“This gives us a very high resolution measure of the strength of fiber bundles throughout the entire brain, which we call the ‘local connectome,’” Verstynen said. “Then using this measure, we showed that the pattern of local connectome integrity is unique to each individual.”
The connectomes of the different brains were so distinct that they could be used to identify each person with 100 percent accuracy. A person’s brain connectome seemed to reflect not only information about genetics, cognition and neurological health, but also life experiences.
A surprising aspect of the findings was just how much an individual’s connectome tended to change over time ― it tended to shift around 13 percent every 100 days ― which suggests that brain connections are highly influenced by our experiences. This reflects what neuroscientists call “plasticity,” meaning the brain’s tendency to reorganize itself by developing new connections.
“If I scanned you once now and once again next month, your local connectome would likely have changed about 13 percent,” Verstynen said. “Also, we looked at genetically identical twins and asked how similar their connection profiles were. It turns out that their brains were more dissimilar than they were similar ― only about 12.5 percent similarity. Thus our experiences go a very long way to sculpting the connections in the brain.”
This technique could be used to study how hereditary and environmental factors shape the brain. It’s still too early to tell how the research might be applied to treating mental illness, but one day, it might be possible to compare connectomes in order to predict cognitive function or risk for psychiatric disease.
The technology is more likely to be used for clinical applications than personal identification, as it’s currently far too expensive to be used like fingerprinting, according to Verstynen.
“Realistically, we would hope that this could be used to better understand how subtle differences in the brain’s wiring can predict certain behaviors and (eventually) clinical pathologies,” Verstynen said.
Still, personal identification via brain patterns is still a possibility for the future. In another study from earlier this year, scientists were able to identify people with 100 percent accuracy using only brainwaves.
“Who knows if someone will develop a fast and cheap way to scan the connectome of your brain and use it as an identity marker,” Verstynen added. “I’ve learned never to say never.”