With apologies to the political-correctness police, nicotine enhances attention — that key driver of neuroplasticity — and cognitive performance in both smokers and nonsmokers, scientists at the National Institute on Drug Abuse reported in a 2010 analysis of 41 double-blind, placebo-controlled studies. Nicotine, they found, has “significant positive effects” on fine motor skills, the accuracy of short-term memory, some forms of attention, and working memory, among other basic cognitive skills. The improvements “likely represent true performance enhancement” and “beneficial cognitive effects.” The reason is that nicotine binds to the brain receptors for the neurotransmitter acetylcholine that are central players in cortical circuits. (Caveat: smoking also increases your risk of dementia, so while cigarettes may boost your memory and attention now, you could pay for it later. To be determined: whether a nicotine patch delivers the benefits without the risks.)
Neuroscience supports the cognitive benefits of stimulants like Adderall and Ritalin, too, at least in some people for some tasks. Both drugs (as well as caffeine) raise the brain levels of dopamine, the juice that produces motivation and the feeling of reward. On balance, finds psychologist Martha Farah of the University of Pennsylvania, studies show that both drugs enhance the recall of memorized words as well as working memory (the brain’s scratchpad, which plays a key role in fluid intelligence). They do not improve verbal fluency, reasoning, or abstract thought, however, nor provide much benefit to people with a gene variant that keeps dopamine activity high, Farah found in a recent study.
These limitations suggest two things. First, if you’re naturally awash in dopamine and are highly motivated to, say, deduce from its source code how a website was built, then increasing dopamine levels pharmacologically is unlikely to help. Farah found no difference between the performance of volunteers given Adderall and volunteers given a placebo on a battery of cognitive tasks, suggesting that you can get the same dopamine-boosting benefits of the drug by simply believing that you’ll do well, which itself releases dopamine. Second, the divide between the mental functions that drugs do and don’t improve suggests that psychological factors such as motivation and reward help with memory, but not higher-order processes such as abstract thought. The drugs “will help some people some of the time, but maybe not by a whole lot,” she concludes. Fun fact for anyone hoping for IQ in a pill: a recent survey of doctors finds they’re more comfortable prescribing sex drugs than smart drugs.
Knowing that Adderall and Ritalin work, when they do, by giving you motivation and a sense of reward from, say, solving a Sudoku puzzle implies that other ways to achieve those feelings will also boost mental performance. That’s probably the mechanism by which a whole slew of tricks work. Take, for instance, the “ancestor effect.” As a paper to be published in the European Journal of Social Psychology reports, “thinking about our genetic origin” — how Grandpa survived the Depression, how Great-Grandma eluded the Cossacks, et al. — “enhances intellectual performance.” The mechanism responsible for that is an increase in confidence and motivation — Adderall without the prescription. Along the same lines, a positive mood — even the kind that comes from watching “Sneezing Panda” on YouTube — can enhance creative problem-solving, finds a new paper in Psychological Science. In this case, reducing stress and the resulting cortisol, which attacks the myelin sheath that coats neurons and thus impairs signal transmission, allows underlying abilities to reach their full potential. Finally, being told that you belong to a group that does very well on a test tends to let you do better than if you’re told you belong to a group that does poorly; the latter floods you with cortisol, while the former gives you the wherewithal and dopamine surge to keep plugging away.
But there’s a difference between reaching your natural potential by removing impediments such as stress and actually raising that potential. The latter requires tapping into one of the best-established phenomena in neuroscience—namely, that the more you use a circuit, the stronger it gets. As a result, a skill you focus and train on improves, and even commandeers more neuronal real estate, with corresponding improvements in performance. London cabdrivers who memorize that city’s insanely confusing streets (25,000 of them) have a larger posterior hippocampus, the region that files spatial memories, than the average Londoner, neuroscientist Eleanor Maguire of University College London discovered in 2003. Conversely, if we offload our navigational ability onto GPS, we’ll lose it.
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 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.