[diacritical]

I had a friend years ago with laser focus. He was read an article on his laptop and I was behind him. I asked him how he tolerating the flashing chumbox ad. "Why don't you install Adblock Plus (the ad blocker of the day)?". He had to look around his screen for a second to find it. He said he didn't even register it before I told him about it.

Even a single dead pixel would seriously distract me but he didn't even notice the gif of some disgusting medical scam ad showing elbows or knees or whatever.

He could also fall asleep seconds after hitting the bed. I need at least 10 minutes - at least. Sometimes an hour. Maybe it's a related phenomenon.

Some people just seem to ignore external stimuli better than others. Whether ads whose purpose is brand recognition work on them subconsciously, idk.

[JoshTriplett]

One aspect of that is people who have learned to ignore ads. One aspect of that is that many people do not perceive their entire screen at once.

I tend to catch almost everything on the screen when I'm taking it in, and if someone asks me about something on the screen I can generally find it in a small fraction of a second; I don't take in every last detail (e.g word of text) simultaneously, but I have every major UI element in mind. I have observed that many people are focused specifically on one thing and don't notice a thing I call attention to without searching the screen for multiple seconds.

[sfRattan]

I'm with you on that intuitive feeling of perceiving the whole screen, but I suspect something is going on for us that is closely related to human sight: just like the eye is constantly moving to account for the optic nerve blindspot and our brain seamlessly stitches things together, we're probably using our latent understanding of the functions on every part of the screen to stitch together an image/awareness-sense while our eyes actually focus on one part at a time.

When introducing non-computer people to a new application, I find it helps (or is sometimes necessary) to walk them through each part of the screen, explaining what it is for and how it relates to the others. If someone doesn't or can't retain that explanation, usually nothing will help them. But if they do/can retain it, I find even non-computer people are much quicker in noticing particular updates to the application's or OS's GUI.

[gzread]

The human eye only really focuses on an area about the size of one word, but moves quickly (saccades) to focus on whatever part you want to see at that moment. The rest of your vision (peripheral vision) has limited functionality to quickly guide a saccade towards any part of it, to detect changes (raisin an IRQ) and an extremely low resolution of general vision (enough to make our . You can't even read one word of text while looking at the one next to it, and if you think you can, it's because you already know what it says. Part of this effect seems to be a lower physical resolution and part of it is because your visual cortex spends its neurons interpreting the center more precisely rather than interpreting more area more loosely.

[JoshTriplett]

I don't think that's entirely accurate, because this can also apply to perceiving entirely new UIs you've never seen before. Familiarity helps, but I don't think it's entirely that.

[sfRattan]

> perceiving entirely new UIs

I think this experience is now rare if you are computer-adept, though it was more common even just a few decades ago. But the first thing I do when I see a totally unfamiliar UI is stare at it for a bit until I think I understand the information hierarchy. And then try to verify that understanding by clicking things. Eventually I acquire that "perceiving the screen as a whole feeling", but I still suspect that it's something resembling the human vision process generally, under the hood of conscious perception.

[JoshTriplett]

(To be clear, obviously the process is based on human vision; the main distinction I'm making is between the need for a focused search vs a quick whole-screen glance.)