There's a standard test for this: The O'Connor Tweezer Dexterity Test.[1] There's a board with small holes, a supply of metal pins, and a tweezer for putting pins in the holes. It's overpriced, because it's "medical". Some electronics assembly plants use such a test to screen new hires. Tweezer dexterity improves with practice. Hands are more precise than vision. Looking through a microscope, you can position somethi…
The toy used in the study is a lot cheaper - about $15. See https://www.johnlewis.com/john-lewis-buzzwire-game/p4349607
I was really expecting to see it was the classic “Operation“ game when I first saw mention in the paper.