the initial information gathering and recording by the sensory structure
what is perception?
interpretation by the brain of sensory information
what are the two tyopes of visual receptor cells in eyes
rods and cones in retina
what is the function of rods?
responsible for dim light and peripheral vision
what is the function of cone?
bright light and color vision
what is the absolute threshold?
minimum amount of enerby in a stimulus detected 50% of the time
what is the signal detection theory?
the detection of faint sensory stimuli depends not only upon a person physiological sensitivity to a stimuli but also upon his decision criterion for detectiuon whis is based on nonsensory factors
What is dark adaptation?
process by which the rods and cones through internal chemical changes become more and more sensitive to light in dim light conditions.
What is the trichromatic theory?
there are 3 types of cones, each only activated by wavelength range of light corresponding roughly to blue, green, and red. All of the various colors that we can see are mixtures of various levels of activation of the 3 types of cones. If all there are equally activated we see white.
what is the opponent process theory?
assumes there are 3 opponent process cells system (red-green, blue-yellow, black and white) which process color information after it has been processed by the cones. The colors in each system appose one another in that if one color is stimulated, the other is inhibited.
what is bottom up processing?
processing of incoming sensory information as it travels up from the sensory structures to the brain
what is top down processing?
brains use of knowledge, believes, and expectation to interpret sensory information
what is the figure and ground principle?
Gestalt perceptual organizationla principle that the brain organizes sensory information intoa figure or figures
what is the contextual effect?
the use of the present context of sensory information to determine its meaning
What is closure?
The Gestalt perceptual organizataional principle that the brain completes incomplete figure to form meneangful objects.
What are subjetive contours?
line or shape that is perceived to be present but does not really exist. The brain creates it during perception
what is perceptual constancy?
refers to the perceptual stability of size, shape, britness, and color of familiar objects seeing at varying distances, angles, and light conditions.
What is reatinal disparity?
binocular depth cue refering to the fact that as the difference between 2 rational images ofn and object increases, the distance of the obect from us decreases
what is linear perspective?
refers to the fact that as parallel lines recede away from us they appear to converge