“…Moreover, ten distinct studies adopted other sensors/de-vices, e.g., fMRI (functional Magnetic Resonance Imaging, e.g., [27], [31]), fNIRS (functional Near Infrared Spectroscopy, e.g., [28], [31]), EEG (electroencephalogram, e.g., [32], [33]) and HRV (heart rate variability, e.g., [22], [34]), either simultaneously or subsequently with eye trackers. Two studies used VR eye trackers instead of screen-based eye trackers to collect gaze data [35], [36].…”