Chris Berdik, a science journalist and former staff editor at The Atlantic, begins with a simple premise: expectations matter. The notion is well-known in medicine, where doctors have known the power of the “placebo effect” for a long time. But it turns out that this same psychological machinery holds sway in many realms, that what we bring to a situation can, in some sense, bend reality. Berdik answered questions about his new book, “Mind over Mind,” from Mind Matters editor Gareth Cook.

We've all heard of the placebo effect in medicine, but you take this idea even further. Can you explain?

Traditionally, the placebo effect has been thought of as triggering self-healing using fake drugs. So, for instance, if I take a sugar pill believing that it’s a pain reliever, that belief causes my brain to release endorphins, which brings pain relief. But now, the placebo effect is being looked at as more than the ability of fake medicine to fool people into feeling better. Research into placebos is broadening out to examine everything that affects a patient's expectations for treatment — how the doctor talks and acts, the side effect information they read online, the news reports of killer diseases — and how, when, and to what extent those expectations can help or hinder healing.

And placebo effects in medicine are just one example of how our expectations can bend reality. For instance, brain scans reveal that expectations about a wine's quality (based on price or a critic's review) actually change the level of activity in the brain's reward centers when a person takes a sip. Highly-trained weight lifters can out-do their personal bests when they believe they've taken a performance booster. People who wear taller, better looking avatars in virtual reality behave in ways that taller and better looking people tend to act. For example, they approach better-looking potential dates and they are more aggressive in negotiations, both in the virtual world and after the headgear is removed. In lab and field experiments, people who stand in powerful poses (think Superman) for a minute or two, have similar hormonal changes to people who are given actual power and authority over another person, and they exhibit the same sorts of behavioral changes.

What do you mean by expectations “bending reality”?

The expectations I write about don’t become reality, but they can shift it in small but often important ways.

Hardly any of the effects are guaranteed or one-size-fits all. For instance, at some point, a wine will taste lousy enough that we’ll spit it out even though the premium price tag suggests it’s delicious. In medicine, there’s no evidence of placebos curing diseases, shrinking tumors, or mending broken bones. In athletics, there are physical limits that no amount of positive thinking will supersede.

But subtle and conditional effects can make a big difference, because expectations bend reality in so many areas of life. Our minds are constantly jumping to conclusions about the world we live in and who we are. Instead of just accepting them, we can examine some of those expectations and maybe put them to the test by trying out some alternatives.

Why the title, "Mind over Mind"?

A lot of the expectations that affect us – the assumptions that shape what we see, hear, smell, and taste, for instance, or the expectations we may have that a more expensive drug will work better than a cheap one – happen on automatic. We don't spend a lot of time wondering about our expectations and considering the alternatives, and that lack of attention helps give their effects an aura of permanence and inevitability. From time to time, it may be worthwhile to examine and question our expectations, to look for the connections between what we think and what we experience, and to try using our mind to shake things up.

For instance, many people worry that they're likely to choke under pressure. They look to coaches and elaborate training techniques to overcome this tendency. Or they just worry and bite their nails before important presentations or competitions. But in one study, researchers told some track athletes that what they thought of as pre-race jitters actually improved performance, while telling another group that this sort of arousal was usually detrimental. The athletes performed accordingly when the pressure was on. In another athletics study, the researchers gave every subject a personality questionnaire and then randomly gave some of them false feedback that their answers indicated they were the sort of person who thrives under pressure. When it came time to compete, the athletes told they would likely do better under pressure did so.

How can cheering for a team backfire?

This is one of those things that can happen, under certain circumstances, even though it normally doesn't. Normally, teams benefit when they're playing in front of friendly, supportive crowds hoping for victory. But, psychologist Roy Baumeister has shown in controlled lab conditions where subjects played video games competitively, that players' performance suffered when they had a supportive audience. They sensed the expectations, and they didn't want to disappoint. They seemed to try too hard not to mess up rather than to win. It's a classic sort of choking under pressure — to try and over-control and over think, when we would be better served by allowing more automatic skills and movements to take over.

Outside of the lab, there's the example of British soccer players who play for their national team. They are among the best in the world, beloved by millions. But they know that those who cheer for them, who so want their success, also harbor doubts based on many years of the English team not living up to their high expectations on the international stage. Most pointedly, the English teams are notorious for losing high-pressure penalty kick shootouts in big tournaments. They are among the most highly skilled players around, but studies show they are rock-bottom among soccer powers when it comes to penalty kick conversion. Too much is riding on their shots. Penalty kick shootouts are typically won and lost based on who can handle the pressure and who will crack. And being on a team whose fans are so rabid that wins and losses can radically impact their national pride and self worth brings intense pressure that can be murder on the penalty spot.

