This fall, Robert Reinhart of Boston University published a study finding that electrical stimulation can boost memory - and Reinhart was surprised to discover the effects lasted a full month.
Scientists believe brain circuits tend to uncouple as we age. Since brain neurons communicate by exchanging electrical impulses with each other, the breakdown of these links and associations could be what causes the “senior moment”—when you can’t remember the name of the movie you just watched.
In 2019, Boston University researchers led by Robert Reinhart, director of the Cognitive and Clinical Neuroscience Laboratory, showed that memory loss in healthy older adults is likely caused by these disconnected brain networks. When Reinhart and his team stimulated two key areas of the brain with mild electrical current, they were able to bring the brains of older adult subjects back into sync — enough so that their ability to remember small differences between two images matched that of much younger subjects for at least 50 minutes after the testing stopped.
Reinhart wowed the neuroscience community once again this fall. His newer study in Nature Neuroscience presented 150 healthy participants, ages 65 to 88, who were able to recall more words on a given list after 20 minutes of low-intensity electrical stimulation sessions over four consecutive days. This amounted to a 50 to 65 percent boost in their recall.
Even Reinhart was surprised to discover the enhanced performance of his subjects lasted a full month when they were tested again later. Those who benefited most were the participants who were the most forgetful at the start.
An older person participates in Robert Reinhart's research on brain stimulation.
Robert Reinhart
Reinhart’s subjects only suffered normal age-related memory deficits, but NIBS has great potential to help people with cognitive impairment and dementia, too, says Krista Lanctôt, the Bernick Chair of Geriatric Psychopharmacology at Sunnybrook Health Sciences Center in Toronto. Plus, “it is remarkably safe,” she says.
Lanctôt was the senior author on a meta-analysis of brain stimulation studies published last year on people with mild cognitive impairment or later stages of Alzheimer’s disease. The review concluded that magnetic stimulation to the brain significantly improved the research participants’ neuropsychiatric symptoms, such as apathy and depression. The stimulation also enhanced global cognition, which includes memory, attention, executive function and more.
This is the frontier of neuroscience.
The two main forms of NIBS – and many questions surrounding them
There are two types of NIBS. They differ based on whether electrical or magnetic stimulation is used to create the electric field, the type of device that delivers the electrical current and the strength of the current.
Transcranial Current Brain Stimulation (tES) is an umbrella term for a group of techniques using low-wattage electrical currents to manipulate activity in the brain. The current is delivered to the scalp or forehead via electrodes attached to a nylon elastic cap or rubber headband.
Variations include how the current is delivered—in an alternating pattern or in a constant, direct mode, for instance. Tweaking frequency, potency or target brain area can produce different effects as well. Reinhart’s 2022 study demonstrated that low or high frequencies and alternating currents were uniquely tied to either short-term or long-term memory improvements.
Sessions may be 20 minutes per day over the course of several days or two weeks. “[The subject] may feel a tingling, warming, poking or itching sensation,” says Reinhart, which typically goes away within a minute.
The other main approach to NIBS is Transcranial Magnetic Simulation (TMS). It involves the use of an electromagnetic coil that is held or placed against the forehead or scalp to activate nerve cells in the brain through short pulses. The stimulation is stronger than tES but similar to a magnetic resonance imaging (MRI) scan.
The subject may feel a slight knocking or tapping on the head during a 20-to-60-minute session. Scalp discomfort and headaches are reported by some; in very rare cases, a seizure can occur.
No head-to-head trials have been conducted yet to evaluate the differences and effectiveness between electrical and magnetic current stimulation, notes Lanctôt, who is also a professor of psychiatry and pharmacology at the University of Toronto. Although TMS was approved by the FDA in 2008 to treat major depression, both techniques are considered experimental for the purpose of cognitive enhancement.
“One attractive feature of tES is that it’s inexpensive—one-fifth the price of magnetic stimulation,” Reinhart notes.
Don’t confuse either of these procedures with the horrors of electroconvulsive therapy (ECT) in the 1950s and ‘60s. ECT is a more powerful, riskier procedure used only as a last resort in treating severe mental illness today.
