Eye tracking Lab

Eye tracking lab

The eye tracking lab is equipped with a head-mounted Eyelink 2 system (SR Reseach) with a 500 Hz sampling rate and an average accuracy of gaze osition less than 0.5 degrees. The Eyelink 2 provides the following features: online access to gaze position data with a delay of 3 msec, making it ideal for experiments with gaze contingent displays. Online detection of gaze events (saccades, fixations) with a delay < 32 ms. Tracking of gaze position on a real world scene video being captured from a head mounted scene camera. Visual C++ and Matlab Psychtoolbox + Eyelinktoolbox are available for programming experiments. Research in the lab includes studies on fixational eye movements and on visual attention.

EyeLink II System

The EyeLink II System (SR-Research) is based on a small “helmet” upon which are three infrared video cameras that are placed on the subject’s head. The infrared signal is generated by 2 leds placed on each side (left and right) of the two videocameras that are under the subject’s eyes and by a set of 4 led infrared patterns (IR display marker set) that are applied to the top of the monitor in front of the subject. The system required the use of two PCs: one dedicated to the recording of eye movements, which is connected via cable to the helmet, and the other is dedicated to stimuli generation; the two PCs are constantly communicating with one another via Ethernet.
The system was recently upgraded by a “scene camera” : the scene, captured by the videocamera on top of the helmet, is sent to the recording PC that is able to associate the eye movements to the actual scene by using a dedicated software.Two other workstations have been set-up for data analysis next to the eye movement recording lab.