Vision
Night-active species are more likely than day-active species to have:
A greater rod to cone ratio
Light energy converts 11-cis-retinal to:
All-trans-retinal
Cells in the retina that provide connections among themselves, as well as with bipolar and ganglion cells, are known as:
Amacrine cells
Various types of __ cells refine the input to ganglion cells, enabling them to respond specifically to shapes, movement, or other visual features.
Amacrine cells
Which of the following is TRUE according to the law of specific nerve energies?
Any stimulation of the auditory nerve is perceived as sound
In comparison to cones, rods:
Are more sensitive to dim light
Foveal vision has:
Better acuity
In the most common form of color vision deficiency, people have difficulty distinguishing:
Between red and green
In the human retina, messages go from receptors at the back of the eye to ___.
Bipolar cells
Parvocellular neurons most likely receive input from:
Bipolar cells that receive input from cones
The name of the point at which the optic nerve leaves the retina is called the:
Blind spot
Based on the relative distribution of the three kinds of cones in the retina, which color of road sign would be most difficult to see from a distance?
Blue
Light from above our head strikes the:
Bottom half of the retina
The principle that allows you to perceive an orange shirt to be the same color under varying lighting conditions is known as:
Color constancy
Which receptors are responsible for the perception of color?
Cones
According to the retinex theory, we perceive color by:
Contrasting the activity in one area of the visual field with that of the others
Which of the following is NOT a factor in color vision deficiency?
Elongated shape of the eye
The law of specific nerve energies states that:
Every stimulation of the optic nerve is perceived as light
More than a century ago, researchers had evidence that the human retina contained three kinds of color-sensitive receptors. What was the basis of their evidence?
Experiments on mixing colors of light together
Because blood vessels and ganglion cell axons are almost absent near the __, it has nearly unimpeded vision.
Fovea
Most retinal cones are concentrated in the:
Fovea
The optic nerve is composed of axons from which of the following cells?
Ganglion
__ cells axons make up the optic nerve.
Ganglion
The bipolar cells send their messages to __, located closer to the eye.
Ganglion cells
The optic nerve is composed of axons from which kind of cell?
Ganglion cells
After staring at your instructor's red shirt for an entire class period, the negative afterimage will most likely be:
Green
In humans, the optic nerves from the two eyes follow what pathway?
Half of the axons from each eye cross to the other side at the optic chiasm
The retinas of predatory birds such as hawks:
Have a greater density of receptors than do humans on the top half of the retina
How do the retinas of predatory birds, such as hawks, differ from the retinas of prey species, such as rats?
Hawks have greater density of receptors on the top half of their retinas than do rats
In the vertebrae retina, which cells are responsible for lateral inhibition?
Horizontal cells
The enhancement of contrast at the edge of an object is primarily due to lateral inhibition by the:
Horizontal cells
While light is striking a visual receptor, light begins also to strike the receptor next to it. What effect will this additional light have on the response of the first cell?
Inhibition
How does light excite a rod or cone?
It converts 11 cis-retinal into all-trans-retinal
Which of the following characterizes the fovea?
It has the greatest perception of detail
Why are men more likely to experience color vision deficiency than women?
It is a sex-linked genetic disorder
Which of the following is TRUE related to peripheral vision?
It is easier to recognize single objects in the periphery that are not surrounded by other objects
If light shines in the receptive field of a bipolar cell of the visual system, what effect will it have on the activity of that cell?
It may excite or inhibit the cell
Branches of the optic nerve go directly to what areas of the brain?
Lateral geniculate and superior colliculus
Suppose someone has a genetic defect that prevents the formation of horizontal cells in the retina. Which visual phenomenon is most likely to be impaired?
Lateral inhibition
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
Light is focused as it enters through which of the following structures?
Lens and cornea
The most common form of color vision deficiency is due to:
Long- and medium- wavelength cones making the same photopigment
If you wanted to see a faint star at night, you should:
Look slightly to one side
The ability to detect movement better than color in our peripheral vision is largely due to:
Magnocellular neurons in the periphery
What is the relationship of color blindness between males and females?
