I just went back to the Shultz table I had downloaded on my old iMac to see how well I did with it.

On the second time through, I again missed one of the smaller changes after a click.

With the older version, it's now clear to me, in general, many fewer numbers are changing with each click of the mouse, which makes it easier to miss a change, and which, I think, makes it more challenging and interesting a game.

I think if someone notices big changes with every click, they can just say, " Oh, I can do this easy, no problem.

However if the changes are not so obvious, and I miss some of them, this may encourage me to play with the game more and work on softening my visual field more before I move onto something else.

I think the fact that there are only 0's and 1's in the older version might be significant also.

There's not that much going on as they actually change, and they don't look that different after a change than they did a moment before, unless I actually see it all happen.

I was wondering then how just 0's and 8's might be an added challenge or just 7's and 1's?

I think the more times people miss seeing a change, because they were small, subtle changes, the more they will be challenged and want to pay attention to notice every little change.

Big movements attract our focused attention, small movements can be more easily taken in as part of the whole.

I'm envisioning a random change rate of something like this: click, 5 changes, click 2changes, click, 3c, click 4c, click, 1c, click 2c, click 4c, click 1c, click 1c, click 2c, click 3c, click 4c, click 1c, click 1c, click 2c, etc. but weighted heavily towards minimal changes with only 2 different numbers being used at the same time, i.e. 0's & 8's.