Question 1

According to Stevens's power law, for which judgment is the perceived magnitude actually equal to the physical magnitude?

Accepted Answer

Stevens's power law suggests that for line length, the perceived magnitude of a stimulus is directly proportional to its actual physical magnitude, meaning our perception of line length scales linearly with its actual size.

Question 2

The difference threshold is the minimum difference between two stimuli detected _____ percent of the time.

Accepted Answer

The difference threshold is also known as the just noticeable difference (JND), and it is the smallest difference between two stimuli that a person can detect 50% of the time. Therefore, the correct choice is C - 50.

Question 3

According to Weber's law, if the difference threshold for a 10-pound weight were .20 pounds, the difference threshold for a 50 pound weight would be_____.

Accepted Answer

Weber's law states that the difference threshold is a constant fraction of the original stimulus. The constant fraction is called the Weber fraction, and it varies depending on the sense and the stimulus being measured. In this case, the Weber fraction for weight perception is 0.02 (0.20 pounds / 10 pounds). To find the difference threshold for a 50-pound weight, we need to multiply the Weber fraction by the weight of the stimulus. Therefore, the difference threshold for a 50-pound weight would be (0.02 x 50 pounds) = 1 pound.

Question 4

Which constant fraction of a standard stimulus would indicate the ability to detect smaller differences between the same stimuli?

Accepted Answer

A smaller fraction, such as 1/16, indicates a higher sensitivity to differences between stimuli, as it means the individual can detect smaller differences compared to larger fractions.

Question 5

David is holding a surprise birthday party for Ellen and has asked Fredo to stand outside his apartment door to signal when Ellen is approaching. According to signal detection theory, if Fredo is more concerned about noticing when Ellen is approaching than about being incorrect, he is likely to adopt a _____ decision criterion and thus have more _____ than _____.

Accepted Answer

Fredo's concern about noticing Ellen's approach over being incorrect leads him to adopt a lax decision criterion, which increases the likelihood of false alarms (thinking Ellen is approaching when she is not) over misses (failing to notice when Ellen is actually approaching).

Question 6

According to Stevens's power law, for which judgment is the perceived magnitude greater than the actual magnitude?

Accepted Answer

The answer of According to Stevens's power law, for which...

Question 7

In a signal detection task, Josh often indicates he has seen the signal, even when he is not sure. Josh is using a criterion that will result in _____ false alarms and _____ misses.

Accepted Answer

Josh's tendency to say he has seen the signal even when he is not sure indicates a liberal criterion, which increases the number of false alarms (saying there is a signal when there is not) and reduces the number of misses (failing to detect an actual signal). Therefore, the best choice is B, which indicates many false alarms and few misses.

Question 8

According to signal detection theory, if your life depended on an X-ray technician's ability to detect a cancerous tumor, you would want her to have a _____ detection criterion, which would result in a high rate of _____.

Accepted Answer

A lax detection criterion means the technician would prefer to err on the side of caution, leading to more hits (correctly identifying tumors) and false alarms (identifying non-tumors as tumors), which is preferable when the cost of misses (failing to detect actual tumors) is high.

Question 9

Based on signal detection theory, a "yea" sayer is to _____ as a "nay" sayer is to _____.

Accepted Answer

A "yea" sayer, according to signal detection theory, is someone who is more likely to say "yes" to detecting a signal, thus they are prone to making many false alarms. Conversely, a "nay" sayer is more likely to say "no" to detecting a signal, leading to many misses.

Question 10

Don is in an experiment in which the researcher has him hold a constant weight in one hand. The researcher varies the amount of weight in Don's other hand, and each time the weight is changed, Don has to determine whether it differs from the constant weight. Don is participating in an experiment measuring _____.

Accepted Answer

Don is participating in an experiment measuring difference thresholds (also known as just noticeable differences), which refers to the minimum amount of difference required for a person to detect a difference between two stimuli. In this case, the stimuli are weights held in each hand, and the researcher is varying the weight in one hand to see if Don can detect the difference compared to the constant weight in the other hand.

Question 11

Based on signal detection theory, a "yea" sayer is to _____ as a "nay" sayer is to _____.

