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How to Build a More Resilient Brain

Your executive control center has helped your mental health survive the pandemic thus far. Here’s how to strengthen it for the future.

A Lot has been written (including by this reporter) about the mental health toll of the pandemic, and for good reason. The latest numbers from the National Pulse Survey, a weekly mental health screen conducted by the National Center for Health Statistics and the U.S. Census Bureau, estimate that nearly 40% of Americans are currently experiencing symptoms of either anxiety or depression, a 50% increase over pre-pandemic times.

In some ways, though, it’s surprising that this number isn’t even higher given the stress, trauma, loss, and loneliness of the past year. The vast majority of people have spent the last 12 months locked inside their homes, terrified of catching a deadly virus, and trying not to kill their spouse, children, or roommates — in more ways than one. People living alone have marked births, deaths, graduations, and layoffs with no one to hug but our pillows. And yet the majority of Americans seem to have made it through with their mental health still intact. How?

If the root of much of the mental illness that’s emerged during the pandemic is unrelenting chronic stress, the opposite is also true: Resilience to trauma lies in the ability to adapt positively to stress.

“Resilience is really this ability to bounce back in the face of adversity,” says Steven Southwick, MD, an emeritus professor of psychiatry at Yale University. “From a biological standpoint, it’s the ability to modulate and hopefully constructively harness the stress response.”

In the brain, resilience means protecting against many stress-induced changes, particularly in regard to the size, activity, and connectivity of the amygdala, hippocampus, and prefrontal cortex — the brain’s fear, memory and mood, and executive control centers, respectively.

How does one prevent these neural changes? Some of it is genetic — gene variants affect the levels and activity of circulating stress hormones, as well as the hormones that counteract them. But perhaps more importantly, behavioral interventions can also build resilience and serve as a buffer against stress for those important brain systems.

“Resilience is not an on-off switch,” says Deborah Marin, MD, a professor of psychiatry and director of the Mount Sinai Center for Stress, Resilience, and Personal Growth, which was launched in 2020 to help health care workers cope with pandemic stress. “Some people may be born with more resilience, there may be some genetic component there, but there’s a lot of environmental interaction at play — everything from poverty, access to health care, education, community support.”

Southwick has been studying resilience for decades, interviewing countless combat veterans and other trauma survivors with and without post-traumatic stress disorder. Based on these conversations, he, along with collaborator Dennis Charney, MD, dean of the Icahn School of Medicine at Mount Sinai, developed a rubric of 10 behaviors and traits that contribute to people’s resilience.

“We and many others believe that a big part of resilience is knowing how to regulate the stress response,” Southwick says. “Resilience, in many ways, is a set of skills that can be learned, and pretty much any of us can, to some significant degree, learn these skills.”

Several of these skills, along with a few other strategies, are outlined below, but the basic premise is to engage in activities that strengthen your brain’s executive control center (the prefrontal cortex) so that it doesn’t get overrun by the brain’s fear and arousal center (the amygdala) during times of stress.

Optimism and cognitive flexibility

Negative emotions — fear, anger, disgust — prepare the body to fight or to flee through activation of the sympathetic nervous system, which narrows people’s focus and restricts our behaviors to those actions. Positive emotions, on the other hand, lower arousal levels, broaden attention, and increase creativity, which helps people be more flexible in their thoughts and behaviors.

While some people are naturally more optimistic than others, you can train yourself to think more positively through the skill of cognitive reappraisal. During times of stress, this means seeing a threat not as an insurmountable problem but as a challenge to be solved. For example, many people have tried to see the bright side of the extra time spent at home during the pandemic, viewing it as an opportunity to learn a new skill or pick an old hobby back up. It doesn’t change the outcome of the pandemic, but it does make the best of a bad situation. Instead of being bored at home and lamenting the loss of your social life, you might have learned a new language or started playing the guitar again now that you have more free time.

Southwick calls this type of reframing “realistic optimism.” “The realistic optimist basically has a future-oriented attitude and the belief that things will turn out okay,” he says. “The realistic optimist actually tends to see as much of the negative information that a more pessimistic person might, but they don’t remain focused or glued to this negative perception, and they have the ability to rapidly disengage, particularly from those negative perceptions that are not solvable. And they tend to be pretty darn good at turning their attention to solvable problems.”

