Man who sees the world upside down due to a birth defect Scientists help explain why faces are so difficult to recognize when they’re upside down

When you see a familiar face, you instantly recognize it. But if you see the same face upside down, it will be very difficult to locate it. but why?

To answer this question, researchers studied Claudio, a 42-year-old man with a strange birth defect. His head rotates about 180 degrees, so he sees the world upside down. Since he sees the world around him in a completely different way, scientists asked him to participate in an interesting experiment. In this experiment, the researchers wanted to understand why faces displayed upside down are so difficult to recognize.

Upside down
Scientists have known for some time that our ability to recognize faces is greatly diminished, or even completely eliminated, when a face is rotated 180 degrees. However, it has proven difficult to determine whether this phenomenon is due to evolutionary mechanisms, or is simply due to the fact that we see faces upright. “Almost everyone has much more experience seeing straight faces,” says first author of the new study Brad Duchene. “It is therefore difficult to determine whether our difficulty with inverted faces is due to development or experience. But since Claudio’s head is in an almost inverted position relative to the faces he sees, his position provides an opportunity to explore what happens when the faces he sees have a different orientation than his own.” .

an experience
During experiments conducted between 2015 and 2019, the research team tested Claudio’s ability to recognize and identify faces. They also studied how well it differentiated between abnormalities such as modified eyes and mouths, known as the Thatcher illusion. In this case, the question was: How does Claudio’s unique perspective affect his ability to recognize faces? Does this difference in perspective have any effect at all?

hasty
The results are interesting. It turned out that Claudio performed better than the control group in recognizing inverted faces. It was also better at identification “Tatcherdy” Faces. Remarkably, he recorded similar results to the control group when it came to matching the identity of faces.

Thatcher illusion
Researchers were surprised by how Claudio perceived “Thatcherite” faces. In this case, Claudio performed better when the manipulated faces appeared upright. Although researchers admit they don’t know exactly why this is, they suspect that the Thatcher illusion arises from visual mechanisms other than face detection and recognition. Furthermore, they believe that these different processes likely have their own separate evolutionary histories.

According to the researchers, the study gives us interesting clues about how we perceive and process faces in general. Thus, they conclude that our ability to recognize straight faces most likely arises from evolutionary mechanisms and our own experiences.

Mix
“It is striking that Claudio does not perform better at recognizing upright faces than inverted faces,” says Duchene. “The fact that there was no advantage for orienting faces with which he had more experience suggests that our stronger sensitivity to upright faces is likely influenced by both our personal experience and innate mechanisms in our visual system, which are specifically tuned to recognize upright faces.”

Researchers have not given up on this interesting topic yet. In future studies, they hope to gain more knowledge about other aspects of facial perception, such as facial expressions, age, gender, attractiveness, eye direction, and reliability. They also want to study Claudio further. For example, they plan to measure his brain activity when he sees faces. In this way, they hope to find out whether the way it processes faces is based on the same visual processes that most people do.