I made all three disappear within a few seconds. Although, all three were harder to maintain than two -- and one even easier -- but it was a tiny battle of "don't notice what you're doing while doing it". I don't think I could make all three go away for more than one or two seconds, not the five seconds+ for "truly extraordinary".
I made all three disappear within a few seconds.
At most I can get the top dot to go away for like... 1/8th a second.
However, this begs the question: "is it really attention, though"? Perhaps it's also determinate upon the distractions at hand, for some people. Stress hormones, etc.
I always thought I had rather abysmal attention span, but according to this, I have fairly normal attention span. I think this means there is a different spectrum at work.