Simultaneous electronic recording of video and digital information on the video channel of a VTR or VCR

A technique is described that permits precise synchronization of video recorded behavior with discrete stimuli and responses. These discrete events are recorded as digital data on the video channel of a video recorder on a horizontal line that lies above the visible video information. These data may be observed in single-frame playback mode by underscanning the playback monitor. A circuit is described for computerized decoding of the digital data. Because each video field is uniquely coded, an updating of the data is possible 60 times each second. The described technique has several advantages over current approaches for synchronizing discrete stimulus and response events with video recorded behavior.