Chapter 2. Research Methods

Question 1

What is a psychophysical scale?

Answer 1

A scale which people rate their psychological experiences as a function of the level of a physical stimulus (the scoville scale, rank on how hot it feels)

Question 2

What is the “Method of Limits”?

Answer 2

Experimental Method where stimuli are presented on a graduated scale and participants must judge the stimuli along a certain property that goes up or down

Question 3

What is an absolute threshold?

Answer 3

the smallest amount of a stimulus necessary to allow an observer to detect its presence.

Question 4

What is the difference threshold?

Answer 4

The smallest difference between two stimuli that can be detected

Question 5

What is 1 JND?

Answer 5

Ex: The smallest difference in the wavelengths of the lights that can be detected is the difference threshold, or 1 JND.

Question 6

Are absolute thresholds absolute?

Answer 6

They depend on many internal and external conditions

Question 7

What is the crossover point?

Answer 7

The point at which people change from detecting to not detecting or vice versa

Question 8

What is the two-point touch threshold?

Answer 8

The minimum distance along the skin at which two touches are perceived as two touches and not one.

Question 9

What is the “Method of constant stimuli?

Answer 9

The threshold determined by presenting the observer with a set of stimuli presented in random order

Question 10

What is the method of adjustment?

Answer 10

The observer controls the level of the stimulus and adjusts it to be at the perceptual threshold. (The participant increases or decreases the level of the stimulus until it feels as if it is just at detectable level)

Question 11

What is a disadvantage of the method of adjustment?

Answer 11

Leads to great variance from one participant to the next and between successive trials for each participant

Question 12

What is the point of subjective equality?

Answer 12

The PSE designates the settings of two stimuli at which the observer experiences them as identical

Question 13

What is sensitivity?

Answer 13

The ability to perceive a particular stimulus

Question 14

How is threshold connected to sensitivity?

Answer 14

A lower threshold means a higher sensitivity

Question 15

What is magnitude estimation?

Answer 15

A psychophysical method in which participants judge and assign numerical estimates to the perceived strength of a stimulus (If this tone is 20 what would you rank the others)

Question 16

What is response compression?

Answer 16

The strength of the stimulus increases, so, too, does the perceptual response but does not increase by as much as the strength of the stimulus increases

Question 17

What is response expansion?

Answer 17

The strength of the stimulus increases, the perceptual response increases even more (opposite to response compression)

Question 18

What is stevens’s power law?

Answer 18

P = cI b An equation that tries to encapsulate response compression and expansion

Question 19

What is a catch trial?

Answer 19

A trial in which the stimulus is not presented, therefore catches participants who are giving untruthful answers to being able to perceive a certain stimulus

Question 20

What is the forced-choice method?

Answer 20

In every trial, the subject is asked to report either when the stimulus occurred or where it occurred

Question 21

What is the difference between a false alarm and a miss?

Answer 21

False alarm: occurs when the observer mistakes a nonsignal for an active signal
Miss: Incoming signal is not detected

Question 22

What is the difference between a correct rejection and a hit?

Answer 22

Correct rejection: a nonsignal is perceived as not occurring
Hit: When a signal is correctly perceived as occurring

Question 23

high vs. low criterion

Answer 23

If your car is relatively new and has a history of smooth running, perhaps you will decide that you didn’t really hear anything (high criterion). Your hearing is “playing tricks” on you. However, if you are driving an old car that has a history of spending nearly as much time in the shop as on the road, you might decide that you did hear something and head to the nearest service center (low criterion).

Question 24

True or false: Criterion vary depending on the situation

Question 25

What does sensitivity measure?

Answer 25

How easy it is to tell if a signal is present or absent

Question 26

What is the receiver-operating characteristic?

Answer 26

The ROC curve is a graphical plot of how often false alarms occur versus how often hits occur for any level of sensitivity.

Question 27

What is EEG?

Answer 27

Electroencephalography: 256 electrodes are positioned on person's scalp, electrodes detect electrical signals created by the brain

Question 28

What is Magnetoencephalography? MEG

Answer 28

MEG: magnetic sensors detect small magnetic fields produced by the electrical activity of the brain

Question 29

How does MRI work?

Answer 29

Dealing with oxygen molecules within our brains

Question 30

What is TMS?

Answer 30

Transmagnetic stimulation: Stimulate the brain via electric current