Some 400,000 current and former American soldiers suffer from traumatic brain injuries, which can cause memory loss, lack of concentration, depression, anxiety attacks and other problems. In some cases symptoms last only weeks or months; sometimes they persist indefinitely.
Finding any sort of treatment, much less a cure, has not been easy. But some neuroscientists now see great potential in techniques of manipulating the brain’s "neuroplasticity," its propensity to rearrange its neuronal structure in response to behavior and stimuli.
Earlier this year, the Department of Defense awarded a $2 million grant to Brain Plasticity Inc. to study the effectiveness of Posit Science software in restoring memory and attention in victims of traumatic brain injury, or T.B.I. Posit Science, based in San Francisco, is one of several companies, including Nintendo and Luminosity, that sell brain health software products to consumers.
If the Posit Science software is proved effective, it could become one of the first medical applications of an approach to brain improvement that remains controversial. Such software could potentially help T.B.I. patients and also those who have been determined to have autism, Parkinson’s disease, schizophrenia and other psychiatric and neurological diseases.
"This is the beginning of a revolution," said Michael Merzenich, the co-founder and chief scientist of Posit Science; the president of Brain Plasticity; and a celebrated University of California, San Francisco, neuroscientist who pioneered the idea of neuroplasticity.
The Posit Science software, sold commercially under the names Brain Fitness Program and InSight, is supposed to strengthen memory, attention, language skills and visual-spatial abilities in aging adults. Studies of it have shown improvement in those areas, but critics like Dr. P. Murali Doraiswamy, a Duke University psychiatrist, are not convinced that those gains translate into long-term benefits that can be generalized to daily challenges like remembering where the car is parked.
"There is a big gap between the claims and the evidence," said Dr. Doraiswamy, who said he doubted whether short-term improvements in memory would last longer than the three-month period most studies test.
"If they were a drug," he said of the software, "they would have been pulled from the market."
Whether the computer-game-like software can be harnessed to improve overall mental acuity in those with brain damage from trauma to the head is an even bigger question.
"It is theoretically reasonable," said Gary Abrams, director of neurorehabilitation at U.C.S.F. and head of the T.B.I. support clinic at the San Francisco VA Medical Center. "But will it actually work to help veterans? I can’t talk to that."
The idea of neuroplasticity dates to the 1980s, when the conventional scientific wisdom held that once people reached adulthood, their brains were hard-wired and would remain that way for life. Dr. Merzenich did not think that was true, and eventually his research showed that the brains of primates continued to change well into maturity.
By the mid-2000s, Dr. Merzenich and his colleagues at the university had brought much of the neuroscience field around to the idea that brain change, or plasticity, was the rule rather than the exception.
Dr. Merzenich’s core claim is that brain structure is always changing, based on what people do and what they pay attention to. By doing specific brain exercises that focus and refine attention, he says, you can adjust the underlying structure of your brain. It is well established that this happens when we learn a new skill, like dancing. The question is, Can the same processes be employed to correct for brain damage?
The malfunctioning brain, or what Dr. Merzenich calls the "noisy" brain, is like a radio that, for any number of reasons, is badly tuned to its intended station. The objective of his software, he says, is to clarify a strong signal by repeatedly practicing simple tasks, like recognizing repeated visual patterns.
The commercially available software, which will be modified only slightly for the veterans study, presents challenges that increase in difficulty in increments small enough that fine-tuning adjustments can be made and then reinforced in the users’ brains.
Brain Plasticity’s randomized clinical trial will include 132 service members who have mild T.B.I. Half of them will train on the company’s software. The other half, a control group, will play video games. Before training starts, all will be tested for memory, learning, attention, planning, social control, post traumatic stress disorder symptoms, depression, and several other factors. The patients will be retested after three months of training, and then again, three more months later. Any persistent improvements would be an advance on the status quo.
T.B.I. patients are mostly helped with "compensatory" strategies, said Tiffanie Sim, a neuropsychologist who sees many such patients at the VA’s Polytrauma Transitional Rehabilitation Program in Palo Alto. Patients are given scheduling apps for their hand-held devices and taught ways to compensate for memory loss, Dr. Sim said.
Doctors sometimes prescribe medications to treat anxiety or depression in T.B.I. patients in the hope of freeing up a patient’s cognitive reserves, said Dr. David Elkin, a psychiatrist at San Francisco General Hospital. But otherwise not much is even tried to address the underlying injury.
Specialist Orlando Gonzalez, 23, is recovering from a brain injury received when a suicide bomber hit his infantry squad in Afghanistan. Specialist Gonzalez is currently a patient at the polytrauma center in Palo Alto undergoing physical therapy for partial paralysis to his left side. For the first month after his injury, he said, he "could barely remember things at all." He has improved under treatment.
If software like Posit Science’s proves effective, future patients like Specialist Gonzalez may do an hour of software-driven brain training exercises each day, in conjunction with physical therapy, to help restore cognitive functions.
Theoretically, the brain training software could address both cognitive problems and post-traumatic stress, said Henry Mahncke, Posit Science’s chief executive, a neuroscientist and a former student of Dr. Merzenich.
To make sure the product will appeal to this generation of veterans, the company is "re-skinning" its Brain Fitness software — "so it has a look and feel that’s right for guys who’ve been playing 50 hours of Xbox a week," Dr. Mahncke said.
Thinking of people who sign up for a gym but quickly tire of the routine, Dr. Doraiswamy said he was skeptical that veterans would stick with the software. Still, he said, the trial is worthwhile.
"They have to start somewhere," he said.