Wearable Brain Devices Will Challenge Our Mental Privacy

A last bastion of privacy, our brains have remained inviolate, even as sensors now record our heartbeats, breaths, steps and sleep. All that is about to change. An avalanche of brain-tracking devices—earbuds, headphones, headbands, watches and even wearable tattoos—will soon enter the market, promising to transform our lives. And threatening to breach the refuge of our minds.

Tech titans Meta, Snap, Microsoft and Apple are already investing heavily in brain wearables. They aim to embed brain sensors into smart watches, earbuds, headsets and sleep aids. Integrating them into our everyday lives could revolutionize health care, enabling early diagnosis and personalized treatment of conditions such as depression, epilepsy and even cognitive decline. Brain sensors could improve our ability to meditate, focus and even communicate with a seamless technological telepathy—using the power of thoughts and emotion to drive our interaction with augmented reality (AR) and virtual reality (VR) headsets, or even type on virtual keyboards with our minds.

But brain wearables also pose…