Normally, neuroscientists try to discover things about the brain, as if it were one monolithic thing. Might the differences between individual brains be important, or useful?
A recent article in New Scientist describes recent efforts to use each person's unique brain activity patterns as a kind of fingerprint (or 'brainprint') for security purposes. The system uses EEG.
According to the article, "This novel biometric system should be difficult to forge, making it suitable for high-security applications". I'm trying to imagine a CIA operative putting on a little red EEG cap before being allowed into a top secret location…