Clinical studies on NIBS remain scarce. Standardized parameters and measures for testing have not been developed. The high heterogeneity among the many existing small NIBS studies makes it difficult to draw general conclusions. Few of the studies have been replicated and inconsistencies abound.
Scientists are still lacking so much fundamental knowledge about the brain and how it works, says Reinhart. “We don’t know how information is represented in the brain or how it’s carried forward in time. It’s more complex than physics.”
Lanctôt’s meta-analysis showed improvements in global cognition from delivering the magnetic form of the stimulation to people with Alzheimer’s, and this finding was replicated inan analysis in the Journal of Prevention of Alzheimer’s Disease this fall. Neither meta-analysis found clear evidence that applying the electrical currents, was helpful for Alzheimer’s subjects, but Lanctôt suggests this might be merely because the sample size for tES was smaller compared to the groups that received TMS.
At the same time, London neuroscientist Marco Sandrini, senior lecturer in psychology at the University of Roehampton, critically reviewed a series of studies on the effects of tES on episodic memory. Often declining with age, episodic memory relates to recalling a person’s own experiences from the past. Sandrini’s review concluded that delivering tES to the prefrontal or temporoparietal cortices of the brain might enhance episodic memory in older adults with Alzheimer’s disease and amnesiac mild cognitive impairment (the predementia phase of Alzheimer’s when people start to have symptoms).
Researchers readily tick off studies needed to explore, clarify and validate existing NIBS data. What is the optimal stimulus session frequency, spacing and duration? How intense should the stimulus be and where should it be targeted for what effect? How might genetics or degree of brain impairment affect responsiveness? Would adjunct medication or cognitive training boost positive results? Could administering the stimulus while someone sleeps expedite memory consolidation?
Using MRI or another brain scan along with computational modeling of the current flow, a clinician could create a treatment that is customized to each person’s brain.
While Sandrini’s review reported improvements induced by tES in the recall or recognition of words and images, there is no evidence it will translate into improvements in daily activities. This is another question that will require more research and testing, Sandrini notes.
Scientists are still lacking so much fundamental knowledge about the brain and how it works, says Reinhart. “We don’t know how information is represented in the brain or how it’s carried forward in time. It’s more complex than physics.”
Where the science is headed
Learning how to apply precision medicine to NIBS is the next focus in advancing this technology, says Shankar Tumati, a post-doctoral fellow working with Lanctôt.
There is great variability in each person’s brain anatomy—the thickness of the skull, the brain’s unique folds, the amount of cerebrospinal fluid. All of these structural differences impact how electrical or magnetic stimulation is distributed in the brain and ultimately the effects.
Using MRI or another brain scan along with computational modeling of the current flow, a clinician could create a treatment that is customized to each person’s brain, from where to put the electrodes to determining the exact dose and duration of stimulation needed to achieve lasting results, Sandrini says.
Above all, most neuroscientists say that largescale research studies over long periods of time are necessary to confirm the safety and durability of this therapy for the purpose of boosting memory. Short of that, there can be no FDA approval or medical regulation for this clinical use.
Lanctôt urges people to seek out clinical NIBS trials in their area if they want to see the science advance. “That is how we’ll find the answers,” she says, predicting it will be 5 to 10 years to develop each additional clinical application of NIBS. Ultimately, she predicts that reigning in Alzheimer’s disease and mild cognitive impairment will require a multi-pronged approach that includes lifestyle and medications, too.
Sandrini believes that scientific efforts should focus on preventing or delaying Alzheimer’s. “We need to start intervention earlier—as soon as people start to complain about forgetting things,” he says. “Changes in the brain start 10 years before [there is a problem]. Once Alzheimer’s develops, it is too late.”
Q. We are sitting here in the so-called pop-up network state Zuzalu temporarily realized in the village of Lusticia Bay by the beautiful Mediterranean Sea. To me this is an entirely new concept: What is a network state?
