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Posts Tagged ‘science’

01 JULY, 2014

The Science of Mental Time Travel: Memory and How Our Ability to Imagine the Future Made Us Human


Shedding light on “the cognitive rudder that allows our brains to navigate the river of time.”

Lewis Carroll’s Alice in Wonderland remains one of my all-time favorite books, largely because Carroll taps his training as a logician to imbue the whimsical story with an allegorical dimension that blends the poetic with the philosophical. To wit: The Red Queen remembers the future instead of the past — an absurd proposition so long as we think of time as linear and memory as beholden to the past, and yet a prescient one given how quantum physics (coincidentally, a perfect allegorical exploration of Wonderland) conceives of time and what modern cognitive science tells us about how elastic our experience of time is. As it turns out, the Red Queen is far more representative of how human memory actually works than we dare believe.

Illustration from Alice in Wonderland by Lisbeth Zwerger. (Click image for details)

“To be human,” writes Dan Falk in In Search of Time: The History, Physics, and Philosophy of Time (public library), “is to be aware of the passage of time; no concept lies closer to the core of our consciousness” — something evidenced by our millennia-old quest to map this invisible dimension. One of the most remarkable and evolutionarily essential elements of experiencing time through human consciousness is something psychologists and cognitive scientists call mental time travel — a potent bi-directional projection that combines episodic memory, which allows us to draw on our autobiographical experience and call up events, experiences, and emotions that occurred in the past, with the ability to imagine and anticipate future events. Falk puts it unambiguously:

Without it, there would be no planning, no building, no culture; without an imagined picture of the future, our civilization would not exist.

As it turns out, episodic memory — a term coined in the early 1970s by Canadian neuroscientist Endel Tulving, author of the seminal book Elements of Episodic Memory — is central to our capacity for mental time travel and, according to many scientists, fairly unique to humans. Unlike other facets of memory, such as the acquisition of new skills, which are rooted in the here-and-now, Falk points out that episodic memory allows us “to peer back across time, using our imagination to revisit just about any event that we choose.” This mental reliving of the past may be the root of some distinct human maladies — take the wistful reminiscence over a lost love, for instance — but it is also central to our evolutionary survival, allowing us to anticipate future outcomes based on past ones and thus to plan better and be more prepared for what tomorrow may bring. (The dark side of this evolutionarily beneficial faculty is that our over-planning often ends up shortchanging our happiness.)

And yet the benefits outweigh the costs, in evolutionary terms. Falk explains:

The capacity for mental time travel gave our ancestors an invaluable edge in the struggle for survival. They believe there is a profound link between remembering the past and imagining the future. The very act of remembering, they argue, gives one the “raw material” needed to construct plausible scenarios of future events and act accordingly. Mental time travel “provides increased behavioral flexibility to act in the present to increase future survival chances.” If this argument is correct, then mental time travel into the past — remembering — “is subsidiary to our ability to imagine future scenarios.” Tulving agrees: “What is the benefit of knowing what has happened in the past? Why do you care? The importance is that you’ve learned a lesson,” he says. “Perhaps the evolutionary advantage has to do with the future rather than the past.”

Modern neuroscience appears to confirm that line of reasoning: as far as your brain is concerned, the act of remembering is indeed very similar to the act of imagining the future.

Discus chronologicus, a depiction of time by German engraver Christoph Weigel, published in the early 1720s; from Cartographies of Time. (Click image for details)

Though we might not be able to “remember” the future, as the Red Queen does, we do envision it in ways strikingly similar to how we picture events from the past — Falk notes that fMRI studies indicate we use similar regions in the brain’s frontal and temporal lobes when thinking about events in either direction of time. What’s more, psychologists have found that much like it’s harder for us to remember an event in the distant past than a recent one, it’s harder for us to imagine an event in the distant future than one expected to take place soon. This hints at the massively misguided way in which we think of and evaluate memory, which we falsely depict as a recording device, versus foresight. Falk writes:

When we imagine the future, we know what we picture is really just an educated guess; we may be right in the broad brushstrokes, but we are almost certainly wrong in the details. We hold memory to a higher standard. We feel — most of the time — that our memories are more than guesses, that they reflect what really happened. When confronted with a conflicting account of how last week’s party unfolded, we cling to our beliefs: He must be mistaken; I know what I saw.

