With a swipe across an iPad, a game player becomes a bottlenose dolphin. Everything the gamer does, the dolphin does, too. She can dive deep into the water, shoot 20 feet up and twist into a full-body spin in midair. Amid the acrobatics, the gamer hunts fish, outsmarts sharks and takes on other challenges.
"I Am Dolphin" functions purely as entertainment and has been released this month as a $2.99 game app. But it's the product of a collaboration by a game-development team, an animation artist and a neuroscientist at a Johns Hopkins medical lab. That same team has created two variations: one that they hope will help rehabilitate stroke patients and one that will help them study how both healthy and brain-injured people learn.
Dr. John Krakauer, the Hopkins neurology professor who runs the lab, looks to people's fascination with movement and sports to fuel his research.
"I think what intrigues us is that feeling of control — that we are the master of our moves. With that thought, I envisioned an emotionally charged game where you control another creature through its movement. If you control it, you become it."
And if you become it as you play, he surmised, he could study naturalistic behaviors and the neuroscience behind them.
The core technology, fine-tuned through "I Am Dolphin," will be put to the test on stroke patients through a version tweaked for them.
"The experience is a mix of controlling the animal by telling it where to go, and feeling like you are actually in its body," said Dr. Omar Ahmad, the Hopkins physics and computer guru who developed the technology.
This type of simulation is the first of its kind, according to Ahmad. What distinguishes it, he says, is that it lacks pre-rendered responses that depend on the turn of a joystick or flick of a button.
"Rather we programmed simulations that act on the laws of physics. The fish has virtual bones and hundreds of muscles surrounding the bones. When the muscles contract, the bones move," he said.
"It's kind of like 'Avatar,' only in a computer. We basically built a robot into the computer. So there is unpredictability as you change variables and watch your choices play out as they would in real life," he said of the technology, developed after the team clocked hundreds of hours observing dolphins at the National Aquarium in Baltimore.
As they developed the game, the team decided that developing likable characters was as important as the physics-based bells and whistles.
The leading "good guy" in 'I Am Dolphin' is Bandit, modeled after young bottlenose dolphins at the National Aquarium.
"Bandit is playful and mischievous. He's got a glint in his eye and a baby face, as dolphins go. And he likes to explore," said Kat McNally, the artist who designed Bandit, his pals, enemies and their nautical surrounds.
The key to mastery of "I Am Dolphin" is all in the hand, as players swipe and tap to set the animal in motion.
In the version Krakauer hopes to offer stroke patients, players would control the creature using an assistive device called an exoskeleton robot.
"Think of a robotic suit for the arm," said Krakauer. "Patients place their arm in, and it applies force so that they can move without having to lift the weight of their arm."
As players improve, they would be challenged to go after prey that require them to be faster and more accurate, and use a greater range of joint movements.
"We don't know yet if we can get patients to recover more than with conventional rehabilitation," he said. But he does know that most recovery after a stroke happens in the first three months, and he will take advantage of that short window using gaming.
"The brain has a heightened degree of plasticity then, meaning it responds more to training than it will later. So we hope we can make a difference with gaming as a therapeutic tool early after stroke," said Krakauer.
He believes the game may have potential as therapy with other brain injuries, orthopedic injuries and even depression.
Krakauer says the concept was a tough sell at Hopkins. But his immediate boss had no qualms about pumping department funds into this unconventional approach to medicine; he was intrigued.
"The genius here is the link between neuroscience, computer science, art, gaming, and robotics," said Justin C. McArthur, director of the medical school's neurology department.
"That was what attracted me — trying something completely new for a very old problem where we have, to be honest, made only limited progress in 100 years. We hope this investment will pay off for people living with strokes and those with other brain injuries."
Meanwhile, the lab is working on a third platform that Krakauer believes will help him learn how healthy and brain-injured people improve their motor skills over time.
There is no dolphin in this game; rather subjects will drive an "ant car."
"It's a vehicle that looks like an ant with wheels, and it seems to have a little of a life of its own. You have to steer it over a complex, narrow track, without falling off," said Krakauer.
What you see is a bird's-eye view of the track. Gamers take control by tilting and moving the iPad with both hands.
"This is very difficult at first and seems to require weeks, if not months, of practice to master," said Krakauer.
He hopes this application will help answer questions such as: When you become highly specialized at one skill, do you become less adept at similar skills? Is there a tradeoff?
"So basically, we are trying to discover the rules of learning and the best way to practice," he said.
"We don't know why you get better at movement over time. We want to learn why.