Reaction & Movement Time

Question 1

Steps of reaction time

Answer 1

1. Stimulus identification
2. Decision making
3. Movement Initiation

Question 2

What is reaction time

Answer 2

• > the time from stimulus identification to response initiation
• > indicates how quickly information can be processed
• > provides a window into the mental processes underlying motor skill performance

Question 3

Types of Reaction time

Answer 3

1. Simple RT
   - > stimulus = 1 signal; response = 1 action
2. Choice RT
   - > more than one signal, each with its own response

Question 4

Is reaction time trainable?

Answer 4

No, but the system can be cheated through prior knowledge and working on anticipation

Question 5

What is Hick’s Law

Answer 5

*HICKS LAW DOES NOT ACCOUNT FOR ERROR; MEASURES THE REACTION TIME OF TASK REGARDLESS IF IT WAS THE RIGHT CHOICE*

RT = b x log₂(n + 1)

b is a constant, related to the difficulty of the task

n = number of coices

Question 6

Bits of information

Answer 6

The units of the log2(n) term in the Hick’s Law equation is in “bits”.

◦# of choices = 2n(bits)

• > if there is one yes/no choice = 1 bit

Question 7

Fitts’s law

Answer 7

*CONSIDERS ERROR*

• > if you’re at a red light and you start to go at the left turn signal, this is considered a “wrong” reaction under Fitt’s law
• > predictive model of human movement primarily
• > This scientific law predicts that the time required to rapidly move to a target area is a function of the ratio between the distance to the target and the width of the target

Question 8

Index of Difficulty

Answer 8

a factor which quantifies the difficulty of a movement

• > includes the amplitude of the movement and the width of the target
• > units are in Bits (similar to Hick’s law)

ID = log₂[2 (A/W)]

Question 9

Movement time vs reaction time

Answer 9

Movement time involves the execution of a subsequent motor task response, and is included in many reaction time tests.

Simple reaction time, assessed as the time taken to respond to a single stimulus with a single response

Question 10

What does the R² indicate

Answer 10

R2 is a statistical measure that represents the proportion of variance for a dependant variable that’s explained by an independant variable

i.e. if R2 value was 0.92 then 8% of our data was obtained by something that we did not control