You have a fascinating discussion of phantom limbs. Can you explain this phenomena, and what it reveals?

Phantom limbs are a sensory illusion experienced by most people who have lost a limb. Periodically, they actually feel their lost limb re-form but often in strange and painful ways – as if the limb is twisted or being wrenched up behind them. The phenomenon and the pain had been observed for centuries and no drugs or surgery could help.

In the early 1990s, a neuroscientist named V.S. Ramachandran hypothesized that the sensation of the lost limb and the pain are both conjured by the brain based on its expectations that we have an intact body – two arms and two legs — under our control. Accordingly, the brain gives motor commands to an arm or leg that isn’t there anymore, and when nothing happens, the neural confusion results in pain.

The fact that our brains operate with these expectations for our bodies also has implications for people who haven’t lost a limb. It means that our brains are constantly assessing and re-assessing who we are based on matching these expectations with sensory feedback. For instance, when subjects are in a virtual reality world looking at themselves moving in a virtual mirror, their brains takes ownership of their digital avatar. Consciously, the brain knows this is a computer simulation, but at a more automatic level the brain accepts the avatar as its body, moving where and when it’s commanded: OK, this is me. And research shows that if the avatar is taller, or better looking, or older, or a different race, this can subtly change who we think we are, and thereby shift our attitudes, choices and behaviors.

What is known about “how the mind conjures value,” as you write?

Partly this has been a staple of economics for centuries – the value we see in something shifts according to our situation and proclivities. Just browse Ebay sometime. You may have no use for an obsolete Polaroid camera that shoots out tiny self-adhesive photographs. So, it has no value for you. But somebody out there really wants one for a party, and they are going to outbid all comers (yes, this is autobiographical). However, I write about research that takes this idea a step further, showing how our brains adjust the value we see in something based on how much we expect others value it. So, it’s not just our personal situation and proclivities that weigh into this equation, but everybody else’s too.

In brain scan studies, for example, the reward centers in the brains of young men looking at photos of young women go up and down based on learning that their peers supposedly thought that this particular woman was more or less attractive than they did originally. This isn’t just peer pressure. Their brains have adjusted the “value” of that face.

Think of the recent housing bubble and how much value we saw in a three bedroom house in our neighborhood during the boom and how much now, after the bust. There’s a rational market explanation for the change – too many sellers and not enough buyers, and not enough cash – but the research suggests brain changes, too. We really saw more value in that house during the boom, based on the expectations of what others valued.

Have you experienced any of these effects first hand?

I'm certain that I have, although most of the examples I could bring up are naturally speculative, rather than controlled experiments. For instance, I was a fairly successful student growing up, and much of the credit goes to my teachers and parents for preparing me and instilling discipline and study habits. But I'm pretty sure that some of it was due to the self-fulfilling potential of expectations. I became a good student partly because my teachers expected me to do well, my parents expected me to do well, and so I expected to do well.

Plus, I know that I almost always enjoy a wine that I know is expensive. But, last summer, I hosted a blind-wine tasting of with friends and family where we tried to guess the prices of the wines we tasted — which ranged from $15 a bottle to about $60 a bottle. The tasters, myself included, generally preferred wines that we thought were the most expensive. But, in reality, those preferred wines were often among the cheapest.

Finally, when I was in my 20s, I had my first bout with insomnia. Two nights with zero sleep, and I was freaking out. Over the course of those two nights, I'd tried over the counter sleep medication. I'd tried alcohol. I slept not a wink. I finally went to a walk-in clinic and talked with a psychologist who later handed me a couple of small pills in a vial and told me they would help me sleep. There was no label on the vial, no marking on the pills. He just said to take one and then avoid driving and operating power tools, etc, because these were powerful. I took one that night and slept soundly. I think about that every now and then. I know that I would have eventually slept no matter what. But I also suspect I was given a placebo.

Why did you want to write this book?

I think we're too insistent on separating what's imagined from what's real. A lot of scientific endeavor involves making such distinctions, and that's worthwhile and necessary. But it's worth taking stock of how often our imagination, our expectations and assumptions, bleed into reality and actually change experience or change our bodies. This isn't about denying, disguising, or not seeing what's true, it's about the cases when truth may be malleable.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.