Stephanie Pappas
First Time Here?
08 February

In 1996, a 22-year-old Louisiana man confessed to raping, beating and murdering his 14-year-old step-cousin and leaving her body under a Mississippi River bridge. He was convicted of the crime and sentenced to death.

But Damon Thibodeaux was not a murderer. The details of the crime that he confessed didn't match what had actually happened, according to The Innocence Project, a legal group that works to exonerate the wrongfully convicted. Thibodeaux told police that he'd strangled his cousin with a gray or white wire from his car, for example. She'd actually been killed with a red wire, which was found near her body.

Thibodeaux is no isolated example; as many as 25 percent of people wrongfully sentenced to death in the United States (an estimated 4 percent of those on death row) falsely confessed to the crime, research suggests. Eighty-eight of the first 325 DNA exonerations by The Innocent Project involved a case where the suspect had confessed despite being innocent. But why would anyone confess to a crime they didn't commit?

A new study finds that one answer may be sleep deprivation. And it doesn't take much. After one night of lost sleep, almost 70 percent of people participating in a lab experiment made a false confession — urged on only by a couple of stern computer warnings.

University of California cognitive psychologist Elizabeth Loftus and her colleagues used a well-established laboratory method to evoke false confessions from study participants. They brought volunteers into the lab and had them do some computer questionnaires and tasks, all while warning them not to press the "escape" key, lest they erase data and wreck the experiment.

A week later, the participants — 88 in this study — returned and did more computer work after seeing another warning against pressing the "escape" key. Then they all spent the night in a sleep laboratory. Half of them got to sleep, while the other half were randomly assigned to stay up all night.

The next morning, participants filled out more questionnaires. At the end of the task, each person saw a screen stating that a research assistant had witnessed them pressing the forbidden "escape" key and asking them to confirm this account and sign the confession. If they refused, they saw the screen a second time, and were again urged to confess. In reality, none of the participants were guilty.

Despite this, the sleep-deprived had a hard time maintaining their innocence. While 82 percent of the well-rested participants resisted signing the first confession, only half of the sleep-deprived participants refused to sign. When urged a second time, 68.2 percent of the sleep-deprived participants falsely admitted to pressing the key, compared with a 38.6 percent of the well-rested participants. The findings appear this week in the journal Proceedings of the National Academy of Sciences (PNAS).

"People don't want to do this very much if they're rested, because they didn't hit the key," Loftus told Brain Decoder. "But if they're not rested, the data sort of speak for themselves."

Participants were more likely to make a false confession if they scored high on tests of impulsive decision-making, the researchers found. And regardless of whether they'd stayed up all night or gotten shut-eye, self-reported sleepiness was linked to making a false confession. Those who said they were the sleepiest were 4.5 times more likely to confess than those who said they were not sleepy or only somewhat sleepy.

In the real world, suspects of crimes are often interrogated into the wee hours of the night, Loftus said. Prisoners at Guantanamo Bay were also subject to long hours of sleep deprivation, according to reports by the International Committee of the Red Cross and accounts by detainees.

Previous work by Loftus and her colleagues found that sleep deprivation makes eyewitnesses more susceptible to false memories. Suspects falsely confess for multiple reasons, Loftus said. Some are mentally unstable and want to be associated with a famous crime. Others see confession as the lesser of two evils. Someone accused of child abuse might confess if the police tell them that coming clean is the only way to see their kid again, Loftus said.

"There's maybe a little of that happening here," Loftus said of the latest research. "Maybe some of these sleep deprived people just want to go home and just don't feel like having a confrontation."

There's another, more insidious way that sleep deprivation can work, though. When pressured enough, people may actually believe that they are guilty. They start "remembering" the crime and even provide details about what they did and how they did it. Sleep deprivation might have made participants less confident in their own memories, Loftus said.

"Certainly sleep deprivation affects cognitive functioning, your speed of processing, your judgment," she said.

