Mental reading in the brain scanner? It’s possible, new research shows

Scientists at the University of Texas asked test subjects to listen to a story in a brain scanner, after which a computer was able to reproduce the outline of what was being told. It also worked when test subjects simply imagined a story or when they watched a silent movie.

Although the computer’s “translation” was not error-free, it often went in the right direction: nine of the sixteen background questions could be answered correctly if you only used the “decoded” version. computer text. story seen.

What is also innovative about the research of computer scientists and neuroscientists Alexander Huth and Jerry Tang is that their method does not require major brain surgery. The researchers simply placed their test subjects in the brain scanner: an fMRI scanner in this case, which shows which parts of the brain are active. “This makes this method much more widely applicable than the neurosurgical method,” they write in a article Natural neuroscience.

Until now, it was only possible to derive individual words or phrases from brain signals in this way, and only when the computer had a limited number of options to choose from. Now, for the first time, entire stories, each lasting fifteen minutes, have been read from the brain.

Artificial intelligence

“An impressive study,” replies Iris Groen, who also conducts research at the intersection of computer science and neuroscience at the University of Amsterdam. “Recently there has been headline news that it is possible to use the brain scan to reconstruct images that someone has seen. Now it appears that it is also possible with what someone has heard or said internally, with language. This is really the beginning of mind reading.

Groen points out that this is another application of artificial intelligence. “The researchers used a GPT (Generative Pre-trained Transformer), something everyone is familiar with now thanks to ChatGPT. With this, the computer always predicted the next sentence in the stories told to the test subjects. Then it was checked which of the predicted options best matched the measured brain activity, and thus the whole story was reconstructed.

American scientists point out that it could be useful for people who have lost their ability to speak. They show that their method works not only when the whole brain is scanned, but also when looking at a single region of the brain: the same information is apparently displayed in different places. This can be useful when certain parts of the brain are damaged.

Privacy

But of course less noble applications are also possible, for example when even thoughts are no longer free in a dictatorship. To reassure themselves, the American scientists write that the computer is much less successful in reading minds when the test subjects do not cooperate. For example, if they list as many animals as possible or recite the multiplication table by 7 while listening to a story, it is nearly impossible to distill the content of that story from their brain signals.

In addition, brain signals vary greatly from person to person, so much so that the computer must be retrained for each individual. But, say the researchers: Where cooperation is still needed today, it could be different in the future.

Pim Haselager, professor of the social implications of artificial intelligence at Radboud University Nijmegen, is also not convinced that mental privacy is guaranteed. ‘It’s true for that brain reading one person’s cooperation is required. But on the other hand: you can see it when someone suppresses their thoughts. And it can also be used against him.

Take sexual preference, for example. Haselager: “If you show people gay and straight images, you can use an fMRI scanner to read what turns them on the most. And yes, it is possible to suppress this excitement. But it is also seen in the brain.

soul emotions

In short, freedom of thought is at stake, warns Haselager. ‘Your thoughts, your feelings, your sexual preference, your political preference, your dreams: it all can be visualized more and more with the right equipment. In 1984 George Orwell says the only intimacy is in your skull. Well, that time has passed. That means we soon have to start talking about the right to mental privacy.

Although, according to Haselager, there is still a practical limitation for those who are curious about the inner workings of others. “An fMRI scanner is a huge device, with incredibly strong magnets. To give you an idea: if you stand next to it with a bunch of keys in your pocket, it will fly through your clothes. It’s not something that you simply use in everyday life. Not yet, at least.