Martha Farah, Ph.D., Walter H. Annenberg Professor of Natural Sciences at the University of Pennsylvania, is a cognitive neuroscientist who works on problems at the interface of neuroscience and society.
Sandra Aamodt: How is neuroscience changing the way we think of ourselves as human beings?
Martha Farah: The science is showing us that our behavior can be understood in physical, mechanistic terms. This is quite a jarring change of perspective on ourselves. Our age-old intuitions are that people behave as they do because of their reasons, while objects behave because of causes. If you ask, “Why is Martha talking to me?”, the most natural answer would be something like “She believes we will have an interesting discussion” or “She would like to have her interview on the Being Human site.” But if you ask “Why did the bell ring, or crack, when struck?” the answer will be something about the shape of the bell, the properties of the material, and the forces applied to it. Neuroscience is showing us that human behavior can also be explained in physical terms. What seemed like a big wide metaphysical divide between human beings and other objects or systems seems to close right up!
Seeing ourselves as behaving for causes rather than reasons has all kinds of ramifications, from legal ones to more general moral ones to trying to make sense of the meaning of your own life. Seeing yourself as being along for the ride while your brain does what it has to do for physical reasons—because of the genetics it starts with and the experiences it’s had—is very different from the view of yourself as an active agent. From the neuroscience perspective, we can view bad things and good things as less personal, less our failings, less our successes, and more the results of understandable neural processes.
This dual perspective is pretty mind-boggling, at least to me. I think we can understand the mechanistic view, and we can understand the persons-with-reasons view, but we are just dumbfounded by the fact that they both seem to be valid. This makes sense evolutionarily. We evolved intellectual abilities to reason about the natural world, which have given us the modern neuroscience understanding of human beings, but we also evolved tendencies to understand reasons and to value our lives, other people, to find things funny or sad or beautiful or despicable. You can see the evolutionary pressure for each of these two separate systems. But there is no apparent evolutionary pressure to have them work with each other in any coordinated way.
Sandra Aamodt: What about improving our capacities with cognitive enhancement drugs? It sounds exciting, but I’ve heard scientists say that our current options are no better than caffeine.
Martha Farah: That’s not a bad summary. People with ADHD have trouble with executive function: working memory, shifting from one set of instructions to another, inhibitory control. If medications such as Ritalin and Adderall (methylphenidate and amphetamine) make people with deficient executive function better, then they might make people with normal executive function extra good. That does seem worth a try.
In the literature on cognitive enhancement, the most frequently cited papers find positive results with these drugs. But when negative results get published, nobody pays attention. Last year I reviewed the research on ADHD medications in normal, healthy people, and I became much less certain that there is much of an enhancing effect of these drugs. There’s a mix of negative results, which in many cases don’t get published, and positive results that make it look like these drugs have a big effect by chance because they didn’t test many people. I think there is a positive effect for some people, but the effects are probably small.
Sandra Aamodt: Do you think the effects are important enough to matter in real life?
Martha Farah: Nobody knows how a small increase in working memory capacity, for instance, translates into school performance or workplace performance. In a winner-take-all situation, if you can get the tiniest edge over the competition, you may get the scholarship—the whole scholarship, not just slightly more of it.
Much of what these stimulant drugs seem to do is amp up the motivation to work. Students feel as though they have a lot of energy, the work is interesting, and they’re motivated to do it. They say they have to be careful once they’ve taken one of these pills that they don’t let themselves get interested in something else, like talking to a friend or tidying their apartment, because whatever they’re doing, they do with great energy and sustained effort and determination.
Sandra Aamodt: Some people say that on methylphenidate they have a hard time switching tasks.
Martha Farah: Students report being amazed by how long they can study or work on a single project when they’re on these drugs, which is a little different from a “smart pill” but it certainly could help a person with work. The study that comes closest to capturing that effect was one that Nora Volkow did with methylphenidate. When the subjects weren’t doing anything, there was no effect of the drug, but when they were doing tedious mental arithmetic, they felt like “Oh, I’m really enjoying this math problem” on the drug and not on the placebo. That could be important in the real world. We’ve all got boring stuff that we don’t want to do.
Sandra Aamodt: If the effects are small, how do we account for the glowing testimonials from users?
Martha Farah: One of the effects of stimulants is to make you believe you’re doing better. We have a study coming out in Neuropharmacology reporting that amphetamine failed to enhance any of a dozen cognitive tasks, but people reliably thought they did better when given Adderall compared to the placebo. It’s not a simple placebo effect, like “Oh, I’ve taken a pill, so I’m going to do better,” because both groups had taken a pill. Students have told me that they just feel tremendous enthusiasm and confidence when they’re on the drug.
Of course, there may still be ways that these drugs could be said to enhance cognition. Many people, including the ambitious types, are sleep deprived. A very few people only need five or six hours a night, but most of us need more. Sleep-deprived people might be getting rescue of cognition that is impaired, not enhancement of normal cognition. Likewise if their idea of a great day is working for sixteen hours, then the pill is enhancing performance by letting them avoid feeling tired.
Sandra Aamodt: Should we worry that these drugs might harm healthy people?
