TOKYO - Becoming invisible and uploading human consciousness may sound like something out of the world of the famed cyberpunk anime and manga series "Ghost in the Shell," but two Japanese scientists are working to turn such science fiction concepts into reality.
Wearing a cloak made of retroreflective material, Masahiko Inami, a professor at the University of Tokyo's Research Center for Advanced Science and Technology, appears to blend into his surroundings as a projector displays an image of the background behind him onto the cloak.
Drawing on a concept featured in the science fiction series known as "thermoptic camouflage," which allows characters to blend into their surroundings, Inami has developed a technology he calls "optical camouflage."
The material, which gives the cloak its apparent invisibility, reflects incoming light back toward its source.
"Just as octopuses and chameleons change their body color to match their surroundings, if we project a three-dimensional image that perfectly matches the background, it would essentially appear transparent," Inami said.
"I think we are entering an era where we can easily change our bodies to match our clothes," he said.
Except for her brain and spinal cord, the body of "Ghost in the Shell" protagonist Motoko Kusanagi is entirely synthetic, giving the cyborg superhuman strength and other abilities.
In one iconic scene in the 1995 anime film "Ghost in the Shell," a cybernetic character's fingers mechanically split into multiple smaller appendages to type rapidly on a keyboard.
Inami, for his part, has also developed Jizai Arms, a wearable robotic-arm system that allows users to control up to six additional arms.
"Jizai" is a Japanese term conveying a sense of freedom and autonomy. Inami designed the arms to enable social interaction between multiple wearers and explore how people might interact in a future cyborg society.
"A jizai system must have a sense of agency -- something that gives the sensation that it can be perfectly controlled by myself," Inami said. "If I can feel a sense of agency over a system, after several trials, I start to get a sense of ownership, so my brain starts to believe the system is part of my body."
Inami noted that as such concepts from science fiction start to become reality, people's perceptions of skills acquisition and their mindsets toward it may start to change.
Meanwhile, much like Kusanagi, who can transfer her consciousness between prosthetic bodies and computer networks, another University of Tokyo scientist is exploring whether human consciousness could one day be uploaded to a machine, potentially paving the way for digital immortality.
Masataka Watanabe, an associate professor specializing in cognitive neuroscience at the university's Graduate School of Engineering, hopes to digitally preserve his consciousness long after his physical body has died.
"As a scientist I want to decipher the neural mechanics of consciousness. I think it's the most challenging problem in modern science," he said. "We feel that this is the final frontier."
With the body gone and only consciousness remaining, Watanabe said, the range of experiences available to it could be virtually limitless.
"I think that's the beauty of having a digital world," he said. "Some people might say, 'If we're stuck in the same kind of world, what is the whole point of being uploaded?'"
Watanabe hopes to test the integration of biological and artificial brain hemispheres.
"The idea is to connect a machine to your own brain and test whether you can become consciously aware of what is perceived through the machine," he said. "What is interesting about the brain is that the left side of vision is handled by the right side of the brain, and the left side of the brain is the opposite."
Watanabe explained that if the corpus callosum, the thick nerve tract connecting both sides of the human brain, is severed, consciousness can reside independently in each hemisphere.
Even in a healthy brain, where the two hemispheres are connected, visual consciousness initially emerges separately in each hemisphere before merging through this connection, Watanabe said.
"If we turn that constraint to our advantage, we can create a machine that is like a cerebral hemisphere. The machine is responsible for the right visual hemifield, for example, while my biological brain is responsible for the left visual hemifield," he said.
"If my remaining brain were suddenly able to see the machine's side as well, then at that point, there is no other way to explain it than that the (two streams of) consciousness had converged."
Watanabe hopes that the technology can be created within his lifetime, needing about 30 billion yen ($190 million) to fund the experiment, 10 years to successfully conduct it and prove that machine consciousness exists, and another 10 to achieve mind uploading.
With the universe of "Ghost in the Shell" set in the mid-21st century, it remains to be seen whether Watanabe's theory will become a reality as fictional and real timelines converge.
