Ask people what might constitute the basis of a permanent self, and often they’ll point to their memories. We tend to assume that a memory is like a DVD recording — stable, permanent, and unchanging. But research on memory shows that this isn’t the case. Smithsonian Magazine highlights the work of Karim Nader, who has suggested that our memories are in a state of flux.
Nader, now a neuroscientist at McGill University in Montreal, says his memory of the World Trade Center attack has played a few tricks on him. He recalled seeing television footage on September 11 of the first plane hitting the north tower of the World Trade Center. But he was surprised to learn that such footage aired for the first time the following day. Apparently he wasn’t alone: a 2003 study of 569 college students found that 73 percent shared this misperception.
Nader believes he may have an explanation for such quirks of memory. His ideas are unconventional within neuroscience, and they have caused researchers to reconsider some of their most basic assumptions about how memory works. In short, Nader believes that the very act of remembering can change our memories.
Much of his research is on rats, but he says the same basic principles apply to human memory as well. In fact, he says, it may be impossible for humans or any other animal to bring a memory to mind without altering it in some way. Nader thinks it’s likely that some types of memory, such as a flashbulb memory, are more susceptible to change than others. Memories surrounding a major event like September 11 might be especially susceptible, he says, because we tend to replay them over and over in our minds and in conversation with others—with each repetition having the potential to alter them.
For those of us who cherish our memories and like to think they are an accurate record of our history, the idea that memory is fundamentally malleable is more than a little disturbing. Not all researchers believe Nader has proved that the process of remembering itself can alter memories. But if he is right, it may not be an entirely bad thing. It might even be possible to put the phenomenon to good use to reduce the suffering of people with post-traumatic stress disorder, who are plagued by recurring memories of events they wish they could put behind them.
Mariana Caplan just gave this glowing recommendation for “Living as a River.”
“At a time when it’s increasingly challenging to find clear and honest direction on the spiritual path, Living as a River offers contemporary insight into an ancient practice and wise counsel we can trust. This book is both beautifully written and useful to all serious seekers.”
—Mariana Caplan, PhD, author of Eyes Wide Open: Cultivating Discernment on the Spiritual Path and Halfway Up the Mountain: The Error of Premature Claims to Enlightenment
Book extract: Although our world is drenched in water, we rarely appreciate just how little water there actually is. As we look at a globe and see 71 percent of the world’s surface covered in water, we rarely consider that it is spread in an incredibly thin film over the planet’s surface, less than a thousandth of the diameter of the earth at its deepest point, and on average three ten thousandths. If the earth were shrunk to the size of a soccer ball, the average depth of the ocean covering it would be 65 microns, or about twice the thickness of a grocery store plastic bag.
Based on “Global water and air volume” (Adam Nieman, Science Photo Library). Photograph credit: NASA
The image above gives a graphic representation of the size of the Earth, its total water supply (the white sphere), and the accessible fresh water reserves (the tiny, dark sphere at 9 o’clock relative to the white sphere). 97% of the total water on Earth is salt water, roughly 1.7 percent is locked up in the ice caps, glaciers, and permanent snow, and a similar amount is soaked deep into the earth. Approximately 0.007 percent of all the water on the Earth is available for direct human use, including water in rivers, lakes, reservoirs, and accessible aquifers. You may have to look at the diagram above very hard to notice the tiny dot representing this.
Here are two recent stories illustrating some of the problems we’re facing because of our lack of respect for the Water Element.
The people who brought you “The Story of Stuff” have a new feature coming soon on the bottled water industry. The video above is a trailer. “The Story of Bottled Water” looks like it’ll be really fascinating.
“You may think of your body as a fairly permanent structure, but most of it is in a state of constant flux as old cells are discarded and new ones are generated.”
Even your bones, which you may think of as static and non-living, are full of cells called osteoclasts and osteoblasts that are forever (respectively) breaking down and rebuilding your bones as they adapt to the stresses they’re subjected to. (This is why bed-rest or being in weightlessness results in bone loss).
A fascinating article from the New York Times highlights the work of Doctor Jonas Frisén, of the Karolinska Institute in Stockholm, who hit on a method to estimate the average age of tissues. The method involves measuring the amount of Carbon-14 in the DNA of various tissues.
A pulse of artificially-generated Carbon-14 was created in the atmosphere in the years that above-ground nuclear testing was allowed, and since then the level (which was double the normal background level) has been slowly returning to normal. This Carbon-14 entered the food chain as plants absorbed it and incorporated it into their bodies, and from there it percolated into all living things, including us. The amount of Carbon-14 in the DNA of our tissues reveals the average age of the cells making up those tissues, since the DNA is fabricated at the birth of the cell.
