mental chronometry and simple decisions

Question 1

is nerve conduction velocity fast or slow?

Answer 1

SLOW

Question 2

what is NCV?

Answer 2

way to measure electric stimulation on nerve and contraction of muscle

Question 3

how was the first direct measure of NCV obtained?

Answer 3

in 1850, Helmholtz obtained the first direct measure of NCV in frogs

Question 4

what equation was created in Helmholtz’s studies on humans and NCVs?

Answer 4

reaction time (RT) = time of response (Tr) minus time of stimulus (Ts)

Question 5

why use reaction time?

Answer 5

• marker of mental processing speed
• varies with many things: intelligence, memory capacity, depression, fatigue, sleep quality/deprivation

Question 6

how to plot reaction times?

Answer 6

• Y axis = R-value (-1 to +1)
• X axis = chronological age
• robust correlations between how fast people are to press buttons and complex concepts like fluid intelligence

Question 7

what is mental chronometry?

Answer 7

using reaction time to study the structure and function of mental processes

Question 8

what was the subtraction method by Donders (1868): Task A?

Answer 8

• task A - press a button when see a light
• simple RT = detection & execution
• as only one button and one type of light so very simple
• expect fast RTs

Question 9

what was the subtraction method by Donders (1868): Task B?

Answer 9

• task B - press button 1 when see a yellow light and press button 2 when see a blue light
• choice RT = detection & identification & selection & execution
• expect slower RTs
• RT is the sum of 4 different processes here

Question 10

what was the subtraction method by Donders (1868): Task C?

Answer 10

• task C - press button 1 when see a yellow light and do nothing when see a blue light
• Go/No-Go RT = detection & identification & execution

Question 11

what was the logic of Donder’s subtraction method?

Answer 11

• task C minus Task A
• Go/No-Go RT minus Simple RT = Duration of stimulus identification
• task B minus Task C
• choice RT minus Go/No-Go RT = Duration of response selection
• allows to infer the speed/time of internal mental processes, which may not be directly observable
• it relies on two strong assumptions

Question 12

what 2 assumptions does Donder’s subtraction method rely on?

Answer 12

• serial processing
• pure insertion

Question 13

what is serial processing?

Answer 13

• processes are arranged sequentially
• output of one serves the input to the next
• at a given time, only one process can be active
• non-overlapping in time
• each process takes a certain amount of time
• RT = the sum of the durations of all the processes
• subtraction occurs when you want to know how long each of the 4 stages took place for
• detection -> Identification -> Selection -> Execution (all over time)

Question 14

what is pure insertion?

Answer 14

• a stage can be added or omitted to a sequence of processes, without altering other processing stages
• stages are not affected when you add or remove other stages
• e.g., whether or not a stimulus needs to be “identified” does not affect the later execution stage

Question 15

what is the additive factor method?

Answer 15

• factor: an independent variable with different values/levels
• additive: Test if two factors have additive effects on RT
• can infer the existence of independent processing stages
• can use RT to see if 2 factors have the additive effect

Question 16

what did Sternberg propose about the additive factor method?

Answer 16

• if we can find 2 factors which effort on RT are additive
• then this means the factors selectively affect 2 independent stages

Question 17

do MDD patients have slower RTs?

Answer 17

YES

Question 18

what would be the results of a choice RT task done by MDD patients?

Answer 18

• interaction between compatibility and groups (over-additive)
• MDD group suffers more from incompatibility of stimulus- response mapping
• MDD likely affects response selection