Falk cites the Harvard psychologist Daniel Schacter:

[The brain is] a fundamentally prospective organ that is designed to use information from the past and the present to generate predictions about the future. Memory can be thought of as a tool used by the prospective brain to generate simulations of possible future events… We tend to think of memory as having primarily to do with the past… And maybe one reason we have it is so that we can have a warm feeling when we reminisce, and so on. But I think the thing that has been neglected is its role in allowing us to predict and simulate the future.

Artwork by Andy Goldsworthy from his project 'Time.' (Click image for details)

In order to mentally time-travel into the future, the brain has to accomplish a couple of things at once — we activate our “semantic memory,” which encompasses our basic knowledge of facts about the world and thus helps paint a backdrop for the imagined scene, and we call on our episodic memory, which pulls on our autobiographical library of remembered experiences to fill in specific details for this general scene. Curiously, episodic memory tends to be rather flawed but, according to two scientists Falk quotes, that’s okay since its core purpose is to provide “a more general toolbox that allowed us to escape from the present and develop foresight, and perhaps create a sense of personal identity.”

To be sure, just like elsewhere in cognitive science, human exceptionalism may be misplaced here — scientists have found that other species are also capable of varying degrees of mental time travel. Falk cites one of the most intriguing experiments, involving scrub jays. He writes:

Psychologist Nicola Clayton and her colleagues housed the birds on alternate days in two different compartments — one in which the jays always received “breakfast,” and one in which they did not. Then the birds were unexpectedly given extra food in the evening, at a location where they could access either compartment. The jays promptly cached their surplus — and they preferentially cached it in the “no breakfast” compartment. Because the birds were not hungry at the time of the caching, the researchers claim that the birds truly anticipated the hunger they would experience the next morning.

Still, the fact that humans are capable of remarkably elaborate and detailed mental time travel reveals something unique about our evolution and the development of such hallmarks of humanity as language and theory of mind. Falk writes:

In all likelihood, the capacity for mental time travel did not develop in isolation but rather alongside other crucial cognitive abilities. “To entertain a future event one needs some kind of imagination,” [the prominent psychologists Thomas] Suddendorf and [Michael] Corballis write, “some kind of representational space in our mind for the imaginary performance.” Language could also play an important role. Our language skills embrace mental time travel by the use of tenses and recursive thinking; when we say “A year from now, he will have retired,” we’re imagining a future time in which some event — which has not yet happened — will lie in the past… Mental time travel may have been “a pre-requisite to the evolution of language itself.” If mental time travel is indeed unique to humans, it may help us understand why complex language is also, apparently, unique.

In fact, the development of mental time travel may even be how the concept of time itself came into existence — according to Suddendorf and Corballis, our species emerged victorious in “an extraordinary evolutionary arms race” largely due to our growing capacity for foresight and sophisticated language, which not only gave us culture and “coordinated aggression” but also, for the first time in evolutionary history, enabled us to understand the concepts of “past” and “future.” The mental reconstruction of what has been and the imagining of what could be, they argue, created the concept of time and enabled us to understand the continuity between the past and the future. Falk, once again, puts it succinctly:

Mental time travel may indeed be the cognitive rudder that allows our brains to navigate the river of time.

In Search of Time is a fantastic read in its entirety, covering such facets of life’s most intricate dimension as how the calendar was born, why illusion and reality aren’t always so discernible from one another, and what the ultimate fate of the universe might be. Complement it with these seven excellent books on time and a fascinating read on how our memory works.

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27 JUNE, 2014

Alan Watts on the Difference Between Belief and Faith


How to master the delicate dance of unconditional openness to the truth.

