Mendi is a Swedish neurotechnology company that specializes in at-home brain training through a non-invasive neurofeedback headset and companion app. Unlike many consumer devices that use EEG to track electrical brainwaves, Mendi uses fNIRS (functional Near-Infrared Spectroscopy) to measure blood flow and oxygenation levels in the prefrontal cortex—the brain's center for focus, emotional regulation, and decision-making.