Coding gaze tracking data with chromatic gradients for VR exposure therapy

This article presents a simple and intuitive way to represent the eye-tracking data gathered during immersive virtual reality exposure therapy sessions. Eye-tracking technology can be used to observe gaze avoidance behaviors to provide cognitive and behavioral therapists with valuable information on the severity of a phobic disorder. However, basic eye-tracking systems only supply 2D gaze point coordinates on the recorded video images of the subject’s view. The use of eye-tracking during virtual reality sessions allows to directly associate the gaze behavior to the 3D environment. The gaze-map color coding presented here uses a color picking technique and a specific data representation which provides precise visual gaze information per 3D object. This article presents our technological solution and its relevance for therapeutic needs, as well as the experiments performed to demonstrate its usability in a medical context. Results show that the gaze-map technique is fully compatible with different VR exposure systems and provides clinically meaningful data.