The rule that “neurons that fire together, wire together” suggests that cognitive training should boost mental prowess. Studies are finding just that, but with a crucial caveat. Training your memory, reasoning, or speed of processing improves that skill, found a large government-sponsored study called ACTIVE. Unfortunately, there is no transfer: improving processing speed does not improve memory, and improving memory does not improve reasoning. Similarly, doing crossword puzzles will improve your ability to?.?.?.?do crosswords. “The research so far suggests that cognitive training benefits only the task used in training and does not generalize to other tasks,” says Columbia’s Yaakov Stern.
The holy grail of brain training is something that does transfer, and here there are three good candidates. The first is physical exercise. Simple aerobic exercise, such as walking 45 minutes a day three times a week, improves episodic memory and executive-control functions by about 20 percent, finds Art Kramer of the University of Illinois at Urbana-Champaign. His studies have mostly been done in older adults, so it’s possible the results apply only to people whose brain physiology has begun to deteriorate—except that that happens starting in our 20s. Exercise gooses the creation of new neurons in the region of the hippocampus that files away experiences and new knowledge. It also stimulates the production of neuron fertilizers such as BDNF, as well as of the neurotransmitters that carry brain signals, and of gray matter in the prefrontal cortex. Exercise stimulates the production of new synapses, the connections that constitute functional circuits and whose capacity and efficiency underlie superior intelligence. Kramer finds that a year of exercise can give a 70-year-old the connectivity of a 30-year-old, improving memory, planning, dealing with ambiguity, and multitasking. “You can think of fitness training as changing the molecular and cellular building blocks that underlie many cognitive skills,” he says. “It thus provides more generalizable benefits than specifically training memory or decision making.”
The second form of overall mental training is meditation, which can increase the thickness of regions that control attention and process sensory signals from the outside world. In a program that neuroscientist Amishi Jha of the University of Miami calls mindfulness-based mind-fitness training, participants build concentration by focusing on one object, such as a particular body sensation. The training, she says, has shown success in enhancing mental agility and attention “by changing brain structure and function so that brain processes are more efficient,” the quality associated with higher intelligence.
Finally, some videogames might improve general mental agility. Stern has trained older adults to play a complex computer-based action game called Space Fortress, which requires players to shoot missiles and destroy the fortress while protecting their spaceship against missiles and mines. “It requires motor control, visual search, working memory, long-term memory, and decision making,” he says. It also requires that elixir of neuroplasticity: attention, specifically the ability to control and switch attention among different tasks. “People get better on tests of memory, motor speed, visual-spatial skills, and tasks requiring cognitive flexibility,” says Stern. Kramer, too, finds that the strategy-heavy videogame Rise of Nations improves executive-control functions such as task switching, working memory, visual short-term memory, and reasoning in older adults.