They call it the pucker effect.

I’m referring to the instant tensing of all muscles in the body when it realizes it is tumbling 14,000 feet above the ground it much prefers to be resting on.

My father alerted me to this phenomenon when I, after much deliberation, decided that it would be prudent to tell a next-of-kin I would be jumping out a plane as part of an independent research study by a Marquette graduate student.

“Your muscles will be so tight that if you stuck a pin in your ass, you couldn’t pull it out with a tractor,” my dad informed me.

And after I somersaulted from a plane last Saturday and zoomed toward Earth at 115 mph with every minor muscle tensed, I believe he was quite right. My jump was one of the most thrilling and emotionally arousing experiences I’ve ever had, which made me a perfect lab rat for the study.

The study, led by psychology master’s student Steve Byers, is testing how high levels of emotional arousal affect memory. To do so, Byers, 29, asks tandem skydivers who are typically beginners to memorize a list of words, then recall them after they’ve jumped.

It’s too early to know the results, but Byers’ hypothesis is that high emotional arousal will enhance memory. Emotional experiences are more memorable, so when participants memorize the words while they are aroused from anticipation of their jump, they may have better recall. After the jump, they may remember not only which words were on the list but have vivid recollection of conditions like ambient noise when the words were presented.

Byers said the results of this study, titled “Freebird,” have potential to be applicable to research on victims of post-traumatic stress disorder, who also may experience vivid memories of instances of high emotional arousal.

“This could really give us something really interesting,” Byers said. “It has a lot of unforeseen potential.”

To maximize emotional arousal, Byers has limited the study to inexperienced tandem jumpers, who are strapped to a licensed jumper that carries the parachute.

Byers said he began the experiment because other studies that analyze arousal are too tame in a lab setting to get participants really fired up, using stimuli like surgery videos to heighten participants’ emotional arousal.

Byers, himself a licensed skydiver, thought his hobby would be a stronger stimulus and help to shed more light on skydiving, which he found has surprisingly little psychological research on it.

“I would definitely categorize myself as a thrill seeker,” he said.

His interest in skydiving began after he finished his undergraduate degree. Byers, a Mequon native, moved to Colorado and started skiing professionally.

“I’ve always just loved going fast,” he said.

High-level skiers would ski off cliffs requiring a parachute to land. After Byers conquered the fastest slopes, his pro skiing colleagues told him he was ready for the next step.

“It was just kind of put out there by these pros that the next progression would be skydiving,” Byers said.

So for his birthday three years ago, he and some friends took the plunge. He attempted a few maneuvers, pulled his own chute and landed unscathed.

Since then, he’s acquired his own skydiving license and jumps regularly.

“My first time doing it, it was really the thrill of it (that got me hooked). It was just so exhilarating to do it,” he said. “As I was going down, it was difficult to do what other people made look really easy.”

The challenge compelled him to learn and perfect new maneuvers.

He said every jump is different, and he is constantly learning and improving his technique. In fact, minutes before my own jump, he rolled out the plane, plummeting headfirst at twice the speed that my arched, air-resistant body fell.

I was stunned at my own lack of fear as the plane reached dropping altitude. I scooted toward the open door — an eerie thing to see when you’re in a moving airplane — and dangled my toes over the edge. I leaned my head back as instructed, then with a one-two-three, the licensed jumper strapped to me launched us out the door.

I couldn’t hold a mighty “WAHOO!” once I left solid ground. There was one flip in the air, then I spread my limbs wide. There was no dropping sensation in the pit of my stomach like I feel on roller coasters. No flailing limbs or realization of terror. Just the wind in my hair and a goofy grin on my face, partly induced by the air forcing my skin back into a hysterical-looking caricature of myself.

The rushing air froze my exposed skin and forced a lovely wad of snot out my nose, but the view of East Troy, Wis., growing in my field of vision was not as frightening as it was thrilling.

A minute later, a sudden jerk seemed to pull me back up toward the plane, then we slowly parachuted down for about six minutes and landed more gracefully than I ever thought myself capable.

I now see the appeal for the whackos who do this regularly. With more spare time, I wouldn’t mind being one of those whackos myself.

I have no idea how I performed on the memory test afterward, although I did vividly remember seeing about half of the words on the computer screen before the jump. But I can definitely attest that the experimental condition of emotional arousal is completely valid.

Byers admitted to me that a major motive in starting the study was to introduce more people to the sport of skydiving, and to dispel some of the myths. He knew he wanted to do both research and skydiving.

“This was really just kind of the simple answer to that problem,” he said.