A whole multidimensional universe inside our own brain? More and more people are able to hear colors, taste words, or see sounds. It is what we know as synesthesia , a non-pathological neurological condition that allows us to understand the world in four dimensions. Now, new work by scientists from the Blue Brain Project (Switzerland) has discovered structures in the brain with up to eleven dimensions. We continue to unravel the deepest architectural secrets of our thinking organ.
Specifically, using algebraic topology in a way that has never been used before in neuroscience, researchers have discovered a universe of multidimensional geometric structures and spaces within networks of the brain.
The research, published in the journal Frontiers in Computational Neuroscience , shows that these structures arise when a group of neurons forms a junction or group: each neuron connects to another neuron in the group in a very specific way that generates a very precise geometric object. The more neurons in that neuronal grid, the larger the dimension of the geometric object.
“ We found a world that we had never imagined. There are tens of millions of these objects even in a small particle of the brain, up to seven dimensions, and in some networks we even find structures of up to eleven dimensions”, explains Henry Markram, leader of the work.
The scientists conducted multiple tests on virtual brain tissue to verify that the discovered multidimensional brain structures did not appear by chance. Then, in tests on real brain tissue in the laboratory, they confirmed that the brain is continuously ‘reconnected’ during development in order to build a network with as many dimensional structures as possible.
Upon stimulation, the virtual brain tissue momentarily created high-dimensional holes or cavities.
“ The appearance of high-dimensional cavities when the brain processes information means that the neurons in the network react to stimuli in an extremely organized way . It is as if the brain reacts to a stimulus by building a tower of multidimensional blocks, starting with bars ( 1D), then tables (2D), then cubes (3D), and then more complex geometries with 4D, 5D, etc. The progression of activity through the brain resembles a multidimensional sand castle that materializes out of the sand and then disintegrates, “explains Ran Levi, co-author of the study.
The complexity of the brain, exposed
If 4D worlds extend our imagination, worlds with 5, 6 or more dimensions are too complex for most of us to understand. This is where algebraic topology comes into play: a branch of mathematics that can describe systems with any number of dimensions.
“ Algebraic topology is like a telescope and a microscope at the same time , you can zoom in on networks to find hidden structures – the trees in the forest – and see the empty spaces – the clearings in the forest – all at the same time,” explains Kathryn Hess. , co-author of the work.
Are the memories hidden in one of these dimensional cavities?
Referencia: Cliques of Neurons Bound into Cavities Provide a Missing Link between Structure and Function Frontiers in Computational Neuroscience (2017). DOI: 10.3389/fncom.2017.00048
The image tries to illustrate a universe of multidimensional structures and spaces. On the left, a digital copy of a part of the neocortex, the most evolved part of the brain. On the right, the shapes of different sizes and geometries of the brain, in an attempt to represent structures ranging from 1 dimension to 7 or even 11 dimensions. Image credit: Blue Brain Project.
