1.2 Research Methods

Question 1

psychophysics

Answer 1

relation between physical stimuli and sensation

Question 2

3 aspects of psychophysics

Answer 2

stimulus, subjective experience, response

Question 3

Absolute Threshold

Answer 3

detection threshold, minimal amount of stimulus needed for detection

Question 4

method of limits

Answer 4

method to assess absolute threshold (using both ascending and descending trials) AT: mean intensity across all trials

Question 5

ascending trial

Answer 5

method of limits trial where present small undetectable stimuli and increase intensity until detectable

Question 6

descending trial

Answer 6

method of limits trail where present easily detectable stimuli and decrease until undetectable

Question 7

Method of constant stimuli

Answer 7

present set of stimuli that you judge around a subjective threshold
Score = proportion of yes responses
AT = point where there is a 50 % change of saying yes

Question 8

Signal detection theory

Answer 8

expectation of detection affects the detection itself (response bias: attention, memory, motivation)

Question 9

Outcome matrix of SDT

Answer 9

signal present/absent and response yes or no (Hit/False Alarm/ Miss / Correct Rejection)

Question 10

Response Bias

Answer 10

Large = Stringent Criteria to accept signal as present (NO > Yes) Small = lax criteria to accept signal as present (YES > No)

Question 11

Sensitivity Measurement (d’)

Answer 11

amount of shift elicited by presence of signal in
large d’ = large # of hits, small # of false alarms
small d’ = small # of hits , large # of false alarms

Question 12

discrimination

Answer 12

by how much are 2 stimuli different in order to be discriminated as not the same

Question 13

measuring discrimination

Answer 13

present standard stim. observer distinguishes this from series of other stimuli. using method of limits or constant stimuli .

Question 14

point of subjective equality in discrimination

Answer 14

50 %

Question 15

interval of uncertainty

Answer 15

25 - 75%

Question 16

JND

Answer 16

just noticable difference. divid difference between 2 points by 2

Question 17

Webers Law

Answer 17

relation between JND and size of standard
Linear relationship
= KI (where K is webers fraction)

Question 18

Webers fraction

Answer 18

JND/I smaller = better discrimination

Question 19

Scaling

Answer 19

how much of x is there (indirect or direct)

Question 20

Fechner’s Law

Answer 20

indirect scaling. logarithmic S=WLogI .

Question 21

Direct scaling

Answer 21

stevens. give people a task and make it feasable (IE: category judgment or magnitude estimation)

Question 22

Category Judgement

Answer 22

observers asked to put stimuli of similar intensity in arbitrary categories (ends up logarithmic)

Question 23

Magnitude estimation

Answer 23

give observers freedom in quantifying stimulus. (exponential). fixes categories for continuous variable issue

Question 24

stevens power law

Answer 24

law for magnitude estimation S= al^n (s is sensation I is intensity and a and n are constants)

Question 25

large exponent in steven law

Answer 25

sensation overestimates physical stimulus (ex electric shock)

Question 26

small exponent in steven law

Answer 26

sensation underestimates physical stimulus (ex brightness)

Question 27

cross modality matching

Answer 27

to counter criticism that magnitude estimation is more about numbers. observer presented w series of stimuli and asked to indicate magnitude by adjusting intensity of another stimuli (ex: handgrip and liquor mixture) (POWER FUNCTION)