A wearable scanner can record brain activity while a subject is moving. The prototype headset, described online in Nature this week, could help researchers to assess brain function in previously inaccessible situations.

Traditional studies of brain activity using magnetoencephalography (MEG) or functional magnetic resonance imaging are limited because they rely on using compliant adults who are able to remain still inside cumbersome brain scanners. Matthew Brookes and colleagues developed a new MEG system that incorporates quantum sensors and a new technique for cancelling ambient magnetic fields. The result is a lightweight helmet that can record MEG data at millisecond resolution. To prove the device works, measurements were taken while a single subject made natural movements, like head nodding, stretching, drinking and playing a ball game. Robust recordings were obtained, which compared well with current state-of-the-art scanners.

The potential applications of this system are widespread. Brain function can now be assessed in a whole new range of situations, such as during social interactions or while navigating around an external environment. For the first time, babies, children and people with movement disorders can have their brain activity directly measured. The system will lend insights into the diagnosis and management of patients with psychoses, and help researchers to assess brain function in people with developmental and degenerative disorders.