Further study of the man revealed he was convinced there was not much he felt he not experienced before, even when watching the news on TV. When challenged on his assertion, he either demurred, claiming to have a condition, or argued convincingly that he had seen them.
Being able to study his condition offered potential new insights into déjà vu. But besides looking at people who suffered from the chronic disorder, Moulin and a team of scientists researched ordinary people too. They wanted to figure out how exactly the sensation is triggered in people who didn’t have the disorder.