Human Brain Project (HBP) researchers from Forschungszentrum Jülich and the University of Cologne (Germany) have uncovered how neuron densities are distributed across and within cortical areas in the mammalian brain. They have unveiled a fundamental organizational principle of cortical cytoarchitecture: the ubiquitous lognormal distribution of neuron densities.

Numbers of neurons and their spatial arrangement play a crucial role in shaping the brain’s structure and function. Yet, despite the wealth of available cytoarchitectonic data, the statistical distributions of neuron densities remain largely undescribed. The new HBP study, published in Cerebral Cortex, advances our understanding of the organization of mammalian brains.

The team based their investigations on nine publicly available datasets of seven species: mouse, marmoset, macaque, galago, owl monkey, baboon and human. After analyzing the cortical areas of each, they found that neuron densities within these areas follow a consistent pattern—a lognormal distribution. This suggests a fundamental organizational principle underlying the densities of neurons in the mammalian brain.

A comprehensive new study provides evidence that various personality traits and cognitive abilities are connected. This means that if someone is good at a certain cognitive task, it can give hints about their personality traits, and vice versa.

For example, being skilled in math could indicate having a more open-minded approach to new ideas, but might also be associated with lower levels of politeness. These connections can help us understand why people are different in how they think and act.

The research has been published in the Proceedings of the National Academy of Sciences.