A. A network state is a highly aligned online community that has a level of in-person civility; it crowd-funds territory, and it eventually seeks diplomatic recognition. In a way it's about starting a new country. The term was coined by the crypto influencer and former CTO of Coinbase Balaji Srinivasan in a book by the same title last year [2022]. What many people don't know is that it is a more recent addition or innovation in a space called competitive governance. The idea is that you have multiple jurisdictions competing to provide you services as a customer. When you have competition among governments or government service providers, these entities are forced to provide you with a better service instead of the often worse service at higher prices or higher taxes that we're currently getting. The idea went from seasteading, which was hardly feasible because of costs, to charter cities getting public/private partnerships with existing governments and a level of legal autonomy, to special economic zones, to now network states.
Q. How do network states compare to charter cities and similar jurisdictions?
A. Charter cities and special economic zones were legal forks from other existing states. Dubai, Shenzhen in China, to some degree Hong Kong, to some degree Singapore are some examples. There's a host of other charter cities, one of which I'm based in myself, which is Prospera located in Honduras on the island Roatán. Charter cities provide the full stack of governance; they provide new laws and regulations, business registration, tax codes and governance services, Estonia style: you log on to the government platform and you get services as a citizen.
When conceptualizing network states, Balagi Srinivasan turns the idea of a charter city a bit on its head: he doesn't want to start with this full stack because it's still very hard to get these kinds of partnerships with government. It's very expensive and requires lots of experience and lots of social capital. He is saying that network states could instead start as an online community. They could have a level of alignment where they trade with each other; they have their own economy; they meet in person in regular gatherings like we're doing here in Zuzulu for two months, and then they negotiate with existing governments or host cities to get a certain degree of legal autonomy that is centered around a moral innovation. So, his idea is: don't focus on building a completely new country or city; focus on a moral innovation.
Q. What would be an example of such a moral innovation?
A. An example would be longevity—life is good; death is bad—let's see what we can do to foster progress around that moral innovation and see how we can get legal forks from the existing system that allow us to accelerate progress in that area. There is an increasing realization in the science that there are hallmarks of aging and that aging is a cause of other diseases like cancer, ALS or Alzheimer's. But aging is not recognized as a disease by the FDA in the United States and in most countries around the world, so it's very hard to get scientific funding for biotechnology that would attack the hallmarks of aging and allow us potentially to reverse aging and extend life. This is a significant shortcoming of existing government systems that groups such as the ones that have come together here in Montenegro are now seeking alternatives too. Charter cities and now network states are such alternatives.
Q. Would it not be better to work within the current systems, and try to improve them, rather than abandon them for new experimental jurisdictions?
A. There are numerous failures of public policies. These failures are hard, if not impossible, to reverse, because as soon as you have these policies, you have entrenched interests who benefit from the regulations. The only way to disrupt incumbent industries is with start-ups, but the way the system is set up makes it excessively hard for such start-ups to become big companies. In fact, larger companies are weaponizing the legal system against small companies, because they can afford the lawyers and the fixed cost of compliance.
I don't believe that our institutions in many developed countries are beyond hope. I just think it's easier to change them if you could point at successful examples. ‘Hey, this country or this zone is already doing it very successfully’; if they can extend people’s lifespan by 10 years, if they can reduce maternal mortality, and if they have a massive medical tourism where people come back healthier, then that is just very embarrassing for the FDA.
Q. Perhaps a comparison here would be the relationship between Hong Kong and China?
A. Correct, so having Hong Kong right in front of your door … ‘Hey, this capitalism thing seems to work, why don't we try it here?’ It was due to the very bold leadership by Deng Xiaoping that they experimented with it in the development zone of Shenzhen. It worked really well and then they expanded with more special economic zones that also worked.
Próspera is a private city and special economic zone on the island of Roatán in the Central American state of Honduras.
