Define sensation and perception. Distinguish between the two terms. (p. 138)
Define psychophysics.(p. 139)
Define threshold and absolute threshold. Provide and recognize original examples of each. (p. 139)
How is the absolute threshold typically measured? (p. 139)
What is a just noticeable difference (JND)? Provide and recognize original examples of different JNDs. Explain an absolute threshold in terms of a JND. Define Weber’s law. (p. 140)
Define Fechner’s law. Explain its ramifications. (p. 140)
Describe signal-detection theory. Define hit, miss, false alarm, and correct rejection. (pp. 140-141)
What is subliminal perception? Be able to provide and recognize original examples of the use of subliminal perception for the purpose of advertising. Does subliminal perception occur? Should its use be a significant concern? (pp. 141-142)

Comment: Weiten and McCann's main conclusion is that subliminal messages can be effective, but that the effects are relatively small and of little practical importance. But are even small changes important? Advertising is an effective means of behaviour control and because we encounter so many advertising messages every day, we are left with an overall tendency to go shopping and make purchases. Sneddon (2001) regards this influence as a moral problem because it "works against the willingness of people to examine their lives against a rich background of values and possibilities" (p. 23). With so many advertising messages, we are left with a culture in which people neglect the things money cannot buy (Waide, 2001), and many people develop a trivialized personal identity based on the products they use rather than based on more substantial and important human values (Cushman, 1990; Fromm, 1976; Jhally, 2002; Walker, 2008). Subliminal advertising has all these problems, and it is capable of influencing us without our knowledge, so Weiten and McCann may have dismissed this issue too quickly.
Define sensory adaptation. Discuss its importance for detecting changes versus constants in the environment. Be able to provide and recognize original examples of sensory adaptation. (pp. 142-143)
List the physical properties of light and the aspects of visual perception that these properties influence. (p. 143)
Describe the path of a ray of light through the various structures of the eye to the point of most-effective focus. Describe nearsightedness and farsightedness. (pp. 143-147)
Explain the function of rods and cones. Describe their distribution in the retina. (pp. 146-147)
Describe the role of rods and cones in adaptation to darkness and light. (p. 147)
Describe the processing of visual information within the retina, with special focus on the concepts of receptive fields and lateral antagonism. (p. 148)
Describe the routing of signals from the eye to the brain. (p. 149)
Describe Hubel and Weisel’s work on information processing in the visual cortex. What happens when organisms are also deprived of specific types of visual stimulation early in the development of the visual cortex? Explain. (pp. 149-152)
What is visual agnosia? How may it be explained? What is prosopagnosia? (p. 152)
Describe the McCollough effect. (pp. 152-153)
Define subtractive colour mixing and additive colour mixing, and give examples of each. (pp. 153-154)
Describe the trichromatic and opponent process theories of colour vision. What evidence indicates that both theories are required to explain colour vision? What are complimentary colours, and why are these discussed when the opponent-process theory of colour vision is discussed in the textbook? (pp. 154-156)
Define colour-blindness. Describe the effects of gender on colour-blindness. Are most people who are colour-blind completely blind to differences in colours? Explain. (p. 155)
Do colours have an effect on our behaviour? Why? What effect does red clothing have when a woman wears it? What effect does a red moving object produce? (pp. 156-157)
What is a reversible figure? What is a perceptual set? What is inattentional blindness? (pp. 157-159)
Describe the process of feature analysis as it relates to the perception of shape and form. Define bottom-up processing and top-down processing. Define subjective contours. (pp. 159-160)
Describe the phi phenomenon. Provide an example. (p. 160)
Define figure-ground relationship. What is a reversible perspective? (pp. 160-161)
Define the Gestalt principles of proximity, closure, continuity, simplicity, and similarity. Be able to recognize examples of these principles. (p. 161)
Differentiate distal stimuli and proximal stimuli as they relate to visual perception. What is a perceptual hypothesis? (pp. 161-163)
Define depth perception. Describe two types of binocular depth cues. Describe the following monocular depth cues: motion parallax, linear perspective, texture gradient, interposition, relative size, height in place, ligh,t and shadow. Why are most monocular depth cues called pictorial depth cues? (pp. 163-165)

Comment: While Weiten and McCann cover monocular and binocular cues to depth perception, they do not cover the biological processes involved in the binocular situation. The biological process of depth perception depends on retinal disparity. The greater the distance between non-corresponding retinal points, the greater the degree of disparity. Binocular depth perception occurs, then, because the degree of disparity between retinal images also signals the distance of a person or object from the horopter (the line of fixation). The greater the degree of disparity, the greater the distance from the horopter. Thus, the degree of disparity between retinal images indicates how far something is from where we are standing.

