Saccade contingent updating in virtual reality

We are interested in saccade contingent scene updates where the visual information presented in a display is altered while a saccadic eye movement of an unconstrained, freely moving observer is in progress. Since saccades typically last only several tens of milliseconds depending on their size, this poses dif cult constraints on the latency of detection. We have integrated two complementary eye trackers in a virtual reality helmet to simultaneously 1) detect saccade onsets with very low latency and 2) track the gaze with high precision albeit higher latency. In a series of experiments we demonstrate the system s capability of detecting saccade onsets with suf ciently low latency to make scene changes while a saccade is still progressing. While the method was developed to facilitate studies of human visual perception and attention, it may nd interesting applications in human-computer interaction and computer graphics.