Learning About Learning
One of the most intriguing challenges facing the neurotech industry has been to enhance learning and memory, either as a rehabilitation therapy for individuals with brain disorders, or as a way to improve cognitive performance in nonimpaired people. As we report on page 1 of this issue, the Pentagon has taken a deep interest in using neurotechnology to exploit cortical plasticity and has funded research at seven U.S. institutions as part of its Targeted Neuroplasticity Training program.
One of the pioneers in the field of cortical plasticity was Michael Merzenich of UC San Francisco, who founded the firm Posit Science to use software and games to exploit cortical plasticity. The company conducted numerous research studies that demonstrate the effectiveness of its brain training techniques. Since that time, several other firms have sprung up offering brain games to enhance brain function.
But there is considerable disagreement in the field as to whether brain-training apps can reliably improve cognitive performance. A recent article in the journal Frontiers in Aging Neuroscience from a team at Florida State University found little evidence to support that claim. “Our findings and previous studies confirm there’s very little evidence these types of games can improve your life in a meaningful way,” said Wally Boot, an expert on age-related cognitive decline and one of the paper’s authors. The FSU team’s study focused on whether brain games could boost the “working memory” needed for a variety of tasks.
Meanwhile, Posit cited a recently published Australian study that concluded that “current evidence supports that at least some commercially available computerized brain training products can assist in promoting healthy brain aging.” Posit’s BrainHQ product met that study’s criteria for the highest level of scientific evidence.
Regardless of whether brain training games alone can improve cognitive performance, there is a mounting evidence that brain stimulation coupled with cognitive training regimens can produce significant improvements in mental function in both impaired and nonimpaired individuals. Dan Rizzuto’s team at Penn recently published a paper in Current Biology demonstrating that appropriately timed cortical stimulation can improve memory formation in impaired individuals, although stimulation inappropriately timed can produce the opposite effect.
And therein lies the rub. Whether investigators are using implanted or noninvasive stimulation, tDCS, or VNS, and whether in impaired or nonimpaired populations, the challenge will be to identify the optimal location, timing, and stimulation parameters to produce the desired effect. Clearly, more studies are called for. But it will also be useful to develop models that explain and predict how neurostimulation impacts cognitive performance.
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