1. ## Reaction Times

What's the upper range of reaction times for humans?

We had to do a reaction time test in Biology today in which you dropped a ruler from a point into someones open grasp for them to grab then measuring the length of the ruler where they grabbed it and converting that into a reaction time.

It gave a list of reaction times for every cm below the grabbing point(IE, you grab it at 20 your reaction time is .202 of a second).

If you grabbed it at 1cm(basicaly as soon as they dop it) it said that eqauled a reaction time of 0.0048 of a second.

As many people managed to acheive that(some more than once even) i contested that a reaction time of .0048 of a second is impossible and so anything less than a certain point would be an innaccurate result as the person grabbing would basicaly have guessed when it was going to be dropped taking reaction time out of the equation.

He said i was wrong, and that .0048 is possible by a human.

Who's right?

2. I think 0.048 would be theoretically possible, but you wouldn't be able to determine it from that test. If it was happening often I'd say you're right in thinking that it was due to people anticipating when it would be dropped rather than a genuine reaction. It doesn't sound like a particularly scientific test.

Try something like this and I think it'd be exceedingly difficult to get 0.1 or less.
http://www.bbc.co.uk/science/humanbo...n_version5.swf

3. You. 1/200 of a second is utterly ridiculous. I think the lower bound is approximately 0.2.

I think 0.048 would be theoretically possible, but you wouldn't be able to determine it from that test. If it was happening often I'd say you're right in thinking that it was due to people anticipating when it would be dropped rather than a genuine reaction. It doesn't sound like a particularly scientific test.

Try something like this and I think it'd be exceedingly difficult to get 0.1 or less.
http://www.bbc.co.uk/science/humanbo...n_version5.swf
The claim isn't 0.048. It's 0.0048!

5. Originally Posted by Neil Pickup
You. 1/200 of a second is utterly ridiculous. I think the lower bound is approximately 0.2.
Less than that, we did reaction times as our Stats coursework and several people got under that, and that was three years ago. Suppose reaction times improve with age.

6. Originally Posted by Neil Pickup
The claim isn't 0.048. It's 0.0048!
Oh, right. Yeah, sounds impossible then.

7. In athletics it's a false start if your 'reaction time' is less than 0.1 seconds (which presumably is impossible without anticipation etc.) and generally the times are usually between 0.1 and 0.2.

8. The reaction time in this case isn't from "you see ruler moving", it's from "you see person moving muscles to get ready for ruler moving".

Might not be such a big difference, but if you can predict when the other guy's gonna drop the ruler (and there is a delay between someone moving their hands and the ruler actually moving, due to friction), then obviously you have a fairly useful chance of lowering your "reaction time".

9. Originally Posted by Neil Pickup
The claim isn't 0.048. It's 0.0048!
Wiki: "Simple reaction time is the time it takes to react to stimuli. The average human's reaction time falls somewhere between 200 and 270 milliseconds, although athletes and others who train themselves can achieve reaction times approaching 150 milliseconds"

10. Originally Posted by Neil Pickup
Wiki: "Simple reaction time is the time it takes to react to stimuli. The average human's reaction time falls somewhere between 200 and 270 milliseconds, although athletes and others who train themselves can achieve reaction times approaching 150 milliseconds"
Wouldn't trust Wiki tbh, from experience the average adult human's reaction time would be a fair bit under that, and our testing method was totally unpredictable.

11. That reliable source which gets you marks taken off you if you reference it in any of your courseworks.

12. Originally Posted by Tom Halsey
Wouldn't trust Wiki tbh, from experience the average adult human's reaction time would be a fair bit under that, and our testing method was totally unpredictable.
Especially as the article he quoted was one listing as "needing citation".

However, it did link to a rather interesting bunch of stats based on this test, which looks equally unpredictable.

13. I averaged 210-215ms.

14. Originally Posted by PY
That reliable source which gets you marks taken off you if you reference it in any of your courseworks.
Is it? Haha, we still get to use it, although politics has banned us from referencing from Wiki..

15. Average male reacution times are supposed to be between 0.2 and 0.3 seconds, average female is slightly higher from memory maybe 0.25 - 0.35.

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