Having a hand that doesn't do what you want it to do or does things on its own is horror flick fare. Two prime examples of this in cinema would be Evil Dead and The Hand. If those flicks give you the creeps, you might want to look away now. Researchers at Tokyo University worked with Sony to create a new and weird contraption that allows them to hack your body and take control of your hand. I could see this tech leading to some impressively control prosthetics with a few tweaks too.
The tech is dubbed the PossessedHand and uses a series of wires and electrodes to shoot electrical pulsed into the muscles of the forearm causing the hand to move depending on the sequence of shocks delivered. The contraption can be taught to send certain signals to the muscles to replicate the movement of a normal wrist and fingers. The team says that it could be used for things like musical instrument training.
The wearer of the tech says that it feels like a gentle hand massage rather than other tech that does similar things that requires a glove or electrodes put into the skin. Perhaps the more intriguing thing would be to allow people that have had a stroke to regain use of their hands, even if it was for limited tasks like automated sign language.