According to an article in Neuroscience News, researchers at Virginia Tech have been studying the fact that individuals with PTSD do not have diminished levels of certain neurotransmitters–norepinephrine and serotonin–during REM sleep as they should, which seems to result in a failure to inhibit fear memories and, in turn, bad dreams.

They used this information and found that when they lowered norepinephrine and serotonin levels in the brain, the rhythmic connections between the front of the brain where executive functions are processed, called the pre-frontal cortex, and the emotion-memory processing part of the brain, called the amygdala, were strengthened.  (Those connections are important because one cannot be calmly aware and upset at the same time.) Then, to break the cycle of fear-related dreams, the researchers tried first to increase theta brainwaves, which did not work, then worked to increase alpha waves in the brain, which did work.

Most neurofeedback practitioners understand that alpha waves are important. Called alpha because they were the first brainwaves that researchers discovered over 100 years ago, they are easy to find, because in well-functioning brains, the alpha frequency activates and is easy to detect once one closes her eyes. The alpha brainwave serves as a bridge between internal and external awareness and can be developed through practice. Creating more alpha, up to a point, is calming for almost everyone.

The Virginia Tech researchers increased the alpha frequency in their study using auditory stimulation, but there are other ways to increase alpha, including meditation, neurofeedback, and brainwave entrainment devices.

You may access the Neuroscience News article here. The published study in the Journal of Neuroscience is behind a pay wall, but you can read the abstract here.