Question 1

The actual physical percentage of light reflected by a surface is called:
A) constancy
B) albedo
C) brightness
D) lightness

Accepted Answer

The physical percentage of light reflected by a surface is known as albedo. Constancy refers to the ability of the human visual system to perceive color as consistent despite changes in lighting conditions. Brightness refers to the perceived intensity or luminance of a light source, while lightness refers to the perceived brightness of a surface in comparison to its surroundings.

Question 2

Your perception that the white sheet on your bed appears to be white in the morning and evening when lighting conditions are dim as well as at noontime when lighting conditions are very bright is due to the fact that:
A) the albedo of the sheet is constant throughout the day
B) the absolute amount of light energy from the sheet that falls on the retina is constant
C) the sheet reflects the same amount of light at all hours
D) we rely on the lightness constancy to determine lightness

Accepted Answer

Our perception of the color of the white sheet is influenced by the concept of lightness constancy, which allows us to perceive an object as having a constant lightness despite changes in lighting conditions. This means that our brain adjusts our perception of the sheet's whiteness based on the surrounding lighting conditions. Therefore, the sheet could be reflecting different amounts of light throughout the day, but our brain interprets it as being the same color due to lightness constancy.

Question 3

The notion that we determine an object's lightness by comparing its brightness to that of other objects in the scene was proposed by: (p. 94)
A) Egon Brunswik
B) Gustav Fechner
C) Hans Wallach
D) Hermann von Helmholtz

Accepted Answer

The notion that we determine an object's lightness by comparing its brightness to that of other objects in the scene was proposed by Hans Wallach in the theory of "brightness constancy."

Question 4

The probabilistic functionalism approach to explaining lightness perception states that:
A) our previous experiences shape our perceptions of lightness
B) we rely on an object's relative intensity rather than its absolute intensity
C) we rely on an object's absolute intensity rather than its relative intensity
D) we unconsciously infer the level of illumination of a Surface

Accepted Answer

Probabilistic functionalism states that our previous experiences shape our perceptions of lightness. This means that we rely on our past experiences to infer the lightness of an object, rather than relying solely on its absolute or relative intensity.

Question 5

Which of the following statements about lightness perception is TRUE?
A) We first perceive the lightness of objects in a visual scene and then organize them.
B) We first make depth perception judgments and then make lightness judgments.
C) We first organize the visual scene and then determine the lightness of objects.
D) both B and C

Accepted Answer

Both depth perception and the organization of the visual scene influence how we perceive the lightness of objects. We typically interpret depth and organize the elements in a scene before making judgments about the lightness of objects, as these processes help us understand the context and lighting conditions that affect lightness perception.

Question 6

Which of the following statements is TRUE?
A) Our lightness judgment of Object A is independent of other objects in the scene.
B) Our lightness judgment of Object A is dependent upon other objects that are similar to Object A, even if they are not adjacent to 
 Object
C) Our lightness judgment of Object A is dependent upon other objects that are similar to Object A, but only if they are adjacent to Object
D) Our lightness judgment of Object A is dependent upon other objects that are similar to Object A, but only if they are nonadjacent to Object

Accepted Answer

Our lightness judgment of an object is influenced by the presence of other objects in the scene, even if they are not adjacent. This phenomenon is part of the context effect in visual perception, where the appearance of an object can be affected by the surrounding visual environment.

Question 7

Which of the following theories can fully explain lightness perception?
A) Wallach's ratio principle
B) Helmholtz' theory
C) Brunzwik's probabilistic functionalism theory
D) none of the above

Accepted Answer

No single theory can fully explain lightness perception, as it is a complex process that involves both bottom-up and top-down processing, as well as contextual factors. Wallach's ratio principle and Helmholtz' theory offer some insights into how brightness contrast and spatial frequency may contribute to lightness perception, respectively, but they do not provide a comprehensive account of the phenomenon. Brunswik's probabilistic functionalism theory is a general framework for understanding perception, but it does not focus specifically on lightness perception.

Question 8

Our ability to see fine details in a scene or in text is our:
A) visual angle
B) visual acuity
C) visual constancy
D) visual accommodation

Accepted Answer

Visual acuity refers to our ability to see fine details, such as small letters or objects, in a scene or in text. Visual angle refers to the angle at which an object or scene is viewed. Visual constancy refers to our ability to perceive objects as maintaining their size, shape, and color despite changes in their visual appearance due to changes in viewing conditions. Visual accommodation refers to the ability of the lens of our eye to change shape in order to focus on objects at different distances.

Question 9

The visual angle of a person facing you in the distance:
A) changes as she moves left or right
B) changes as she moves forward or backward
C) remains constant despite any changes in her position
D) both A and B

Accepted Answer

The answer of The visual angle of a person facing...

Question 10

Which of the following statements about the fovea is TRUE?
A) The fovea has a visual angle of 2°. The center is rod-free and has a visual angle of 1°.
B) The fovea has a visual angle of 2°. The center is cone-free and has a visual angle of 1°.
C) The fovea has a visual angle of 5°. The center is rod-free and has a visual angle of 2°.
D) The fovea has a visual angle of 5°. The center is cone-free and has a visual angle of 2°.

Accepted Answer

The answer of Which of the following statements about the...

Question 11

Scott uses the Snellen eye chart and discovers that his eyesight is 20/100. This means that:
A) he would have to be at 20 feet to read what someone with normal vision could read at 100 feet
B) he could stand as far back as 100 feet to read what someone with normal vision could read at 20 feet
C) the visual angle of the eye chart is 20°
D) his vision is equal to that of 1/5 of the population

Accepted Answer

In the 20/100 measurement of visual acuity, the first number represents the distance at which the person is standing from the eye chart (20 feet in this case), while the second number represents the distance at which a person with normal vision can read the same line (100 feet in this case). So, Scott would have to stand 20 feet away from the chart to read what someone with normal vision could read at 100 feet.