For eyewitnesses, experts advise interrogation by someone who doesn't know who the suspect is in the crime, in order to avoid memory contamination. Something like that would be harder to do when questioning suspects themselves, Loftus said, but there might be other ways to combat the suggestive effects of interrogation. One way to combat false confessions would be to videotape all interrogations, she said. The footage might be able to show if a suspect was exhausted or not, or if they were being badgered or otherwise pressured by the interrogators.

In the 1996 murder case, Thibodeaux recanted his confession the next day, and no physical evidence linked him to the crime. But confessions are powerful. As a study published in the journal Law and Human Behavior in 1997 (the year Thibodeaux was convicted) revealed, juries are more likely to convict a suspect who falsely confessed, even if they know the confession was untrue. Thibodeaux spent 16 years behind bars before DNA testing exonerated him. He was released in 2012.

04 February

There is a story in my family of my grandfather's homecoming from the Korean War. His father, a medic in the German army in World War I, took him into his study. "You saw horrible things over there," he told his son. "But you have to forget them. When you leave this room, you just don't think about it anymore."

I can't say whether my grandfather took this advice, but he kept his memories to himself; my mother didn't know he was a Korean war vet until well into her teen years. Still, whatever he saw in Korea didn't go away. Two years ago, when he was seriously ill in the hospital, my grandfather woke up in tears. Why, he asked my dumbfounded mother, had he lived through the war when all of his buddies had died?

I was stacking frozen corpses like cordwood, he said. Was there a reason I was spared?

The silence of my grandfather and his father was long the norm for returning combat veterans. But there are hints — in literature, in ancient texts — that warriors have always had these feelings. Psychiatrists believe that what we now know as posttraumatic stress disorder (PTSD) is universal, and very old. Shakespeare wrote about the symptoms. So did ancient Mesopotamians and ancient Greeks. So did medieval knights and Florence Nightingale.

PTSD may manifest differently from culture to culture and across time, said Terence Keane, a psychiatrist at the Boston University School of Medicine and the associate chief of staff in research and development at the Veterans Administration Boston Healthcare System. But there's a biological substrate at the disorder's core.

"Something has happened in the brain and in the central nervous system that has caused a permanent change, or a relatively permanent change, in how they feel, how they think and how they behave," Keane told me.

This explains why hints of trauma show up in war writings dating back thousands of years. And it would be easy, now, to show you some examples. Look, I could write: Here's an ancient text describing nightmares. Here's one describing suicidal behavior, flashbacks, guilt. Poor saps. Too bad they didn't have the Diagnostic and Statistical Manual to solve their problems.

But I'm wary. Why did my grandfather live, while his friends ended their lives in terror in the cold of a Korean peninsula winter? What do you do next, after surviving something like that? These aren't questions answered in a psychiatry manual.

So this is what I want you to keep in mind: The point of looking back into the past to understand PTSD isn't to feel superior to the ignorant people of earlier times who didn't understand the role of the hypothalamic-pituitary-adrenal axis in PTSD. It's not to imply that we have solved the problem of trauma. It's to understand the common psychology linking humanity across time and distance. And it's to learn what the people of the past might have to teach us about recovery from war.

The case for ancient PTSD

The Diagnostic and Statistical Manual (DSM) 5 defines PTSD as a cluster of symptoms that occurs after someone is exposed to death, serious injury, sexual assault or the threat thereof. Symptoms include re-experiencing the trauma, as in nightmares or intrusive memories, avoiding talk or triggers, negative mood and thoughts and unusual patterns of arousal, such as hyper-vigilance or problems concentrating. Between 15 percent to 30 percent of people with combat experience have serious problems with these symptoms afterward, Keane said. The greater the exposure to trauma, the more likely a person is to have long-term problems.


Some researchers have noted an additional factor that often plays a role in combat PTSD, specifically: Moral injury. This term, first coined by VA psychiatrist Jonathan Shay, refers to a betrayal of "what's right"—no matter what that might mean in a particular culture—by a legitimate authority figure in a high-stakes situation. (Other researchers use the same term to refer to a person not living up to his or her own ideals in a life-or-death situation.)

Shay, author of "Achilles in Vietnam: Combat Trauma and the Undoing of Character" (Simon & Schuster, 1995), sees moral injury in combat as an issue dating back at least to Homer's Iliad, the epic poem about the siege of Troy that's dated to around the eighth century B.C. The poem opens with the commander of the Greek army, Agamemnon, taking a captive woman, Briseis, from the warrior Achilles. Achilles, offended by this betrayal of "what's right" in Greek military culture, refuses to fight. He withdraws from all but his close companion, Patroclus — until Patroclus is killed and Achilles goes mad with grief, killing Patroclus' killer Hector and desecrating the corpse.

Achilles' berserker rage echoes the experiences of the Vietnam War veterans Shay worked with for 20 years at a Boston VA outpatient clinic. Many saw their ideals crumble in combat. One soldier whose story is retold in "Achilles in Vietnam" describes watching for hours as suspected Vietcong unloaded boats in the South China Sea. Finally, he and his comrades got the order to shoot. They unloaded their weapons into the boats. When daylight came, they learned they'd killed a group of fishermen and children.

To add to the horror, the military leadership assured the soldiers that everything was fine — and then gave them awards for their valor. Shay's patient got a Combat Infantryman Badge for his participation, an award that is supposed to mark a soldier's experience of ground combat. The betrayal of getting kudos for killing civilians shook the soldier to his core.

After such a betrayal, Shay told me, veterans report feeling as attacked as if their actual life was at risk. Often, they retreated into themselves, trusting only a few men in their immediate unit and developing almost maternal feelings of protectiveness toward these trusted brothers-in-arms. When a beloved friend was killed, the survivors often went into a berserk state, sometimes committing atrocities that horrified them later. It's hard not to see the parallels with the grief-stricken, revenge-obsessed Achilles, dragging Hector's corpse around Troy's city walls.

Restoring trust, treating PTSD

Ancient cultures often write of visitations by ghosts and spirits after battle.

The oldest reported text describing something like PTSD comes from Mesopotamia during the Assyrian dynasty, which was in power between 1300 B.C. and 609 B.C. Medical cuneiform texts provide records of an Assyrian soldier haunted by the "spirits" of those he'd killed, researchers reported in December 2014 in the journal Early Science and Medicine. The symptoms might ring familiar in modern psychiatrists' ears: depressed mood, poor sleep, flashbacks to battle.

Attributing trauma to the spirit world might seem like ignorant superstition, but Vietnam veterans often speak of seeing their dead friends and enemies in dreams, Shay said.

"I have been twisting the arms of historians, saying, look, if you are interested in the subject of combat trauma in past eras or across cultures and you're only looking for a medicalized picture, you're probably not going to find it very much," Shay said. "But where you see intrusions of the supernatural, that may be — and I'm not saying it always is or must be — the spin-off of a post-traumatic syndrome."

There's no doubt that the modern medical definition of PTSD is a godsend. Likewise, modern treatments can truly help: Cognitive behavioral therapy, mindfulness meditation, and therapy that challenges skewed thinking patterns are all crucial tools for the treatment of trauma.

"So much of what happens in a war zone, for example, is chance," Kean said. "It's almost random and it's out of your individual control. If you feel like 'Bad things happened, therefore it was my failure,' it is a particularly difficult problem to recover."

But PTSD isn't a diagnosis without problems. In discussions of how to update the criteria for the disease in the 5th edition of the DSM, psychiatrists debated whether to change the name from posttraumatic stress disorder to posttraumatic stress injury, with some arguing that military members are less likely to seek help for a "disorder" than for an "injury." Others argued that it's the military culture, not psychiatric nomenclature, that needs to change.

The popular conception of PTSD treatment needs an overhaul, too, Shay said.

"There's model that involves the stereotype: a white-coated mental health professional saying, 'You, Mr. Veteran, you've got a problem, and I'm here to help.'" Shay said. "That is not a winning starting point."

