Conversations on Trauma, Resilience, and Healing
“Once the signal comes into the brainstem”—here I directed their attention to the bottom of the triangle—“it is processed. Basically, the incoming signal is matched against previously stored experiences. In this case, the matching process connected the motorcycle backfire with gunfire—remember that combat-related memory? And since your brainstem can’t tell time, or know that many years have passed, it activates the stress response and you have a full-blown threat response. You feel and act as if you are under attack. Your brainstem can’t say, ‘Hey, don’t get so stirred up, Korea was thirty years ago. That sound was simply a motorcycle backfiring.’”
I watched this sink in. “Now, when the signal finally gets up to the cortex, the cortex can figure out what’s really going on. But one of the first things that happens when you activate the stress response is that systems in the higher parts of the brain, including our ability to ‘tell time,’ get shut down. So the information about the motorcycle backfire did ultimately get to the cortex, but it took a while. And until it did, you were back in Korea and then confused. It took you all night to calm down, right?”
“I didn’t sleep at all.” Mike looked exhausted but relieved. “So I’m not crazy?”
—Dr. Perry