Q. Tell us about Prospera, the charter city in Honduras, that you are intimately connected with.
A. Honduras is a very poor country. It has a lot of crime, never had a single VC investment, and has a GDP per capita of 2,000 per year. Honduras has suffered tremendously. The goal of these special economic zones is to bring in economic development. That's their sole purpose. It's a homegrown innovation from Honduras that started in 2009 with a very forward-thinking statesman, Octavio Sanchez, who was the chief of staff to the president of Honduras, and then president. He had his own ideas about making Honduras a more decentralized system, where more of the power lies in the municipalities.
Inspired by the ideas of Nobel laureate economist Paul Romer, who gave a famous Ted Talk in 2009 about charter cities, Sanchez initiated a process that lasted for years and eventually led to the creation of a special economic zone legal regime that’s anchored in the Hunduran constitution that provides the highest legal autonomy in the world to these zones. There are today three special economic zones approved by the Honduran government: Prospera, Ciudad Morazan and Orchidea.
Q. How did you become interested and then involved in Prospera?
A. I read about it first in an article by Scott Alexander, a famous rationalist blogger, who wrote a very long article about Prospera, and I thought, this is amazing! Then I came to Prospera and I found it to be one of the most if not the most exciting project in the world going on right now and that it also opened my heart to the country and its people. Most of my friends there are Honduran, they have been working on this for 10 or more years. They want to remake Honduras and put it on the map as the place in the world where this legal and governance innovation started.
Q. To what extent is Prospera autonomous relative to the Honduran government?
A. What's interesting about the Honduran model is that it's anchored within the Honduran constitution, and it has a very clear framework for what's possible and what's not possible, and what's possible ensures the highest degree of legal autonomy anywhere seen in the world. Prospera has really pushed the model furthest in creating a common law-based polycentric legal system. The idea is that you don't have a legislature, instead you have common law and it's based on the best practice common law principles that a legal scholar named Tom W. Bell created.
One of the core ideas is that as a business you're not obligated to follow one regulatory monopoly like the FDA. You have regulatory flexibility so you can choose what you're regulated under. So, you can say: ‘if I do a medical clinic, I do it under Norwegian law here’. And you even have the possibility to amend it a bit. You're still required to have liability insurance, and have to agree to binding arbitration in case there's a legal dispute. And your insurance has to approve you. So, under that model the insurance becomes the regulator and they regulate through prices. The limiting factor is criminal law; Honduran criminal law fully applies. So does immigration law. And we pay taxes.
Q. Is there also an idea of creating a kind of healthy living there, and encourage medical tourism?
A. Yes, we specifically look for legal advantages in autonomy around creating new drugs, doing clinical trials, doing self-medication and experimentation. There is a stem cell clinic here and they're doing clinical trials. The island of Roatán is very easily accessible for American tourists. It's a beautiful island, and it's for regulatory reasons hard to do stem cell therapies in the United States, so they're flying in patients from the United States. Most of them are very savvy and often have PhDs in biotech and are able to assess the risk for themselves of taking drugs and doing clinical trials. We're also going to get a wellness center, and there have been ideas around establishing a peptide clinic and a compound pharmacy and things like that. We are developing a healthcare ecosystem.
Q. This kind of experimental tourism raises some ethical issues. What happens if patients are harmed? And what are the moral implications for society of these new treatments?
A. As a moral principle we believe in medical freedom: people have rights over their bodies, even at the (informed) risk of harm to themselves if no unconsenting third-parties are harmed; this is a fundamental right currently not protected effectively.
What we do differently is not changing ethical norms around safety and efficacy, we’re just changing the institutional setup. Instead of one centralized bureaucracy, like the FDA, we have regulatory pluralism that allows different providers of safety and efficacy to compete under market rules. Like under any legal system, common law in Prospera punishes malpractice, fraud, murder etc. This system will still produce safe and effective drugs, and it will still work with common sense legal notions like informed consent and liability for harm. There are regulations for medical practice, there is liability insurance and things like that. It will just do so more efficiently than the current way of doing things (unless it won’t, in which case it will change and evolve – or fail).
A direct moral benefit ´to what we do is that we increase accessibility. Typical gene therapies on the market cost $1 million dollars in the US. The gene therapy developed in Prospera costs $25,000. As to concern about whether such treatments are problematic, we do not share this perspective. We are for advancing science responsibly and we believe that both individuals and society stand to gain from improving the resiliency of the human body through advanced biotechnology.