This type of cognitive flexibility is associated with activity in the prefrontal cortex, and stronger executive control from the region, particularly over the threat response triggered by the amygdala, is important for not letting stress and anxiety run wild. Chronic stress can damage the connection between the prefrontal cortex and the amygdala, taking the brakes off of the brain’s alarm system and potentially leading to anxiety and PTSD. Having a stronger prefrontal network that can protect against this negative effect of chronic stress may help support resilience.

Meditation

Another resilience strategy that exercises the prefrontal cortex is meditation, which can largely be thought of as a practice of attention. Every time your mind wanders while you meditate, it requires cognitive control exerted by your prefrontal cortex to bring it back to focusing on your breath. And just like working out your biceps will make them stronger, so will working out a brain region in this way. Activate an area enough times, and your neurons start to wire new connections there, making the thought process more automatic.

“Our brain structure is changing from moment to moment. It’s much more plastic than we ever thought; it’s like a muscle, you can strengthen it or weaken it,” Southwick says. “It’s called ‘use-dependent neuroplasticity’ — the more I practice accurately, the more my brain will respond, and it will be less effortful in the future.”

On a more immediate time scale, taking a few deep breaths in a moment of stress can turn on the parasympathetic nervous system — the counterpart to the fight-or-flight response — and start to undo some of the body’s stress response. Deep breathing also lowers levels of noradrenaline, a brain chemical that increases arousal, which is also released in response to stress.

Stress inoculation and facing your fears

You can also train your brain to handle stress better through exposure to smaller stressors, particularly early in life. Scientists call this stress inoculation: Just like exposure to a tiny amount of a virus will educate your immune system on how to respond to it better next time, learning how to deal with mild stressors teaches your brain how to handle bigger stressors later.

“There’s some evidence that exposure to chronic stress early in life can actually make you resilient to stress later in life. Like that initial experience changes your resilience capacity,” says James Herman, PhD, a professor of psychiatry and behavioral neuroscience at the University of Cincinnati and director of the Laboratory of Stress Neurobiology. “You have all of these stressors that are present all the time, but if you’re used to them, you become resilient to them. They can help you later on in life, and they might even be beneficial.”

Part of this process is facing your fears, which, again, involves the prefrontal cortex overcoming the alarm bells ringing from the amygdala.

“Fear is completely natural. It’s, in many ways, a signal or something that is warning us, it’s a guide,” Southwick says. “But if you allow fear to hang around too long, it might evolve into panic. And when someone’s panicked, there tends to be a flooding of noradrenaline to the prefrontal cortex, which has a tendency to take the prefrontal cortex offline, which means that I’m now operating much more via my amygdala because my prefrontal cortex is no longer inhibiting the amygdala to the same degree that it normally does.”

Practicing facing your fears in lower stakes situations teaches your brain how to maintain control during stressful scenarios so that fear doesn’t turn into panic and spiral out of control. This isn’t something you can magically do right now to help you deal with the rest of the pandemic, but as things quiet down, consider it to help build your resilience for the future. Maybe challenge yourself to sign up for a class you’ve been intimidated to take or speak up in a meeting if normally you stay silent. In clinical settings, facing your fears is called exposure therapy and is used to treat anxiety disorders, particularly phobias and PTSD. With it, you gradually build up your exposure to the thing you’re afraid of while practicing relaxation techniques to prevent your amygdala and sympathetic nervous system from running out of control. The goal is ultimately to desensitize yourself to your fear, but the therapy can help you learn how to remain calm in any stressful situation.

Exercise and sleep

Maintaining good physical health is also critical for your mental capabilities. If you’ve heard it once, you’ve heard it a million times: Exercise is one of the best things you can do for your brain. Physical activity helps the brain grow new connections between brain cells and maybe even new neurons themselves. Much of this growth takes place in, you guessed it, the prefrontal cortex, as well as in the hippocampus, an area involved in regulating mood and memory. The new growth can help offset the loss of connections that occurs in those regions with chronic stress. Exercise also boosts levels of the feel-good neurochemicals dopamine and serotonin, both of which are depleted in people with depression.

