“If we’re under a lot of stress, sometimes it can very negatively impact retrieval of information,” said Daniel Schacter, a professor of psychology and director of the Schacter Memory Lab at Harvard University. He’s also the author of “The Seven Sins of Memory: How the Mind Forgets and Remembers.”

One effect is “blocking,” in which information is available in memory but we can’t retrieve it when we want to, Schacter said.

“The tip-of-the-tongue phenomenon we all are familiar with would be an example of blocking,” he said. “There’s good research to show that people, if you put them in a stressful situation, will have more retrieval blocking and tip-of-the-tongue experiences.”

Another effect is absent-mindedness, he said, which is “when there’s kind of a breakdown at the interface of attention and memory, and we forget to do things because we’re not really focused.” That could potentially happen if someone is worrying a lot about Covid, he said.