A century and a half before Carl Sagan explored the relationship between science and religion, Ada Lovelace, the world’s first computer programmer, contemplated the subject in a beautiful letter. Two centuries later, Alan Lightman crafted an enchanting definition of secular spirituality. This question has also been addressed by Albert Einstein in answering a little girl’s question about whether scientists pray, Flannery O’Connor in considering dogma, belief, and the difference between religion and faith, and Jane Goodall in her exquisite conversation with Bill Moyers on science and spirituality — and yet the question is, and perhaps is bound to remain, an open one.

One of the most articulate and lucid attempts to answer it comes from Alan Watts, who popularized Eastern philosophy in the West, in his fantastic 1951 book The Wisdom of Insecurity: A Message for an Age of Anxiety (public library) — the same treasure trove of insight that gave us Watts on happiness and how to live a full life and his prescient admonition about our modern media gluttony.

Watts writes:

We must here make a clear distinction between belief and faith, because, in general practice, belief has come to mean a state of mind which is almost the opposite of faith. Belief, as I use the word here, is the insistence that the truth is what one would “lief” or wish it to be. The believer will open his mind to the truth on the condition that it fits in with his preconceived ideas and wishes. Faith, on the other hand, is an unreserved opening of the mind to the truth, whatever it may turn out to be. Faith has no preconceptions; it is a plunge into the unknown. Belief clings, but faith lets go. In this sense of the word, faith is the essential virtue of science, and likewise of any religion that is not self-deception.


The present phase of human thought and history … almost compels us to face reality with open minds, and you can only know God through an open mind just as you can only see the sky through a clear window. You will not see the sky if you have covered the glass with blue paint.

But “religious” people who resist the scraping of the paint from the glass, who regard the scientific attitude with fear and mistrust, and confuse faith with clinging to certain ideas, are curiously ignorant of laws of the spiritual life which they might find in their own traditional records. A careful study of comparative religion and spiritual philosophy reveals that abandonment of belief, of any clinging to a future life for one’s own, and of any attempt to escape from finitude and mortality, is a regular and normal stage in the way of the spirit. Indeed, this is actually such a “first principle” of the spiritual life that it should have been obvious from the beginning, and it seems, after all, surprising that learned theologians should adopt anything but a cooperative attitude towards the critical philosophy of science.

The Wisdom of Insecurity is the kind of book that stays with you for life. Complement it with Watts on money vs. wealth and your ego, the universe, and becoming who you really are.

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23 JUNE, 2014

Rethinking the Placebo Effect: How Our Minds Actually Affect Our Bodies


The startling physiological effects of loneliness, optimism, and meditation.

In 2013, Neil deGrasse Tyson hosted a mind-bending debate on the nature of “nothing” — an inquiry that has occupied thinkers since the dawn of recorded thought and permeates everything from Hamlet’s iconic question to the boldest frontiers of quantum physics. That’s precisely what New Scientist editor-in-chief Jeremy Webb explores with a kaleidoscopic lens in Nothing: Surprising Insights Everywhere from Zero to Oblivion (public library) — a terrific collection of essays and articles exploring everything from vacuum to the birth and death of the universe to how the concept of zero gained wide acceptance in the 17th century after being shunned as a dangerous innovation for 400 years. As Webb elegantly puts it, “nothing becomes a lens through which we can explore the universe around us and even what it is to be human. It reveals past attitudes and present thinking.”

Among the most intensely interesting pieces in the collection is one by science journalist Jo Marchant, who penned the fascinating story of the world’s oldest analog computer. Titled “Heal Thyself,” the piece explores how the way we think about medical treatments shapes their very real, very physical effects on our bodies — an almost Gandhi-like proposition, except rooted in science rather than philosophy. Specifically, Marchant brings to light a striking new dimension of the placebo effect that runs counter to how the phenomenon has been conventionally explained. She writes:

It has always been assumed that the placebo effect only works if people are conned into believing that they are getting an actual active drug. But now it seems this may not be true. Belief in the placebo effect itself — rather than a particular drug — might be enough to encourage our bodies to heal.

