I’m thinking of someone right now. Can you guess who it is? Probably not! Yet, incredible as it may sound, we’re now able to read into people's brains. Through a new process developed by a team of researchers from the Department of Psychology at the University of Scarborough (Canada), we’re now able to digitally recreate the image of the person someone is thinking about. How is this possible?

According to Dan Nemrodov, a co-author of the article published in eNeuro: “When we see something, our brain creates a mental percept, which is essentially a mental impression of that thing. We were able to capture this percept using EEG to get a direct illustration of what’s happening in the brain during this process.”

In general, neuroscientists use two methods to study mental images. Brain activity can be measured either by EEG (electroencephalography), using electrodes, or by fMRI (functional magnetic resonance imaging), by detecting changes in blood flow in different parts of the brain. In a previous study, Adrian Nestor (a member of the research team) was able to reconstruct images of faces based on a person’s thoughts using the latter of these techniques. But for this new study, the first technique was used to reconstruct the image. The researchers wanted to use EEG for the sake of precision. EEG can be used to measure brain activity to the millisecond rather than the second, as is the case with fMRI. In practical terms, this means that it is then possible to observe in great detail how the perception or mental image of a face develops in the brain.

The neuroscientists recruited participants for the study and connected them to an EEG device where they were shown images of faces on a computer screen. The subjects’ brainwave recordings were processed using algorithms, making it possible to digitally recreate the faces the participants had just seen. This experiment showed that our brain only needs about 0.17 seconds to create a good representation (mental image) of the faces we see.

According to the authors, this first demonstration of the ability to recreate face perception based on EEG data has: “great theoretical and practical potential from a neurotechnological standpoint.” Indeed, being able to recreate what someone has just seen is undoubtedly only the beginning because the researchers are now going to test the process using participants' memories and imagination. In addition, this discovery could provide a means of communication for people who are unable to speak or move. Moreover, it would help investigators create sketches of suspects. Imagine if in addition to relying on verbal descriptions from a witness, a brain EEG could create an image of the face he or she has in mind? You can imagine the possibilities, but also the dangers…

Indeed, the ability to read our thoughts is somewhat frightening, and the researchers don’t neglect to mention that all of this neurotechnological potential must be regulated when the time comes.