Tag Archives: psychology

My Body or Yours?

April 30, 2013 By in Brains, Minds Tags: 3 Comments

liztan_bodiespic

Today we’re talking bodies. Not how they look in skinny jeans or whether they can win a Tour de France without steroids. We’re talking about how it feels to have a body of your own, one that is (or seems to be) conveniently connected to your head and neck.

I’ve written about body ownership before in the context of pregnancy. Although I focused on how I dreamt of my body during sleep, I also mentioned that my ballooning physical dimensions affected my coordination. I’d bump into countertops or doorways with my big belly and sometimes struggled to locate my center of gravity. Yet as strange as my new body was, it always felt like it belonged to me. This was an enormous blessing, of course, but it’s somewhat surprising  as well. After all, before my pregnancy I’d lived with the same body since puberty. After more than a decade and a half of experience with that body, I suddenly had to adjust to my new body in a matter of months. Or rather days, because that new body kept growing larger still. Although my belly would feel surreal at times, overall I had remarkably little trouble adjusting to my metamorphosis. The body was still mine in all its lumpy glory.

I was reminded of this experience recently when I came across a scientific paper about body swapping. I know it sounds as if the only science in something called body swapping must come from the term science fiction. Actually, body swapping is a remarkable perceptual illusion that requires nothing more than a second person, a set of head mounted cameras and a set of head mounted displays. Someone facing you wears the cameras mounted on a helmet and you wear the visual displays (which are presented to your two eyes like goggles as part of a virtual reality-style headset). The camera footage, filmed from the visual perspective of the second person, is fed directly into your visual display. Thus, you see your own body from the second person’s perspective.

But we haven’t made it to Freaky Friday just yet. The illusion requires something more. You and the other person take each other’s hands and begin squeezing them simultaneously. Nothing fancy. But in the words of the write up by Valeria Petkova and Henrik Ehrsson, this simple setup alone “. . . evoked a vivid illusion that the experimenter’s arm was the participant’s own arm and that the participants could sense their entire body just behind this arm. Most remarkably, the participants’ sensations of the tactile and muscular stimulation elicited by the squeezing of the hands seemed to originate from the experimenter’s hand, and not from their own clearly visible hand.”

So after a lifetime in your own body, it only takes a video feed and a few hand squeezes for you to make yourself at home in someone else’s arms and legs. If this setup sounds familiar, it is a more impressive incarnation of the classic rubber hand illusion. And a new and remarkable twist on the illusion just appeared in the news: scientists in the same lab have made people feel as if they have an invisible hand. (For a great discussion of this new illusion, read this.)

In science, we tend to think about human perception in general and illusions in particular in terms of adaptations and optimizations. Lots of visual illusions are based on the statistical probability of objects and events in our environment. Our brains learn to predict and extrapolate information about our settings because they jump to the likeliest conclusions. In this way illusions, while technically errors, often reveal clever shortcuts our brain takes to help us understand or parse our surroundings faster, better, or at less of an energy cost.

But what about the body swap? Since we never actually swap bodies, why should we mentally be able to do it? What’s the advantage? Well, the advantage seems to come down to the very fact that we never actually swap bodies. In our ever-changing world, a rare given is that you will have the same body tomorrow that you had today and yesterday. So why should your brain waste precious time or energy soliciting proof from every finger and toe, curve and joint, flex and bend? Take a smidge of visual evidence (in this case, the video display) and a dab of tactile confirmation (hand squeezing) and you have a recipe for body ownership. How often in the natural world would this recipe ever lead you astray?

So in essence you only think that you feel that you own your body. In truth, your brain is creating that sensation on the fly all the time. You could think of it as a philosophical conundrum or cause for an existential crisis. I prefer to think of it as good news for pregnant ladies everywhere.

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Photo credit: Elizabeth Tan

ResearchBlogging.org

Petkova VI, & Ehrsson HH (2008). If I Were You: Perceptual Illusion of Body Swapping PLOS One DOI: 10.1371/journal.pone.0003832

The End of History

March 2, 2013 By in Books, Minds Tags: , , , 3 Comments

Intersection 12-12-12 Day 347 G+ 365 Project 12 December 2012I just read a wonderful little article about how we think about ourselves. The paper, which came out in January, opens with a tantalizing paragraph that I simply have to share:

“At every stage of life, people make decisions that profoundly influence the lives of the people they will become—and when they finally become those people, they aren’t always thrilled about it. Young adults pay to remove the tattoos that teenagers paid to get, middle-aged adults rush to divorce the people whom young adults rushed to marry, and older adults visit health spas to lose what middle-aged adults visited restaurants to gain. Why do people so often make decisions that their future selves regret?”

