I tried on Bryan Johnson's brain helmet — it's a futuristic Apple Watch for your noggin

Kernel's Flow headset, designed by a former Oakley employee, uses time-domain functional near-infrared spectroscopy (TD-fNIRS) and EEG data to measure brain health. Tech entrepreneur Bryan Johnson founded Kernel in 2016, investing over $150 million to develop the device, now available at U.S. longevity clinics for cognitive performance monitoring.