Systems and methods of this invention display data using pixels with information indicated by color and intensity changes, particularly used for monitoring of physiological variables in real time. For certain methods, physiological data can be acquired by sensors, acquired data can be stored in data frames, data frames can be processed using computer-implemented methods, and processed data frames can be scaled to a display frame for display on a display device. Using such methods, a spot made up of a group of pixels can be updated during a time frame, or cycle using a computer-implemented method, such as addition, subtraction, multiplication, division or a time dependent function. Newly received data can be combined with prior received data to indicate time-dependent changes. In this way, each spot contains a cumulative history of data starting at some initial time. In other embodiments, visual contrast can be enhanced between desired data and other data. In further embodiments, two or more different types of data can be plotted together to indicate relationships between variables. Real time monitoring of signals during therapeutic treatment using light, electricity or other nerve or muscle stimuli can allow a user to monitor physiological responses during stimulation and to make rapid decisions about medical treatment.