Sure, but “being dumb” isn’t an exclusive club for people with low intelligence. There plenty of very smart people that are also dumb. Hell, most AIs could be classified as smart but dumb.

Wouldn’t the knock-on effects of a reduced attention span pretty much look like ‘dumber’?

I’m gonna guess 17:25:20

It’s not an “if” detector, it’s a “how much” detector. It looks like it’s using the LED chamber to light the film in a consistent way, and then the phone camera measures the color change to quantify how much radiation it was exposed to.

Aren’t we?