Saccadic Overshoots – A few Things you Should Know about Video-Based Eye Position Monitors

Past Event Date: 


Manfred Mackeben

Meeting room: 

Room 204 - Main Conference Room

Event Type: 


Various branches of vision research start with the question of where a person is looking. The video-based systems have recently become very popular in measuring eye movements. Similar to older techniques, these systems have their advantages and idiosyncrasies. Anyone interested in fast eye movements, e.g., those we make to read 'text' should be prepared to deal with this problem. I will introduce a special feature of video-based systems that use the center of the pupil as a landmark: If you look at recordings of fast eye movements (saccades), you will notice that at the end of all saccades, the registration shows an overshoot that looks like an artifact. I will also discuss three papers that have shed some light on this phenomenon. Their work has shown that the overshoots are not artifacts at all, but rather actual measurements of something quite real a side effect of the mechanics of fast eye movements. Fortunately, the same clever scientists who have explained the phenomenon have also provided a way that promises to eliminate the side effects.