A notable exception is Posit Science, which markets Brain Fitness, the video training program used by Hanson. Brain Fitness was developed by a team of neuroscientists led by Michael Merzenich, a coinventor of both the cochlear implant and a highly regarded software package for treating dyslexia in children (see “The Elastic Brain” by Katherine Ellison in DISCOVER, May 2007). Merzenich insists on getting independent researchers to evaluate the efficacy of Brain Fitness. His latest results are encouraging enough to have had a trickle-down effect, aiding the credibility of the whole brain-fitness movement.
Strategies modeled on Brain Fitness are being developed for attention deficit disorder.
The Posit Science system strives to enhance the speed and accuracy of auditory processing and recall in the elderly. Exercises that become progressively more difficult teach discrimination of tones of different frequencies and speech sounds that the elderly often confuse. In many instances the computer slows down difficult-to-discern syllables and then gradually speeds them up to match the more challenging conditions in which natural conversation occurs. Like a game, the program engages the user with funny, whimsical stories and has other built-in rewards to stoke motivation.
The earliest clinical tests of Brain Fitness, from 2006, were preliminary and regarded with caution. Sherry L. Willis, professor of human development at Pennsylvania State University, expressed doubts at the time about brain-boosting programs in general. “The researchers need to see if they can train more-complex abilities, if they’re durable over five years, and whether training on these skills will transfer to everyday functioning,” she said.
Now an expanded investigation of the Posit Science method—the largest test ever of a widely available computer-based cognitive intervention—answers most of those questions. A randomized, prospective trial, it has involved 437 people 65 and older who either received 40 hours of training with Brain Fitness or spent the same duration of time in a placebo intervention that consisted of watching educational DVDs and taking quizzes afterward. Last November at the annual meeting of the Gerontological Society of America, researchers reported results of the study. Compared with the control group, the Brain Fitness subjects increased their information processing speed (on tasks like picking out key details from a conversation) an average of 131 percent. Overall they showed a 10-year improvement in memory, so that 75-year-olds displayed the auditory recall of a typical 65-year-old. Subjects reported that they could hear better in noisy restaurants and recall names more easily; they were also less inclined to grope for words in midsentence. (Posit Science paid for the study, but some trials were conducted by outside scientists with no financial stake in the company, such as Zelinski at USC and neuropsychologist Glenn Smith at the Mayo Clinic in Rochester, Minnesota.)
Brain-plasticity training might also help older people struggling with memory disturbances of a more serious nature, according to MIT’s Gabrieli and cognitive neuroscientist Allyson Rosen at Stanford University. The two researchers evaluated the Brain Fitness program’s impact on patients diagnosed with mild cognitive impairment (MCI), a condition that typically progresses to Alzheimer’s within a few years. Six of the subjects did the standard Brain Fitness course; another six, constituting the control group, played a video game and read The New York Times. Over a two-month trial, all six subjects in the control group showed a decline in the activation of the left hippocampus, which processes auditory memory, and on average deteriorated on tests of verbal recall. In contrast, five out of the six subjects in the treatment group showed no reduction of activity in the hippocampus and on average improved their performance on verbal memory tests.
“Even though the study was very small, the findings were so robust that the results were statistically significant,” Gabrieli says. He cautions that more research is needed to confirm the benefits of the intervention, but he is enthusiastic about its potential: “The main thrust of treatment for MCI [pdf] has been drug development, but drugs have side effects and so far have not been very effective. This is a much more naturalistic approach toward rejuvenating the brain.”
It is not clear how well these results apply to other brain-plasticity tools based on games and play because Merzenich’s approach is rather different from other behavioral strategies. Most mental training programs on the market emphasize the learning of mnemonic tricks. Those may be useful for younger people, Merzenich argues, but for the older person they are like “kicking a dead horse.” A major reason cognitive function declines with age, he says, is that “the brain’s decoding process is degraded, and if you can’t fix that then you can’t restore memory.”
A young person processes about 8 to 10 auditory samples per syllable; an 80-year-old processes fewer than 2 samples per syllable. “That’s why the older individual’s understanding of speech and verbal memory are so fuzzy, and the same is true of the visual system,” Merzenich says. The only way to remedy the situation, in his view, is to speed up neural processing by challenging the brain with increasingly difficult stimuli. For his next version of Brain Fitness, Merzenich is expanding the program, which currently emphasizes auditory processing, to include exercises that strengthen visual processing as well as complex reasoning and planning. When the whole package is put together, he says, “I honestly believe we’re going to see 25 to 30 years in cognitive rejuvenation. That means the average 80-year-old will function cognitively like a 50-year-old.”
That is a grand goal, far beyond what Posit has achieved to date or what the current brain-plasticity studies have documented. But if Merzenich is right, a strenuous approach could do much more than mere fun and games to help the elderly maintain the intellectual firepower of their youth. Regular brain workouts may benefit other groups as well; strategies modeled on Brain Fitness are now being developed for youngsters with attention deficit disorder and for people suffering from head trauma, schizophrenia, and chemotherapy fog.
“We’re just at the start of figuring out what a really smart, systematic, and aggressive approach to behavioral intervention can achieve,” Gabrieli says. “It’s an exciting time.”