Accepted Answer

According to signal detection theory, individuals set their own decision criteria for detecting a signal. A "yea" sayer is more likely to have a lax decision criteria, meaning they may be more likely to say "yes" or signal detection is more sensitive. A "nay" sayer, on the other hand, is more likely to have a strict decision criteria, making it less likely for them to say "yes" or signal detection is less sensitive. Therefore, the correct answer is A - lax decision criteria; strict decision criteria.

Question 12

How is Stevens's power law different from Weber's law?

Accepted Answer

Stevens's power law is different from Weber's law in that it was developed to apply to perceptions that are well above threshold levels, relates to scaling rather than to detection or difference, and was developed to relate changes in actual physical magnitude to perceived magnitude.

Question 13

According to Weber's law, the constant for loudness of tones, measured in decibels, is .05. This means that a person should be able to tell the difference between a standard stimulus of 50 decibels and a comparison stimulus of _____ decibels.

Accepted Answer

The answer of According to Weber's law, the constant for...

Question 14

Which of the following would be MOST useful in describing differences in how our perceptions of the magnitude of a stimulus relate to its actual physical intensity?

Accepted Answer

Stevens's power law describes the relationship between the physical intensity of a stimulus and our perception of its magnitude. This law suggests that a stimulus must be increased by a certain proportion in order for its perceived magnitude to increase by a constant amount. In other words, our perception of the magnitude of a stimulus is not directly proportional to its physical intensity, but instead follows a specific nonlinear relationship. Weber's law, sensory adaptation, and signal detection theory do not specifically address this relationship between physical intensity and perceived magnitude.

Question 15

If the Weber fraction for lifted weights is 1/50 and the standard stimulus used to determine the just noticeable difference (jnd) is 500 pounds, the jnd would be _____ pounds.

Accepted Answer

The Weber fraction formula is (JND / standard stimulus) = Weber fraction. To find the JND, we can rearrange the formula to JND = Weber fraction x standard stimulus. Plugging in the given values, JND = (1/50) x 500 = 10 pounds. Therefore, the jnd would be 10 pounds.

Question 16

According to signal detection theory, a "yea" sayer has _____, whereas a "nay" sayer has _____.

Accepted Answer

According to signal detection theory, a "yea" sayer has many hits but also many false alarms, while a "nay" sayer has many correct rejections but also many misses. Therefore, option B is the best choice as it reflects this relationship. Option A is incorrect because it suggests that both "yea" and "nay" sayers have many hits and correct rejections, which is not true. Option C is also incorrect because it suggests that "yea" sayers have few misses, which is not true. Option D is incorrect because it suggests that both "yea" and "nay" sayers have few hits and correct rejections, which is not true.

Question 17

_____ states that the perceived stimulus magnitude is equal to the actual physical intensity raised to some constant power.

Accepted Answer

Stevens's power law states that the perceived stimulus magnitude is equal to the actual physical intensity raised to some constant power. The other options (B, C, and D) are not related to this concept.

Question 18

When studying the difference threshold, the stimulus that remains the same across trials is called the _____ stimulus.

Accepted Answer

The standard stimulus is the one that remains the same across trials when studying the difference threshold. It serves as a reference point for the comparison stimulus, which is the stimulus that is changed in various ways to determine the difference threshold. The test stimulus is another term used to refer to the comparison stimulus in some contexts, while the control stimulus is not typically used in this area of study.

Question 19

Another name for the difference threshold is the _____ noticeable difference.

Accepted Answer

The just noticeable difference (JND) is another term for the difference threshold. It refers to the smallest amount of change in a stimulus that a person can detect at least 50% of the time.

Question 20

_____ states that for each type of sensory judgment that we make, the measured just noticeable difference (jnd) is a constant proportion of the standard stimulus value used to measure it.

Accepted Answer

Weber's law states that the just noticeable difference (jnd) for a given stimulus is a constant proportion or percentage of the magnitude of the stimulus. This means that the difference between two stimuli must be a certain percentage of the original stimulus in order for the difference to be noticeable. For example, the jnd for weight is about 2%, so a 100-gram object would need to be changed to 102 grams in order for the difference to be noticeable.

Quiz 3: Section 2: Sensation and Perception