The young man sitting in the waiting room of our neuroimaging facility wearing skinny jeans and trainers looked like a typical Spanish 20-year-old of Moroccan origin. Yassine* was bouncy, chatting up the research assistants, and generally in good spirits. He was like so many other Barcelona youths, except he openly expressed a desire to engage in violence for jihadist causes.

As we took him through a battery of tests and questionnaires, we were barely able to keep him in his seat as he kept proclaiming his willingness to travel to Syria to kill himself. “I would go tomorrow, I would do it tomorrow,” he said. When we probed for the sincerity of his claim, he responded, “only if we go together. You pay for the tickets”, with a wink and a smile. Less budding foreign fighter and more extremist provocateur, he enjoyed insulting us with impunity and showed us the middle finger as he left. And yet, Yassine agreed to let us scan his brain – for the first ever brain scan study on radicalisation …