Two-detector Corrected Near Infrared Spectroscopy (C-NIRS) detects hemodynamic activation responses more robustly than single-detector NIRS

► This study compared two fundamental geometries for functional near infrared spectroscopy. ► Dedicated detectors, 5 mm from the sources, were added to provide sensitivity to the scalp hemodynamics. ► These “near” detector signals were subtracted from conventional measurements made using 3 cm spacings. ► Visual stimulation responses were detected more frequently and with better quality when the “near” information was included. ► The advantage is readily implemented in both hardware and software.