From everyday objects to cloud formations: Why do we tend to recognize faces in many structures and assign emotions to them? The ability to quickly grasp faces and their expressions is so important to humans that this side effect has arisen, researchers say. This explanation is reflected in their test results: According to them, the processing of imaginary faces is based on the same cognitive processes as the perception of real ones.
Often three lines or dots are enough to cause the so-called facial spareidolia. This phenomenon sometimes has strange flowers: some people recognize the face of Jesus in cheese structures on toast or a face in images of the surface of Mars. We often assign emotional expressions to these structures – they can appear friendly, sad or frightening to us. But to what extent does the processing differ from real and imaginary facial impressions? The researchers led by David Alais from the University of Sydney have now devoted themselves to researching the background to the facial paridolia.
Mechanisms on the trail
In their study, they examined the extent to which a pareidolian face is rejected as a false recognition by face processing. The researchers presented test subjects with images of human faces with various emotional expressions as well as of structures that typically cause facial spareidolia. “The participants were asked to rate the expression they felt on a scale from angry to happy,” says Professor Alais. As he and his colleagues report, the evaluations initially showed that, on average, the subjects were very unanimous about the interpretation of the emotional expression – both for human faces and for illusory faces.
However, the researchers interpreted a further observation as the clearest indication of similar neuronal processing: When perceiving imaginary faces, a well-known distortion is evident in the assessment of human faces. A previous study had shown that when people judge one face at a time, our assessment of the current face is influenced by our assessment of the previous one. In other words: If we have received a grim or friendly impression, we also project this onto the next image. In this context, their experiments now showed that the same effect also occurred when real and pareidolian faces were mixed in the experiments, the researchers report.
Stubborn facial impression
“Accordingly, Pareidolian faces are apparently not discarded as incorrect identifications, but go through the same facial expression analysis as real faces,” explains Alais. “We know that these objects are not really faces, but the perception of a face remains,” says the neuroscientist. “So in the end we have a kind of parallel experience”.
According to Alais, this seems to reflect the great importance of face recognition and interpretation for humans. “Is there a potential enemy there?” As a deeply social being, it is not enough to simply grasp a face. It is important for us to quickly recognize whether an expression is friendly, sad, angry or filled with pain. “From an evolutionary point of view, the advantage of not missing a face seems to far outweigh the mistakes in which inanimate objects are perceived as faces,” says Alais.
“The brain apparently has neural mechanisms that act ‘quickly and easily’ by using a rough template of two eyes over a nose and a mouth. Many things can produce this picture and thus trigger a facial recognition reaction, ”the neuroscientist sums up.