The Berkeley, California-based company said it measured a 20% improvement in working memory and a rate of learning that was 120 times faster than a placebo after a 15-minute session with the wearable patch.
and
You wear the neurostimulation device on your forehead, and it provides a mild electrical stimulation called tACS that has been investigated for 30 years.
...
Unlike other devices designed for sleep or sports performance enhancement, which may cost as much as $10,000 for a lab research model or $500 for consumer versions, the new easy-to-use Humm patches are available for about $5 each, making it extremely easy for people to simply give it a try rather than committing to an expensive investment in a complicated device.
and
This helps temporarily connect and prime more parts of the brain to process new information, immediately improving your working memory and ability to learn, and the effects last for up to an hour and a half afterward.