module 5.1
____ are chemicals that release energy when struck by light.
Photopigments
Light energy converts 11-cis-retinal to ____.
all-trans-retinal
In comparison to cones, rods ____.
are more sensitive to dim light
The name of the point at which the optic nerve leaves the retina is called the ____.
blind spot
Which receptors are responsible for the perception of color?
cones only
Light enters the eye through an opening in the center of the iris called the ____.
pupil
In comparison to the rods, cones are more ____.
sensitive to detail
Which statement characterizes the fovea?
It has the greatest perception of detail.
Why does the fovea provide the clearest, most detailed visual information?
It has tightly packed receptors.
Which statement is TRUE with regard to peripheral vision?
It is easier to recognize single objects in the periphery that are not surrounded by other objects.
Why do humans perceive faint light better in the periphery of the eye?
More receptors in the periphery than in the fovea funnel input to each ganglion cell.
In the human retina, messages go from receptors at the back of the eye to ____.
bipolar cells
According to the retinex theory, we perceive color by ____.
contrasting the activity in one area of the visual field with that of the others
The law of specific nerve energies states that ____.
every stimulation of the optic nerve is perceived as light
Bipolar cells send their messages to ____, which are located close to the center of the eye.
ganglion cells
The optic nerve is composed of axons from which kind of cell?
ganglion cells
The most common form of color vision deficiency is due to ____.
long- and medium-wavelength cones making the same photopigment
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
According to the trichromatic theory of color vision ____.
our perception of color depends on the relative activity of three types of cones
Chemicals that release energy when struck by light are called ____.
photopigments
Color constancy is the ability to ____.
recognize the color of an object despite changes in lighting
Difficulty distinguishing between ____ and ____ is the most common form of color vision deficiency.
red; green
According to the trichromatic theory of color vision, the most important factor in determining the color we see is the ____.
relative activity of short, medium, and long wavelengths
According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by ____.
which neurons are active
____ modify the ____ sensitivity to different wavelengths of light.
Opsins; photopigments
Color and brightness constancy are best explained by the ____ theory of color vision.
retinex
Light from the right half of the world strikes which part of the retina?
the left half
Rods are to ____ as cones are to ____.
the periphery; the fovea
At the level of rods and cones, the ____ theory seems to fit best, while at the level of the bipolar cells, the ____ theory seems to fit best.
trichromatic; opponent process