Why our brains see human faces everywhere

It’s so common that we barely think about it, but the human brain doesn’t seem to have any human face on objects as varied as the moon, toys, plastic bottles, tree trunks, and vacuum cleaners. Some have even seen an imagined Jesus with cheese on toast.

So far scientists have not understood exactly what the brain does when it processes visual signals and interprets them as representations of the human face.

The neuroscientists at the University of Sydney are now explaining how our brains identify and analyze real human faces using the same cognitive processes that identify illusory faces.

“From an evolutionary perspective, it seems that the advantage of never losing a face far outweighs the mistakes in which inanimate objects are seen as faces,” said Professor David Alais, lead author of the study of the Faculty of Psychology.

“There’s a big advantage to detecting faces quickly,” he said, “but the system plays ‘fast and loose’ by applying a raw two-eye template over the nose and mouth. A lot of things can satisfy that template, and for thus, triggering face detection response. “

This facial recognition response occurs rapidly in the brain: in a few hundred milliseconds.

“We know that these objects are not truly expensive, but the perception of a face endures,” Professor Alais said. “We end with something strange: a parallel experience that is both an attractive face and an object. Two things at once. The first impression of a face does not leave the second perception of a object. “

This error is known as “facial pareidolia”. It’s such a common fact that we accept the notion of detecting faces in objects as “normal,” but humans don’t experience this. cognitive process so strong for other phenomena.

The brain has developed specialized neural mechanisms to quickly detect faces and exploits the common facial structure as a shortcut for rapid detection.

“Pareidolia faces are not ruled out as false detections, but are subjected to facial expression analysis in the same way as real faces,” Professor Alais said.

We don’t just imagine faces, we analyze them and give them emotional attributes.

The findings are published today in the Proceedings of the Royal Society B.

Researchers say that this analysis of expressions of inanimate objects is due to the fact that, as deeply social beings, it is not enough to detect a face.

“We must read the identity of the face and discern its expression. Are they friends or enemies? Are they happy, sad, angry, in pain?” Professor Alais said.

What was studied was whether once a pareidolia face was detected, facial expression was subsequently analyzed or discarded from the face processing as a false detection.

Research shows that once the brain retains a fake face, its facial expression is analyzed in the same way that a real face is.

“We demonstrated this by presenting face sequences and getting participants to value the expression on each face on a scale ranging from anger to happiness,” Professor Alais said.

What was intriguing is that a known bias in judging human faces persisted with the analysis of inanimate imagined faces.

A previous study by Professor Alais showed that in a Tinder-like situation of judging face to face, a bias is observed in which the assessment of the current face is influenced by our assessment of the previous face.

Scientists tested it by mixing real faces with pareidolia faces and the result was the same.

“This‘ crossover ’condition is important as it shows that the same underlying facial expression process is involved regardless of the type of image,” Professor Alais said.

“That means seeing faces in the clouds is more than a childish fantasy,” he said.

“When objects have an attractive face look, it’s more than an interpretation: they’re really pushing the brain’s face detection network. And that buzz or smile; that’s your brain’s facial expression system at work. . brain, false or real, faces all are processed in the same way. ”