Select Page

The Brain’s Inner Map 

Is Shaped Like a Donut

by | Mar 22, 2023 | Education

Brain Donut

Have you seen the brain from the inner side? Well, it has been said by several references and researchers that the internal map of the brain is like a doughnut. Well, that’s quite an exciting thing to know. 

The first accurate understanding of how the brain organizes abstract knowledge has been achieved. By collecting and analyzing information from a grid of neurons, scientists were able to determine that the overall brain activity has the form of a doughnut. Recent work published in Nature demonstrates that the toroidal manifold is home to the collective action of the neuronal cells that make up spatial mapping circuits, with locations on the torus corresponding to places in the environment through which a person travels. Let’s detail how the inner brain map looks, similar to DONUT. 


How Does the Brain Perform?

The coordinated actions of neural networks consisting of tens of thousands of neurons allow the brain to perform complex tasks. These exchanges in the brain’s neural network between grid cells will enable us to place ourselves in the world, navigate, and form mental maps. As we move through the environment, the hippocampal formation, the area of the brain responsible for encoding memories, updates the cognitive maps of its surroundings by incorporating new information about our location and direction.

Studies on neural circuits have shown that the hippocampal formation, which consists of the hippocampus and entorhinal cortex, is home to many different kinds of cells that aid with spatial orientation and memory. The hippocampus place cell is a crucial aspect of this system since it stores the animal’s current position to help navigation and memory formation in 3D space.


Different Experiments Revealing Donut Trajectory in Brain 

The researchers designed three experiments to probe the brain network’s underlying behavior.

  • The first test lets the rat roam about in broad terrain. It is typical for single cells in this setting to form regular hexagonal grids. 
  • The rat navigates a labyrinth as a wagon wheel in the second test. It is well-known that linear pathways of this kind warp regular grid structures. 
  • In the third study, the rat sleeps in both the rapid eye movement (REM) and slow-wave (SWS) stages. Rapid Eye Movement, or REM, is the state of sleep most often associated with dreaming. The brain of a person in the slow-wave sleep stage is not receiving any sensory or motor information from the body or the surroundings. It is not simulating sensory experiences as it does during REM sleep when dreams occur.

Donut Meme

Ultimately, this last experiment is the actual litmus test for the theories since it would confirm or disprove one of the most important predictions of the CAN theory of grid cells. Neuropixels probes were used throughout all trials to collect data from hundreds of grid cells inside the same neural network, providing a consistent and reliable basis for analysis.


A map is Used to Get a Sense of Terrain to Know Brain’s Inner Map Shape

Neuroscientists recorded the rat’s brain activity per unit of time while the rodent performed various tasks throughout the studies. During each time interval, each grid cell in the captured network is assigned the number 1 or 0, depending on whether or not it is actively processing data. “Mathematicians then employ topological and geometrical approaches to decipher the data from cell activity and back to behavior,” said Nils A. Baas, a professor of mathematics at NTNU.

They discovered that the collective behavior of the grid cell network existed on and propagated throughout the surface of a torus or doughnut. The action on the doughnut followed the rat’s every step as it explored the room while awake. Edvard Moser said, “At any instant, we could represent the rat’s network activity by coordinates on that doughnut.


All experiments had the same results.

Furthermore, the findings were consistent across several experiments. Joint activity from the population of grid cells firmly moved along the surface of a doughnut, regardless of whether the single-cell grid data looked excellent or poor and irrespective of whether the rat was engaged in free exploration, running along a linear maze, or sleeping in either REM stage or slow-wave sleep stage. According to the theory’s bold hypotheses, the data show that the brain’s dynamics are very dynamic.

Experiments have shown that a substantial portion of the neural system for mapping an individual’s position within a physical environment resides in the medial entorhinal cortex. This is accomplished by grid cells, which fire in a characteristic hexagonal pattern of locations and are organized in modules that collectively form a periodic representation of self-location. With the help of the toroidal manifold, the modules of grid cells may keep their correlation structures constant, limiting the joint activity of cells to a low-dimensional repertoire of conceivable coactivation patterns despite the large variety of environmental inputs.

Overall these findings have made us all more hungry for those round objects that taste so good, after all, we may be related 😉


Mr. Mush Man Psychedelic Writer

Mr. Mushy Man: "A walking encyclopedia"

As an Earth grounded far-out experiencer, Mr. Mush Man is a prolific writer and researcher in all things "psychedelic." He enjoys long walks in the galactic void while learning about others' experiences.


Submit a Comment

Your email address will not be published. Required fields are marked *

recent news