Frisén’s work, and that by other researchers, tells us the following:
“The epithelial cells that line the surface of the gut have a rough life and are known to last only five days. Ignoring these surface cells, the average age of those in the main body of the gut is 15.9 years.”
“Red blood cells, bruised and battered after traveling nearly 1,000 miles through the maze of the body’s circulatory system, last only 120 days or so on average before being dispatched to their graveyard in the spleen.”
“The epidermis, or surface layer of the skin, is recycled every two weeks or so.”
“An adult human liver has a turnover time of 300 to 500 days.” This means that you have a new liver just about every year!
“The entire human skeleton is thought to be replaced every 10 years or so in adults.”
“The average age of all the cells in an adult’s body may turn out to be as young as 7 to 10 years.”
About the only pieces of the body that last a lifetime, on present evidence, seem to be the neurons of the cerebral cortex, the inner lens cells of the eye and perhaps the muscle cells of the heart. But even there, it’s the age of the DNA that Frisén’s method measures. There are ongoing processes that replace individual components of the cells around that DNA, meaning that even in the cerebral cortex and other “static” tissues, there may be considerable change taking place. And other work has shown that new neurons are in fact generated in the cerebral cortex, although presumably not in numbers sufficient to show up in Frisén’s work. Additionally, although cells in the brain may be long-lived, they still change; brain cells have a life-long ability to develop new connections with each other. This is how learning takes place.
The upshot is that the body is continually changing.
And yet we are attached to our bodies. This brings up the question, how can we be attached to something that is constantly changing? How can we cling to something that doesn’t remain the same from one moment to the next? Well, we can’t. We identify with our bodies, thinking that if the body fails, we fail. We think that when others judge the body, they judge us. And so clinging (or trying to cling) to something impermanent leads to suffering.
The Buddhist tradition encourages us to regard all things as being like mist, or flowing water, or a mirage — what the mind takes to be solid, substantial, and graspable is actually ever-changing and characterized by impermanence. The Six Element Practice — the subject of my new book, Living as a River, is a way of developing an experiential appreciation of the transience of the body. This helps us to let go, stop identifying the body with the self, to suffer less, and to experience a profound sense of freedom.
It’s remarkably difficult for us to perceive change, because of the relative poverty of the brain’s processing power compared to the sheer volume of information is has to deal with. This causes a failure to notice changes that we might think would be obvious, and so we consistently over-estimate our ability to detect change.
This, I argue, in Living as a River, is one of the reasons we think that we have a static self. If we can’t notice something “obvious” changing, like a building being there one minute and gone the next, how are we going to appreciate less tangible changes on our own being?
Here are a few examples showing how hard it is to detect change. In each of these movies, two photographs will alternate, separated by a blank slide. It’s surprising how many times we have to compare the two photographs before we can see the change. (Warning: these photographs are strobe-like. They give me headaches and I’d hate someone with epilepsy to have a seizure as a result of viewing them).
Extracts from Chapter 13: The Consciousness Element
I’m driving along New Hampshire’s long, winding, and rather monotonous Route 4, on my way to teach a class at the men’s prison in Concord. It’s easy to space out, and as usual I’m trying to make the act of driving into a mindfulness practice. The radio is switched off. I’m not listening to any podcasts. I’m not eating or drinking. I’m trying not to multitask in any way. I simply pay attention to what’s going on as I drive. I notice the physical sensations in my body. When another driver is too close or makes a risky maneuver I notice the emotions that arise and let go of them as best I can, while wishing both of us well. I pay attention (of course) to what I’m seeing in front of me and in my car’s mirrors.
Noticing how my gaze can often become fixated on a narrow area in front of me, I become aware of the entirety of my visual field, allowing everything from the center of my visual field to the periphery into awareness. It’s like moving from a kind of “dial-up” connection between the world and my brain to a broadband connection. Doing this generally has a very calming effect on my inner chatter, as if the sheer volume of incoming data I’m paying attention to leaves no bandwidth available for my inner dramas. So as I expand my awareness of my visual field I notice a marked decrease in my inner monologues. A sense of spaciousness arises in my experience. I become distracted less frequently, and it’s easier to keep my awareness in the present moment.
