One of the many tests at cognitive fun! is the Visual Reaction Time test. It is a simple test: position the cursor within the four arrows close to the red dot and then click the mouse as soon as the large green dot appears. The aim is to click in less than 250 milliseconds, although I don’t know the significance of that particular number.
I did 100 sequential tries this morning, while writing down the time for each. I started the test assuming that the distribution of my times would be normal, but soon it dawned on me that my performance had a lower limit, which appeared to be 187 ms. After I had scored several of those, it became obvious that the distribution wasn’t going to be normal*. Here is the histogram for my 100 time scores.
The 4 longest times were the results of distractions; I had looked away for a moment or something like that.
Here is the histogram for all the values at or below 300 ms. It is a peculiarly skewed distribution. There is a cluster of very short times (187 and 188 ms), then a gap followed by another cluster and finally, a few long values.
My average for all 100 tries is 229 ms. If the 4 longest times (all above 297 ms) are deleted, the mean becomes 218 ms.
Give it a try and see how fast you can react to green.
*Theoretically, any and all normal distributions extend from negative to positive infinity, the only differences between the individual distributions being the mean and the standard deviation values.