It looks like something someone created with a spirograph, but it's called a connectogram, and it's increasingly being used by neuroscientists to map and interpret the complex connections of white matter fiber buried deep inside the human brain.
These circular representations — a kind of intersection between data, neuroscience and art — can encompass a variety of uses, including as a way to visualize white matter atrophy in traumatic brain injury, or to study structural connectivity in infants. It's also being used in connectomics as part of the brain mapping initiative.
The graphs are compiled through the use of diffusion weighted (DWI) and magnetic resonance imaging (MRI). Using these tools, neuroscientists can assess white matter fiber pathways between brain regions to measure fiber bundle properties, as well as their influence on behavior and cognition.
The connectogram shown above represents the inter-brain-region connections of 110 right-handed men. The left side of the circle represents the left hemisphere, and the right side the right hemisphere.
Broken down even further, the circle is divided neatly into the frontal lobe, insular cortex, limbic lobe, temporal lobe, parietal lobe, occipital lobe, subcortical structures, and cerebellum.
Within each lobe, each cortical area is assigned an abbreviation and a unique color. The color codes themselves represent the strength of the connections (including fractional anistropy, or white matter integrity). Image credit: John Darrell Van Horn.
This connectogram belongs to Phineas Gage, who in 1848 survived a large iron bar being shot through his skull and brain. This diagram only shows the connections that are thought to be damaged by the incident. Image credit: John Darrell Van Horn.