Brain scans pinpoint individuals from a crowd

Patterns of neural circuitry in the brain’s frontal and parietal lobes can be used to distinguish individuals on the basis of their brain scans. Our brains are wired in such distinctive ways that an individual can be identified on the basis of brain-scan images alone, neuroscientists report.

In a study published in Nature Neuroscience 1 on 12 October, researchers studied scans of brain activity in 126 adults who had been asked to perform various cognitive tasks, such as memory and language tests. The data were gathered by the Human Connectome Project, a US$40-million international effort that aims to map out the highways of neural brain activity in 1200 people.

To study connectivity patterns, researchers divided the brain scans into 268 regions or nodes (each about two centimetres cubed and comprising hundreds of millions of neurons). They looked at areas that showed synchronized activity, rather like discerning which instruments are playing together in a 268-piece orchestra, says Emily Finn, a co-author of the study and a neuroscience PhD student at Yale University in New Haven, Connecticut.

Scientists analyzed brain scans by dividing them into 268 nodes or regions, each consisting of hundreds of millions of neurons and roughly two cubic centimeters in size, to investigate connectivity patterns. The team, led by Yale University’s neuroscience PhD student Emily Finn, compared the areas that displayed synchronized activity, similar to recognizing which instruments were playing together in a 268-piece orchestra.

The team found that the neural circuitry of some brain regions, such as those responsible for basic vision and motor skills, connected similarly among most individuals. However, other brain regions, like the frontal lobes, had distinct connectivity patterns that varied among individuals.

The researchers matched a person’s brain activity during one imaging session to the same person’s brain scan taken at a different time, even when they were engaged in a different activity during each session. Cognitive neuroscientist Russell Poldrack at Stanford University expressed that before this study, the extent to which a unique individual had a unique connectivity pattern was unclear.