Think about the last time you walked down a crowded street, biked along a rocky hiking trail, or swum in a lake. You probably didn’t have to stop and think about how you were going to navigate those spaces. Your body just knew what to do.
A recent study from the University of Amsterdam found that certain regions of the brain’s visual system not only help you to recognize your surroundings but also tell you how to move your body in different spaces. Whether you are walking, climbing, or swimming, your brain is always plotting your next move.
How Our Brain Navigates the World
Our brain’s built-in GPS is controlled by the hippocampus. Nestled deep in the brain, the hippocampus has specialized place cells that fire when you are in specific places. Each cell is turned into a particular region. Together, their firing patterns form 3D spatial representations of your surroundings called mental maps.
Mental maps help you navigate familiar environments. They store information about the layout and location of unique visual cues, as well as your past experiences and perceptions of those places. This internal GPS helps you get from one point to another. They can be as small as how to get to the closest bathroom, or as big as how to drive from one city to another.
When you go someplace new, your brain immediately starts forming a spatial map using whatever cues are available. It pulls information from signs, objects, and other people to help you orient yourself. Navigating unfamiliar places forces your brain to rely on visual cues. This lights up neurons in an area just outside of the hippocampus known as the parahippocampal cortex.
As part of our brain’s visual system, the parahippocampal cortex helps us process what we see. Cells in a region called the parahippocampal place area specialize in recognizing scenes like landscapes or indoor spaces. Rather than focusing on individual objects or people, these cells help you see the bigger picture. This study found that these cells also play a key role in helping you navigate your environment.
What Human Brains Do That AI Can’t
More than one hundred and fifty people took part in MRI brain imaging for this study. While they were in the scanner, the participants were shown a series of indoor and outdoor photos. They were asked to label each scene based on whether they would walk, bike, drive, swim, boat, or climb.
As the participants made their selections, the scans showed increased activity in the parahippocampal place area and another brain region called the occipital place area. The occipital place area, located in the visual cortex at the back of the brain, picks up on things in your immediate surroundings. These cells detect walls, open spaces, and obstacles that may be in your way.
Together, these regions seem to help your brain make sense of where you are and how to navigate around. The parahippocampal place area identifies potential paths, and the occipital place area helps your brain decide which actions you should take.
In the final part of this study, the team put ChatGPT and other artificial intelligence models to the test. They showed the models more than 200 images to see how well they could interpret different scenes. While the AI did a decent job at recognizing objects, it struggled when it came to figuring out how to move through complex spaces. As Dr. Iris Groen, assistant professor at the University of Amsterdam and a lead author of this study, explains, “Even the best AI models don’t give exactly the same answers as humans, even though it’s such a simple task for us.”
There is some hope that someday AI may be able to learn from us. Understanding how our brains help us move through the world may offer new insights for training AI to move through complex environments just as smoothly.