Question 1

In signal detection, which type of response is more likely if you have a strong expectation that a signal is present?

Accepted Answer

If you have a strong expectation that a signal is present, you are more likely to have a false alarm response, meaning you might detect a signal even when it is not present due to the bias towards the expected presence of a signal.

Question 2

If a 100-Hz tone had to be increased to 110 Hz for a subject to just notice the difference, what would you change a 1000-Hz tone to, in order for that subject to notice the difference?

Accepted Answer

The threshold for the difference in frequency detection is approximately 10% for both high and low frequency tones. Therefore, for a 1000 Hz tone to have a noticeable increase in frequency, it would need to be changed to 1100 Hz, which is a 10% increase. Choice C is the closest option.

Question 3

Which of the following is most accurate regarding our inner measurements of sensory experiences?

Accepted Answer

Our inner measurements of sensory experiences are subjective and influenced by various factors such as expectations, emotions, and past experiences. As a result, there is no one-to-one correspondence with the physical intensity of the stimulus, particularly at higher intensity levels where the perception of the stimulus can be distorted or changed. This phenomenon is known as the Weber-Fechner law.

Question 4

Light has entered Jeff's eye and has stimulated receptors there. Which of the following terms describes this process?

Accepted Answer

Sensation refers to the process of sensing our environment through touch, taste, sight, sound, and smell. In this case, light entering the eye and stimulating receptors is the initial sensory process.

Question 5

Joan was sitting talking with some friends when she suddenly left the room to check on her baby. She was sure she heard little Emily cry out, but when she checked, Emily was sleeping peacefully. What would you call Joan's response based on signal detection theory?

Accepted Answer

Joan's response is a false alarm because she perceived a signal (crying of her baby) when there was no actual signal present.

Question 6

When Celeste was playing her stereo at 40 decibels and she turned it up to 44 decibels, she could notice that it was louder. If Celeste's stereo were playing at 80 decibels, what should her just noticeable difference be?

Accepted Answer

The just noticeable difference (JND) is proportional to the intensity of the stimulus. Since the decibel scale is logarithmic, doubling the intensity (from 40 to 80 decibels) would require doubling the JND, making it 8 decibels.

Question 7

Evelyn turned the thermostat up from 68 degrees to 70 degrees; however, she doesn't think it feels any warmer and she wants to turn it up even higher. Her roommate thinks that it is now too hot, and she wants to turn the thermostat back down. How does Evelyn's just-noticeable-difference compare to her roommate's?

Accepted Answer

Evelyn's just-noticeable-difference is larger because she does not notice the change in temperature as much as her roommate does.

Question 8

Which of the following reflects a distinction between the process of sensation and the process of perception?

Accepted Answer

Sensation refers to the process of gathering information from the sense organs (such as the eyes, ears, nose, etc.) and transmitting it to the brain, whereas perception refers to the process of interpreting and organizing that information within the brain to make sense of it. Therefore, sensation occurs at the level of the sense organs and perception occurs at the level of the brain.

Question 9

In the signal-detection method, what do we call it when a subject detects a stimulus when no stimulus is actually present?

Accepted Answer

When a subject detects a stimulus when no stimulus is actually present, we call it a false alarm.

Question 10

A neural signal from Mary's taste bud has travelled to her cortex and she experiences enjoyment of a sweet flavour. Which of the following terms describes this process?

Accepted Answer

Perception refers to the process of interpreting sensory information and making sense of it in the brain. In this scenario, Mary's brain is not just detecting the sweet flavor (sensation) or converting it into neural signals (transduction), but also interpreting it as an enjoyable experience. Therefore, the correct term to describe this process is perception.

Question 11

Jerry, a nuclear operator, must monitor 50 different gauges that keep track of various aspects of the nuclear reactor. Which of the following theories provides the most specific predictions for Jerry's likelihood of detecting any changes or problems?

Accepted Answer

Signal-detection theory provides specific predictions for detecting changes or problems in situations where there is a lot of noise or distractions. In Jerry's case, he must monitor 50 different gauges, which could create a lot of distractions and noise. Signal-detection theory explains how different factors, such as the level of noise and how motivated Jerry is to detect changes, will impact his ability to monitor the gauges effectively. Fechner's law, pragnanz, and Weber's law are not as applicable to this specific scenario.