Driving mindfully like this, I’m simultaneously aware of the curve of the road, of the vehicles ahead of me, and of the never-ending trees, buildings, signs, and utility poles that flow past me. My mind is quiet and yet full of sensory impressions. Then I notice a curious thing. I can see my hands on the steering wheel, at the 10 o’clock and two o’clock positions. I can see the steering wheel moving clockwise and counterclockwise, with my hands upon it. I can feel my hands and arms moving. And yet I have no sense that “I” am making these movements. I’m not aware of giving my hands and arms any conscious or explicit directions. They seem to be moving of their own volition. They seem to have minds of their own. And yet, they’re making precisely the movements needed in order to keep the car in its lane. There is an intelligence at work here, and yet it is not under conscious direction. The realization is fascinating, and it’s so hilarious that for the next few miles I keep bursting into laughter.
So who is driving the car? It’s certainly not my conscious self, because my conscious self has only just noticed that my hands are moving. My conscious self has been too busy absorbed in the task of being mindful of my driving to bother about such trivial details as the physical movements involved in, well, the act of driving. But now I’m captivated by those movements, observing in the periphery of my visual field these two hands skillfully moving the steering wheel to the left and right, without my intervention, as if the hands belong to someone else. Who is this stranger with whom I am sharing a driver’s seat, sharing a body? With deft finesse he coordinates the movements of my feet on the pedals and my right hand on the gear stick. It’s clearly my body which is involved in the act of driving, but my conscious mind—which I often identify with as being my “self”—doesn’t seem to be doing anything but observing.
In a way it’s rather spooky, this sense that “I” am not driving the car. It’s as though my conscious awareness is sharing a body with a zombie or robot who does most of the grunt work. It’s as if I’m both awake and sleepwalking at the same time. It’s like a kind of spirit-possession. I feel almost that I’m in the presence of another. Someone else is moving the steering wheel. Someone else is pressing the gas, brake, and clutch pedals. Someone else reaches down at the appropriate moment and slides the gear stick forward from fourth gear to third. The only reassuring thing about all this is that he seems to be a good driver.
Some people, who have experienced brain damage that prevents them from consciously seeing anything—that is, they are profoundly blind—can perform actions such as catching balls, weaving their way unerringly around obstacles in their path, and cleanly picking up objects. This phenomenon has been termed “blindsight” and it produces deeply paradoxical situations. Beatrice de Gelder, of Harvard Medical School and Tilburg University in the Netherlands, has a video of a blind man, “TN” successfully navigating a corridor littered with obstacles. TN is profoundly blind as the result of two strokes that destroyed his visual cortex. His eyes work, but his brain simply cannot process the visual information that it receives—or at least TN cannot become conscious of such visual information. And yet, in the video, we see him deftly threading his way past trash cans, a shredder, a camera tripod, and cartons of letter-sized paper. He moves exactly as a sighted person would—although a little more slowly—neatly avoiding every obstacle. And yet he cannot consciously see a single one of them.
Another patient, a woman called DF, became blindsighted after carbon monoxide poisoning from a broken water heater damaged her visual cortex. Like TN, she cannot consciously perceive shapes or objects. And yet she opens her fingers to the appropriate width when picking up an object, and she can twist her hand to the correct angle when asked to put it through a slot. She acts as if she can see, and yet she can’t.
Conscious awareness is clearly not involved with blindsighted individuals, yet they still process sensory information and respond to it. “Seeing” in this case is taking place in visual pathways that operate outside of conscious awareness. Blindsighted individuals such as these clearly act, and yet there is no conscious perception, nor are decisions to act being made with the involvement of conscious awareness. TN does not even know he is avoiding obstacles when maneuvering a cluttered corridor, and DF is unaware of how she “knows” to open her hand the right amount to pick up a cup one moment and a pencil the next.
The implication of these cases frankly sends a shiver down my spine. We are so used to thinking of our conscious self as having the functions of observing and deciding on actions that it’s a shock to realize the extent to which observing and acting can take place with no conscious involvement. We’re back to the inner zombie with whom we share a body—the stranger within who takes care of the driving while I’m busy being mindful. We think “we” are in control, but presumably the mechanisms that allow TN to maneuver through a cluttered corridor or DF to accurately grasp an object she cannot see operate in the rest of us too. We too respond to visual information being processed in channels of the brain not accessible to conscious awareness. We just don’t notice that this is going on. We’re caught up in the grip of the delusion that the conscious mind is in running the show.
