Weaning Off Mental Tasks to Achieve Voluntary Self-Regulatory Control of a Near-Infrared Spectroscopy Brain-Computer Interface

As a noninvasive and safe optical measure of hemodynamic brain activity, near-infrared spectroscopy (NIRS) has emerged as a potential brain-computer interface (BCI) access modality. Currently, to the best of our knowledge, all NIRS BCIs use mental tasks to elicit changes in regional hemodynamic activity. One of the limitations of using mental tasks is that they can be cognitively demanding, and unintuitive. The goal of this work was to explore the development of a neurofeedback-based NIRS BCI that weans users off mental tasks, to instead use voluntary self-regulation. Ten able-bodied participants were recruited for this study. After ten sessions of using two personalized mental tasks to increase and decrease the participant’s hemodynamic activity, the users were asked, for the remaining sessions, to stop performing their tasks and instead use only a desire to modulate their hemodynamic activity. By the final online session, participants were able to exclusively use voluntary self-regulation with an average accuracy of $79 \pm 13\hbox{\%}$ . Additionally, the majority of participants indicated that BCI control via self-regulation was less taxing and more intuitive than BCI operation using mental tasks.