Science Daily reports that an MRI study comparing brain activity in children diagnosed with PTSD with their non-traumatized peers found differences between the two groups:
...subjects were placed inside the fMRI machine... and then asked to push a button each time a letter other than X flashed on a screen in front of them. Because Xs were introduced only after a string of non-Xs, the test is a good way to measure what's known as response inhibition, or a subject's ability to suppress the natural tendency to push the button as soon as any letter appears...
The researchers found that, although the two groups accomplished the task equally well, they used different parts of their brains to do so. The children with PTSD symptoms showed less activity than their non-traumatized peers in the left middle frontal cortex, an area known to be involved in response inhibition, and more activity in several other areas of the brain including a region involved in emotional awareness known as the insula.
"We found that affected kids who injured themselves-a subgroup of our study sample-had more activity in the insula than did kids who did not injure themselves," said Carrion. "What's more, we found a very good correlation between the levels of activation of this structure and the severity of PTSD symptoms experienced by the child."
And in another study reported in the journal Nature Neuroscience, researchers report on a genetic variation associated with better recall for emotionally charged events:
"This was a first proof of principle that we are able to identify genes [specifically] related to emotional memory," says the new paper's lead author Dominique de Quervain, a professor in the University of Zurich's Division of Psychiatry Research. "[This work] may have consequences for anxiety disorders where emotional memory plays a critical role."