Can a Brain-Computer Interface Convert Your Thoughts to Text?


By Srividya Sundaresan, Science Writer

Recent research shows brain-to-text device capable of decoding speech from brain signals 

Ever wonder what it would be like if a device could decode your thoughts into actual speech or written words? While this might enhance the capabilities of already existing speech interfaces with devices, it could be a potential game-changer for those with speech pathologies, and even more so for “locked-in” patients who lack any speech or motor function.

“So instead of saying ‘Siri, what is the weather like today’ or ‘Ok Google, where can I go for lunch?’ I just imagine saying these things,” explains Christian Herff, author of a review recently published in the journal Frontiers in Human Neuroscience.

While reading one’s thoughts might still belong to the realms of science fiction, scientists are already decoding speech from signals generated in our brains when we speak or listen to speech.

In their review, Herff and co-author, Dr. Tanja Schultz, compare the pros and cons of using various brain imaging techniques to capture neural signals from the brain and then decode them to text.


ECoG and audio data are recorded at the same time. Speech decoding software is then used to determine timing of vowels and consonants in acoustic data. ECoG models are then trained for each phone individually by calculating the mean and covariance of all segments associated with that particular phone. Image courtesy of Christian Herff

The technologies include functional MRI and near infrared imaging that can detect neural signals based on metabolic activity of neurons, to methods such as EEG and magnetoencephalography (MEG) that can detect electromagnetic activity of neurons responding to speech. One method in particular, called electrocorticography or ECoG, showed promise in Herff’s study.

This study presents the Brain-to-text system in which epilepsy patients who already had electrode grids implanted for treatment of their condition participated. They read out texts presented on a screen in front of them while their brain activity was recorded. This formed the basis of a database of patterns of neural signals that could now be matched to speech elements or “phones”.

When the researchers also included language and dictionary models in their algorithms, they were able to decode neural signals to text with a high degree of accuracy. “For the first time, we could show that brain activity can be decoded specifically enough to use ASR technology on brain signals,” says Herff. “However, the current need for implanted electrodes renders it far from usable in day-to-day life.”

So, where does the field go from here to a functioning thought detection device? “A first milestone would be to actually decode imagined phrases from brain activity, but a lot of technical issues need to be solved for that,” concedes Herff.


9 Comments on Can a Brain-Computer Interface Convert Your Thoughts to Text?

  1. Made device for reading human thoughts / human mind reading machine / Brain computer interface. In particular, I have created a perfect Speech Generating Device for people with Amyotrophic Lateral Sclerosis / ALS. About the problem look : Jack Gallant, Tom Mitchell and Marcel Just; John – Dylan Haynes; Andrea Stocco and Rajesh Rao, human mind reading machine. Discovery is not published.

  2. Nothing is imposible. I think we will see it in a close future

  3. With the advancement in technology & human intellect nowadays nothing seems impossible. what is more exciting than this news. Human mind reading machine will be introduced then we can not say that mind is the safe place for keeping secrets.

    Well, most of the time people search that how to convert text to speech and they find investing time in such things. But with the Braine machine, we can imagine many benefits. This can help people who cannot speak or have trouble in communicating, express their thoughts. This machine can give them rebirth. I am extremely excited to know more about your research and also new updates.

  4. Many experiments on this area are still in progress. Decoding brain waves to text will be possible in the future. The applications of this achievement are really numerous. I believe science have done a small step on mapping the brain activity. We just have to wait for a compete application.

  5. This looks promising and shows how far technology has gone. However it will take time for devices like these to become accurate.

  6. its really amazing .It will be helpful for the physically disabled person if applied

  7. Ankur agrawal // June 4, 2018 at 8:42 am // Reply

    it may be possible to reverse this technologies to make human brain remember more complex equation n algorithms.

  8. Omkumar Muthusamy // August 29, 2018 at 10:51 am // Reply

    Decoding brain waves to text and then to a possibly matching voice from a trained data pool is a reality…..Though to make a Born-Deaf and Dumb person to speak in his version of the voice, it is a reality that we can make him/her speak.

    • Well I’m experiencing and have done for a few years VtoK voice to skull and still reading in the development/engineering so any enlightenment would be nice.

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