You may remember this middle school teacher who seemed to have eyes in the back of the head, capable of detecting the slightest movement from behind. Imagine that this power is not reserved just for him or her, but is rather a general characteristic of humans. Indeed, researchers at the Tohoku University in Japan found that our brain constantly gather enough visual cues to see… at 360°!
To reach this conclusion, researchers looked at our ability to build a mind map based on visual cues received by our brain. The human eyes themselves are not particularly good. To fill the gaps in these tools, the brain constantly undergoes a process of rebuilding the cues sent by the eyes into a broader virtual mind-map.
Take for example the blind spot: this area on the retina completely devoid of receptors. This place in our field of vision is empty, as you can see by doing a simple blind spot test.
However, how is it still possible for us to perceive an uninterrupted image when we observe our environment? The answer is in the brain.
To remedy the lack of precision of our eyes, our brain uses what scientists call saccades: these permanent micro-eye movements allow us to encompass a broader overview of our environment. Our brain then assembles these tiny pieces into a complete puzzle.
Imagine being asked to take a picture of a room, except that instead of giving you access to it, you are only allowed to see it through a keyhole. So you should take a lot of pictures from all possible angles and then assemble them on your computer to form a composite image. Your real field of vision is the keyhole. Jerking is the movement of your device to capture a new angle. As for the final editing, it is provided by your brain.
From this research, the team sought to find out what size this mental map constituted by our brain could take. Their study, published in the journal Nature, presents the following experience: the subjects are placed in the center of six screens arranged in a circle. On each of these six screens, six letters are presented, for a total of 36 stimuli. The goal, find the letter “T”, hidden among the 35 letters “L” displayed.
To complicate the task, the letters were scattered on the screens and could be turned on their own. One of the provisions was repeated several times during the experiment, without the subject being notified. The results showed that over the course of the trials, the subjects retained better and better this disposition without even realizing and could find the letter T more quickly, even when it was behind them.
This study demonstrates the ability of the brain to unconsciously build a 360° mental map. This allows us to better understand our environment mentally, but also very possibly to facilitate our movements: if we permanently forget what is behind us, we would miss bumping each time we turn around. Basically, we all have a bit of Alastor Moody in us.