She cites a recent study at the Harvard Medical School, in which people with irritable bowel syndrome were given a placebo and informed that the pills were “made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes.” As Marchant notes, this is absolutely true, in a meta kind of way. What the researchers found was startling in its implications for medicine, philosophy, and spirituality — despite being aware they were taking placebos, the participants rated their symptoms as “moderately improved” on average. In other words, they knew what they were taking wasn’t a drug — it was a medical “nothing” — but the very consciousness of taking something made them experience fewer symptoms.

Illustration by Marianne Dubuc from 'The Lion and the Bird.' Click image for more.

This dovetails into recent research confirming what Helen Keller fervently believed by putting some serious science behind the value of optimism. Marchant sums up the findings:

Realism can be bad for your health. Optimists recover better from medical procedures such as coronary bypass surgery, have healthier immune systems and live longer, both in general and when suffering from conditions such as cancer, heart disease and kidney failure.

It is well accepted that negative thoughts and anxiety can make us ill. Stress — the belief that we are at risk — triggers physiological pathways such as the “fight-or-flight” response, mediated by the sympathetic nervous system. These have evolved to protect us from danger, but if switched on long-term they increase the risk of conditions such as diabetes and dementia.

What researchers are now realizing is that positive beliefs don’t just work by quelling stress. They have a positive effect too — feeling safe and secure, or believing things will turn out fine, seems to help the body maintain and repair itself…

Optimism seems to reduce stress-induced inflammation and levels of stress hormones such as cortisol. It may also reduce susceptibility to disease by dampening sympathetic nervous system activity and stimulating the parasympathetic nervous system. The latter governs what’s called the “rest-and-digest” response — the opposite of fight-or-flight.

Just as helpful as taking a rosy view of the future is having a rosy view of yourself. High “self-enhancers” — people who see themselves in a more positive light than others see them — have lower cardiovascular responses to stress and recover faster, as well as lower baseline cortisol levels.

Marchant notes that it’s as beneficial to amplify the world’s perceived positivity as it is to amplify our own — something known as our “self-enhancement bias,” a type of self-delusion that helps keep us sane. But the same applies to our attitudes toward others as well — they too can impact our physical health. She cites University of Chicago psychologist John Cacioppo, who has dedicated his career to studying how social isolation affects individuals. Though solitude might be essential for great writing, being alone a special form of art, and single living the defining modality of our time, loneliness is a different thing altogether — a thing Cacioppo found to be toxic:

Being lonely increases the risk of everything from heart attacks to dementia, depression and death, whereas people who are satisfied with their social lives sleep better, age more slowly and respond better to vaccines. The effect is so strong that curing loneliness is as good for your health as giving up smoking.

Illustration by Marianne Dubuc from 'The Lion and the Bird.' Click image for more.

Marchant quotes another researcher, Charles Raison at Atlanta’s Emory University, who studies mind–body interactions:

It’s probably the single most powerful behavioral finding in the world… People who have rich social lives and warm, open relationships don’t get sick and they live longer.

Marchant points to specific research by Cacioppo, who found that “in lonely people, genes involved in cortisol signaling and the inflammatory response were up-regulated, and that immune cells important in fighting bacteria were more active, too.” Marchant explains the findings and the essential caveat to them:

[Cacioppo] suggests that our bodies may have evolved so that in situations of perceived social isolation, they trigger branches of the immune system involved in wound healing and bacterial infection. An isolated person would be at greater risk of physical trauma, whereas being in a group might favor the immune responses necessary for fighting viruses, which spread easily between people in close contact.

Crucially, these differences relate most strongly to how lonely people think they are, rather than to the actual size of their social network. That also makes sense from an evolutionary point of view, says Cacioppo, because being among hostile strangers can be just as dangerous as being alone. So ending loneliness is not about spending more time with people. Cacioppo thinks it is all about our attitude to others: lonely people become overly sensitive to social threats and come to see others as potentially dangerous. In a review of previous studies … he found that tackling this attitude reduced loneliness more effectively than giving people more opportunities for interaction, or teaching social skills.

Illustration by André François for 'Little Boy Brown,' a lovely vintage ode to childhood and loneliness. Click image for more.

