PSY Chapter 6 Vision
Describe the trichromatic, opponent-process, and retinex theories of color vision.
1) Trichromatic: According to this theory, we perceive color through relative rates of response by three kinds of cones, each one maximally sensitive to a different set of wavelengths. There are three cones for three different colors; red, blue, and green, 2)Opponent-process: We perceive color in terms of opposites; a continuum from red to green, or yellow to blue. 3)Retinex theory: The cortex compares information from various parts of the retina to determine the brightness and color for each area.
The coding of visual information in your brain results in an exact duplicate of the object's shape on the surface of the cortex.
False
Cells in the inferior temporal cortex that are sensitive to a particular shape are also likely to respond to the shape's ______.
Mirror-reversal
Johannes Müller held that whatever excites a particular nerve establishes a special kind of energy unique to that nerve.
True
Astigmatism refers to the ____.
asymmetric curvature of eyes
After you stare at a bright green object for a minute and look away, you see red. Which theory attempts to explain this finding?
opponent-process theory
In what order does visual information pass through the retina?
receptor cells, bipolar cells, ganglion cells
A person with visual agnosia is unable to ____.
recognize visual objects
Horizontal cells receive their input from ____, and they send output to ____.
rods and cones; bipolar cells
The lateral geniculate nucleus is part of the ____.
thalamus
According to the Young-Helmholtz theory, what is the basis for color vision?
three kinds of cones
The receptive field of a receptor is the ____.
point in space from which light strikes the receptor
In foveal vision, ____.
each ganglion cell is excited by a single cone
The law of specific nerve energies states that ____.
every stimulation of the optic nerve is perceived as light
According to the trichromatic theory, we can perceive only three colors.
false
The optic nerve is composed of axons from which kind of cell?
ganglion cells
What is responsible for sharpening contrast at visual borders?
lateral inhibition
The enhancement of contrast at the edge of an object is the result of ____.
lateral inhibition in the retina
Once within the cerebral cortex, the magnocellular pathway continues, with a ventral branch sensitive to ____.
movement
Visual information from the lateral geniculate area goes to the ____.
primary visual cortex
Damage to the ventral stream may interfere with ____.
the ability to describe the shape or size of an object
The point in space from which light strikes the receptor is called the ____.
the receptive field
In vertebrate retinas, receptors send their messages ____.
to bipolar cells within the retina
The fact that all colors on older televisions were created by combining only three different colors of light supports the ____ theory of color vision.
trichromatic
The retinex theory accounts for the principle of color constancy.
true
