process by which our sensory system convert stimulus energy into neural messages
It isn't color that strikes our eyes, it is...
pulses of electromagnetic energy that our visual system experiences as color
the awareness of the world around us via sense receptors
bottom-up processing (sense receptors to brain)
Just Noticeable Difference
minimum amount of change required to detect a difference 50% of time
(How much do you have to turn up the radio before you can hear it?)
The JND increases with the magnitude of the stimulus
(If the music is loud, you have to turn it up a lot more to notice the difference rather than if it is very quiet)
the filtering out of non-changing stimuli, i.e. a buzzing in the room, the water temperature in a pool
the focusing of conscious awareness onto one stimulus in spite of other stimulus
Ring of muscle forms colored portion of the eye around pupil and controls size of pupil opening
Eye's lens is bent forward which makes closer objects appear more clearly, A condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina
A condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina
light sensitive inner surface of the eye. Contains cones & rods and neurons to process visual information.
Retinal receptor cells in inner part of retina that work better in well lit conditions to pick up color conditions
area consisting of a small depression in the retina containing cones and where vision is most acute
The point at which the optic nerve leave the eye creating a _______ because no receptor cells are located there
Feature Detector Neurons
Receive visual information and respond to specific features of a scene like shape, angle, or motion
Processing several aspects of a problem simultaneously (brain uses this)
The brain works on color, depth, movement, and form simultaneously
Young-Helmholtz trichomatic theory
The retina has three types of color receptors each sensitive to one of three colors: red, green, blue.
If you stimulate more than one at a time, you'll see other colors
Subtractive Color Mixing
When we mix red, blue, and green paint we get brown colored paint.
Formation of colors by removing some wavelengths of light, leaving less light than was originally there.
Additive Color Mixing
when all colors of light are mixed the result is white which is what results from the combination of all visible wavelengths
(Hering) the theory that opposing retinal processes (red-green, yellow-blue, 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
The after image shows the inverse of the color
The tendency for vision to dominate other senses.
Watching a roller coaster on a screen, we brace ourselves even though our other senses tell us we're not moving
emphasize our tendency to integrate pieces of information into meaningful wholes
A binocular cue for perceiving depth: By comparing images from the 2 eyes, the brain computes distance - the greater the disparity (difference) between the two images, the closer the object
A binocular cue for perceiving depth; the extent to which the eyes converge inward when looking at an object
(Monocular cue) if we assume that 2 objects are the similar size, we perceive the one that casts smaller retinal images as farther away
(Monocular cue) If one object partially blocks our view of another, we perceive it as closer
(Monocular cue) because light from distant objects passes through more atmosphere, we perceive hazy objects as farther away than sharp, clear ones
(Monocular cue) a gradual change from a coarse, distinct texture to a fine, indistinct one signals increasing distance
(Monocular cue) as we move, objects that are actually stable may appear to move
-Objects beyond the fixation point appear to move with you. The farther away it is, the slower it's apparent speed
Light and Shadow
(Monocular cue) nearby objects reflect more light to our eyes so if you have two objects, the dimmer one seems farther away.
an illusion of movement created when two or more adjacent lights blink on and off in succession
We perceive an object as having a constant lightness even while its illumination varies
Perceived lightness depends on relative luminance - the amount of light an object reflects relative to its surroundings
the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance
a sensory system located in structures of the inner ear that registers body movement and position
Occurs when molecules of what you are smelling reach receptor cells at the top of each nasal cavity
in vision, the ability to adjust to an artificially displaced or even inverted visual field