Males are more likely to be color blind
Ganglion cells near the fovea in humans and other primates are called __ ganglion cells.
Midget
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
Magnocellular cells are to __ as parvocellular cells are to __.
Movement; color
Axons from the lateral geniculate extend to which area of the cerebral cortex?
Occipital lobe
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
Which theory of color vision is best able to explain negative color afterimages?
Opponent-process theory
__ modify the __ sensitivity to different wavelengths of light.
Opsins; photopigments
The optic nerves from the right and left eye initially meet at the:
Optic chiasm
According to the trichromatic theory of color vision:
Our perception of color depends on the relative activity of three types of cones
Being able to detect fine details of a color painting would depend most on which of the following types of ganglion cells?
Parvocellular
Which ganglion cells, if any, are located mostly in or near the fovea?
Parvocellular
Small receptive fields are to __ cells as large receptive fields are to __ cells.
Parvocellular; magnocellular
Chemicals that release energy when struck by light are called:
Photopigments
__ are chemicals that release energy when struck by light
Photopigments
The receptive field of a receptor is the:
Point in space from which light strikes the receptor
Visual information from the lateral geniculate area goes to the:
Primary visual cortex
Light enters the eye through an opening in the center of the iris called the:
Pupil
Stimulating a receptor leads to either excitation or inhibition of a particular neuron; the receptor is part of that neuron's:
Receptive field
The point in space from which light strikes the receptor is called the:
Receptive field
In what order does visual information through the retina?
Receptor cells. bipolar cells, ganglion cells
Why does the fovea provide the clearest, most detailed visual information?
Receptors are tightly packed there
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
Color and brightness constancy are best explained by the __ theory of color vision.
Retinex
Which theory can best explain why people that are wearing yellow-colored glasses can still identify the color of a green apple?
Retinex theory
Peripheral vision mainly depends upon:
Rods
What are the two kinds of receptors in the retina?
Rods and cones
Horizontal cells receive their input from __; they spend output to __.
Rods and cones; bipolar cells
In comparison to the rods, cones are more:
Sensitive to detail
The primary visual cortex is also known as the:
Striate cortex
The lateral geniculate nucleus is part of the:
Thalamus
In the visual system, the __ and __ constantly feed information back and forth.
Thalamus; cortex
Blindsight refers to:
The ability to localize visual objects within an apparently blind visual field
If you want to see something in fine detail, you should focus the light on which part of your retina?
The fovea
Cutting the optic nerve in front of the optic chiasm would result in blindness in __.
The left eye
Light from the right half of the world strikes what part of the retina?
The left half
All of the following are reasons why the fovea is well-suited for highly detailed vision EXCEPT:
The optic nerve connects there
Rods are to __ as cones are to __.
The periphery; the fovea
Light from the left half of the world strikes what part of the retina?
The right half
The blind spot in each eye is blind because:
There are no receptors there
Which of the following characterizes the blind spot?
There are no receptors there
According to the Young-Helmholtz theory, what is the basis for color vision?
Three kinds of cones
Initially, researchers determined how many receptors we have for determining color:
Through psychophysical observations
The primary visual cortex sends its information:
To area V2
In vertebrate retinas, receptors send their messages:
To bipolar cells within the retina
Where does the optic nerve send most of its information?
To the lateral geniculate
The fact that all color on older televisions were created by combining only three different colors of light supports the __ theory of color vision.
Trichromatic
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
The ability of some women to detect slightly finer discriminations of color than other women is most likely due to having:
Two types of long-wavelength cones
Cortical area __ appears to be where conscious visual perception occurs.
V1
According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by:
Which neurons are active
What is perceived when all types of cones are simultaneously and equally active?
White
Which theory emphasizes the idea that color vision depends on the relative responses of three kinds of cones?
Young-Helmholtz theory