Fully sighted individuals have in fact been shown to act without conscious perception taking place, and without decisions being made consciously. Mel Goodale of the University of Western Ontario in London, Ontario, employs a perceptual trick that makes circular blocks of identical size look as if they’re different sizes. Subjects will invariably report after visual inspection that one block is larger than the other, and yet videotape shows that whichever block they reach to pick up, they open their hands to the same width. The conscious self is fooled by the optical illusion, but the body still responds appropriately. The conscious self may think it is acting in such cases, but it clearly isn’t. Where is the “self” in all this?
Andrew, an American student who has volunteered to participate in a psychology study, walks into Dr. Henrik Ehrsson’s laboratory in the Karolinska Institute in Stockholm and stands opposite a plastic mannequin. Ehrsson’s colleague, doctoral student Valeria Petkova, attaches electrodes to the middle and index fingers of Andrew’s left hand, and then slips a video headset over his eyes. Through the headset, Andrew sees the images generated by two video cameras that are fixed to the mannequin’s head and pointed down at its feet.
Andrew is now seeing what the mannequin sees, so when he tilts his head forward and matches the mannequin’s downward gaze, he immediately starts to have a sense that the mannequin is “him.” That feeling becomes even more convincing when Petkova takes a marker and simultaneously strokes Andrew’s belly and that of the mannequin. Andrew can see only the mannequin’s abdomen being touched, but he can feel the pen brushing against his own body. The moment that the touch happens, Andrew, with a kind of jolt, feels that he’s actually inside the mannequin’s body. His sense of identification with his own body “snapped,” he said later. Next, Petkova pulls the blade of a sharp knife across the belly of the mannequin. Although he knows the researchers wouldn’t harm him, Andrew still feels the desire to pull away, and the electrodes on his fingertips register increased electrical activity—a clear indication of anxiety.
In a later experiment, Andrew stands opposite Petkova herself. She’s now wearing the mannequin’s video cameras, so that Andrew sees himself from her perspective. As before, he quickly begins to feel that he is in another body—her body—seeing himself from the outside. The two hold hands, and Andrew experiences Petkova’s grip as his own. She squeezes his hand, and he feels that he’s doing the squeezing. The fact that the two people are of different genders has no effect on the illusion, Ehrsson and Petkova have found. A man can easily identify with a female body and vice versa. Typically, it only takes 10 to 12 seconds for a volunteer to abandon his or her body and to identify with that of their partner or a mannequin, and 70 to 80 percent of volunteers experience the illusion very strongly.
The Space Element brings together the first four element, with the internal element representing the human body as a whole—the shape, form, or appearance that we identify with. Although we undoubtedly cling to our bodies, the identification we have with them turns out to be surprisingly flexible.
It’s even possible to persuade people that they are outside of their bodies altogether. In another experiment, Ehrsson filmed the backs of volunteers with stereo video cameras. As in the experiment above, the volunteers wore headsets that allowed them to see themselves. They reported that they felt as if they were outside and about two meters behind their bodies. When Ehrsson swung a hammer in the direction of the cameras, which were safely behind the participants’ actual bodies, the volunteers experienced anxiety and showed measurable signs of emotional and physiological stress.
Electrical stimulation to specific spots in the brain can also produce out-of-body-experiences. A Swiss team at the Federal Institute of Technology in Lausanne, led by Bigna Lenggenhager, found with one woman that stimulation to a brain region called the temporal parietal junction resulted in a sensation that she was hanging from the ceiling, looking down at her body. The woman had a normal psychiatric history and was reportedly stunned by the bizarre nature of her experience.63
At first sight it seems extraordinary that our sense of self can be so easily manipulated. With only ten to twelve seconds of seeing our own body from the outside, or a tiny jolt of electricity to the brain, we can be induced to abandon our life-long sense of inhabiting the body we have grown up with. Then again, perhaps this isn’t so surprising. Imagine yourself as a newborn baby. You have to learn to coordinate the movements of your body. You have to learn what arms, hands, and legs are for, how to move them in a coordinated way, and how to keep track of where they are. But most fundamentally, you have to learn that these are your body parts. We’ve all been through the stage of having to learn to initially identify something as our bodies. And that process of identification is ongoing—we have to continually adjust our sense of what the body is, because the body changes. As we grow, the size, proportions, and strength of the body change, meaning that we continually undergo a shift in our sense of what constitutes the physical self. If we couldn’t make rapid adjustments to our sense of what our body is and how it functions, it would be hard to adapt our style of walking when we’d injured a foot, or adjust the amount of effort we make when carrying something heavy upstairs, never mind to adapt to dramatic changes to the body such as losing a limb.