absolute threshold
Is the intensity level of a stimulus such that a person will have a 50% chance of detecting it
Threshold
Refers to the point above which a stimulus is perceived and below which it is not perceived
Subliminal stimulus
An intensity that gives a person less than a 50% chance of detecting a stimulus
A just noticeable difference
Refers to the smallest increase or decrease in the intensity if a stimulus that a person is able to detect
Weber’s Law
States that the increase in intensity if a stimulus needed to produce a just noticeable difference grows in proportion to the initial stimulus
Structuralists
Believed that you add together hundreds of basic elements to form complex perceptions
Gestalt psychologists believed that
Our brains follow a set of rules that specify how individual elements are to be organized into a meaningful pattern or perception
Rules of organization
- identified by gestalt psychologists
- specify how our brains combine and organize individual pieces or elements into a meaningful perception
Figure ground rule
States that in organizing stimuli we tend to automatically distinguish between a figure and a ground: the figure with more detail, stands out against the background
The similarity rule
States that we group together elements that appear similar
Closure rule
States that in organizing stimuli we tend to full in any missing parts if a figure and see the figure as complete
Proximity rule
States that in organizing stimuli we group together objects that are physically close to one another
Simplicity rule
States that stimuli are organized in the simplest way possible
Continuity rule
States that in organizing stimuli we tend to favor smooth or continuous paths when interpreting a series of points or lines
Perceptual constancy
Refers to our tendency to perceive sizes, shapes, brightness and colors as remaining the same even though their physical characteristics are constantly changing
Size constancy
Refers to our tendency to perceive objects as remaining the same size even when their images on our retina are continually growing or shrinking
Shape constancy
Refers to hour tendency to perceive an object as retaining it’s same shape even though when you view it from different angles, it’s shape is continually changing it’s image on the retina
Brightness constancy
Refers to the tendency to perceive. Rightness as remaining the same in changing illumination
Color constancy
Refers to the tendency to perceive colors as remaining stable despite differences in lighting
Depth perception
Refers to the ability of your eye and brain to add a third dimension, depth, to all visual perceptions, even though images projected on the retina are in only two dimensions, height and width
Binocular depth cues
Depend on the movement of both eyes
Convergence
Refers to a binocular cue for depth perception based on signals sent from muscles that turn the eyes. To focus on near or approaching objects, these muscles turn the eyes inward toward the nose. The brain uses the signals sent by these muscles to determine the distance of the object