I tested the Muse S Athena, a $475 brain-training headband that combines EEG and functional near-infrared spectroscopy to measure brain activity and oxygen levels to give you real-time feedback.

InteraXon, the makers of the Muse wearable EEG, believe it’s made a big leap ... The Muse S Athena uses the same hardware-and-headband combination from the Muse S, which lets you wear it to ...