The perfectibility of the human mind is a theme that has captured our imagination for centuries—the notion that, with the right tools, the right approach, the right attitude, we might become better, smarter versions of ourselves. We cling to myths like “the 10 percent brain”—which holds that the vast majority of our thinking power remains untapped—in part because we hope the minds of the future will be stronger than those of today. It’s as much a personal hope as a hope for civilization: If we’re already running at full capacity, we’re stuck, but what if we’re using only a small fraction of our potential? Well, then the sky’s the limit.

But this dream has a dark side: The possibility of a dystopia where an individual’s fate is determined wholly by his or her access to cognition-enhancing technology. Where some ultra-elites are allowed to push the limits of human intelligence, while the less fortunate lose any chance of upward mobility. Where some Big Brother–like figure could gain control of our minds and decide how well we function.

What’s possible now, and what may one day be? In a series of conversations with neuroscientists and futurists, I glimpsed a vision of a world where cognitive enhancement is the norm. Here’s what that might look like, and how we can begin thinking about the implications.

Personalized Smart Pills

In many ways, we’re already living in a world of constant neuroenhancement. There’s methylphenidate (a k a Ritalin), intended to treat ADHD and narcolepsy and now used by test takers and paper-writers the world over. In controlled trials, the drug has been shown to improve memory, concentration, and motivation in individuals who have no cognitive impairment. There’s modafinil, developed to treat narcolepsy and other sleep disorders. In people who have gotten a full night’s rest, it has been shown to increase executive function, memory, and attention—and in those who have gone without much sleep, it has helped stave off symptoms of sleep deprivation. There’s also donepezil, developed to treat Alzheimer’s. Like other anti-dementia drugs, it has been shown in clinical trials to improve both verbal and procedural memory (the memory we use to perform a complex set of actions, like driving a car) in healthy individuals.

None of these, of course, is the mythical “smart pill,” a supplement we could take to instantly boost our IQ by 10 points. Instead, each targets specific components of intellectual output: memory, concentration, motivation. And sometimes those functions come at the expense of others. Increase concentration with Ritalin, for instance, and your creativity could suffer. But the day may come, says Guoping Feng, a neuroscientist at MIT, when we understand neural mechanisms well enough to design personalized pills that can bolster your particular strengths and minimize your weaknesses. Several biotech companies are looking to do just that.

Give Yourself a Jolt

The idea of using electric currents to change brain function is not new—the electroconvulsive therapies of yore were based on the concept—but in recent years we’ve gotten much better at controlling where that current goes and how much of it is administered. Today’s electric stimulation is the fine watercolor to electroshock therapy’s finger painting.

The most common approach, transcranial direct-current stimulation, or tDCS, involves applying a small current to the scalp in order to modulate brain activity. It has gotten a lot of attention lately, and with good reason: In several recent studies, tDCS appears to improve concentration, problem-solving ability, and working memory (which enables us to hold in our minds the information we need to carry out a complicated task). The effects can last anywhere from 30 minutes to two hours.

Jamie Tyler, an Arizona State University neuroscientist, co‑founded a company called Thync because he was inspired by the potential benefits of brain modulation. Thync has developed a prototype device, tested on more than 3,000 people to date, that can either calm us down or give us a boost of energy—providing an avenue toward concentration or creative association, respectively. “It’s just another tool to be able to navigate your daily life,” says Tyler—akin to a cup of coffee during a late-night cram session or a few minutes of meditation before a big presentation. (Some kinks remain, though: When I tested a beta prototype in Thync’s Boston office, I received a mild electric shock to the head instead of the promised calming vibe. A failure of a software update and not the device itself, I was told.)

A Pacemaker for Your Head

Another option is to install electrodes deep inside your brain, to stimulate areas that tDCS cannot reliably reach. Deep-brain stimulation is already used to treat Parkinson’s disease as well as some severe cases of depression. A surgeon inserts electrodes directly into the brain—the location depends on the intent—and connects them to a device in the chest that resembles a pacemaker. That device can then regulate the brain’s electrical impulses and chemical levels via the electrodes. Applications of deep-brain stimulation may someday be more enhancing than therapeutic: in 2013, a team from UCLA showed that the procedure could buttress memory and improve the ability to process and store information, and this spring, a study using rats determined that it could potentially stave off memory loss and dementia-like symptoms. In other words, in addition to making us smarter, deep-brain stimulation could also ensure that we remain smart for longer.

Direct Connections

Electrodes aren’t the only things we may someday start implanting in our brains. Consider what you could do with a chip in your head that linked directly to the Internet: Within milliseconds, you could retrieve just about any piece of information. And with the collective knowledge of the Web at your disposal, you could quickly fill in your brain’s normal memory gaps—no one would ever guess you slept through that economics seminar. That’s the (distant) future envisioned by people like Anders Sandberg, a computational neuroscientist and self-described transhumanist at Oxford’s Future of Humanity Institute. Sandberg believes in the possibility of the extended mind, a way of transcending our cognitive limits through brain implants. And why stop at the Internet? A future mind could potentially connect directly to other future minds. Whether such connections would make us smarter or just overwhelm and confuse us—we’ll have to wait and see.

Designer Brains

Down the road, the most controversial approach to neuroenhancement could be a way not of stimulating the brain but of reengineering it. Until a few years ago, such a possibility was purely theoretical, the realm of philosophical debates and ethical quandaries. Now, however, researchers have developed a genome-editing technology called crispr (or, more technically, Cas9), which scientists could use to change any part of an embryo’s genome, one nucleotide at a time. It was developed to fight disease by correcting mutations before a baby is born. But one can imagine a day when we are able to identify genes associated with cognitive ability and manipulate them for higher output. Granted, that day is a long way off. “There’s no single gene for intelligence. We can’t just go in and change one gene and become cognitively enhanced,” Feng says. What we can do now is gain a deeper knowledge of the relationship between the genome and brain function—and perhaps in a few decades, we’ll be in a position to evaluate whether such tinkering is a good idea.

When that day comes, health concerns may overshadow the ethical considerations around engineering supersmart babies. The truth is that we have no idea what the long-term effects of any artificial enhancement may be. Will our brains be able to withstand running at artificially heightened capacity? “There’s a discussion going on that our brains have evolved over millions of years and might already be at optimal neurochemical equilibrium, and any attempt to change something there can only do harm and can’t strongly enhance brain function,” Martin Dresler, a German neuroscientist who studies cognitive enhancement, told me. If that’s the case, ethics could be the least of our worries.

A Brief Chronicle of Understanding Intelligence

1800s: Craniometry—the practice of measuring skulls to determine intelligence and other traits—is widespread.

1905: The Binet-Simon test, a precursor to the modern IQ test, is introduced.

1946: Mensa, the society for people with high IQs, is formed.

1962: The MIT scientist Joseph Altman discovers that our brains generate new nerve cells well into adulthood.

1970s: CT scans, pet scans, and later, fMRI technology lead to new discoveries about how the brain works.

1984: The philosopher James R. Flynn observes that IQ scores have been steadily rising for decades.

2065: Personalized intelligence-boosting pills hit the market.