sensation and perception
perception
when we select,organize,and interpret our sensations
sublimial stimulation
when stimuli are below ones absolute threshold for conscious awareness
interposition
objects that occlude (block) other objects tend to be perceived as closer
Size Constancy
Absolute threshold
The minimum stimulation detected 50 percent of the time.
sensation
to represent the world, we must detect physical energy (stimulus) from the environment and convert it into neutral signals
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
Signal Detection Theory
Detection depends on stimulus strength plus alertness, expectations, motivation, and experience.
Inattentional Blindness
People may fail to see a visible object when attention is directed elsewhere.
Difference Threshold
The smallest detectable difference between two stimuli.
bottom up processing
analysis of the stimulus begins with the sense receptors and works up to the level of brain and mind
examples of sensory adaptation
when wearing a band aid, jewelry,glasses, or getting into a cold pool, smells when walking into others houses, etc.
relative size
if two objects are similar in size, we perceived one that casts a smaller retinal image as farther away
Perceptual Constancy
Perceiving objects as unchanging even as illumination and retinal image change. perceptual consistencies of shape and size
sensory deprivation
suggests that vision is at least partly an acquired sense
top-down proccesing
information processing guided by high level men tal processes as we contract perceptions drawing on our experience and expectations
figure ground
Organization of the visual field into objects (figures) that stand out from their surroundings (ground)
retinal disparity
images from the two eyes differ... the greater the difference between the two objects the closer the object
perceptual adaptation
visual ability to adjust to an artificially displaced visual field,prism glasses (drunk goggles in driving school)
perceptual adaptation
visual ability to adjust to an artificially displaced visual field
webers law
the size of the JND is proportional to the intensity of the stimulus, if the stimulus intensity is high, the JND will be large if the stimulus intensity is low, the JND will be smaller
Gestalt Psychology
helps us organize information into meaningful wholes but remember the "whole is different from the sum of it's parts"
Parallel Processing
The brain processes color, motion, form, and depth at the same time.
Cornea
Bends incoming light
perceptual set
mental predisposition to perceive one thing and not another