What is it about?
The standard, but unquantified conception of the major nerve bundles of the human brain is that they directly connect distant cortical areas, allowing them to communicate with each other. We quantitatively estimated the the number of axons connecting distant areas by calibrating diffusion MRI data from the Human Connectome Project with histological knowledge of the corpus callosum. We found the distance areas are directly connected by relatively few axons.
Featured Image
Photo by Natasha Connell on Unsplash
Why is it important?
The standard, but unquantified conception of the major nerve bundles of the human brain is that they directly connect distant cortical areas, allowing them to communicate with each other. However, we and others find rapidly diminishing direct nerve connections with distance which is incompatible with this concept. Theories of distant cortical synchronization must take the sparse direct connectivity into account.
Perspectives
I think there is a bit of a romantic mythology about the human brain having effectively infinite complexity and connectivity. But in reality, there are many biophysical constraints on its structure and organization. I hope this article encourages people to critically and quantitatively examine the limitations of the structure often referred to as the pinnacle of evolution.
Dr. Burke Rosen
Read the Original
This page is a summary of: An estimation of the absolute number of axons indicates that human cortical areas are sparsely connected, PLoS Biology, March 2022, PLOS,
DOI: 10.1371/journal.pbio.3001575.
You can read the full text:
Resources
Contributors
The following have contributed to this page
