Question 1

When a given bipolar cell increases its activity over its spontaneous rate, you see green. According to the opponent-process theory of color vision, when that cell decreases its activity below its spontaneous rate, you will see

Accepted Answer

According to the opponent-process theory, the bipolar cell that responds to green light is paired with a bipolar cell that responds to red light. When one cell is activated, the other is inhibited. Therefore, if the green-sensitive bipolar cell decreases its activity below its spontaneous rate, the red-sensitive bipolar cell will increase in activity, resulting in the perception of red.

Question 2

When red light strikes a certain set of cones, a particular bipolar cell connected to them increases its activity. When green light strikes the same cones, the bipolar cell decreases its activity. This observation tends to support which theory?

Accepted Answer

This observation matches the opponent-process theory, which states that colors are perceived in opposing pairs (red-green, blue-yellow, black-white) and when one is activated, the other is inhibited. The bipolar cell in this scenario shows opposite responses to red and green light, supporting the opponent-process theory.

Question 3

Which of the following would cause someone to experience negative afterimages?

Accepted Answer

Staring at a colored object for an extended period of time can cause the cones in the retina that respond to that color to become fatigued. When the person then looks at a plain surface, the fatigued cones can no longer respond to the color, causing a negative afterimage.

Question 4

Which of these observations gave rise to the retinex theory of color vision?

Accepted Answer

The retinex theory of color vision was developed to explain the phenomenon that the apparent color of an object can vary depending on the color of nearby objects. This is known as color constancy, and it is thought to be due to the brain's ability to account for the illumination of a scene and to use that information to adjust the perceived color of objects. The retinex theory proposes that the color information in the retina is processed by the brain in a way that takes into account the context of the scene, leading to more accurate color perception.

Question 5

One advantage of the opponent-process theory of color vision, in contrast to the trichromatic theory, is that the opponent-process theory can more easily account for

Accepted Answer

The opponent-process theory can more easily account for negative afterimages, which occur when staring at a color and then looking away, causing an afterimage in complementary colors. This phenomenon is not well-explained by the trichromatic theory.

Question 6

According to the retinex theory of color vision, we perceive color by

Accepted Answer

The retinex theory of color vision suggests that the cortex compares light patterns in different parts of the retina to perceive color, rather than relying solely on the activity of photoreceptors (cones and rods) or specific color systems. This theory emphasizes the role of the brain in processing visual information to create a perception of color.

Question 7

When a given bipolar cell in the retina increases its activity, you see yellow. According to the opponent-process theory, when that cell decreases its rate of firing, you'll see

Accepted Answer

According to the opponent-process theory, yellow and blue are opponent colors. When a bipolar cell increases activity for yellow, it decreases for blue, and vice versa.

Question 8

A piece of paper contains a number of tiny colored dots. If you stand far away and look at the paper, which color of dots is most likely to appear black?

Accepted Answer

When you stand far away from the paper, your eyes cannot distinguish the individual colors of each dot. Instead, your eyes blend the colors together and create a new color. Blue light has the shortest wavelength, meaning it scatters the most in the atmosphere. Therefore, when you look at the paper from far away, it is more likely that the blue dots will scatter and blend with the other colors, creating a darker appearance, possibly black.

Question 9

The retinex theory of color vision attempts to account for the fact that

Accepted Answer

The retinex theory of color vision explains how we can perceive consistent colors even under different lighting conditions, such as through tinted lenses, by processing visual information to maintain color constancy.

Question 10

Which of the following most strongly supports the retinex theory of color vision?

Accepted Answer

The retinex theory of color vision suggests that the color of an object is not determined solely by the wavelengths of light that it reflects, but rather by the way that it interacts with the surrounding environment. Choice C, which states that the apparent color of an object depends on the color of other objects we see at the same time, is consistent with this idea.

Question 11

According to the opponent-process theory of color vision, we perceive color by

Accepted Answer

According to the opponent-process theory of color vision, we perceive color through three systems: a red-green system, a yellow-blue system, and a black-white system. This theory suggests that color perception is based on the comparison of opposing colors, such as red and green, or blue and yellow. In other words, the response of one type of cone opposes the response of another type of cone, which creates our perception of color. This theory has been supported by various studies and is widely accepted in the field of vision science.

Question 12

According to the trichromatic (Young-Helmholtz) theory, we perceive green when

Accepted Answer

The trichromatic theory proposes that color vision arises from the activity of three types of cones, each sensitive to different wavelengths of light: short (blue), medium (green), and long (red). Therefore, according to this theory, we perceive green when medium-wavelength cones are more active than other cones.

Question 13

The retinex theory of color vision emphasizes the influence of

Accepted Answer

The retinex theory of color vision suggests that color perception is based on comparisons of the light that objects reflect to what is seen in adjacent areas of the visual field. In other words, it emphasizes the influence of the comparisons from what you see in different parts of the visual field, as opposed to genetically or culturally determined differences or the ratio between wavelengths and intensity of light.

Question 14

The opponent-process theory of color vision accounts for the observation that

Accepted Answer

The opponent-process theory explains the phenomenon of afterimages, where staring at a color for an extended period causes an opposite color to be perceived when looking away. For example, staring at a green surface may cause a red afterimage to be seen when looking away.

Question 15

Which of the following most directly lends support to the opponent-process theory of color vision?

Accepted Answer

The opponent-process theory of color vision suggests that there are three pairs of opposing color sensations: red-green, blue-yellow, and black-white. This theory states that activating one member of the pair will inhibit the other member. Seeing negative afterimages, where the colors are inverted from the original image, supports this theory because it suggests that the opposing color is being activated after the initial color is fatigued. Choices A, B, and D do not directly support the opponent-process theory.

Question 16

According to the trichromatic theory (Young-Helmholtz theory), how do we perceive color?

Accepted Answer

The trichromatic theory proposes that color perception depends on the ratio of activity in three types of cones, each responsive to different ranges of light wavelengths. One type responds to short-wavelength light (blue-violet), another to medium wavelengths (green), and a third to long wavelengths (yellow-red). By comparing the relative amounts of stimulation received by each type of cone, the brain can perceive a wide range of colors.

Question 17

According to the trichromatic (Young-Helmholtz) theory, we perceive white when

Accepted Answer

According to the trichromatic theory, perceives white when all three types of cones (red, blue, and green) are equally active. This imparts the brain with a signal of white light.

Question 18

The term "color constancy" refers to the fact that

Accepted Answer

Color constancy refers to the ability of the human visual system to perceive colors of objects as relatively constant even under different lighting conditions or when viewed through different color filters. Option B best describes this phenomenon by explaining that the perception of the color of an object remains constant even when viewed through a different color filter (red-tinted glasses in this case).

Question 19

According to the trichromatic (Young-Helmholtz) theory, we perceive color by

Accepted Answer

The trichromatic theory, also known as the Young-Helmholtz theory, proposes that we perceive color by the relative levels of activity by three types of cones: red, blue, and green. These cones are located in the retina of the eye and respond to different wavelengths of light. The brain then processes the signals from these cones to create the perception of color. This theory can account for our ability to see millions of different colors.

Question 20

According to the retinex theory we perceive color through the combined contributions of the

Accepted Answer

The retinex theory suggests that color perception is a result of the brain (cortex) interpreting signals from the retina, integrating information about light and context.

Quiz 4: Sensation and Perception