Many of us,including myself at times, worry about our cognition. This will give you a quick indication of how you’re doing.

This is a simple test for Mean Reaction Time (M.R.T.) and Reaction Time Standard Deviation (R.T.S.D., a measure of consistency in reaction speed). Both, R.T.S.D. even more than M.R.T., have a significant (though not high) negative correlation with “g”, or general intelligence.

And, it must be pointed out that reaction time normally increases with age in adults, possibly through the loss of myelination and resulting decrease of nerve conduction velocity. Other than a non-significant negative correlation with birth year, there is not by far enough information in these statistics to study or reveal any development with age.

Correlation between the two SloBrain statistics

r mean reaction time × reaction time standard deviation = .74 (n = 36)

So, persons with shorter reaction times are significantly more consistent, have their reaction times closer together. Statistics of SloBrain

I don’t think so. RTSD Median: 42.2
so you’re just below that. However the average IQ of those 36 is very probably at ‘very superior’ level. Quite a few came from FB high IQ groups.

I’m left handed. It took me ages to get my left hand across ready to press the enter key when the yellow box appeared . Even now I have times when I can’t manage it. Being slow to click when that first yellow box appears can significantly increase the MRT and RTSD.