IOWA CITY, Iowa — On Wednesday afternoon, orthopedic surgeon Reginald Cooper stopped in front of a door at the University of Iowa hoping to catch up with Newt Gingrich.

Gingrich, who was speaking to medical students before an address about the importance of brain science research, befriended Cooper about two years ago on a four-week sweep through Africa. Cooper said Gingrich and about 70 other holiday makers took a reconfigured 757 to a series of nations for a series of safaris. He recalled Gingrich and his wife Callista tracking gorillas in Rwanda for eight hours and posing for pictures with lemurs in Madagascar. Cooper said he talked about a variety of issues on the trip with Gingrich, whom he called a “real trooper,” including wildlife, the economy and science.

“He’s a very intelligent guy,” said Cooper, wearing a white lab coat. “He can talk about anything.”

That afternoon, Gingrich, who peppers his campaign speeches with talk of outer space and the transcontinental railroad, chose to talk about the brain.

“I want to talk to you about brain science,” he said, before protesters from Occupy Iowa City interrupted him. (Gingrich dismissed them as the “one percent” that prevented the rest of the 99 percent from having an “intelligent discussion.”)

When security cleared the protesters, Gingrich explained the origins of his interest in the brain. He said a congressional working group he had chaired on Alzheimer’s disease opened his eyes to how mental diseases drive up costs in the budget. He talked about the jobs that could be created and the costs that could be cut by leaps in brain science. “I think the brain will turn out to be the area that has the most growth,” he said, arguing that its synaptic hardware was still an unexplored frontier. Gingrich concluded by saying, “So you understand why this campaign has been so different. This is a very big idea in an area that many political leaders won’t attack.”

The people who had come to see him appreciated his interest.

“This is something different,” Jaime Vanourny, 29, said approvingly. A dermatology resident, Vanourny sat studying the effects of something called Nevus Sebaceous as she waited for Gingrich to arrive.

Don Johnson, a 76-year-old retired psychologist who arrived two hours early and killed time reading a book titled “The Woman Next Door,” said that his wife suggested the speech would earn him an hour of the Certified Education Units he required to keep his license.

“I said, ‘Doesn’t he have to be an expert?’ ” said Johnson. “And she said, ‘Isn’t he?’”

Under a flat-screen television advertising future talks in the auditorium on “Androgen-Feature Maps” and “Cholinergic Synaptic Signaling,” Anne Michael Langguth, 24, studied for her pharmacology finals. A Democrat, she observed that it made sense for Gingrich to come to the university, one of the largest employers in Iowa City. “He knows his target audience,” she said.

After his speech, Gingrich took questions from the crowd. Most questions had to do with drug approval processes and whether there should be more emphasis on obesity rather than neurology. One residual protester asked about what he called Gingrich’s “PhD” in adultery.

Gingrich then called it a wrap and sat with some of the university’s experts, including Matthew Rizzo, the head of the university’s Aging, Mind and Brain Initiative. Rizzo said that in an earlier meeting with Gingrich, the former speaker explained his keen interest in the brain by telling a personal story about his mother’s bout late in life with a bipolar disorder and her “spiral” into a degenerative condition. “And he’s 68,” said Rizzo. “Like everyone who is older, he thinks, ‘What is going to happen to me?’ ”

Gingrich concluded his visit to the university with a news conference in front of more than two dozen reporters. They tried to get him to respond to the barrage of attacks made against him by his closest competitors, Ron Paul and Mitt Romney. One reporter asked Gingrich to respond to Romney’s comments earlier in the day that suggested Gingrich was “zany.”

“I think a brain science initiative is a way of helping human beings,” Gingrich said. “I’ll let him decide if it’s zany.”