The structural connections in your brain are unique to you, say scientists, who have developed a way to “fingerprint” the human brain.

The researchers used diffusion MRI to map the brain’s structural connections and found that each person’s connections are so unique that they could identify a person based on this brain “fingerprint” with nearly perfect accuracy.

Published in PLOS Computational Biology, the results also show that the brain’s distinctiveness changes over time, which could help researchers determine how factors such as disease, the environment, and different experiences affect the brain.

The new, non-invasive diffusion MRI approach captures the brain’s connections at a much closer level than ever before. For example, conventional approaches obtain a single estimate of the integrity of a single structural connection, or a white matter fiber. The new technique measures the integrity along each segment of the brain’s biological wires, making it much more sensitive to unique patterns.

“The most exciting part is that we can apply this new method to existing data and reveal new information that is already sitting there unexplored. The higher specificity allows us to reliably study how genetic and environmental factors shape the human brain over time, thereby opening a gate to understand how the human brain functions or dysfunctions,” says Fang-Cheng (Frank) Yeh, the study’s first author and assistant professor of neurological surgery at the University of Pittsburgh. Yeh completed the research while at Carnegie Mellon University as a postdoctoral fellow in psychology.

For the study, the researchers used diffusion MRI to measure the local connectome of 699 brains from five data sets. The local connectome is the point-by-point connections along all of the white matter pathways in the brain, as opposed to the connections between brain regions. To create a fingerprint, they took the data from the diffusion MRI and reconstructed it to calculate the distribution of water diffusion along the cerebral white matter’s fibers.

 brainscans fingerprint Souce PLOS Computational Biology
Image: PLOS Computational Biology

The measurements revealed the local connectome is highly unique to an individual and can be used as a personal marker for human identity. To test the uniqueness, the team ran more than 17,000 identification tests. With nearly 100 percent accuracy, they were able to tell whether two local connectomes, or brain “fingerprints,” came from the same person or not.

Additionally, they discovered that identical twins only share about 12 percent of structural connectivity patterns and the brain’s unique local connectome is sculpted over time, changing at an average rate of 13 percent every 100 days.

“This confirms something that we’ve always assumed in neuroscience—that connectivity patterns in your brain are unique to you,” says Timothy Verstynen, assistant professor of psychology at Carnegie Mellon.

“This means that many of your life experiences are somehow reflected in the connectivity of your brain. Thus we can start to look at how shared experiences, for example poverty or people who have the same pathological disease, are reflected in your brain connections, opening the door for potential new medical biomarkers for certain health concerns.”

Additional coauthors are from the US Army Research Laboratory; the University of California, Santa Barbara; the University of Pittsburgh; and the National Taiwan University.

The Army Research Laboratory funded this research.