Spooky mind-reading implant placed deep inside your brain can decode your internal monologue with 80% accuracy
- Scientists have developed a technique to decode people’s internal monologue
- The device works by implanting small electrodes in the brain to collect data
Scientists are one step closer to reading people’s minds after developing new technology that can decode internal speech with nearly 80 percent accuracy.
Some people cannot speak due to illness or injury, but devices called brain-machine interfaces (BMIs) can help patients communicate again.
BMIs, also known as ‘speech decoders’, can record brain activity during inner speech (words thought in the mind without making any movement or sound) and translate it into language.
Until now it has been difficult to achieve highly accurate results.
Researchers at the California Institute of Technology implanted small devices in specific parts of the brains of two participants.
These diagrams show where scientists implanted small microelectrode arrays in the brains of two participants. These arrays collect signals that can be used to decode the internal monologue
After a spoken or visual cue, participants were first asked to think of the word – for example ‘spoon’, ‘python’ or ‘battlefield’ – internally.
In real time, the researchers were able to decode the internally spoken words with an accuracy of up to 79 percent.
This was done via electrodes attached to a part of the brain called the supramarginal gyrus, which plays an important role in both spoken and written language processing.
The device was able to decode several internal speech strategies, including silently reading the word and visualizing the object the word depicts.
The technology works on the same principle as other brain-machine interface devices such as Elon Musk’s Neuralink.
Neuralink, unlike this device, translates the electronic signals it receives from the brain into a series of motor controls that can be used to interact with machines.
However, it has now been revealed that Neuralink’s first human trial almost came to an end after the patient suffered a potentially life-threatening condition shortly after implant surgery.
This chart shows how accurately the scientists were able to decode eight words. The boxes on the far right show how participant one’s internal monologue (top) could be decoded with up to 91 percent accuracy for some words, while participant two (bottom) proved more difficult to decode
In the tests, participants were told a word and asked to pronounce it or say it internally. The graphs show the activity of a single neuron in their brain as they say “python” or “phone.” In the bottom graphs you see the sound waves of the cue and speech in black
Although further research should improve the technology’s functionality by testing more participants and new words, the authors said they recommend the supramarginal gyrus as a promising location for BMIs.
Writing in the journal Nature Human Behavior, the scientists said: ‘In this work, an online BMI internal speech achieved significant decoding… in two participants.
‘The online decoders are trained on just eight 1.5 second repetitions per word, demonstrating that meaningful classification accuracies can be achieved with just a few minutes of training data per day.
‘This proof-of-concept suggests that the supramarginal gyrus may represent a much larger internal vocabulary.
“Our results could translate to people being unable to express their speech or being completely confined.”