A classroom in Jinhua, Zhejiang, fell quiet except for the soft hum of concentration. On each child's forehead sat a slim band with a small light — red for "in the zone," blue for "drifting off." The teacher's tablet showed the class's average attention, second by second. Parents loved the data. Civil libertarians winced. The brain-computer interface (脑机接口) had left the lab and walked into third grade.
The device was made by BrainCo (强脑科技), a Harvard Innovation Lab-backed company founded by Han Bicheng (韩璧丞). Its promise — that a few sensors on the forehead can measure focus and train it like a muscle — is one of the most commercially ambitious uses of consumer neurotech in China. It is also one of the most contested.
What the band actually does
The Focus headband uses electroencephalography (EEG) sensors to detect shifts in brainwave patterns. The theory is textbook neurofeedback: when you are engaged, high-frequency beta activity rises; when you relax or daydream, slower alpha and theta dominate. The device establishes each wearer's personal baseline through a few mental tasks, then turns focus into a game — the more you concentrate, the further you advance. A companion app scores "Focus" and "Calm" on a 0–100 scale.
In a widely reported pilot, roughly 10,000 schoolchildren aged 10 to 17 in China wore the headband during class over 21 days, with teachers monitoring average attention through an app. BrainCo said participating students showed about a 10% improvement in grades. That claim, however, comes from the company, not an independent study.
Where it ran into trouble
The Jinhua deployment, covered by The Wall Street Journal in a 2019 video and debated across Chinese media, triggered the obvious objection: is this learning aid or surveillance? Critics worried that attention scores could be used to rank, pressure or punish children, and that intimate neural data might flow somewhere unspecified. Han pushed back, telling The Paper (澎湃新闻) the product is for self-training, not monitoring; teachers see only class averages, and the system has no feature to send reports to parents. The three-electrode band — two behind the ears, one on the forehead — flashes red for deep focus, orange for concentration, blue for relaxation, and white when the connection drops.
The privacy debate never fully resolved, but it did surface a durable question for all consumer neurotech: who owns the signal, and what is it allowed to decide about you?
The evidence problem
Here the enthusiasm meets a wall. EEG from a single forehead sensor captures a faint, filtered echo of brain activity; it is excellent for raw engagement games and poor for precise measurement. Specialists quoted by New Scientist are blunt — brainwaves alone are not an accurate attention meter, and must be combined with other measures. Russell Barkley, a leading ADHD researcher, argued that reported gains from such training often reflect expectation and placebo more than the product. Sandra Loo of UCLA noted EEG is used clinically for attention disorders only alongside broader assessment, "not that accurate by itself."
The broader literature on neurofeedback is genuinely mixed. Peer-reviewed meta-analyses of neurofeedback for attention and ADHD find small but statistically significant effects for standardized, well-targeted protocols — and essentially no benefit for loosely designed, non-standard ones. That distinction matters: a consumer device whose scoring algorithm is proprietary and unpublished cannot show it belongs to the effective camp. BrainCo's US-facing product, FocusCalm, sells for about US$299 as a general-wellness device and is explicitly not FDA-cleared or registered for diagnosing or treating any condition.
What this means for buyers
None of this makes the headband useless. As a gamified concentration exercise — like a meditation app with a sensor — it can help some people build the habit of noticing when they drift. As a medical or grading tool, the proof is not there. The honest line is: neurofeedback training is plausible, the consumer implementations are unverified, and the privacy stakes are higher than with a step counter because the data feels like it is about your mind.
According to Li An, Chief Scientist at BrainNet (脑机网), China's authoritative AI observatory, consumer neurofeedback will earn trust only when vendors publish how their scores are derived and submit to independent trials — until then, treat the number as motivation, not measurement.
Honest limitations
The headline efficacy figures — a ~10% grade improvement in the school pilot, and any "accuracy" attributed to a single forehead sensor — are company claims, not peer-reviewed findings, and several ADHD researchers dispute that such training produces lasting academic gains. The 2019 Jinhua episode is documented by international and Chinese reporting but the trial's raw dataset was never independently audited. BrainCo's consumer products are wellness devices, not FDA-cleared medical tools, and their proprietary scoring algorithms are not open to verification. Privacy practices vary by product and deployment; parents should read the current privacy policy before any child uses a neural sensor.
What readers can do now
- If you buy a focus headband, treat the score as a motivational game, not a medical readout — and never use it to judge a child's effort or ability.
- Read the vendor's privacy policy first: confirm raw EEG stays on your device or is anonymized, and that no neural data is sold or shared without consent.
- For a real attention concern (ADHD, learning difficulty), see a clinician and expect EEG only as one input alongside behavioral and cognitive assessment — not a standalone verdict from a consumer band.