On the flip side, lack of sleep can exacerbate many of the problems seen in the brain with chronic stress. One study from 2019 showed that sleep deprivation can cause a decrease in activity in the prefrontal cortex, while the amygdala becomes more reactive after a poor night’s sleep. This shift in activity correlated with people’s feelings of anxiety.

Social support

A crucial resilience strengthener experts bring up again and again is social support. In many ways, social connection counters the stress response from the sympathetic nervous system. Being with a friend or family member, especially during a stressful situation, dampens the activity of noradrenaline and cortisol. It also activates the reward center of the brain, providing a boost in dopamine.

“Human beings have many, many sources of resilience, but I think the most important is our relationships and social support and the way that we can help each other,” says Ann Masten, PhD, a psychologist and professor of child development at the University of Minnesota. “Feelings of belonging and support are powerful protective factors for many different kinds of situations.”

This aspect of resilience can be tricky during a pandemic when physical distancing from people outside of your household is necessary for safety. However, just knowing you have people in your corner who love and support you‚ even if you can’t currently be with them, still has a protective effect.

“The perception that you have others you can count on, even if they’re not presently there, has been shown to buffer some of the physiological effects [of stress],” says Julianne Holt-Lunstad, PhD, a professor of psychology and neuroscience at Brigham Young University. “[We’ve shown that] people who simply have more supportive people in their social network are less cardiovascularly reactive to a stressor task. Other studies have shown that even just thinking about someone who is very supportive is enough to buffer some of those physiological responses.”

Purpose and self-efficacy

Another key protective factor is having a sense of purpose and not feeling like you’re helpless in the stressful situation you’re facing. Similar to cognitive reappraisal, viewing the stressful scenario as an opportunity and that you have something to contribute provides a powerful sense of self-efficacy, which can prevent people from despairing. Scientists have known for decades that a feeling of helplessness is strongly tied to the development of depression, while having a sense of control is linked to resilience.

This factor is particularly relevant for frontline health care workers who have seen some of the greatest trauma during the pandemic. While roughly half of doctors, nurses, and other hospital staff are understandably experiencing depression, PTSD, and anxiety as a consequence, the other half have remained resilient. One reason may be because they can directly impact the course of the pandemic and have the ability to save people’s lives.

“Even if you’re working really hard, [if you’re] able to feel that your work has a sense of meaning and purpose, and that sense of meaning and purpose is aligned and shared by your colleagues and your institution, then you can tolerate an incredible amount of stress,” says Ronald Epstein, MD, a professor of family medicine at the University of Rochester Medical Center who has studied physician burnout.

If you’re not a frontline worker, it may be a little harder to feel like you have a role to play or any control over the situation. However, just because you can’t change the larger course of the pandemic doesn’t mean that you can’t take steps to control your own risk and the day-to-day unfolding of your life within it. Staying home for a year and forgoing social interactions and a normal life has been hard on everyone, but keep in mind that you’re doing it for a really important purpose — you’re potentially saving a life, maybe even your own. Every time you wear a mask, you’re taking your health into your own hands. Even just making and sticking to a daily schedule that slots in exercise or meditation can give you back some semblance of control.

“The pandemic and catastrophes like this can give you a sense that everything is out of control,” Masten says. “We don’t have a lot of control over what’s happening at a global level, but in our own lives, day by day, we can plan, take things one step at a time, and we can give ourselves a sense of accomplishment just in daily planning and setting manageable goals that provide us with a sense of self-efficacy.”

Preparation

Another reason that there isn’t more mental illness among health care workers is that they’ve trained for these types of situations. If someone was pulled off the street to work a day in the intensive care unit, their stress levels would go through the roof and they could very quickly become overwhelmed by the pressure and high stakes of the work, not to mention being exposed to so much suffering and death. But health care workers deal with this every day as part of their jobs.

