WATCH: Doctor laughs at Trump’s bizarre boast about passing a cognitive test

Arthur Caplan of New York University School of Medicine, who holds seven honorary degrees from colleges and medical schools, couldn't help but chuckle when discussing President Donald Trump's recent comments about passing a cognitive test.

"I actually took one very recently when, you know, the radical left was saying, 'Is he all there? Is he all there?' I proved I was all there, because I aced it,” Trump told Fox News host Sean Hannity on Thursday night. “I aced the test... I took it at Walter Reed Medical Center in front of doctors and they were very surprised. They said, ‘That’s an unbelievable thing. Rarely does anyone do what you just did.'"

Appearing on CNN Friday, Caplan said cognitive tests were standard during comprehensive physicals of those in Trump's age group. "You're looking to see if there might have been any type of a stroke or any early onset Alzheimer's, so that's pretty routine as part as a physical."

CNN host Brianna Keilar asked what Trump meant when he said he aced the test.

"It's kind of interesting," Caplan said, laughing. "The test he took is not a difficult cognitive test. It's basically a screening test, and I was not there, but I doubt astonishment was the reaction of the doctors."

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