The mysteries of the mind and how to heal and manipulate the central nervous system have fascinated mankind for eons. Long fodder for the science fiction realm, consider the vast amount of sci-fi books and films featuring implanted memories or mechanized limbs.

Now, thanks to advances in technology and research, manipulating the brain and the central nervous system to regain lost abilities are no longer the subject of the imagination. Neurostimulation and neuromodulation, essentially the electrical stimulation or suppression of muscles or nerves, offer some control of injured limbs. In practical terms, the visions of the future are closer than ever.

Putting the spotlight on these advancements affecting the body’s most enigmatic organ is this year’s Brain Awareness Week, March 13-19. Organized by the Dana Alliance for Brain Initiatives, the worldwide event seeks to expand public awareness about the progress and benefits of brain research.

In her own words, after a devastating spinal cord injury, Jen was told she should get comfortable in her wheelchair as she would have to witness the rest of her life at a seated level. Just a few years later on her wedding day, Jen – with the assistance of a walker adorned with flower garlands – walked down the aisle to her waiting husband. Jen received the Stand and Transfer Functional Electrical Stimulation (FES) system developed by the team at the Cleveland FES Center. The system allows her to exercise, transfer and stand using implanted electrodes in her lower limbs.

Jen benefited from a neural prosthesis – essentially an implanted medical device that interfaces with the central nervous system to restore function, according to Hunter Peckham, PhD, executive director of the Cleveland FES Center and professor of biomedics at Case Western Reserve University.

A more advanced cousin of other neurostimulation devices – such as the cochlear implant, for example – implanted neural prostheses assist in restoring the activities of daily living. By utilizing neurostimulation and essentially circumventing the nervous system and the brain, patients regain lost function and an improved quality of life, Peckham says.

“[The patients] are enormously functionally enhanced,” he notes. “They can’t do the things they’re doing without neurostimulation.”

During neurostimulation, electrodes are positioned on or into the muscle or nerve to be controlled. Different devices actually control the muscles or nerves. In some cases, the myoelectric signal from a muscle that has some retained voluntary activity is utilized. Otherwise, sensors that detect movement of the shoulder or wrist or even simple switches exert control. Researchers are also in the very early stages of exploring the possibility of using brain signals for control, Peckham says.

The applications and advantages of neural prosthetics are abundant. The cochlear implant, which bypasses damaged hair cells in the auditory system by direct electrical stimulation of the auditory nerve, has significantly assisted the deaf community in gaining hearing. Deep brain stimulation allows implanted electrodes in the brain to regulate the irregular motor movements of Parkinson’s patients, controlling spasticity and flailing.

In terms of physical therapy, neural prostheses allow therapists to build on the patient’s muscle strength and control. When working with stroke victims, rather than simply strapping a fork onto the affected hand, the neural prostheses’ electrical stimulation allows the hand to open, hold the utensil and move. Electrical stimulation takes the intended movement and amplifies it, to create a stronger movement.

“Because the patient has movement that they didn’t have before, the physical therapist can work with a larger range of motion,” says Terri Zmina, a 20-year PT veteran and manager of business development for the Cleveland-based NDI Medical, a manufacturer of neurostimulation devices.

Additionally, the increased motor control assists in preventing secondary medical complications commonplace in spinal cord patients, such as muscle atrophy, urinary tract infections and pressure sores.

“As with all therapy, the goal is to help the patient become as independent as possible. Technology helps with that,” Zmina observes.

And the government is helping to facilitate technology breakthroughs. As part of Ohio Gov. Robert Taft’s Third Frontier Program, the Cleveland FES Center and NDI Medical teamed to translate the latest neurostimulation and neural prostheses research findings of universities and labs into commercial opportunities. The Ohio Neurostimulation Neuromodulation Project implements the research conducted by universities to product implementation and makes it available to the patients who most need the technology, Peckham says.

Delving into the Mysterious Process of Sight

Research continues to point to key clues as to how the brain processes information and guides essential functions. In the long term, understanding exactly how the information is processed may lead to more advanced neural prosthetics – artificial replacements for lost sensory, motor and perhaps even memory and cognitive functions. In the short term, such work is driven by curiosity about one of the fundamental mysteries: how the brain works.

When a human looks at a number, letter or other shape, neurons in various areas of the brain’s visual center respond to different components of that shape, almost instantaneously fitting them together like a puzzle to create an image that the individual then “sees” and understands, researchers at the Johns Hopkins University in Baltimore report. A team from the university’s Zanvyl Krieger Mind/Brain Institute describe the complex but speedy process in detail in a recent issue of the journal Neuron.

The question of how the brain sees, recognizes and understands objects is one of the most intriguing in neuroscience, says associate professor and the paper’s co-author Charles E. Connor.

“This may not even seem like a scientific question to some people, because seeing is so automatic and we are so good at it – far better than the best computer vision systems yet devised," Connor says. "That is because a large part of the human brain is devoted to interpreting objects in our world, so that we have the necessary information for interacting with our environment.”

And, according to Connor, vision doesn’t happen in the eye. “It happens at multiple processing stages in the brain. We study how objects are signaled or encoded by large populations of neurons at higher-level stages in the object-processing part of the brain.”

“Humans do a rough categorization of objects very quickly,” Connor explains. “For instance, in just a tenth of a second, we can recognize whether something we see is an animal or not. Our results show that this immediate, rough impression probably depends on recognizing just one or more individual parts of what we see. Fine discriminations – such as recognizing individual faces – take longer to happen, and our study suggests that this delay depends upon emerging signals for combinations of shape fragments. In a sense, the brain has to construct an internal representation of an object from disparate pieces.”

“Our ability to see is one of the great evolutionary accomplishments of the human brain,” Connor says.

 “We still don’t know how the visual system accomplishes this marvel of information processing. Such experiments are beginning to reveal how large networks of neurons in the brain extract meaning from the eye image.”

The Future Threshold?

What happens to the brain after some of these interventions? Can you change the brain? Is the brain irreversibly damaged after a devastating injury?

According to Peckham, studies in stroke victims have shown that constraint induced therapy – wherein patients are forced to use the damaged limb – garners a modest, but measurable success, especially in patients with a moderate injury. Such evidence suggests that the brain is changing its function.

Given the evidence of how the brain processes neural and sensory information, how can medical personnel facilitate the recovery?

“Unfortunately, we don’t know yet how to make that a product,” Peckham says. “It’s an evolving dream.”

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Annette Stierwalt is a Cincinnati-based freelance writer.