To answer this question, the study’s authors recruited nearly 20,000 participants from the website of “a popular television show.” (I personally think they should have told us which one. I’d imagine there are differences between the people who flock to the websites for Oprah, The Nightly News, or, say, Jersey Shore.)

The study subjects ranged in age from 18 to 68 years of age. For the experiment, they had to fill out an online questionnaire about their current personality, core values, or personal preferences (such as favorite food). Half of the subjects—those in the reporter group—were then asked to report how they would have filled out the questionnaire ten years prior, while the other half—those in the predictor group—were asked to predict how they will fill it out ten years hence. For each subject, the authors computed the difference between the subject’s responses for his current self and those for his reported past self or predicted future self. And here’s the clever part: they could compare participants across ages. For example, they could compare how an 18-year-old’s prediction of his 28-year-old future self differed from a 28-year-old’s report of his 18-year-old self. It sounds crazy, but they did some great follow up studies to make sure the comparison was valid.

The results show a remarkable pattern. People believe that they have changed considerably in the past, even while they expect to change little in the future. And while they tend to be pretty accurate in their assessment of how much they’ve changed in years passed, they are grossly underestimating how much they will change in the coming years. The authors call this effect The End of History Illusion. And it’s not just found in shortsighted teenagers or twenty-somethings. While the study showed that older people do change less than younger people, they still underestimate how much they will continue to change in the decade to come.

The End of History Illusion is interesting in its own right. Why are we so illogical when reasoning about ourselves – and particularly, our own minds? We all understand that we will change physically as we age, both in how well our bodies function and how they look to others. Yet we deny the continued evolution (or devolution) of our traits, values, and preferences. We live each day as though we have finally achieved our ultimate selves. It is, in some ways, a depressing outlook. As much as we may like ourselves now, wouldn’t it be more heartening to believe that we will keep growing and improving as human beings?

The End of History Illusion also comes with a cost. We are constantly making flawed decisions for our future selves. As the paper’s opening paragraph illustrated, we take actions today under the assumption that our future desires and needs won’t change. In a follow up study, the authors even demonstrate this effect by showing that people would be willing to pay an average of $129 now to see a concert by their favorite band in ten years, while they would only be willing to pay an average of $80 now to see a concert by their favorite band from ten years back. Here, the illusion will only cost us money. In real life, it could cost us our health, our families, our future well-being.

This study reminded me of a book I read a while back called Stumbling on Happiness (written, it turns out, by the second author on this paper). The book’s central thesis is that we are bad at predicting what will make us happy and the whole thing is written in the delightful style of this paper’s opening paragraph. For those of you with the time, it’s worth a read. For those of you without time, I can only hope you’ll have more time in the future. With any luck we’ll all have more – more insight, more compassion, more happiness—in the decade to come.

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Photo credit: Darla Hueske

ResearchBlogging.org

Quoidbach J, Gilbert DT, & Wilson TD (2013). TheEnd of History Illusion Science DOI: 10.1126/science.1229294

Sandy, Science, and a New Campaign

November 4, 2012 By in Minds, Science Tags: , , , 3 Comments

As Tuesday’s election approaches and news coverage of super storm Sandy recedes, I’m struck by the absurdity of our current situation. While cities on the East Coast are still pumping water out of tunnels and salvaging belongings from ruined homes, we get back to talking about the economy. That and reproductive rights.

Yet we are surrounded by evidence of climate change, even beyond our recent run-ins with Sandy and Irene. We have seen increases in the frequency and severity of storms, droughts, and wildfires. Already, drought has affected food prices here in the U.S. and caused widespread famine in Africa. Massive ice shelves in Antarctica are melting and crumbling into the sea, demonstrably raising sea levels worldwide. And this past year brought us record-breaking temperatures, one after another, as we watched a freakishly warm winter give way to a sweltering summer.

Despite the mountain of scientific evidence that climate change is real and ample demonstrations of the devastation it can wreak, the topic has not been an issue in this year’s presidential election. It wasn’t discussed in any of the three presidential debates. This is not an oversight on the part of the candidates and the moderators. Americans are simply not worried about climate change. In a Gallup poll from September, only 2% of respondents ranked environmental issues as the most important problem facing our country today. Most ranked unemployment and our lagging economy as the nation’s greatest woe.