Notably, many of the health care workers who did develop symptoms of depression or anxiety said that they had been transferred to a different department during the pandemic. In other words, they wound up doing a job that they had not been trained for. For example, nurses and doctors who normally work in rehabilitation were redeployed to the intensive care unit, where they saw much more death than they were used to. Some health care workers had to use ventilators for the first time since graduating from medical school, a skill they may not have felt as competent at.

“Redeployment was definitely a factor that contributed to having more symptomatology, either depression or anxiety or PTSD,” says Marin, the Mount Sinai psychiatrist who directs the Center for Stress, Resilience, and Personal Growth. “That probably is because when you’re redeployed, you’re doing a new skill set that you haven’t been doing or you’re used to, and you’re removed from an environment that may have your own community resilience.”

Virtually no one was prepared for the pandemic and all that it threw at us (how could you be?), and many people — and systems — broke down as a result. But there are at least lessons to be learned should disaster strike again in the future. Perhaps you still have a cache of beans and toilet paper stocked away that can give you a little peace of mind if there’s another stress on grocery store chains. Maybe you finally got to know your neighbors, and now you know who on your street might need a little more help getting groceries, or who has kids around the same age as yours. Or if your pandemic hobby was gardening or hiking or spending more time outdoors, maybe you developed some new survival or self-sufficiency skills you can keep in your back pocket to feel a little more competent and confident going forward.

Hopefully, government and institutions have also learned how to better support under-resourced groups, including parents, the elderly, and the unemployed. “I think this pandemic is a wake-up call for a lot of disasters that probably are going to come in the future, either other pandemics or climate disasters related to weather,” says Masten. “I think we need to think about how do we organize work and cities, and how do we support families with enough child care and financial support to give us flexibility?” These are big complicated questions, but many organizations, particularly those focused on public health, are starting to ask them, which is an important first step.

The past year has turned our lives upside down. People have lost loved ones, jobs, social lives, and any sense of normalcy. It’s entirely understandable, and even expected, that living through a year of a deadly pandemic would take a toll on mental health. But it’s also important to remember that depression, anxiety, and PTSD aren’t an inevitable result, although it does take some work to protect against them.

“As humans, we have this immense capacity to get through transient stresses,” Epstein says. “That’s why humans have survived — we’re not physically strong creatures, and we don’t have a lot of natural protection, so we rely on our ability to adapt to different circumstances.”

Epstein, who leads resilience workshops for health care workers, advises people to embed small habits into their day that can help relieve their stress, at least temporarily. This could be a five-minute meditation or breathing exercise when you feel yourself getting worked up; a quick walk around the block every day at lunch; a standing text or phone check-in with a friend; or a daily gratitude list you make at bedtime.

“Try to find something really, really small that you can do every day that will improve your own sense of positive potential, gratitude, community presence, your ability to be attentive — something that will actually make you feel a bit more aware and in control of your own inner life,” he says. “There’s a whole catalog of things that people can do that are awfully simple, easily accomplished, and doable, it’s just a question of reminding yourself and making that commitment.”

It’s also important to keep in mind that you don’t have to go through this alone. Again, social support is one of the most beneficial factors when it comes to resilience, so reach out to a friend or colleague if you’re struggling — they probably need to talk just as much as you do.

“Yes, we each can take actions, we each can be optimistic or practice meditation by ourselves to help deal with trauma. But a lot of the capacity for human resilience comes from the ways we interact with each other in relationships, in our friendships, in our congregating in cultural practices,” says Masten. “Human beings have a lot of capabilities to come up with ideas and share them of how to deal with whatever current issues are coming up with the pandemic or other kinds of struggles.”

She continues, “We’re great at ingenuity, and you can see […] as the challenges unfold, the mobilization unfolding at the same time. We respond when we’re challenged.”

By Dana G Smith Ph.D., (Medium). Illustration: Carolyn Figel

Directly Reprogramming a Cell's Identity with Gene Editing

Researchers have used CRISPR—a revolutionary new genetic engineering technique—to convert cells isolated from mouse connective tissue directly into neuronal cells.

