1.
1. The human eye has three cone photopigments that are important for the perception of color. What photopigment below is NOT one of those three cone photopigments?
Correct Answer
D. Rhodopsin
Explanation
Rhodopsin is the rod photopigment that is responsible for monochromatic vision in low-light conditions.
2.
Gestalt principles of object recognition refer to the idea that the _______ is more than the sum of the ______.
Correct Answer
A. Whole; parts
Explanation
The Gestalt principles of object recognition suggest that the whole object is more than just the sum of its individual parts. This means that when we perceive an object, we don't just see the individual elements or lines that make it up, but we perceive it as a whole entity. Our brain automatically organizes the parts of an object into a unified whole, allowing us to recognize and understand the object as a complete entity rather than just a collection of separate elements.
3.
An OFF-center ganglion responds most vigorously to light when that light appears where?
Hint: refer to the OFF-Center ganglion cell figure in Week 3's slides.
Correct Answer
C. As a spot that fills the entire surround without spilling into the center.
Explanation
OFF-center ganglion cells respond to light most vigorously when it appears only in the surround. These cells are less active when light hits the OFF-center. Light that illuminates the ENTIRE surround, but does not enter the OFF-center would produce the most vigorous activation of that ganglion cell.
4.
The problem of univariance can be visualized by:
Correct Answer
C. Rod-dominated vision in low light conditions like dusk.
Explanation
The problem of univariance is demonstrated by rod-dominated vision that occurs in low-light conditions. During this type of vision, there is not enough light to activate the cone photoreceptors. Due to this, vision is not colored and colors appears as varying shades of light and dark; details are also harder to discern.
5.
L-cones are most sensitive to:
Correct Answer
A. Longer wavelength light (~565 nm)
Explanation
L-cones are most sensitive to longer wavelengths of light, with peak sensitivity at approximately 565 nm.
6.
A metamer can be defined as mixtures of wavelengths that are:
Correct Answer
D. Perceptually identical but pHysically different.
Explanation
Metamers are mixtures of wavelengths that are perceptually identical (the same color), but are physically different.
7.
At least two different cone photopigments are needed to produce ANY perception of color.
Correct Answer
A. True
Explanation
Two different cone photopigments are the minimum necessary for humans to perceive any color information. The most common examples of this are humans that are colorblind. The colorblindness is usually caused by some deficiency in one of the three cone photopigments.
8.
_________ in the visual pathway is defined as a larger portion of the striate cortex devoted to processing information from the fovea, which is a very small part of the retina.
Correct Answer
B. Cortical magnification
Explanation
A larger portion of the cortex devoted to a small portion of the retina (fovea) is termed cortical magnification. This means that there is more area available for processing information that falls into the fovea than there is brain area available for processing information that falls outside of the fovea.
9.
Additive color mixing is very similar to the painting technique known as pointalism.
Correct Answer
A. True
Explanation
Additive color mixing is indeed similar to the painting technique known as pointillism. In both cases, colors are created by combining smaller dots or points of different colors. In additive color mixing, different colors of light are combined to create new colors, while in pointillism, small dots or strokes of different colors are placed next to each other to create the illusion of new colors. Both techniques rely on the principle that the human eye can blend different colors together to perceive a new color. Therefore, the statement is true.
10.
Vision in the periphery of the retina is much more detailed than vision in the fovea of the retina.
Correct Answer
B. False
Explanation
The statement is false because vision in the fovea of the retina is actually much more detailed than vision in the periphery. The fovea is the central part of the retina that contains a high concentration of cones, which are responsible for detailed vision and color perception. In contrast, the periphery of the retina contains a higher concentration of rods, which are more sensitive to light but do not provide as much detail. Therefore, the fovea provides sharper and more detailed vision compared to the periphery.
11.
There is a physiological limit to human vision; it is a consequnece of the spacing of the photoreceptors on the retina.
Correct Answer
A. True
Explanation
The statement is true because the spacing of photoreceptors on the retina determines the resolution and acuity of human vision. The photoreceptors, called cones and rods, are responsible for detecting light and transmitting visual information to the brain. The closer the spacing of these photoreceptors, the higher the resolution and ability to discern fine details. However, there is a limit to how closely these photoreceptors can be packed, which ultimately sets the limit to human vision. This physiological limit is why humans have a finite visual acuity and cannot see beyond a certain level of detail.
12.