Specialized cells that respond to retinal disparity, called binocular depth cells, have been found in the visual cortex of cats. One cell responds most dramatically to stimuli presented to both eyes and separated by half a degree. Stimuli at different distances cause different groups of binocular cells to fire and give the visual cortex appropriate information about depth and distance.
What is meant by the term perceptual constancy? Illustrate your answer with reference to shape constancy and size constancy. (pp. 165-168)

Comment: Perceptual constancies are probably learned behaviours. Very early in life, for example, we learn that a person who is far away from us is not 30 centimetres tall; instead, we learn that the person is at some distance from us and this distance is responsible for the appearance of diminished size. Relatively little is known about this kind of perceptual learning, but we can speculate that we come to respond to the world as a perceptual constant because it leads to more effective behaviour than responding to the world as lacking in perceptual constancies and/or as a chaotic system.
Define optical illusion. Discuss the possibility of cultural factors in illusion susceptibility, with reference to the Müller-Lyer illusion, the Ponzo illusion, and the Ames room. (pp. 165-168)
Define impossible figures. (pp. 166-167)
Explain why Goodale and his colleagues have concluded that there are two vision pathways to the brain: a dorsal stream and a ventral stream. Describe the functions of each stream. (pp. 168-170)
What are sound waves? Define frequency, amplitude, and purity as properties of sound. Explain how frequency and amplitude are measured and how they are interpreted as parts of the auditory stimulus. (pp. 170-171)

Comment: Just as visual stimuli can vary in amplitude, resulting in brightness differences, auditory stimuli can vary in amplitude, resulting in loudness differences. Loudness is cited in Weiten and McCann as a causative factor in hearing loss, which is often mentioned in connection with loud music. Pete Townsend, of the rock group The Who, has suffered permanent damage to his hearing due to years of exposure to loud music. This type of hearing loss is particularly acute at the upper end of the hearing range, which results in difficulty hearing some consonants in speech. Other factors, such as viral infections and tumors of the auditory nerve, can result in loss of sensitivity to lower frequencies. Aspirin use causes greater vulnerability to noise, and, in large doses, can bring about temporary hearing loss.
What is the range of frequencies humans can hear? How does this compare to the hearing of other animals? What is the relation between amplitude of sound waves and perceived loudness? What is the rule of thumb for the relationship between decibels and perceived loudness? (p. 171)
Describe the routing of auditory signals from the ear to the brain. Be able to identify the key structures involved in the processing of auditory signals, and be able to explain their functions. (pp. 171-173, Figure 4.47)
Compare and contrast the place and frequency theories of pitch perception. Discuss the resolution of the debate between these theories. (pp. 173-174)
Define auditory localization. Describe the cues that appear to be critical to auditory localization. (p. 174)
Does exposure to music have beneficial effects? Explain, citing data from research. (p. 175)
Describe the procedure and results of the featured study entitiled "Decoding Speech Prosody: Do Music Lessons Help?" What is a ceiling effect? (p. 176)
Define gustatory system and olfactory system. Describe how the gustatory system operates. (pp. 177-179)
What are the four primary tastes and the fifth taste some scientists have suggested be added? Summarize Weiten and McCann’s discussion of taste preference. Describe the characteristics of those individuals named nontasters, medium tasters, and supertasters. (pp. 177-179)
Why do wine tasters roll the wine in their mouths before commenting on it? (p. 179)
Describe the routing of olfactory information to the brain. Why is this arrangement unique? Describe Buck and Axel’s (1991) findings regarding the operation of the olfactory receptor cells. Are people good at detecting different odours and naming different odours? Are there gender differences in ability to detect odours? Explain. What are pheromones? (pp. 179-180)
Describe the structures and functions involved in feeling pressure. Describe the concept of receptive fields as it pertains to the sense of touch. (pp. 180-181)
Describe the structures and functions involved in feeling pain, including the C fibres and the A-delta fibres. (p. 181)
Describe the gate-control theory of pain. Describe how endorphins are thought to affect our perception of pain. Describe how the midbrain’s periaqueductal gray is also thought to affect our perception of pain. (pp. 182-183)
What is the kinesthetic system? Describe its operation. (p. 184)
Describe the structures and functions involved in the operation of the vestibular system. How does this system keep you informed of your position in space? (p. 184)
Describe the way in which artists and groups of artists have (a) made use of pictorial depth cues, (b) applied the theory of feature analysis, and (c) provoked viewers to consider the principles of perception. What techniques did the Cubists tend to use? What were the French Impressionists concerned with in their paintings? (pp. 188-193)
Define and describe the door-in-the-face technique of selling, contrast effects, and comparitors. Explain the relationship of these concepts to the processes involved in critical thinking. (pp. 194-195)

	Created by Patrick Schorno about 8 years ago

Chapter 4: Sensation and Perception

Unit 4: Study Questions