Scientists Able to Change the Way People Feel About Faces

Collage of faces
In a 2016 experiment, scientists changed how subjects felt about other people's faces without the subjects being aware of it. Dimitri Otis/Getty

The brain can be tweaked to induce people into feeling differently about the faces they see.

That's according to some Brown University scientists, who have achieved such changes on subjects through a method called decoded neurofeedback (or DecNef).

People's faces, as co-author Takeo Watanabe points out, are associated with emotions. Seeing a smiling face fosters positive emotions. A RBF, maybe, pushes us the other way.

But successfully manipulating a certain area of the brain could help people feel differently about the faces they see. Meaning it could help them work through fear or trauma or even depression.

"If someone develops a traumatic memory that makes him or her suffer," Watanabe says, "even a small reduction of the suffering would be helpful."

Scientists have long studied how experimenting with certain parts of the brain can trigger different functions. In this study, the researchers concentrated on the cingulate cortex (CC), an area that plays a role in your preference of faces and other daily objects you see.

Using functional magnetic resonance imaging (fMRI) to compare a current pattern of brain activity in the CC to a pattern they were trying to induce, the scientists then went about trying to see if they could bring one pattern closer to the other.

The researchers first showed a group of subjects a set of faces and had them rate them as positive, negative or neutral, measuring their brain activity with the fMRI for each of the three facial types. That gave the scientists their baseline.

They pulled up the neutral faces again, and then went about messing with their subjects' minds.

A part of the group was shown an image of a disk and asked by the experimenters to make the disk grow larger. With their mind. When the fMRI readouts of their hard-working brains started to get closer to the activity that was present with positive faces — the subjects had no idea that making the disk larger was connected to the faces in any way — the researchers showed the disk getting larger. The group was, in other words, given positive feedback.

Another part of the group, asked to mentally make the disc grow larger, was rewarded when their brain activity closed in on what was measured when they first saw a negative face.

(A third part of the group did not do the DecNef, make-the-disk-larger step.)

After a few hours of training, the scientists found that the group pushed toward positive-face thinking saw previously neutral faces more positively. The negative-face group saw neutral faces more negatively. (The third group didn't see things differently at all.)

From Science News:

"These results are fascinating in showing how nonconscious brain activity can be utilized to modify brain function and behavior in a targeted way," says neuroscientist Rafi Malach of the Weizmann Institute of Science in Israel.

The paper, "Differential Activation Patterns in the Same Brain Region Led to Opposite Emotional States," was published Sept. 8 in the journal PLOS Biology.