Question 12

The main problem with the Snellen eye chart is that:
A) it can measure whether an individual is hypermetropic, but not if they are myopic
B) it requires letter identification skills
C) it does not have any practical significance
D) it is very time-consuming to administer

Accepted Answer

The Snellen eye chart requires the individual to have letter identification skills, which may not be the case for everyone. Therefore, it may not accurately measure visual acuity for those who struggle with letter recognition.

Question 13

Acuity is greatest at the center of the fovea because:
A) the number of cones is great and each photoreceptor gets its own ganglion cell
B) the number of rods is great and each photoreceptor gets its own ganglion cell
C) the number of cones is great and more photoreceptors are connected to each ganglion cell
D) the number of rods is great and more photoreceptors are connected to each ganglion cell

Accepted Answer

The fovea is the center of the retina and contains only cones that are responsible for color vision and visual acuity. Each cone in the fovea has its own ganglion cell, which means that the visual signal from each cone is transmitted to the brain without any convergence or loss of information. This results in the highest visual acuity at the center of the fovea. Therefore, option A is the best choice as it correctly states that the number of cones is great and each photoreceptor gets its own ganglion cell in the center of the fovea.

Question 14

Which of the following statements about accommodation is FALSE?
A) During accommodation, the lens becomes thinner.
B) Accommodation takes place as objects draw nearer to the eye.
C) Accommodation bends the light to focus it on the retina.
D) none of the above

Accepted Answer

During accommodation, the lens actually becomes thicker, not thinner, to increase its refractive power and focus near objects on the retina.

Question 15

Jeff has presbyopia, so he:
A) has trouble seeing distant objects because the image is focused in front of the retina
B) has trouble seeing distant objects because the image is focused behind the retina
C) has trouble seeing nearby objects because the image is focused in front of the retina
D) has trouble seeing nearby objects because the image is focused behind the retina

Accepted Answer

Presbyopia is a condition associated with aging where the eye's lens loses its flexibility, making it difficult to focus on close objects. This results in the image being focused behind the retina.

Question 16

The ciliary muscle is used during:
A) vergence eye movements
B) saccadic eye movements
C) pursuit eye movements
D) accommodation

Accepted Answer

The ciliary muscle is responsible for accommodation, which is the process of changing the shape of the lens in the eye to adjust focus on objects at different distances. Vergence eye movements involve the coordinated movement of both eyes to maintain binocular vision, but the ciliary muscle is not directly involved. Saccadic eye movements are rapid jerky movements used for visual scanning, and pursuit eye movements are used to track moving objects, but neither of these types of eye movements involve the ciliary muscle.

Question 17

The "near point" is:
A) the distance at which you must be from an object so that it is fully projected onto the fovea
B) the closest point to your eye that you can see clearly
C) the distance at which you can read all of the letters on the Snellen eye chart
D) the point at which accommodation is not necessary for clear viewing

Accepted Answer

The "near point" is the closest point to your eye that you can see clearly. This distance varies depending on one's age and the ability of the eye to accommodate.

Question 18

Another term for someone who is nearsighted is:
A) presbyopic
B) achromatic
C) hypermetropic
D) myopic

Accepted Answer

Myopic is the correct term for someone who is nearsighted. Presbyopic refers to age-related farsightedness, achromatic refers to colorblindness, and hypermetropic refers to farsightedness.

Question 19

Alana is nearsighted and so she:
A) has trouble seeing nearby objects because her eyeballs are longer than normal
B) has trouble seeing nearby objects because her eyeballs are shorter than normal
C) has trouble seeing distant objects because her eyeballs are longer than normal
D) has trouble seeing distant objects because her eyeballs are shorter than normal

Accepted Answer

Nearsightedness, also known as myopia, is a condition where a person can see objects up close but has trouble seeing objects far away. This is usually caused by the eyeball being longer than normal, which causes light to focus in front of the retina instead of directly on it. As a result, distant objects appear blurry.

Question 20

The corrective lenses that help correct nearsightedness:
A) affect vision for distant objects but not vision for nearby objects
B) focus distant objects further back in the eye and onto the retina
C) cause the light rays to converge more
D) all of the above

Accepted Answer

Nearsightedness, or myopia, occurs when distant objects are focused in front of the retina. Corrective lenses for nearsightedness help by focusing distant objects further back onto the retina.

Quiz 4: Basic Visual Functions

The actual physical percentage of light reflected by a surface is called:

Your perception that the white sheet on your bed appears to be white in the morning and evening when lighting conditions are dim as well as at noontime when lighting conditions are very bright is due to the fact that:

The notion that we determine an object's lightness by comparing its brightness to that of other objects in the scene was proposed by: (p. 94)

The probabilistic functionalism approach to explaining lightness perception states that:

Which of the following statements about lightness perception is TRUE?

Which of the following statements is TRUE?

Which of the following theories can fully explain lightness perception?

Our ability to see fine details in a scene or in text is our:

The visual angle of a person facing you in the distance:

Which of the following statements about the fovea is TRUE?

Scott uses the Snellen eye chart and discovers that his eyesight is 20/100. This means that:

The main problem with the Snellen eye chart is that:

Acuity is greatest at the center of the fovea because:

Which of the following statements about accommodation is FALSE?

Jeff has presbyopia, so he:

The ciliary muscle is used during:

The "near point" is:

Another term for someone who is nearsighted is:

Alana is nearsighted and so she:

The corrective lenses that help correct nearsightedness: