Trauma changes not only the way we think, but also the way our brains work.

“After combat, vets have to live with an altered neural network,” said Dr. Bessel van der Kolk, founder and medical director of the Trauma Center at the Justice Resource Institute in Massachusetts.

And that has profound implications for combat vets with PTSD. If neurological reasons prevent them from controlling some of the things they do, how can we hold them accountable? And what therapies work best for these damaged brains? We’ll look more closely at those two issues in subsequent blogs.

But first, let me tell you about a remarkable lecture that van der Kolk gave at the Center for Ethics and the Rule of Law at the University of Pennsylvania in Philadelphia last week.

Early in his career, one of van der Kolk’s patients told him that he had killed some Vietnamese children, shot an innocent farmer and raped a woman to avenge the deaths the previous day of all the members of his platoon, including his best friend. So van der Kolk used revenge killings as one example of moral injury at the PTSD conference.

“After something like that happens, vets don’t feel safe with themselves anymore,” he said. “And they may not feel safe being around their wife and kids.”

One problem is desensitization. As a soldier becomes numb to the chaos around him, he also loses his sense of compassion for others.

Even worse, it’s as though those traumas get stuck in a vet’s brain and he can’t get on with his life. “That’s because PTSD emerges from a part of the brain over which we have no control,” van der Kolk explained.

In the past few decades, neurologists have been able to use brain scans to determine how people’s brains respond to various stimuli and to memories. Van der Kolk showed several slides to illustrate how a traumatized brain operates differently from a so-called “normal” brain.

When a combat vet remembers traumatic events from his past, the prefrontal cortex of the brain – the center of rational thinking – shuts down. That makes it impossible to try to use logic to confront his memories, van der Kolk said.

In particular, one part of the left frontal lobe of the brain called the Broca’s area shuts down when confronted by trauma. “Without a functioning Broca’s area, you cannot put your thoughts and feelings into words,” van der Kolk said in his newest book, The Body Keeps the Score. “Our scans showed that Broca’s area went offline whenever a flashback was triggered….

“Under extreme conditions, people may scream obscenities, call for their mothers, howl in terror or simply shut down,” he wrote. “Victims of assaults and accidents sit mute and frozen in emergency rooms; traumatized children ‘lose their tongues’ and refuse to speak. Photographs of combat soldiers show hollow-eyed men staring mutely into a void.”

At the same time, the brain’s limbic system – the seat of emotions – is ramped up, and the amygdala sends out hormones and neurochemicals that drive up blood pressure, heart rate, and oxygen intake to ready the body for fight or flight.

There’s no known neural pathway to allow reason to moderate the emotions stemming from the limbic system, van der Kolk told the PTSD conference.

Trauma victims also have a harder time focusing because they’re distracted by everything around them.

“The left anterior cingulate filters out distractions around us,” said van der Kolk, “but trauma disables it. So traumatized people are unable to filter out outside influences, which makes it hard for them to learn new behaviors.”

Childhood trauma makes an adult more susceptible to being re-traumatized, he said. That’s especially troubling he added, because more than 12 million American women have been the victims of rape, with more than half of all rapes being forced upon girls younger than 15 years old. And each year, around 3 million children are abused and neglected, one third of whom so severely that local child protective services or the courts are required to take action.

“So if you want to eliminate PTSD in the military, only let people with perfectly safe childhoods serve in your army,” he added. “Of course, it would be a very small army.”

Van der Kolk closed his lecture by illustrating two dramatically different responses to the terror attacks of 9-11.

One was a 5-year-old child’s drawing of the plane slamming into the World Trade Center. It showed what looked to be a fireball explosion, people screaming and jumping out of the windows. It portrayed all the sights and sounds of the attack that had been registered by the limbic system.

But there was also one important element of rational thinking: the young artist had added a trampoline on the ground beside the World Trade Center so that the people who were jumping would not be hurt.

By contrast, the response from Washington, D.C., was completely limbic, van der Kolk said.

“After 9-11, the president said we’re going to bomb them alive or dead,” he said. “And that was totally a limbic response, not a rational one. Because our government operated on a limbic response instead of a rational one, more than 2,000 Iraqis who had nothing at all to do with 9-11 have been killed.”

So what kind of therapy does this neuroscientist favor?

“We need to bring that portion of the traumatized brain back online if we are to provide effective therapy for PTSD,” van der Kolk told the group.

In many ways, that involves the same techniques that a mother uses to comfort a frightened child: rocking, holding, soothing and singing. It’s also important that the vet, like the child, feel a sense of safety.

“Man is a social animal,” said Aristotle, and that concept is key to van der Kolk’s therapy. We connect with others by working in synchronicity, building rhythms that connect us with others, he said. That’s why breath exercises, chanting, martial arts like qigong, drumming, group singing and dancing are so important.

All rely on interpersonal rhythms, visceral awareness and vocal and facial communications that help shift people out of their fight-or-flight stages, reorganize their perception of danger, and increase their capacity to manage relationships, he said.

“Americans use alcohol and drugs to treat PTSD,” said van der Kolk. “But other cultures turn to dance, song, music and drumming. Yoga shows greater effectiveness than any pill you can take.”