_______ is conceptually-driven processing that emphasizes an observer's expectations.
Correct Answer
A. Top-down
Explanation
Top-down processing refers to the cognitive process in which an individual's expectations and prior knowledge influence their perception and interpretation of sensory information. It involves using pre-existing knowledge and context to guide the understanding of new information. In this case, the correct answer suggests that the conceptually-driven processing that emphasizes an observer's expectations is top-down processing.
13.
There are areas in this picture where the shape you perceive and the background are the same color. This means that there are areas on this shape where the border is NOT continuous, but you still perceive a continuous border. These areas are referred to as:
Correct Answer
illusory contour
illusory contours
Illusory contours
Illusory contour
Explanation
Illusory contours are perceived borders or edges that are not actually present in the image. In this picture, there are areas where the shape and the background have the same color, creating an illusion of a continuous border where there is none. These illusory contours are created by our brain filling in the missing information to perceive a complete shape.
14.
The pink '31' in this image that is seen as distinct from the 'BR' is an example of the Gestalt law of similarity (color).
Correct Answer
A. True
Explanation
The explanation for the given correct answer is that the pink '31' in the image stands out and is perceived as distinct from the 'BR' because of the Gestalt law of similarity (color). This law suggests that elements that are similar in color tend to be grouped together and perceived as a whole. In this case, the pink color of the '31' stands out from the rest of the image, creating a distinct visual grouping. Therefore, the statement is true.
15.
The Rubin Vase-Face is an example of an ambigious figure where the information for _________ is not clear, which results in the illusion of a vase or two faces emerging from the same picture.
Correct Answer
B. Figure-Ground assignment
Explanation
The Rubin Vase-Face illusion is a classic example of figure-ground assignment. In this image, the information for whether the image is a vase or two faces is not clear. This ambiguity allows our brain to interpret the image in different ways, resulting in the illusion. The concept of figure-ground assignment refers to the brain's ability to separate an image into a foreground (figure) and a background (ground), and this illusion demonstrates how our perception of the figure and ground can switch back and forth.
16.
_________ are images or pictures that do not provide the viewer enough information concerning depth and distance cues. These pictures/objects usually produce visual illusions, such as the Necker cube.
Correct Answer
C. Ambiguous figures
Explanation
Ambiguous figures are images or pictures that do not provide enough information about depth and distance cues. These pictures often create visual illusions, such as the Necker cube, where the viewer may perceive different interpretations or perspectives. The term "ambiguous" refers to the uncertainty or lack of clarity in the visual information presented, making it challenging for the viewer to determine the intended depth and distance relationships within the image.
17.
A T-junction is a non-accidental feature that NEVER signals occulsion of an object by another object.
Correct Answer
B. False
Explanation
A T-junction is a non-accidental feature that signals occlusion of an object by another object.
18.
Y and arrow junctions correspond to corners and and do not signal occulsion.
Correct Answer
A. True
Explanation
Y and arrow junctions correspond to corners and do not signal occlusion. This means that when we encounter a Y or arrow junction in a visual scene, it indicates a corner or a change in direction, rather than an object being hidden or obscured. Therefore, the statement "Y and arrow junctions correspond to corners and do not signal occlusion" is true.
19.
Given that each cone photoreceptor (and rod photoreceptor) can only send a neural firing rate to the brain, these photoreceptors are said to be 'univariate'.
Correct Answer
A. True
Explanation
The statement is true because it states that each cone and rod photoreceptor can only send a neural firing rate to the brain. This means that these photoreceptors can only transmit one type of information, making them univariate.
20.
Humans are dichromats, not trichromats.
Correct Answer
B. False
Explanation
Humans are actually trichromats, not dichromats. This means that they have three types of color receptors in their eyes, allowing them to perceive a wide range of colors. The three types of receptors are sensitive to different wavelengths of light, which allows the brain to interpret and differentiate between different colors. Therefore, the correct answer is False.
21.
Click the box next to each Gestalt Law or Grouping Principle (there are five correct answers; worth 5 points).
Correct Answer(s)
A. Occlusion
C. Proximity
E. Common Fate
F. Similarity
G. Closure
Explanation
The correct answers are Occlusion, Proximity, Common Fate, Similarity, and Closure.
Occlusion refers to the visual cue where one object partially blocks or hides another object, indicating that the occluded object is farther away.
Proximity is the principle that states that objects that are close to each other tend to be perceived as a group.
Common Fate refers to the perception of objects that move together in the same direction as being part of a group or having a common purpose.
Similarity suggests that objects that are similar in shape, color, or texture are perceived as belonging to the same group.
Closure is the tendency to perceive incomplete or fragmented objects as complete by mentally filling in the missing parts.