Q. How does Prospera relate to the local Honduran population?
A. I think it's very important that our projects deliver local benefits and that they're well anchored in local communities. Because when you go to a new place, you're seen as a foreigner, and you're seen as potentially a danger or a threat. The most important thing for Prospera and Ciudad Morazan is to show we're creating jobs; we're creating employment; we're improving people's lives on the ground. Prospera is directly and indirectly employing 1,100 people. More than 2/3 of the people who are working for Prospera are Honduran. It has a lot of local service workers from the island, and it has educated Hondurans from the mainland for whom it's an alternative to going to the United States.
Q. What makes a good Prosperian citizen?
A. People in Prospera are very entrepreneurial. They're opening companies on a small scale. For example, Vehinia, who is the cook in the kitchen at Prospera, she's from the neighboring village and she started an NGO that is now funding a school where children from the local village can go to instead of a school that's 45 minutes away. There's very much a spirit of ‘let's exchange and trade with each other’. Some people might see that as a bit too commercial, but that's something about the culture that people accept and that people see as a good thing.
Q. Five years from now, if everything goes well, what do we see in Prospera?
A. I think Prospera will have at least 10,000 residents and I think Honduras hopefully will have more zones. There could be zones with a thriving industrial sector and sort of a labor-intensive economy and some that are very strong in pharmaceuticals, there could also be other zones for synthetic biology, and other zones focused on agriculture. The zones of Prospera, Ciudad Morazan and Orchidea are already showing the results we want to see, the results that we will eventually be measured by, and I'm tremendously excited about Honduras.
Through her research and companies, Dr. Picard has developed wearable sensors, algorithms and systems for sensing, recognizing and responding to information about human emotion. Her products are focused on using fitness trackers to advance clinical quality treatments for a range of conditions.
Meanwhile, in just the past few years, numerous fitness tracking companies have released products with their own stress sensors and systems. You may have heard about Fitbit’s Stress Management Score, or Whoop’s Stress Monitor – these features and apps measure things like your heart rhythm and a certain type of invisible sweat to identify stress. They’re designed to raise awareness about forms of stress such as anxieties and anger, and suggest strategies like meditation to relax in real time when stress occurs.
But how well do these off-the-shelf gadgets work? There’s no one more knowledgeable and experienced than Rosalind Picard to explain the science behind these stress features, what they do exactly, how they might be able to help us, and their current shortcomings.
Dr. Picard is a member of the National Academy of Engineering and a Fellow of the National Academy of Inventors, and a popular speaker who’s given over a hundred invited keynote talks and a TED talk with over 2 million views. She holds a Bachelors in Electrical Engineering from Georgia Tech, and Masters and Doctorate degrees in Electrical Engineering and Computer Science from MIT. She lives in Newton, Massachusetts with her husband, where they’ve raised three sons.
In our conversation, we discuss stress scores on fitness trackers to improve well-being. She describes the difference between commercial products that might help people become more mindful of their health and products that are FDA approved and really capable of advancing the science. We also talk about several fascinating findings and concepts discovered in Dr. Picard’s lab including the multiple arousal theory, a phenomenon you’ll want to hear about. And we explore the complexity of stress, one reason it’s so tough to measure. For example, many forms of stress are actually good for us. Can fitness trackers tell the difference between stress that’s healthy and unhealthy?
Show links:
- Dr. Picard’s book, Affective Computing
- Dr. Picard’s bio
- Dr. Picard on Twitter
- Dr. Picard’s company, Empatica - https://www.empatica.com/ - The FDA-cleared Empatica Health Monitoring Platform provides accurate, continuous health insights for researchers and clinicians, collected in the real world
- Empatica Twitter
- Dr. Picard and her team have published hundreds of peer-reviewed articles across AI, Machine Learning, Affective Computing, Digital Health, and Human-computer interaction.
- Dr. Picard’s TED talk
Rosalind Picard