In this era of understanding the brain as just another organ, it's easy to fall into the trap of thinking of PTSD as a defect, something fixable with the right mental attitude. It's easy to lose sight of the human suffering at the heart of this disorder: The real corpses, the real horror of watching friends suffer and die, the real pain of wondering for the rest of your life, "Why not me?"

"A level of critique of the PTSD category involves its dangerous potential for medicalizing human suffering; that is, for reducing the social and moral implications of traumatizing events, such as war or genocide, to a strictly professional, even biological, set of consequences," psychiatrists Devon Hinton and Roberto Lewis-Fernandez wrote in a 2010 review of cross-cultural research on PTSD. "This critique suggests that, by emphasizing the 'reality' of PTSD as a universal biopsychological category, research on PTSD may have unintentionally and paradoxically helped decrease social and moral responsiveness to these events. The suffering associated with the Rwandan genocide, for example, cannot be reduced to the PTSD experience."

This is a gap that the words of people who lived hundreds or thousands of years ago may help fill. In the last several years, the Department of Defense has approved hundreds of readings of ancient Athenian war plays on military bases around the country. The first, in 2008, was a reading of two Sophocles plays, "Ajax," and "Philoctetes," both about Trojan war veterans. The post-play discussion between the Marine audience and the actors went on for three hours before it had to be shut down, according to the New York Times.

"Prior to the advent of modern scientific medicine, it doesn't mean that nobody ever did anything about combat trauma," Shay said. "They did it differently. I think there's still plenty to learn from it, and honestly, I think that the medical model that involves a clinician and a patient alone in a room with the door closed is not the optimum model for recovery from war trauma. Not even close."

01 February

If the person next to you on the bus yawns, chances are you know that you'll soon be yawning, too. What you may not realize is that you may also be mimicking your seatmate's grimaces, smiles and frowns.

Emotions are contagious. And interestingly, much of this process may be subconscious — though not any less important for how people interact.

Studies going back decades have found that when people observe someone's facial expression, electrodes on their own facial muscles record muscle activity, as if they were making a tiny version of the same expression. Typically, these micro-moments of mimicry are invisible to the naked eye.

Other studies find that people similarly copy other people's posture and vocal tics. And they seem to be quite good at it. One 2010 study, published in the journal Attention, Perception & Psychophysics, found that when people lipread, they sound like the person they're lipreading from, even though they've never heard that person's voice.

But the copycatting doesn't end with muscular movements. Research finds that emotions propagate from person to person, too. The theory, according to University of Hawaii psychologist Elaine Hatfield, is that emotions don't always start in the mind. They also travel from body to brain. So if your coworker's posture is slouched and the corners of his mouth are turned down, you'll subtly mimic his posture. Then, your brain will take cues from your own body language, and you'll start to feel like you look: Totally bummed out.

Emotional matters

Some scientists explain the neurological roots of emotional contagion through the concept of mirror neurons. These much-ballyhooed brain cells are thought to fire both when people perform an action and when they observe someone else performing that action. Some researchers suspect these mirror neurons are at the root of the human ability to put ourselves in others' shoes, though it's likely that their role is nuanced and complex. (Researchers can investigate mirror neurons in monkeys by inserting electrodes next to a single neuron in the brain, but evidence for the mirror system in humans is based on cruder brain imaging techniques. As a result, there is a lot of academic debate about what mirror neurons do in humans or if the system even exists.)

Whether mirror neurons are involved in emotional contagion or not, the catching nature of emotions has caught the attention of psychologists studying everything from workplace culture to the spread of terrorism. What they've found suggests that emotional contagion makes a big difference in daily life.

Sigal Barsade, a professor of management at the University of Pennsylvania's Wharton School, launched a study of emotional contagion more than a decade ago in which she asked undergraduates to work together in groups to assign salary bonuses to imaginary employees. Unbeknownst to the participants, one member of each group was an actor. The actor pretended to be either in a good mood or a bad mood, at varying levels of energy. In a good, high-energy mood, for example, he was warm, alert and enthusiastic. In a good, low-energy mood, he gave off a sense of serenity and calm.

