A system is provided for testing and enhancing the alertness of operators who monitor video surveillance imagery. Alertness is tested by displaying any of a variety of visual elements on top of or near the video imagery, and receiving input from human operators in response to the visual elements, via one or more input devices. The system further allows for economic management of human operators by transmitting imagery from many video sources to any number of operators. Video feeds are automatically switched, via software, away from an operator who wishes to take a break or has poor alertness. In this fashion, the system maximizes operator vigilance while also maximizing workflow for all available operators.