Eavesdropping on the Brain: Mind-Reading Devices Could be Possible in the Future

Could we read minds? Scientists are certainly one step closer after this latest study. Researchers have managed to collect the first solid evidence that the pattern of brain activity seen in someone performing a mathematical exercise under experimentally controlled conditions very similar to that observed when the person engages in quantitative thought in the course of daily life. The findings could lead researchers to a way to "eavesdrop" on the brain in real life.

"This is exciting and a little scary," said Henry Greely who played no role in the study but is familiar with its contents, in a news release. "It demonstrates, first, that we can see when someone's dealing with numbers and, second, that we may conceivably someday be able to manipulate the brain to affect how someone deals with numbers."

In order to examine the thought processes of volunteers, the researchers monitored electrical activity in a region of the brain called the intraparietal sulcus. This part of the brain is known to be important in attention and hand motion. Previous studies have hinted that some nerve-cell clusters in this area are also involved in numerosity, the mathematical equivalent of literacy.

The scientists used a method called intracranial recording, which allowed them to monitor brain activity while people were immersed in real-life situations. The researchers tapped into the brains of three volunteers who were being evaluated for possible surgical treatment of their recurring, drug-resistant epileptic seizures; this involved removing a portion of the patient's skull and positioning packets of electrodes against the exposed brain surface.

It turned out that electrical activity in a particular group of nerve cells in the intraparietal sulcus spiked when volunteers were performing calculations. More interestingly, they found that when a patient mentioned a number, there was a spike of activity in the same nerve-cell population.

"We found that this region is activated not only when reading numbers or thinking about them, but also when the patients were referring more obliquely to quantities," said Josef Parvizi, one of the researchers, in a news release. "These nerve cells are not firing chaotically. They're very specialized, active only when the subject starts thinking about numbers." In other words, it was possible to know, simply by consulting the electronic record, whether a volunteer was engaged in quantitative thought.

The findings could one day lead to "mind-reading" applications that could potentially help those who are mute to communicate via passive thinking. That said, these applications are a long way off. For now, scientists have merely gotten a closer glimpse as to how our brains function.

The findings are published in the journal Nature Communications.