L4B: Information Processing Stages - Response Selection

Question 1

What 3 factors affect Response
Selection (decision making)?

Answer 1

1. Event Predictability/Spatial Anticipation
2. S-R Compatibility
3. # of S-R Alternatives

Question 2

How does Event predictability (advance information) affect response selection?

Answer 2

Advance information in choice situations, allows the performer to anticipate and bias preparation processes most related to response selection

Question 3

How does Event predictability (advance information) affect RS?

Is there a way to bypass response selction?

Answer 3

“precue” method: If you have information about the upcoming response you can plan the correct response
(saving or bypassing response selection)

Results in lower RT - example of spatial anticipation

Question 4

Example

Event predictability: Advance information
allows anticipation of where (how) to respond

Answer 4

• Before the ball has been hit (“go” stimulus), there is advance information about where it’s going to go.
• This aids spatial anticipation and response preparation.
• The decision time (RT) about where and how to respond is now decreased.

Question 5

What is the Benefit from spatial anticipation in terms of faster RT?

Answer 5

Response Selection Bypassed

Question 6

What is the Cost from incorrect spatial anticipation?

Answer 6

Advance planning will involve the same processes as before,
but before actual response (R)… will need to re-process stimuli
(SI2) and choose and program a new response (RS2 + RP2)

Question 7

How does S-R (Stimulus-Response) compatibility affects response selection

Answer 7

Degree of “naturalness” between a stimulus & its paired response. …the stimulus leads to an almost
automatic response

S-R pairings are either:

• Inherent: spatial position, size/shape of object
• Learnt (habitual): practice or cultural norms

Question 8

Example

S-R spatial relationships can be naturally
compatible (inherent) or incompatible

Compatible

Answer 8

Incompatible

Question 9

What happens to RT when S-R are incompatible?

Answer 9

Question 10

What is the Simon Effect?

Answer 10

The Simon Effect is the tendency for reaction times to be faster and more accurate when the stimulus and response locations are congruent, even if location is irrelevant to the task.

“When a green stimulus appears, press the green key”
“When a red stimulus appears, press the red key”

Question 11

What are Population Stereotypes?

Answer 11

Other S-R mappings may not be as “natural”

• Association of the stimulus and response is likely learned in population stereotypes
• e.g., red for stop, green for go; clockwise for increase, counterclockwise for decrease.
• Errors are made or RT increases if S-R pairing violates stereotypical relationship.

Question 12

How does Response selection change as the number of choices increases?

Answer 12

Response selection increases as the number of choices increases and thus uncertainty increases

Question 13

What is a “Bit”?

Answer 13

In information theory, the single unit of “information” is referred to as a bit

bit = the amount of information required to decide between two equally likely alternatives (or reduce uncertainty by half)

Question 14

How do we calculate Bits?

Answer 14

Question 15

Example

Answer 15

Question 16

How do the # of S-R alternatives affect response
selection in a lawful manner?

Answer 16

As the # of S-R alternatives (S-R pairs or “choices”) increases, choice RT increases.
- As N increases, RT increases
- When RT is plotted as a function of ‘bits’, there is a linear relationship.

Question 17

What is Hick’s Law?

Answer 17

As Log2(N) increases, RT increases in a linear fashion. This is known as Hick’s Law

Question 18

Example

Using Hick’s Law we can calculate RT if a,b & N
known or calculate a & b if RT and N known

Answer 18

Question 19

Answer 19