Question 12

Werner was having his hearing tested, and a number of the tones that were presented were so faint he was not able to detect them. What can you say about the faint sounds?

Accepted Answer

The fact that Werner was not able to detect the faint sounds suggests that they fell below his absolute threshold for sound, which is the minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time.

Question 13

You have a lamp with a three-way light bulb. You can use the light at 50 watts, 100 watts, or 150 watts. When you change between settings, which of the following changes will be perceived as a larger increase in brightness?

Accepted Answer

The perceived brightness of light is not linear with wattage; it follows a logarithmic scale. The increase from 50 to 100 watts is a doubling of power, which is perceived as a larger increase in brightness compared to the increase from 100 to 150 watts.

Question 14

What is your absolute threshold?

Accepted Answer

The absolute threshold is the point at which you detect a stimulus about half of the time. This means that option D is the best choice. Option A is incorrect because it states that you detect any portion of a stimulus, which is not accurate. Option B is incorrect because it describes sensory memory, which is not the same as the absolute threshold. Option C is also incorrect because it does not accurately describe the concept of absolute threshold.

Question 15

Which type of signal-detection error becomes more likely when the expectation of a stimulus is weak?

Accepted Answer

When the expectation of a stimulus is weak, there is a higher chance of missing the stimulus because it may not be detected even if it is present. This is because the threshold for detecting the stimulus is high when the expectation is weak. A miss is a type of signal-detection error in which the stimulus is present but not detected.

Question 16

Dalton was sitting in the hallway outside his chemistry class. Some students said they thought they could smell smoke, but Dalton didn't smell anything. When they all checked the lab to see if there were any problems, everything was fine and nothing was burning. What would you call Dalton's response based on signal detection theory?

Accepted Answer

Dalton did not detect a signal (smoke), and upon checking, confirmed that there was indeed no signal (nothing burning). Therefore, his response can be classified as a correct rejection.

Question 17

Giovanni was watching the night sky on a clear evening in November. He noticed that sometimes when he looked directly overhead he could detect a very faint star. A few minutes later it seemed that the star had disappeared, and then it "appeared" again. How would you describe the light from the star, in this case?

Accepted Answer

The fact that Giovanni is able to detect the star, even if it is faint and appears and disappears, suggests that it is at or just above his absolute threshold for light.

Question 18

Which of the following is being measured if a subject is presented with a series of light bulb pairs of different wattages and is asked whether the members of each pair differ in brightness?

Accepted Answer

The subject's ability to distinguish the difference in brightness between two light bulbs of different wattages is measuring their just noticeable difference (JND) for brightness. The JND is the minimum amount of difference between two stimuli that is detectable 50% of the time. It is a measure of sensitivity to differences and is related to the concept of Weber's law. The other options are not relevant to this particular task, as visual acuity refers to the sharpness of vision, absolute threshold is the minimum amount of stimulation needed to detect a stimulus, and physical intensity difference is simply the difference in physical characteristics of the two stimuli.

Question 19

Juanita was drinking some warm punch and she thought she could just detect a faint taste of nutmeg in the punch. When she took another sip the taste wasn't there. On the third sip she could just make out the taste of nutmeg again. What could you say about the taste of nutmeg in this situation?

Accepted Answer

The taste of nutmeg is just at her absolute threshold for taste, meaning it is the minimum level of stimulus that she can detect, which is why she can only taste it intermittently.

Question 20

Raul is making potato soup. His roommate tastes it and tells Raul it is great, but Raul thinks it needs more salt. He adds just a little salt, and thinks the soup now tastes perfect. However, his roommate tastes it again and tells Raul that the soup is ruined because it is too salty. Which of the following is most accurate?

Accepted Answer

This scenario is related to the just noticeable difference (JND). Raul added just a little salt which was enough for him to notice a difference, but not enough for his roommate to notice a difference. This suggests that Raul has a larger JND than his roommate. Therefore, the correct choice is D - Raul's roommate can detect a smaller JND than Raul can.

Quiz 4: A: Sensation and Perception