In 2006, Shinya Yamanaka, a professor at the Institute for Frontier Medical Sciences at Kyoto University at the time, discovered how to revert adult connective tissue cells, called fibroblasts, back into immature stem cells that could differentiate into any cell type. These so-called induced pluripotent stem cells won Yamanaka the Nobel Prize in medicine just six years later for their promise in research and medicine.

Since then, researchers have discovered other ways to convert cells between different types. This is mostly done by introducing many extra copies of “master switch” genes that produce proteins that turn on entire genetic networks responsible for producing a particular cell type.

Now, researchers at Duke University have developed a strategy that avoids the need for the extra gene copies. Instead, a modification of the CRISPR genetic engineering technique is used to directly turn on the natural copies already present in the genome.

These early results indicate that the newly converted neuronal cells show a more complete and persistent conversion than the method where new genes are permanently added to the genome. These cells could be used for modeling neurological disorders, discovering new therapeutics, developing personalized medicines and, perhaps in the future, implementing cell therapy.

The study was published on August 11, 2016, in the journal Cell Stem Cell.

“This technique has many applications for science and medicine. For example, we might have a general idea of how most people’s neurons will respond to a drug, but we don’t know how your particular neurons with your particular genetics will respond,” said Charles Gersbach, the Rooney Family Associate Professor of Biomedical Engineering and director for the Center for Biomolecular and Tissue Engineering at Duke. “Taking biopsies of your brain to test your neurons is not an option. But if we could take a skin cell from your arm, turn it into a neuron, and then treat it with various drug combinations, we could determine an optimal personalized therapy.”

“The challenge is efficiently generating neurons that are stable and have a genetic programming that looks like your real neurons,” says Joshua Black, the graduate student in Gersbach’s lab who led the work. “That has been a major obstacle in this area.”

In the 1950s, Professor Conrad Waddington, a British developmental biologist who laid the foundations for developmental biology, suggested that immature stem cells differentiating into specific types of adult cells can be thought of as rolling down the side of a ridged mountain into one of many valleys. With each path a cell takes down a particular slope, its options for its final destination become more limited.

If you want to change that destination, one option is to push the cell vertically back up the mountain—that’s the idea behind reprogramming cells to be induced pluripotent stem cells. Another option is to push it horizontally up and over a hill and directly into another valley.

“If you have the ability to specifically turn on all the neuron genes, maybe you don’t have to go back up the hill,” said Gersbach.

Previous methods have accomplished this by introducing viruses that inject extra copies of genes to produce a large number of proteins called master transcription factors. Unique to each cell type, these proteins bind to thousands of places in the genome, turning on that cell type’s particular gene network. This method, however, has some drawbacks.

“Rather than using a virus to permanently introduce new copies of existing genes, it would be desirable to provide a temporary signal that changes the cell type in a stable way,” said Black. “However, doing so in an efficient manner might require making very specific changes to the genetic program of the cell.”

In the new study, Black, Gersbach, and colleagues used CRISPR to precisely activate the three genes that naturally produce the master transcription factors that control the neuronal gene network, rather than having a virus introduce extra copies of those genes.

CRISPR is a modified version of a bacterial defense system that targets and slices apart the DNA of familiar invading viruses. In this case, however, the system has been tweaked so that no slicing is involved. Instead, the machinery that identifies specific stretches of DNA has been left intact, and it has been hitched to a gene activator.

The CRISPR system was administered to mouse fibroblasts in the laboratory. The tests showed that, once activated by CRISPR, the three neuronal master transcription factor genes robustly activated neuronal genes. This caused the fibroblasts to conduct electrical signals—a hallmark of neuronal cells. And even after the CRISPR activators went away, the cells retained their neuronal properties.

“When blasting cells with master transcription factors made by viruses, it’s possible to make cells that behave like neurons,” said Gersbach. “But if they truly have become autonomously functioning neurons, then they shouldn’t require the continuous presence of that external stimulus.”

The experiments showed that the new CRISPR technique produced neuronal cells with an epigenetic program at the target genes matching the neuronal markings naturally found in mouse brain tissue.

