Can change prejudices perceptions

How prejudices manipulate our perception

Distorted vision: How our brain perceives a person depends not only on their objective facial features - but also on stereotypical expectations. This is now shown by an experiment by US researchers. According to this, the brain processes faces in such a way that they correspond more to our prejudices and clichés, as the scientists report in the specialist magazine "Nature Neuroscience". That means: Anyone who ascribes aggressive characteristics to men as a matter of principle will also react to a neutral man's face as if it were seeing an angry one.

What we think of others and how we deal with them is often determined by stereotypes. Clichés and prejudices lead even children and young people to think fat people are stupid. In day-to-day work, they ensure that happy women in particular are not trusted with leadership skills - and even political voting decisions sometimes depend on stereotypes.

Accordingly, such internalized ideas unconsciously influence our behavior. But could their influence go much further? The neuroscientists Ryan Stolier and Jonathan Freeman from New York University have now asked themselves this question - and have shown that stereotypes can even manipulate visual perception.

Unconscious reactions to faces

For their study, the researchers examined how people assess people in photos. To do this, they first showed the test subjects pictures with different faces - sometimes a man, sometimes a woman, sometimes an African, sometimes an Asian. The emotions of the faces also varied. While the participants looked at the photos, Stolier and Freeman recorded their brain activity using functional magnetic resonance imaging.

Then the test subjects had to assign the gender, ethnicity and emotions of the faces to certain categories with a click of the mouse on the computer. The trick: with the help of a special mouse tracking technique, the scientists were able to register hardly noticeable hand movements of the participants themselves.

In this way, they noticed when a subject initially tended to one category before deciding on another. "Such initial hand movements reveal unconscious cognitive processes - and can thus reveal something about a person's prejudices," the researchers write.

Hand movements reveal prejudices

The evaluation of these mouse movements revealed: Independent of the consciously given answers of the participants, the hand movements showed the presence of stereotypes. For example, the hand of the men in the picture, and especially black men, often twitched first in the direction of the adjective “angry”, even when the faces looked objectively friendly.

According to the hand movements, women were often initially perceived as happy by the test subjects, the scientists report. The participants often perceived Asian faces as female and black as male - regardless of their actual gender. According to Stolier and Freeman, these ideas correspond to the stereotypes that many US citizens typically have.

Stereotypes also show up in the brain

But can one also read these stereotypes in the brain? The team analyzed this with a look at the brain scans. In fact, it turned out that the prejudices and clichés learned could possibly even be anchored in the visual system of the brain - especially in the fusiform gyrus, a convoluted brain in the cortex that is necessary to recognize faces.

"The activity patterns in this area that were caused by black, male faces, for example, were similar to those that also produce angry faces - although the face that was seen did not look angry at all," the researchers report. The brain reacts to the prejudice that black men are hostile and angry.

How much the actually seen and the associated image are similar in the brain obviously depends on how pronounced the prejudice is. This was shown by a comparison with the hand movements. Yes, the more the hand of a test person had initially turned towards the category "angry" when classifying a non-angry black male face, the more his reaction in the fusiform gyrus to this face was similar to the reaction to an actually angry face .

Visual distortion as an amplifier

“This observation suggests that stereotypical associations can influence how the brain perceives a person,” says Freemann. "The prejudices systematically change the visual processing of faces and thus distort what we see - in such a way that the picture corresponds more to our expectations."

The scientists conclude that visual stereotyping may even contribute to reinforcing existing prejudices. In the future, she said, it was important to consider how such unconscious processes of distortion could possibly be counteracted. (Nature Neuroscience, 2016; doi: 10.1038 / nn.4296)

(New York University, May 3, 2016 - DAL)

May 3, 2016