While people are certainly suffering in today’s economy, the dismissal of climate change is terribly shortsighted. Climate change is an economic threat. It has already raised (and will probably continue to raise) the cost of food. We have also faced steep costs as a result of extreme weather. New York State’s economy alone lost as much as 18 billion dollars due to Sandy and fortifying New York from future flooding could cost upwards of 20 billion dollars. Those figures don’t include the damage in other states and they don’t include the expense to homeowners who are rebuilding or who will try to insure their homes in the wake of this storm. And of course it can’t include the personal devastation and loss of life.

So why aren’t we talking more about climate change? And why aren’t we doing more, both in our own lives and in our voting choices, to try to stem the tide?

It seems to me that we are witnessing a human psychology experiment on the grandest scale. How can we ignore (and in fact perpetuate) an impending disaster of such magnitude? In fact, humans have quite a bit of practice at ignoring future doom. After all, we live out our lives with the certainty that we will die and we function in large part by not thinking about it. Death? What death? Climate change? What change?

I wrote before about how our disappearing glaciers may be suffering from a PR problem. They need a spokesman or a mascot – something that might tug at our heartstrings and make people care. Now I think we need a similar approach for climate change itself. The climatologists have done their job and demonstrated that climate change is real. But our first and greatest obstacle in fixing it may lie within ourselves or, more specifically, our skulls.

I think it’s time to call in the psychologists, the marketing specialists and the public relations gurus. Through years of research, we already know the many ways that human beings are illogical and we know how to persuade and manipulate them. Beer has bikini-clad women. Cigarettes have cowboys. Viagra and Cialis have politicians and quarterbacks. Why can’t we do the same for our planet? It’s time we held focus groups and raised ad dollars. It’s time for a climate campaign.

Popular opinion has always driven political will. We need to use every resource we have to raise awareness and change minds. So let’s bring in the psychologists. Let’s bring in the bikini-clad women if need be. (After all, it’s going to be hot!) But before we can influence others, we have to begin by changing ourselves. By changing our lifestyles. By changing our priorities. By changing our minds and then voting our minds. And there’s no better time to start than this Tuesday.

I’ll see you at the ballot box!

Tooling Around

September 16, 2012 By in Brains, Kids Tags: , , , , , 2 Comments

tools1There was a time when my daughter used her hands exclusively to shovel things into her mouth. Not so anymore. For the last few months, she has been hard at work banging objects together. This simple action is setting the stage for some pretty cool neural development. She is learning to use tools.

Of course it doesn’t look too impressive right now. She might bang a ball with a block and then switch and strike the block with the ball. In one recent playtime she tore a cardboard flap out of her board book and examined it, trying different grips and holding it from different angles as she watched how it cut the air. Then, brandishing her precious flap, she went to work. She wielded it with a scooping motion to lift other flaps in the book, and later, to turn the book pages themselves. After that, she descended on her toy box with the flap. She used it to wipe her blanket, poke her stuffed animal, and finally scrape its face like she was giving it a close shave.

Although my daughter’s fun with flaps may seem aimless, it had an important purpose. Through experimentation and observation, she was learning how two objects can interact and how such interactions are affected by object shape, configuration, and pliability. Such details are so well known to adults that we forget there was anything to learn. But consider how often we use objects against one another. We hammer nails, rake leaves, and staple pages. When using scissors, we must apply different levels of force to cut through paper versus cardboard or fabric. When lifting a pan with a potholder, we must adjust our grip depending on the weight of the pan and whether we are lifting it by the base, side, or handle. We must know the subtle differences between holding a sponge to wash a glass and using a towel to dry it, and we must do each deftly enough that our glassware comes out clean and intact at the end.

There are also countless tools we create on the fly every day. When you use a magazine to nudge your cell phone within reach or flip a light switch with a book because your hands are full, you are devising novel tools to fit your momentary needs. To do this, our brains must store extensive knowledge about the properties of household objects. Through experimentation, like the kind my daughter is doing, we learned to predict how objects will interact and to capitalize on those predictions.

