"They seemed to enjoy themselves," Dr. Gemma Williams tells PEOPLE

By Simon Perry
Updated June 07, 2016 03:00 PM
Rebecca Naden - WPA Pool/Getty Images

In his almost 95 years, Prince Philip has seen countless coins decorated with the head of his wife, Queen Elizabeth.

But rarely has he been so struck by a collection of so many pennies in one place – sculptured into a seahorse, no less – as he was on Tuesday.

Philip, who served as president for more than 40 years of the Royal Mint committee that chose coin designs, was shown the unique artwork that the Queen unveiled to mark the opening of Cardiff University’s Brain Research Imaging Centre in Wales.

Called “Penny For Your Thoughts,” the sculpture is the work of Dr. Gemma Williams, a psychiatrist and Ph.D. student at the university’s $64 million department. Looking closely at some of the coins among the $58 worth stuck to the sea horse, he asked if they were “coins of the realm” and “he was pointing out that he had chosen the design of specific coins,” Williams tells PEOPLE.

The sea horse signifies the part of the brain, the hippocampus (Greek for sea horse), which is shaped like the marine creature. It is known as the seat of memory in the brain.

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During her tour, the Queen was told about the sculpture and “She said, ‘Oh yes, it does look like a part of the brain,’ ” says Williams. “She was very sweet. They were really relaxed and friendly and happy. They seemed to enjoy themselves.”

The couple of 68 years watched as Professor Chris Chambers, head of brain stimulation at the center, underwent Transcranial Magnetic Stimulation (TMS), as lab manager Jemma Sedgmond made his right hand move by controlling the stimulation to the correct part of his brain. TMS can help recovery from strokes. “They were interested in how different brains vary and the consequences for strokes and how strokes affect the brain,” Chambers adds. “They were fascinated. It’s not the kind of thing you see every day.”

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Local school kids greeted the couple on their arrival, which followed the Queen opening the fifth session of the Welsh Assembly in Cardiff Bay earlier. Then, inside, they watched as two children tried to move a ball with mind control via electrodes on the front of their heads. Prince Philip animatedly urged them on.

“He was asking them what they were thinking of to get their brain racing to the end, and one of them said they were imagining being chased by a cheetah,” says Ph.D. student Hannah Furby.

Three pupils from Llandaff City Church in Wales Primary School, who drew pictures of how the brain works for a competition, also met the couple. And Philip showed he is still king of quips. “He was funny,” 10-year-old Katrin Powell told reporters.

“He asked us if we could speak Welsh, and we said yes. He said, ‘You must have really good brains to speak Welsh.’ “