# The Frequent Complete Subgraphs in the Human Connectome

## TL;DR

This study identifies and analyzes the most common complete subgraphs in human brain connectomes, revealing robust structural patterns and sex differences across a large sample of 414 subjects.

## Contribution

It maps frequent complete subgraphs in human connectomes and highlights sex-specific differences, providing insights into brain network structures.

## Key findings

- Identified 812 subgraphs more frequent in males.
- Found 224 subgraphs more frequent in females.
- Established robustness of certain substructures across individuals.

## Abstract

While it is still not possible to describe the neural-level connections of the human brain, we can map the human connectome with several hundred vertices, by the application of diffusion-MRI based techniques. In these graphs, the nodes correspond to anatomically identified gray matter areas of the brain, while the edges correspond to the axonal fibers, connecting these areas. In our previous contributions, we have described numerous graph-theoretical phenomena of the human connectomes. Here we map the frequent complete subgraphs of the human brain networks: in these subgraphs, every pair of vertices is connected by an edge. We also examine sex differences in the results. The mapping of the frequent subgraphs gives robust substructures in the graph: if a subgraph is present in the 80% of the graphs, then, most probably, it could not be an artifact of the measurement or the data processing workflow. We list here the frequent complete subgraphs of the human braingraphs of 414 subjects, each with 463 nodes, with a frequency threshold of 80%, and identify 812 complete subgraphs, which are more frequent in male and 224 complete subgraphs, which are more frequent in female connectomes.