In his high-energy bad mood, the actor came across as pessimistic and actively hostile. In his low-energy bad mood, he was slouched and sluggish. Barsade expected that bad moods would spread easier than good moods, given the fact that humans tend to pay more attention to negative stimuli than to positive stimuli.

That's not what happened. In the study, published in December 2002 in the journal Administrative Science Quarterly, both pleasant and unpleasant moods spread at similar levels. There were suggestions that level of energy might have mattered. When emotions were intense, negatively spread more easily than positivity. But the emotion that spread best of all was what Barsade calls the California Condition: calm serenity.

Most importantly, the emotions at play mattered for how much the groups cooperated and how effective they were at their task. This real-world applicability is something that has come up again and again in research. In another study, published in 2011 in the Journal of Personality and Social Psychology, Barsade and her team set out to learn whether it's better to start a tough negotiation in a good mood and then get angry, or whether it's better to start out as a tough guy and then soften up. They had pairs of people negotiate and found that the winning strategy was to start happy and get mad.

This sort of emotional Jekyll-and-Hyde trick might seem counterintuitive, but anger is known to be a winning strategy in short-term negotiations, Barsade said. (Long-term negotiations are another story.) Starting out happy let people keep all of the monetary benefits of an angry negotiating style, but it also kept their negotiating partner from disliking them. Part of the reason? The initial happy mood was contagious, and its spread kept the second partner from becoming as upset with the anger as they otherwise would have been.

Questions about contagion

These days, of course, many work conversations take place over email or on Slack or other messaging services. But emotions spread through electronic media, too. Contagion is powerful, said the University of Hawaii's Hatfield, and people tend to mimic others' word choice and emotional tone online. A famous study of Facebook users found that when people see more positive posts in their feed, they made more positive posts. When they saw more negative posts, their posts got gloomier, too.

Researchers have looked at the transmission of emotions through email, Barsade said, and they've found that the emotions that land in your inbox can affect you. The problem is that people are notoriously bad at judging the emotions in an email, she said, so misinterpretations abound. In other words, it's quite possible that a sender could infect you with an emotion they were never actually feeling.

Other workplaces conundrums need more research. What if a Debbie Downer and a Chipper Charlie share a cubicle? Whose mood wins out? No one knows, Barsade said. Attention is clearly key, because the more we pay attention to a person, the more we catch their emotions. But it's not clear whether negative emotions or positive emotions ultimately carry the day.

Nor is it clear how people consciously grapple with their unconscious tendency to feel other people's feelings. Emotional contagion is a largely automatic process, but that doesn't mean the conscious cognitive processes can't swoop in and make adjustments. Along with Boston University researcher Kristin Smith-Crowe and the Wharton School's Jaime Potter, Barsade is studying how people respond when their enemies display an emotion. Preliminary results suggest that sports fans initially get a millisecond's happiness from seeing the opposing team's fans cheer. But very quickly,. "the brain comes in and says, 'wait, wait, wait,'" Barsade said. At that point, their emotions turn negative as they realize that happiness for the other guys likely means bad news for their own side.

It's also important to remember that people don't wear their every emotion on their sleeves. Emotional displays are a communication system, said Guillaume Dezecache, a researcher in the department of comparative cognition at the Université de Neuchatel. Ignoring the flexibility with which humans display and respond to emotions hinders research into the factors that affect those responses, he said.

Meanwhile, researchers like Hatfield are increasingly interested in studying how emotions are transmitted not just between two people but also across large groups, hoping to explain a variety of social phenomena, for example, how terrorist groups recruit followers.

"Given the current climate of hatred, people have started to examine why appeals to hate are so powerful," Hatfield said. "An intellectual appeal to tolerance and understanding has a hard time competing with messages that stir up emotions."