This thread has devolved into what sounds like a bunch of web devs that think that makes them experts on perception and psychophysics. But on this point there

This thread has devolved into what sounds like a bunch of web devs that think that makes them experts on perception and psychophysics. But on this point there isn’t anything inherently more abstract about Arabic numerals as a representation of numbers than the angles of the hands on a clock face (ie a short hand to the right is 3 and upright is 12, etc is a pretty efficient way to convey a number). As for what can be read quicker probably has overwhelmingly a lot to do what was learned in youth. Similar to stenographic shorthand this can probably be acquired but there just isn’t much incentive to do so. There isn’t necessarily any extra “cognitive step” in the pattern recognition of a clock face vs that of a numeral. I don’t know much about research on this particular area but there is some in the related area of written language.