“The method that introduces extra genetic copies with the virus produces a lot of the transcription factors, but very little is being made from the native copies of these genes,” explained Black. “In contrast, the CRISPR approach isn’t making as many transcription factors overall, but they’re all being produced from the normal chromosomal position, which is a powerful difference since they are stably activated. We’re flipping the epigenetic switch to convert cell types rather than driving them to do so synthetically.”

The next steps, according to Black, are to extend the method to human cells, raise the efficiency of the technique and try to clear other epigenetic hurdles so that it could be applied to model particular diseases.

“In the future, you can imagine making neurons and implanting them in the brain to treat Parkinson’s disease or other neurodegenerative conditions,” said Gersbach. “But even if we don’t get that far, you can do a lot with these in the lab to help develop better therapies.”

The Myth of Prometheus

Before the creation of humanity, the Greek gods won a great battle against a race of giants called the Titans. Most Titans were destroyed or driven to the eternal hell of Tartarus. But the Titan Prometheus, whose name means foresight, persuaded his brother Epimetheus to fight with him on the side of the gods. 

As thanks, Zeus entrusted the brothers with the task of creating all living things. Epimetheus was to distribute the gifts of the gods among the creatures. To some, he gave flight; to others, the ability to move through water or race through grass. He gave the beasts glittering scales, soft fur, and sharp claws.

Meanwhile, Prometheus shaped the first humans out of mud. He formed them in the image of the gods, but Zeus decreed they were too remain mortal and worship the inhabitants of Mount Olympus from below. Zeus deemed humans subservient creatures vulnerable to the elements and dependent on the gods for protection. However, Prometheus envisioned his crude creations with a greater purpose. So when Zeus asked him to decide how sacrifices would be made, the wily Prometheus planned a trick that would give humans some advantage. He killed a bull and divided it into two parts to present to Zeus. On one side, he concealed the succulent flesh and skin under the unappealing belly of the animal. On the other, he hid the bones under a thick layer of fat. When Zeus chose the seemingly best portion for himself, he was outraged at Prometheus’s deception. 

Fuming, Zeus forbade the use of fire on Earth, whether to cook meat or for any other purpose. But Prometheus refused to see his creations denied this resource. And so, he scaled Mount Olympus to steal fire from the workshop of Hephaestus and Athena. He hid the flames in a hollow fennel stalk and brought it safely down to the people. This gave them the power to harness nature for their own benefit and ultimately dominate the natural order. 

With fire, humans could care for themselves with food and warmth. But they could also forge weapons and wage war. Prometheus’s flames acted as a catalyst for the rapid progression of civilization. When Zeus looked down at this scene, he realized what had happened. Prometheus had once again wounded his pride and subverted his authority. 

Furious, Zeus imposed a brutal punishment. Prometheus was to be chained to a cliff for eternity. Each day, he would be visited by a vulture who would tear out his liver and each night his liver would grow back to be attacked again in the morning. Although Prometheus remained in perpetual agony, he never expressed regret at his act of rebellion. His resilience in the face of oppression made him a beloved figure in mythology. He was also celebrated for his mischievous and inquisitive spirit, and for the knowledge, progress, and power he brought to human hands. 

He’s also a recurring figure in art and literature. In Percy Bysshe Shelley’s lyrical drama “Prometheus Unbound,” the author imagines Prometheus as a romantic hero who escapes and continues to spread empathy and knowledge. Of his protagonist, Shelley wrote, “Prometheus is the type of the highest perfection of moral and intellectual nature, impelled by the purest and the truest motives to the best and noblest ends.” His wife Mary envisaged Prometheus as a more cautionary figure and subtitled her novel “Frankenstein: The Modern Prometheus.” This suggests the damage of corrupting the natural order and remains relevant to the ethical questions surrounding science and technology today. As hero, rebel, or trickster, Prometheus remains a symbol of our capacity to capture the powers of nature, and ultimately, he reminds us of the potential of individual acts to ignite the world.

From the TED-Ed Lesson The myth of Prometheus - Iseult Gillespie

Animation by Léa Krawczyk ( @lea–krawczyk )

Ad Astra, John Glenn (1921-2016)

An astronaut. 

A pilot. 

A husband. 

A father. 

A United States Senator.

