Investigating a Gaze-Tracking Brain Computer Interface Concept Using Steady State Visually Evoked Potentials

This project investigated the possibility of a user´s gaze being tracked within the area of a computer monitor bounded by multiple light sources, each stimulating an SSVEP. If realised, such a system would allow a spatial arrangement of interactive elements around a screen, rather than the discrete list of commands accessible through existing SSVEP based BCIs. Research-level EEG equipment would make the proposed BCI prohibitively expensive for home users. Thus, investigation was made into the utility of inexpensive consumer-grade EEG equipment, as is available for computer-gaming. SSVEPs were elicited using initially a traditional strobe light source and then a set of individual LEDs, as necessary for the simultaneous stimulation of multiple SSVEPs. Clear responses were recorded using the research EEG system for both the strobe and LED sources; however the consumer system lacked sufficient sensitivity to reliably detect the SSVEPs. Tests with two stimulating LEDs showed that two SSVEPs of differing frequencies be resolved simultaneously, and that the amplitude of the response decreases as the user´s gaze is directed further from the stimulating light source. Further work will aim to derive the user´s gaze location within an area bounded by multiple stimulating LEDs, using the relative amplitudes of the elicited SSVEPs.