Emiliano Bruner, who leads the paleoneurology line of research at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has published a study in the journal Anatomical Record which applies network analysis to brain maps (Brodmann maps), to investigate the topological relationships between these regions and the possible geometric links that could create spatial conflicts and influences, during either morphogenesis (growth and development) or evolution.

Network analysis is frequently employed in neuroanatomy, but it is generally used to study the neuronal connections between different parts of the brain. In this case, however, the objective was to assess the physical relationships to see which areas are the most likely to suffer constraints on their growth, or to exercise anatomical influence on nearby regions.

The results highlight the anatomical blocks that are interrelated spatially, the areas with the greatest weight in terms of cortical contact, and the regions that act as bridges between distant blocks. The anterior regions are more isolated and less integrated than the posterior ones, and the medial areas are positioned to link them together.

These data are necessary when formulating theories or hypotheses in human neuroanatomy, whether looking at individual variability or interpreting changes over the course of evolution, as well as those detected in fossils.

Brodmann maps

The brain maps devised by Korbinian Brodmann, published in 1909, are based on studies that were pioneering in their day of the cerebral cortex cytoarchitecture, in other words, considering the cellular composition of the neuronal layers.

Today, these maps have been superseded at the level of neurobiological knowledge, but they continue in use in many fields of medicine, evolutionary anthropology, and the cognitive sciences because they offer a simple anatomical nomenclature for well-known brain regions, and shared by the majority of specialists.