NBC News anchor Brian Williams apologized on Wednesday for falsely claiming that he was on board a helicopter that was shot down in Iraq in 2003, blaming his story on “the fog of memory.” But pundits don’t seem to be buying it. “I think you would know if you were in a helicopter that was actually hit by a missile,” Rosie O’Donnell told the audience of The View. “‘Conflating’ the experience of taking incoming fire with the experience of not taking incoming fire seems verily impossible,” wrote Erik Wemple at The Washington Post. But scientists in the thorny field of memory research have a more nuanced view. I asked Lawrence Patihis, a psychologist researching memory at the University of California, Irvine, to weigh in.

Alice Robb: How common are false memories?

Lawrence Patihis: We don't know for sure how common false memories are in the real world, but we can approximate using experiments done in the lab. I suspect that no one is immune from memory distortion. Even people with superior memory seem to be susceptible to misleading information that is presented after the original event.

In one of our studies, about 20 percent of our participants generated false memories of an event when something false was suggested. [For instance, if Patihis mentioned video footage of Flight 93 crashing in Pennsylvania on September 11, one in five participants said they remembered seeing it. No such footage exists.] If we repeated the false suggestion many times over a period of weeks or months, I am sure an even larger percentage would develop a false memory.

In the case of Brian Williams, that misleading information may have been in the form of seeing the footage of him and his film crew examining the damage of the helicopter that was actually hit, and seeing it over and over again.