Sequential and simultaneous tactile stimulation with multiple actuators on head, neck and back for gaze cuing

Interacting with the environment using mobile eye-tracking is accompanied with challenges in providing non-visual feedback related to gaze events and monitoring the gaze vector estimation quality. Recent studies point to haptic stimulation as a promising feedback channel in this context. In this work we focused on applying haptic stimulation to inform users of pointing inaccuracies by cuing their gaze in the direction of nearby interactive objects. To decrease the cognitive load, short repetitive vibrations from four actuators were applied to the head and neck of the user. The head area stimulation was compared to the back that has often been used in earlier studies. The results showed that the haptic stimulation on the head and neck cued users as efficiently as the stimulation of the back, although smaller stimulation signal amplitude would be desirable. Another important implication refers to the design of the stimulation signal pattern: if multiple actuators are used in stimulation, then they should be activated sequentially and not simultaneously.