So far I’ve described the value of tools in terms of what they can do: push, pull, gather, polish, lift, etc. But there is another side to tool use that may play a role in my daughter’s little experiments: sensory information gleaned through the tool. As I watched her probe one object with another, I was reminded of research described in Sandra and Matthew Blakeslee’s book The Body Has a Mind of Its Own. The book discussed neurons in the parietal cortex that are tuned to the sight or feel of objects near a particular body part. For example, cells representing your right hand would fire if something touched your right hand, if you saw an object near your right hand, or both. Neuroscientists have discovered that experience using a tool can change the properties of these cells in monkeys (and therefore likely in us as well). They found that if monkeys used a rake to gather goodies otherwise beyond their reach, the parietal neurons that had responded to objects around the hand now fired for items located anywhere along both the hand and the rake it held. In a sense, object manipulation can temporarily extend certain neural body representations to include the tools we wield. The Blakeslees suggest that this may be how a blind person learns to perceive the contour of items encountered at the tip of his cane. In effect, the cane and the hand are one.

For now, our house is filled with smashing, scraping, banging and bending as our baby descends on toys and her parents’ belongings alike. In the midst of such havoc, it’s good to know that the destruction is part of a crucial learning process. And someday, once it slows down, I can buy her a new board book with all the flaps intact.

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Photo credit: zzpza

Dreaming of Me

October 10, 2011 By in Pregnancy, Sleep Tags: , , 5 Comments

My belly button has all but disappeared. In its place, an odd little pillow of skin lies flush with the rest of my stomach. A dark line – the linea nigra – now runs down the length of my abdomen, dividing me in two. My appendix and intestines, previously at home in my abdominal cavity, have been pushed up and to the sides so that they now form mysterious bulges just below my ribs. Stranger still, I find myself in possession of someone else’s breasts. And then there’s the most noticeable change: the beach ball sized stomach that wholly eclipses my view of my feet.

Of course these changes didn’t come on all at once. I’ve had many months to notice and adjust to them. Still, they’ve happened more rapidly than any other physical changes I’ve experienced in my life. Faster than an adolescent growth spurt, certainly, or any weight gain or loss. My brain has had trouble keeping up. I bump into things with my belly, forgetting its size. I struggle to maintain my balance as my vestibular system tries to adjust to my changing weight distribution. But the lag that has fascinated me most is how I envision myself in my dreams.

Even months into my pregnancy, after my stomach had visibly ballooned, the self I inhabited while dreaming remained as lean as ever. Although thoughts of my pregnancy filled my waking hours, at night I wasn’t the least bit pregnant. In fact, I often dreamt of myself as a high schooler again, wandering the halls without a class schedule or scrambling to find a bus that would deliver me there on time. Why high school? I don’t put much stock in the elaborate interpretation of dream symbols, but I imagine that my dreams of being a lost high school student reflect my waking awareness that parenthood is at my doorstep and I am unprepared. In the face of such a dramatic life change, I can’t help but feel that I’ve lost my lunchbox or forgotten a homework assignment somewhere.

Then, a month or so ago, my dreams began to change. Or rather my dream self changed. My new self often had a swollen midsection and wore maternity clothes (or in one case, a maternity prom dress). She couldn’t drink alcohol and got worn out just walking from the car. The dreams weren’t usually about my pregnancy; my enormous belly was simply present, just like my arm, hands, and feet. Something about my self-image, my internal body schema, had updated. A switch had been flipped and my mind was caught up with my changing body.

I began to wonder about these internal self-schemas that reveal themselves in our dreams. Do other pregnant women experience the same switch and a similar lag? And how long does it take for them to switch back after they’ve delivered their babies? What about other changes to one’s appearance, like growing or shaving off a beard? Or, in a more dramatic example, what happens when someone loses a limb?

I haven’t found much written on baby bumps and beards, but several people have studied whether amputees dream of themselves with intact or amputated bodies. The answer, in short, is it depends. One study found that a majority of surveyed amputees dreamt of themselves with amputated bodies at least some of the time. Among them, 77% made the switch within the first 6 months following their amputations. But the study also showed that a surprising percentage of the surveyed amputees (31%) dreamt exclusively of themselves with intact bodies, even a decade or more after their amputations. Preliminary findings suggest that those who undergo the amputation at a later age, those who regularly use a prosthetic limb, and those who experience phantom sensations from the missing limb may all be more likely to dream with their bodies intact.

It should come as no surprise that the results of the studies are complicated and variable. We can’t expect anything as complex as dreams and internal self-representations to be wholly consistent from person to person or from one dream to another. In my case, I may be pregnant in one dream but not in the next. At times I even dream I’m someone other than myself. Wading into dreams can be a messy business, certainly, but my curiosity is piqued and I’m eager for more data. To all those pregnant or post-pregnant ladies, beard growers, or head shavers out there: please comment and share your experiences! How long did it take for your dream self to catch up with the real thing?

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Photo credit: Sabin Dang