Martha Farah: If we’re talking about the traditional ADHD stimulants, there are most definitely side effects, including cardiac problems and psychoses, which are not common, but they’re serious. There’s also the risk of addiction or dependence, because these drugs do cause dopamine release in the nucleus accumbens, like other addictive drugs. Most students aren’t using them for enhancement every day, which probably helps keep them safer. But I’m not an expert on addiction. I know that some addiction experts are quite concerned.
Sandra Aamodt: What about another form of cognitive enhancement, transcranial direct current stimulation?
Martha Farah: I haven’t looked carefully at that literature, but my colleagues who do tDCS think you can get measurable cognitive enhancement in the lab, for everything from learning and memory to mathematical cognition, changes in decision-making, impulsiveness.
Sandra Aamodt: The descriptions of how tDCS feels seem consistent with the idea that it also increases focus.
Martha Farah: Roy Hamilton, a neurology professor at Penn, is currently comparing tDCS to amphetamine for enhancing attentional focus. I’m looking forward to learning what he finds. He and I have spoken about the do-it-yourselfers with tDCS.
Sandra Aamodt: I’ve seen instructions online for how to build your own tDCS machine. Are those people getting out ahead of the science?
Martha Farah: Yes, they absolutely are. Transcranial magnetic stimulation, a related technique, has recognized therapeutic effects, but right now tDCS is a research tool. We’re nowhere near having data from clinical trials to say “If you’re this kind of person and you want that kind of result, then you need the anode there and the cathode there.” It’s funny to me that there are people who are wary of pills but feel comfortable running currents through their brains.
Sandra Aamodt: As far as you know, nobody’s tested the long-term safety?
Martha Farah: The way that the FDA regulates devices is more relaxed than the way they regulate medicines. And of course even with drugs we often lack long-term studies. You can’t run a placebo-controlled trial for years, and it is hard to tease apart effects of treatment from other things like severity of illness, compliance with medical advice, and so forth when you’re looking at naturalistic long-term studies. That said, my Penn colleagues have a lot of experience with TMS and tDCS and believe them to be safe when used properly. They zap themselves regularly.
Sandra Aamodt: Does the growing use of cognitive enhancement threaten to increase the gap between the haves and the have-nots?
Martha Farah: It’s definitely a contributing factor and will be more so. Only the gap is so huge already, related to childhood experiences and educational opportunities, that I’m not sure this is going to register much against all the pre-existing social inequities.
The social effect that I’m more concerned about, with cognitive enhancement, is the ratcheting up of performance standards. It’s crazy that people who are well educated, who have the luxury of studying full-time, feel like they have to work even harder and longer.
Sandra Aamodt: Now I’d like to switch gears to another neuroethics interest of yours, criminal justice. What are the prospects for using neuroscience to predict criminal behavior?
Martha Farah: Neuroscience is contributing to the understanding of criminal behavior, but as far as I know, it hasn’t given us any edge over traditional methods for predicting offending and recidivism, with measures like criminal record, age, sex, socioeconomic status, features of previous crimes, and psychopathy score. Adrian Raine and others are working on long-range prediction of crime and antisocial behavior. They’re trying to figure out which difficult kids are on a trajectory to be lifelong criminals and which ones might stay a little difficult but won’t be breaking laws and transgressing moral boundaries. The recent article in the New York Times Magazine, about early identification of psychopaths, was interesting. Neuroscience is not yet presenting us with the problem of having to decide whether to use these methods and intervene with therapies or even preventive detentions. It wouldn’t surprise me if in another twenty years we will have good predictors, though we’ll never know for sure like in the movie Minority Report.
Sandra Aamodt: What about after people have been convicted of a crime? Does what we know about the brain help us to figure out how to keep them from reoffending?
Martha Farah: I think that’s one of the sleeper issues of neuroethics. If we get effective interventions by means of pills or other methods of brain modification, should we offer them to offenders or even require offenders to participate? You can certainly imagine ways in which that kind of a program could be terribly creepy, like Soviet psychiatry as a tool to silence dissidents. On the other hand, we have a long tradition of trying to rehabilitate as part of the criminal justice system. If there are treatments that help people stay on the right side of the law, then maybe they should be offered. Maybe they should even be required. It’s a question that we need to think about.
Sandra Aamodt: It’s hard to get informed consent to a medical procedure when the alternative is a long prison sentence.
Martha Farah: Yes, it’s not exactly a free choice. But a long sentence, without any choice, is also coercive. We’re saying, “Too bad. We’re locking you up.” Relative to the choices that this person has, we could be giving them more choices.
Sandra Aamodt: My last question is a personal one. How has what you’ve learned about science changed the way you live your life?
Martha Farah: From my own work and the research literature, I’ve concluded that the high-tech methods of cognitive enhancement are not that effective. What neuroscience shows to be helpful are traditional things like getting exercise, a good night’s sleep, spending time with friends, and meditation. There’s interesting work on all of these things in relation to brain function. Reading about those studies has increased my efforts to get exercise and turned me into a meditator, which I find incredibly helpful.
Sandra Aamodt: How often do you meditate?
Martha Farah: I try to do it every day. If I get out of the habit for a week, I notice it mainly in my mood but also in my ability to focus and deal with life’s demands. Then if I start up again, the benefits come right back. I don’t meditate for very long, 15 minutes a day, and that is incredibly powerful. If they could put those effects in a pill, it would be a blockbuster drug.