Our brain is constantly changing. With each year of life, some regions of the brain work together differently than before. In people with autism, communication between different areas of the brain works differently from the outset. But which regions are particularly affected? Researchers are now able to precisely identify this for the first time. A new mathematical method from Leipzig makes this possible.
Researchers from the Max Planck Institute for Mathematics in the Sciences in Leipzig, together with colleagues from India, have developed a method that works like a high-resolution scanner for brain connections. The method specifically identifies those brain regions whose connectivity changes with age or is different in autism spectrum disorders.
The special thing about the study is the combination of two worlds. "We have created a bridge between pure mathematics and clinical neuroscience," say Professor Jürgen Jost and Professor Areejit Samal, the lead authors of the study. The new metric called "node persistence" not only detects changes, but also shows exactly which brain regions are most affected.
How mathematics makes brain processes visible
The scientists used a mathematical tool called topological data analysis. Topology deals with the shape of things. It examines how elements are connected to each other. There are hundreds of regions in the brain that are constantly communicating with each other. These connections form complex networks.
The Leipzig scientists analyzed brain data from over 1,000 people. They observed how strongly different brain regions work together. This creates patterns like a road network. Some connections are as strong as highways, others as weak as small country lanes. Mathematics tracks which structures are particularly stable and persist for a long time. Such enduring features are particularly important biologically.
The team examined the brain on three levels. First, they looked at the entire network. Young adults show more complex and longer-lasting structures than older people. In people with autism, the researchers found other peculiarities in brain organization.
108 regions age differently, 27 are altered in autism
The scientists then looked at seven important brain networks. These control movement, attention and memory. Age has a particular effect on networks for movement, attention and default activity. In autism, networks for movement, attention and social processes are particularly affected.
At the most detailed level, the researchers identified individual brain regions. 108 regions change with age. 27 regions work differently in autism. Many of these are responsible for movement, language, memory and social skills. It is interesting to note that some of these regions respond to non-invasive brain stimulation. This involves stimulating areas of the brain externally using magnetic or electrical impulses.
"Node persistence not only detects changes, but also identifies the specific brain regions that are most altered or vulnerable in these states," emphasize Jost and Samal. This opens up new possibilities for targeted therapies. The method could also be used for other neurological diseases in the future. It helps to understand where exactly in the brain treatments should be targeted.
