A headset worn on the scalp controls a device without surgery

Electrodes pressed against the scalp pick up the faint electrical hum of the brain through the skull. The signal is coarse, but it is enough to pick a letter, steer a toy or tell when a person is calm, and it needs no surgeon. Headsets that do this have been sold to the public since 2007, as toys, meditation aids and gaming controllers, in the hundreds of thousands. It is the only link to a machine on this branch that is in wide use, and by far the weakest.

What would count

A device worn on the scalp, with no surgery, reads the wearer's brain signals and lets them deliberately control something (a cursor, a toy, a game, a sound), at a rate better than chance; the rung in wide use needs such a device on general sale with a public count of units in the hundreds of thousands or more, from the maker or an independent audit.

Who settles it: Peer-reviewed reports for the first human; the makers' own sales statements or audited figures for the count

Where it stands

In wide use. Reached on 28 August 2014, on the record of store.neurosky.com. At the top of the ladder; nothing left to reach.

The last reading

Once a week every upgrade is read against the news, against what would count above. Open a line to see what that week held. Every reading of this upgrade is on this week's reading.

• 16 October 2026 Nothing new

  Read monthly, as an entry at the top of the ladder. No withdrawal and no new count in the window; market reports give revenue, not units, and no dated NeuroSky statement of a million chips was found, so that claim stays on the list. On the other claim still to check: secondary sources (Wikipedia's account and Wolpaw's 2011 review) describe Vidal's 1977 paper in Proceedings of the IEEE as volunteers steering through a maze on a screen in real time by attending to corners of a flashing checkerboard, read from scalp signals, which would meet this entry's first-human test eleven years before the 1988 speller; the paper's own text was not read, so the claim is supported but not settled.

Changes to this entry

• 2026-10-16, stage_reached_on: 2015-12-31 → 2014-08-28. The maker's page is undated and its footer says 2015, so the first date was a guess at the end of that year. The Internet Archive holds a dated copy of the same page, taken on 2014-08-28 (the earliest copy of it), that already carries the sentence 'with over one million in circulation' (https://web.archive.org/web/20140828125802/http://store.neurosky.com/products/eeg-tgam); the date is now that of the earliest dated copy. The statement may be older: a datasheet for the same chip, copyrighted 2011, has the same sentence but carries no date of its own.

Notes

The first-human record is the 1988 Illinois report of volunteers spelling words by attending to flashing letters, the first brain-controlled speller. Consumer headsets based on the same kind of signal reached shops in 2007 (NeuroSky), 2009 (a Mattel toy, Emotiv) and 2014 (Muse). The wide-use count is NeuroSky's own statement that over a million of its sensor chips are in circulation; the maker of the Muse headset says it has over half a million users. The hardware is cheap and the control is coarse, which is why this is the one upgrade on the branch anyone can buy.

Still to check

Claims in this entry written from memory and not yet checked against a source. Each is cleared by checking it and either deleting the line or correcting the entry.

• A 1977 paper by Vidal may be an earlier first human (volunteers steering a cursor through a maze by brain signals). On 2026-10-16 only its abstract could be read (IEEE Xplore, DOI 10.1109/PROC.1977.10542): it describes detecting single evoked responses in real time with feedback to the subject, and does not mention a maze or a cursor; the full text is behind a paywall and no free copy was found. Several secondary sources describe the maze demonstration but are not the paper. Check the full text before moving the first-human date.