Paradoxically, science suggests that one of the most important interventions to offer benefits that counter the ill effects of loneliness has to do with solitude — or, more precisely, regimented solitude in the form of meditation. Marchant notes that trials on the effects of meditation have been small — something I find troublesomely emblematic of the short-sightedness with which we approach mental health as we continue to prioritize the physical in both our clinical subsidies and our everyday lives (how many people have a workout routine compared to those with a meditation practice?); even within the study of mental health, the vast majority of medical research focuses on the effects of a physical substance — a drug of some sort — on the mind, with very little effort directed at understanding the effects of the mind on the physical body.

Still, the modest body of research on meditation is heartening. Marchant writes:

There is some evidence that meditation boosts the immune response in vaccine recipients and people with cancer, protects against a relapse in major depression, soothes skin conditions and even slows the progression of HIV. Meditation might even slow the aging process. Telomeres, the protective caps on the ends of chromosomes, get shorter every time a cell divides and so play a role in aging. Clifford Saron of the Center for Mind and Brain at the University of California, Davis, and colleagues showed in 2011 that levels of an enzyme that builds up telomeres were higher in people who attended a three-month meditation retreat than in a control group.

As with social interaction, meditation probably works largely by influencing stress response pathways. People who meditate have lower cortisol levels, and one study showed they have changes in their amygdala, a brain area involved in fear and the response to threat.

If you’re intimidated by the time investment, take heart — fMRI studies show that as little as 11 hours of total training, or an hour every other day for three weeks, can produce structural changes in the brain. If you’re considering dipping your toes in the practice, I wholeheartedly recommend meditation teacher Tara Brach, who has changed my life.

But perhaps the most striking finding in exploring how our beliefs affect our bodies has to do with finding your purpose and, more than that, finding meaning in life. The most prominent studies in the field have defined purpose rather narrowly, as religious belief, but even so, the findings offer an undeniably intriguing signpost to further exploration. Marchant synthesizes the research, its criticism, and its broader implications:

In a study of 50 people with advanced lung cancer, those judged by their doctors to have high “spiritual faith” responded better to chemotherapy and survived longer. More than 40 percent were still alive after three years, compared with less than 10 percent of those judged to have little faith. Are your hackles rising? You’re not alone. Of all the research into the healing potential of thoughts and beliefs, studies into the effects of religion are the most controversial.

Critics of these studies … point out that many of them don’t adequately tease out other factors. For instance, religious people often have lower-risk lifestyles and churchgoers tend to enjoy strong social support, and seriously ill people are less likely to attend church.


Others think that what really matters is having a sense of purpose in life, whatever it might be. Having an idea of why you are here and what is important increases our sense of control over events, rendering them less stressful. In Saron’s three-month meditation study, the increase in levels of the enzyme that repairs telomeres correlated with an increased sense of control and an increased sense of purpose in life. In fact, Saron argues, this psychological shift may have been more important than the meditation itself. He points out that the participants were already keen meditators, so the study gave them the chance to spend three months doing something important to them. Spending more time doing what you love, whether it’s gardening or voluntary work, might have a similar effect on health. The big news from the study, Saron says, is “the profound impact of having the opportunity to live your life in a way that you find meaningful.”

Philosopher Daniel Dennett was right all along in asserting that the secret of happiness is to “find something more important than you are and dedicate your life to it.”

Each of the essays in Nothing: Surprising Insights Everywhere from Zero to Oblivion is nothing short of fascinating. Complement them with theoretical physicist Lawrence Krauss on the science of “something” and “nothing.”

Donating = Loving

Bringing you (ad-free) Brain Pickings takes hundreds of hours each month. If you find any joy and stimulation here, please consider becoming a Supporting Member with a recurring monthly donation of your choosing, between a cup of tea and a good dinner.

You can also become a one-time patron with a single donation in any amount.

Brain Pickings has a free weekly newsletter. It comes out on Sundays and offers the week’s best articles. Here’s what to expect. Like? Sign up.