Status: 02/21/2023 06:19 a.m
In an experiment, researchers from Austria found out how our spatial orientation works more precisely. The results might contribute to further research into dementia.
In everyday situations you sometimes have to navigate crowds of people, be it through a busy pedestrian zone or along a crowded platform. A certain area in the human brain is responsible for this, in which the so-called grid cells can also be found.
A research team from Austria has now used virtual reality and functional magnetic resonance imaging to examine in more detail which parts of the human internal navigation system are responsible for spatial orientation and tracking the movements of other people.
Grid cells for spatial orientation
Grid cells are a variety of cells in the brain that are important for spatial orientation and spatial memory. They enable us to create spaces like a coordinate system with lengths and widths and store them in the brain. In 2014, John O’Keefe, May-Britt and Edvard Moser were awarded the Nobel Prize for the discovery of these cells.
Grid cells lie in the entorhinal cortex. This is a small area in the middle temporal lobe. This area of the brain is responsible for controlling memory and emotions, among other things. Only the stimuli that the entorhinal cortex transmits result in a stimulus being stored in memory.
It was previously known that the grid cells capture the current and previous own position with line of sight and location. This creates a kind of imaginary map in the brain. Every person has an area in their brain that acts like a kind of GPS and in which the grid cells play an important role.
contribution to dementia research
However, it is precisely this human GPS that is affected by the aging process and, above all, by dementia. The loss of these cells is responsible for memory problems in dementia. The scientist from the University of Vienna and study author Isabella Wagner explains: “The function of grid cells decreases with age and with dementia. This means that people can no longer find their way around and orientation is impaired.”
Therefore, the research results recently published in the journal Nature Communications were published also contribute to further dementia research.
brain activity examined
The Austrian researchers checked which parts of the human navigation system are responsible for tracking the movements of other people.
The research team examined the brain activity of 60 healthy subjects using so-called functional magnetic resonance imaging (fMRT). Layer images of the human body are generated using a strong magnetic field. The scientists can thus watch the brain at work without X-rays. Because the fMRI can distinguish between active and inactive areas.
In a virtual desert landscape, the test subjects were to observe different paths taken by another person. Then they were asked to follow these paths virtually. Meanwhile, the fMRI recorded the brain activities.
New findings and further research approaches
The recordings showed that the brain activity when observing and following others is comparable to the brain activity when moving yourself. Surprisingly, the researchers also found that the activity in the orientation networks of the brain was lower the better the test person was able to follow the movement of the other person.
The interpretation of Wagner’s research team: The grid cells can solve the observation task set more efficiently, so that the entire brain area of the human navigation system has to be put under less strain. With this experiment, the researchers were able to document the important role grid cells play in the perception of other people.
Grid cells also for face recognition?
This is exactly where the researchers at the University of Vienna want to continue their work. Their suspicion: The grid cells might also be involved in recognizing faces. In addition to disorientation, dementia can also mean that familiar faces are no longer recognized.
