Medicine at Yale, May 2016
Great minds think alike, the saying goes. But a new study by School of Medicine researchers suggests something else: every mind thinks a bit differently. A team led by R. Todd Constable, Ph.D., professor of radiology and biomedical imaging, has discovered that subtle individual variations in brain function define one-of-a-kind “fingerprints” that distinguish one person from another.
Constable and colleagues constructed diagrams using data from functional magnetic resonance imaging (fMRI), a non-invasive technique that detects brain activity. The data indicated which parts of the brain were effective in tandem at any given time, and the connectivity patterns turned out to be highly distinctive.
“That was an unexpected finding, just how unique these brain systems are,” Constable says. The differences were apparent even between identical twins, he says. The results were published in Nature Neuroscience in October.
In the study, two Constable lab members, neuroscience graduate student Emily Finn and Xilin Shen, Ph.D., associate research scientist, analyzed fMRI data from 126 healthy young adults who were scanned multiple times over 2 days. By measuring the strength of more than 35,000 connections between 268 different brain regions, Finn and Shen produced what they call connectivity profiles for each person in the study. The surprise came when they compared all those profiles: they found that each was different enough that they could identify with confidence any one person based solely on the person’s profile. The profiles identified people consistently, even when the scans were done on different days or while subjects were doing some kind of mental task, rather than just resting in the scanner.
The connectivity profiles were not just unique: they were also informative. The researchers found connectivity fingerprints that tracked how people scored on a test of fluid intelligence, the type of brainpower used for on-the-spot problem solving. “It’s not just that everyone has a different pattern of these connections, but also that they are relevant to some kind of real world output of the brain,” Finn says.