The button-box we have used for our "sensorimotor synchronisation" experiments is a Cedrus RB-730 response pad. It is on loan from Nenad and the IT office. It connects to the computer via a USB port, and is controlled by the computer as a serial port (or something like that). . To work, you must install a driver from the Cedrus website here:, and surprisingly, I also had to install a USB to serial port driver from a company called Keyspan: . It's the driver for their USA-28x product I used.