According to New Scientist, the sneaky machine has a high-speed camera that monitors humans' wrist and finger movement to beat us to the punch — or, rather, beat us to the paper.
It seems like a vanity device at the moment, but Sara Reardon reports that this development could help with some robotic sleuthing in the future.
The robot's visual recognition program needs only one millisecond to figure out which shape your hand will take, and choose the one that will beat you.
This kind of high speed vision may have a more practical use than arming robots so they'll always get to bat first at robot baseball. Robots can recognize speech in real time by the forms the human mouth takes, cooperate with humans performing precision tasks that take two, and maybe intervene in an accident before it happens. The janken game is an early example of what Oku's lab calls "meta-perception": the Sherlock Holmes-like ability of machines to pick up information humans would miss.
Watch the robot in action AFTER THE JUMP!