The scientists then sat their subjects in front of a computer screen and showed them images of banks, people, and PIN numbers. They then tracked the readings coming off of the brain, specifically the P300 signal.

The P300 signal is typically given off when a person recognizes something meaningful, such as someone or something they interact with on a regular basis.

Source: CBS Seattle

It just sounds far too advanced to translate information storaged in the brain to readable text but I'm no expert in the subject. Is it really possible?

  • 5
    My understanding of that article is they show you an image of, say, the PIN number you just disclosed. When hooked up to the device, they can tell whether or not you "recognise" this number as meaningful - being shown an incorrect PIN will produce a different response to a "real" one.
    – John Lyon
    Aug 29, 2012 at 1:19
  • 2
    Think the title is very misleading - the claim has nothing to do with hacking, but more to do with identifying a positive response.
    – Rory Alsop
    Aug 29, 2012 at 16:07
  • @RoryAlsop - Agreed, this sounds a lot like Van Eck phreaking.
    – rjzii
    Aug 29, 2012 at 17:17

2 Answers 2


This report is based on a paper presented to the USENIX Security Symposium. (Ironically, the web-site is currently unstable. Try hitting refresh.)

The symposium does not appear to do a full peer review of presentations, but has refereed papers and invited talks.

It isn't clear that the referees would be experts in neuroscience.

Therefore, it would be nice to see this novel work reproduced before accepting it.

The paper itself:

describes their experiment (with 28 students), where they had the subject calibrate the EEG device, and then attempted to detect when a known image was displayed to the subject compared to an unknown image. The subjects were prepped to think about particular subjects (first digit of their (temporary) PIN, where they lived, their month of birth, their bank and the people they knew).

They didn't actively "read" the actual information from the brain - they tried to measure whether parts of the brain were active when it was thinking about a certain image. Nor did they deliberately focus on particular signals, but trained on the input during calibration to find whatever signal was best at indicating recognition.

The correct answer was found by the first guess in 20% of the cases for the experiment with the PIN, the debit cards, people, and the ATM machine. The location was exactly guessed for 30% of users, month of birth for almost 60% and the bank based on the ATM machines for almost 30%.

So, a random guess of the first digit would be 10%, they brought that up to 20%. Further, they had a good second guess if the first one was incorrect. They measured their success in terms of the reduction in entropy, which for some measures ranged from 15% to 40%.

While they claim "the classifiers perform significantly better than the random attack", I didn't see an analysis of the significance, which seems a serious shortfall.

The paper performs a basic review of similar experiments.

In conclusion, the experimenters have come up with an interesting idea and produced a exploratory proof-of-concept paper.

However, this will need to be reproduced before it can be accepted. It will require a lot of new development and sophistication before it can be considered a serious threat and/or technology.

  • You may also want to have a look at: sites.google.com/site/gallantlabucb/publications/…
    – nico
    Aug 29, 2012 at 6:47
  • @nico: Ha, another whole set of interesting claims. Separate question? Reminds me of this question.
    – Oddthinking
    Aug 29, 2012 at 6:49
  • well, it kind of goes in the same direction. When looking at P300 we are speaking of EEG, not BOLD but the idea is sort of similar (although I would bet EEG is easier to analyse).
    – nico
    Aug 29, 2012 at 6:56
  • @nico: Part of their idea is that this could be done surreptitiously, while playing a game, using Emotiv (or similar) headsets. Bit trickier to persuade them to slip into an MRI machine for a lark!
    – Oddthinking
    Aug 29, 2012 at 13:03

Scientists use brain imaging to reveal the movies in our mind

Using functional Magnetic Resonance Imaging (fMRI) and computational models, UC Berkeley researchers have succeeded in decoding and reconstructing people’s dynamic visual experiences – in this case, watching Hollywood movie trailers.

As yet, the technology can only reconstruct movie clips people have already viewed. However, the breakthrough paves the way for reproducing the movies inside our heads that no one else sees, such as dreams and memories, according to researchers.

It already looks able to detect large numerals: http://www.youtube.com/watch?v=nsjDnYxJ0bo

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