Every single person is different from the next, with even identical twins having subtle differences. This variation isn’t just limited to what we can see, but also extends to what’s going on inside our heads. Now researchers have discovered that the pattern of brain activity from one person to the next is different enough that it can be used to identify individuals in a similar way to using fingerprints.
Comparing brain scans of 126 volunteers using functional magnetic resonance imaging (fMRI), the researchers measured brain activity while the participants were either resting or doing various tasks, such as trying to hold items in their mind, listening to a story, or doing math problems. The scientists were then able to successfully match the resting state brain scan to scans of the same individual even if they were taken on a different day or during a task.
To do this, the researchers created a “map” of neural activity by dividing the brain into 268 separate regions. They then looked to see which regions showed synchronized activity while the volunteers were conducting each task, and built up a unique picture of connectivity of each participant’s brain. It turns out that this map acts like a fingerprint and changes for each person. It allowed them to correctly identify people based on their resting brain with 98% accuracy, and from their active brain scans with a slightly lower but still impressive 80-90% accuracy.
But their findings didn’t stop there. While looking at the brain activity between the prefrontal and parietal lobes – that is the front of the brain and the mid-region – they found that those with the strongest activity between the regions scored more highly on intelligence tests.
The researchers were careful, however, to highlight that these brain scans should not be used to replace the more traditional paper-based intelligence tests. “None of us would recommend a brain scan over an IQ test,” Emily Finn, who coauthored the study published in Nature Neuroscience, told BBC News. “This is just proof-of-concept that these connectivity profiles are relevant to this very sophisticated cognitive behavior.”
The findings could have applications in how doctors treat people with mental illness. By profiling a patient’s brain activity, they might then be able to tailor therapies using more specific drugs, which could help cut down on the current method which is basically trial and error to see which treatments work, and which don’t.