An American hero. 

An original.

John Glenn (1921-2016) was all those things and more. When he rocketed into space on Feb. 20, 1962, to become the first American to orbit Earth, the flight set the nation on course to meet ever-more ambitious goals.

The life and career of Senator Glenn eclipses those of many. In spite of his accomplishments, he was a humble and gracious man (and 4-term U.S. senator).

During Glenn’s first flight, a scheduled 30-minute test to determine whether Glenn could fly the capsule manually became a matter of life and death when the automatic system malfunctioned after the first orbit.

“I went to manual control and continued in that mode during the second and third orbits, and during re-entry,” Glenn recalled later.  “The malfunction just forced me to prove very rapidly what had been planned over a longer period of time.” Another problem seemed even more serious – telemetry indicated the spacecraft’s heat shield was loose. It seemed possible that Glenn and the spacecraft would be incinerated on re-entry.  Glenn left the retrorocket pack in place to steady the heat shield during re-entry. “It made for a very spectacular re-entry from where I was sitting,” he said. Big chunks of the burning material came flying by the window.

He wasn’t sure whether the flaming debris was the rocket pack or the heat shield breaking up. “Fortunately,” he told an interviewer,“ it was the rocket pack – or I wouldn’t be answering these questions.”

In the words of President Obama, who awarded him the Presidential Medal of Freedom in 2012: “When John Glenn blasted off from Cape Canaveral atop an Atlas rocket in 1962, he lifted the hopes of a nation. And when his Friendship 7 spacecraft splashed down a few hours later, the first American to orbit the Earth reminded us that with courage and a spirit of discovery there’s no limit to the heights we can reach together. With John’s passing, our nation has lost an icon and Michelle and I have lost a friend. John spent his life breaking barriers, from defending our freedom as a decorated Marine Corps fighter pilot in World War II and Korea, to setting a transcontinental speed record … The last of America’s first astronauts has left us, but propelled by their example we know that our future here on Earth compels us to keep reaching for the heavens.  On behalf of a grateful nation, Godspeed, John Glenn.”

Glenn left the Astronaut Corps in 1964 and resigned from the Marine Corps in 1965. And, after some time in private industry ran for and was elected ti the U.S. Senate in 1974, carrying all 88 counties of Ohio. He was re-elected in 1980 with the largest margin in Ohio history. Ohio returned him to the Senate for a third term in 1986. In 1992 he was elected again, becoming the first popularly elected senator from his state to win four consecutive terms. During his last term he was the ranking member of both the Governmental Affairs Committee and the Subcommittee on Air/Land Forces in the Senate Armed Services Committee. He also served on the Select Committee on Intelligence and the Special Committee on Aging. He was considered one of the Senate’s leading experts on technical and scientific matters, and won wide respect for his work to prevent the spread of weapons of mass destruction.

In 1998, Glenn flew on the STS-95 Discovery shuttle flight, a 9-day mission during which the crew supported a variety of research payloads including deployment of the Spartan solar-observing spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, and Glenn’s investigations on space flight and the aging process.

NASA Administrator Charlie Bolden remembers, “Senator Glenn’s legacy is one of risk and accomplishment, of history created and duty to country carried out under great pressure with the whole world watching.”

Today, we honor him for all that he stood for and continues to stand for – grace under pressure, humility, ability, strength. 

Godspeed, John Glenn.

How we determine who’s to blame

How do people assign a cause to events they witness? Some philosophers have suggested that people determine responsibility for a particular outcome by imagining what would have happened if a suspected cause had not intervened.

This kind of reasoning, known as counterfactual simulation, is believed to occur in many situations. For example, soccer referees deciding whether a player should be credited with an “own goal” — a goal accidentally scored for the opposing team — must try to determine what would have happened had the player not touched the ball.

This process can be conscious, as in the soccer example, or unconscious, so that we are not even aware we are doing it. Using technology that tracks eye movements, cognitive scientists at MIT have now obtained the first direct evidence that people unconsciously use counterfactual simulation to imagine how a situation could have played out differently.

