Unit 4 Flashcards
Pupil
The adjustable opening in the center of the eye through which light enters
Iris
The ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
Retina
The light-sensitive version inner surface of the eye, containing the receptor to rods and cones plus layers of neurons that begin the processing of visual information
Cornea
The eye’s clear, protective outer layer, covering the pupil and iris
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina
Rods
Retinal receptors that detect black, white, and grey and are sensitive to movement, necessary for peripheral and twilight vision when cones don’t respond
Cones
Retinal receptors that are concentrated near the center of the body retina and that function in daylight or in well-lit conditions, cones detect fine detail and give rise to color sensations
Blind spot
The point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there
Young-Helmholtz trichromatic (three color theory)
The theory that the retina contains three different types of color receptors - one most sensitive to red, one to green, one to blue - which when stimulation in combination, can produce the perception of any color
Opponent-process theory
The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red, others are stimulated by red and inhibited by green
Psychophysics
The study of relationships between the physical characteristics of stimuli, such as their intensity, and own psychological experience of them
Perceptual set
A mental predisposition to perceive one thing and not another
Accomodation
The process by which the eye’s lens changes shape to focus near or far objects on the retina
Optic nerve
The nerve that carries neural impulses from the eye to the brain
Fovea
The central focal point in the retina around which the eye’s cones cluster
Feature detectors
Nerve cells in the brain’s visual cortex that respond to specific features of the same stimulus, such as shape, angle, or movement
Parallel processing
Processing many aspects of a problem simultaneously, the brain’s natural mode of information processing for many functions, including vision
Gestalt
An organized whole. Gestalt psychologists emphasized our tendency to integrate piecing of information into meaningful wholes.
Figure-ground
The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Grouping
The perceptual tendency to organize stimuli into coherent groups
Depth Perception
The ability to see objects in 3D although the images that strike the retina are 2D, allows us to judge distance
Visual Cliff
A lab device for testing depth perception in infants and young animals
Binocular cue
A depth cue, such as retinal disparity, that depends on the use of two eyes
Retinal disparity
A binocular cue for perceiving depth by comparing retinal images from the two eyes, the brain computes distance - the greater the disparity (difference) between the two images, the closer the object
Monocular cue
A depth cue, such as interposition or 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 color, brightness, shape, and size) even as illumination and retinal images change
Color constancy
Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the objects
Perceptual Adaptation
The ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field
Audition
The sense or act of hearing