Explain the illusion of faces appearing on objects

In life, many people often suddenly see faces on objects or positions that should not appear as on toast, on the wall, in the clouds, even on the Moon.

A new study shows that this happens when our brain undergoes a phenomenon called Pareidolia , which, when a person thinks he sees a face, that thought will awaken a region of the brain responsible for analyzing and identifying faces

This is a very famous phenomenon, and an explanation for people looking at a rock undulating on Mars into a face or water mark on the ceiling of a Chicago tunnel into the image of the Virgin .

However, this phenomenon does not always make people see faces. In 2013, there was a heated debate on the Internet about the camera of NASA's self-propelled explorer robot capturing a mouse on Mars.

To find out what happens in the brain when this phenomenon occurs, the scientists selected 20 men and asked them to observe an image while in a functional magnetic resonance imaging machine. The magnetic field changes due to changes in oxygen levels in the blood will help scientists see which areas of the brain are supplied with blood at any given time, and show the strong activity of neurons in that brain region.

Researchers asked participants to look at a series of blurred photos. Two pictures show the face of a man, one is very easy to see, the other is more difficult. The other two pictures show letters, also an easy-to-see picture and a hard to see picture. The final image is completely black and white and has a stain on it.

Experiments are conducted separately with each photo group, one week apart. Participants are given two buttons, they press the first button when they see faces or letters, and press the other button when they see nothing.

After this experiment, participants were shown a series of other images and were told that half of them had pictures of faces or letters. However this time the images are secretly blurred. They were asked to press the button to determine if they saw anything.

As a result, 34% of the participants said they saw faces, and 38% saw the letters, although in the images they were seen without any faces or letters.

Experimental results show that people tend to create images themselves when searching for objects that can be identified in a random sequence of images.

This experiment has helped scientists find the difference between brain activities that make us mistakenly look at faces and mistakenly look at letters. These differences are located in the FUSiform Face Area (FFA), a small area in the brain behind the ear.

This area has long been responsible for facial recognition as well as distinguishing between objects. For example, a person can use the FFA to tell the difference between a sparrow and a wren.

Finding the link between FFA and the visual hallucination shows that this area not only reacts to real faces but also reacts to the thought of seeing a face.

In other words, the fact that we expect to see a face can make our brain process information and create an image that is very similar to a face , leading to a false feeling.