“This is the first time that we or anybody have been able to see those simulations happening online, to count how many a person is making, and show the correlation between those simulations and their judgments,” says Josh Tenenbaum, a professor in MIT’s Department of Brain and Cognitive Sciences, a member of MIT’s Computer Science and Artificial Intelligence Laboratory, and the senior author of the new study.

Tobias Gerstenberg, a postdoc at MIT who will be joining Stanford’s Psychology Department as an assistant professor next year, is the lead author of the paper, which appears in the Oct. 17 issue of Psychological Science. Other authors of the paper are MIT postdoc Matthew Peterson, Stanford University Associate Professor Noah Goodman, and University College London Professor David Lagnado.

Follow the ball

Until now, studies of counterfactual simulation could only use reports from people describing how they made judgments about responsibility, which offered only indirect evidence of how their minds were working.

Gerstenberg, Tenenbaum, and their colleagues set out to find more direct evidence by tracking people’s eye movements as they watched two billiard balls collide. The researchers created 18 videos showing different possible outcomes of the collisions. In some cases, the collision knocked one of the balls through a gate; in others, it prevented the ball from doing so.

Before watching the videos, some participants were told that they would be asked to rate how strongly they agreed with statements related to ball A’s effect on ball B, such as, “Ball A caused ball B to go through the gate.” Other participants were asked simply what the outcome of the collision was.

As the subjects watched the videos, the researchers were able to track their eye movements using an infrared light that reflects off the pupil and reveals where the eye is looking. This allowed the researchers, for the first time, to gain a window into how the mind imagines possible outcomes that did not occur.

“What’s really cool about eye tracking is it lets you see things that you’re not consciously aware of,” Tenenbaum says. “When psychologists and philosophers have proposed the idea of counterfactual simulation, they haven’t necessarily meant that you do this consciously. It’s something going on behind the surface, and eye tracking is able to reveal that.”

The researchers found that when participants were asked questions about ball A’s effect on the path of ball B, their eyes followed the course that ball B would have taken had ball A not interfered. Furthermore, the more uncertainty there was as to whether ball A had an effect on the outcome, the more often participants looked toward ball B’s imaginary trajectory.

“It’s in the close cases where you see the most counterfactual looks. They’re using those looks to resolve the uncertainty,” Tenenbaum says.

Participants who were asked only what the actual outcome had been did not perform the same eye movements along ball B’s alternative pathway.

“The idea that causality is based on counterfactual thinking is an idea that has been around for a long time, but direct evidence is largely lacking,” says Phillip Wolff, an associate professor of psychology at Emory University, who was not involved in the research. “This study offers more direct evidence for that view.”

(Image caption: In this video, two participants’ eye-movements are tracked while they watch a video clip. The blue dot indicates where each participant is looking on the screen. The participant on the left was asked to judge whether they thought that ball B went through the middle of the gate. Participants asked this question mostly looked at the balls and tried to predict where ball B would go. The participant on the right was asked to judge whether ball A caused ball B to go through the gate. Participants asked this question tried to simulate where ball B would have gone if ball A hadn’t been present in the scene. Credit: Tobias Gerstenberg)

How people think

The researchers are now using this approach to study more complex situations in which people use counterfactual simulation to make judgments of causality.

“We think this process of counterfactual simulation is really pervasive,” Gerstenberg says. “In many cases it may not be supported by eye movements, because there are many kinds of abstract counterfactual thinking that we just do in our mind. But the billiard-ball collisions lead to a particular kind of counterfactual simulation where we can see it.”

One example the researchers are studying is the following: Imagine ball C is headed for the gate, while balls A and B each head toward C. Either one could knock C off course, but A gets there first. Is B off the hook, or should it still bear some responsibility for the outcome?

“Part of what we are trying to do with this work is get a little bit more clarity on how people deal with these complex cases. In an ideal world, the work we’re doing can inform the notions of causality that are used in the law,” Gerstenberg says. “There is quite a bit of interaction between computer science, psychology, and legal science. We’re all in the same game of trying to understand how people think about causation.”

From the TV series “The life of Mammals”.

(The Telegraph)

The Boardwalk at Trouville by Claude Monet