Reaction time, Hick's law and Fitts's law

Measure on yourself the cost of choice and precision: simple and choice reaction time, Hick's law, Fitts's law and anticipation.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Reaction time: what is it?
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The delay between a signal appearing and the response starting.
It is about 200 ms for a simple visual signal.
A handball goalkeeper faces a shooter who feints then shoots. Why is he late?
- The psychological refractory period delays his response to the real shot
- Fitts's law lengthens any movement towards a large target
- Freezing degrees of freedom locks his dive
- Negative transfer from another sport disrupts him
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The psychological refractory period delays his response to the real shot
He is still reacting to the feint when the shot comes.
Hick's law: what is it?
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Choice reaction time rises with the logarithm of the number of possible choices.
Doubling the choices adds a constant time.
Why does an expert seem to have "more time"?
- His simple reaction time is half as long
- He anticipates from cues and narrows his possible choices
- He waits to see the whole trajectory before acting
- He keeps more possible responses in mind at once
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He anticipates from cues and narrows his possible choices
Fewer plausible choices means a faster decision.