Distressing Events, REM Sleep, & EMDR Therapy


Several weeks ago, strolling through our local Barnes & Noble, a book title caught my eye. Why We Sleep; Unlocking the Power of Sleep and Dreams (2017) by Matthew Walker, PhD. Little did I know in that moment, it would become a most interesting and informative read. Dr. Walker is a professor of neuroscience and psychology at the University of California, Berkeley, and the director of the Center for Human Sleep Science. He is also a former professor of psychiatry at Harvard University. I was particularly interested in reading about the stage of REM (Rapid Eye Movement) sleep, and its possible implications for EMDR (Eye Movement Desensitization & Reprocessing) therapy – which I will say more about later.

In Chapter 10 called “Dreaming as Overnight Therapy, Dr. Walker writes:

“It is said that time heals all wounds. Several years ago I decided to scientifically test this age-old wisdom….Perhaps it was not time that heals all wounds, but rather time spent in dream sleep. I had been developing a theory based on the combined patterns of brain activity and brain neurochemistry of REM sleep, and from this theory came a specific prediction: REM-sleep dreaming offers a form of overnight therapy. That is, REM-sleep dreaming takes the painful sting out of the difficult, even traumatic, emotional episodes you have experienced during the day, offering emotional resolution when you awake the next morning.

At the heart of the theory was an astonishing change in the chemical cocktail of your brain that takes place during REM sleep. Concentrations of a key stress-related chemical called noradrenaline are completely shut off within your brain when you enter this dreaming sleep state. In fact, REM sleep is the only time during the twenty-four hour period when your brain is completely devoid of this anxiety-triggering molecule. Noradrenaline, also known as norepinephrine, is the brain equivalent to a body chemical you already know and have felt the effects of: adrenaline (epinephrine).

Previous MRI studies established that key emotion- and memory-related structures of the brain are all reactivated during REM sleep, as we dream….(N)ow we understood that this emotional memory reactivation was occurring in a brain free of a key stress chemical. I therefore wondered whether the brain during REM sleep was reprocessing upsetting memory experiences and themes in this neurochemically calm (low noradrenaline), ‘safe’ dreaming environment. Is the REM-sleep dreaming state a perfectly designed nocturnal soothing balm – one that removes the sharp edges of our daily lives? It seemed so from everything neurobiology and neurophysiology was telling us (me). If so, we should awake feeling better about distressing events of the day(s) prior.

This was the theory of overnight therapy….Think back to your childhood and try to recall some of the strongest memories you have. What you will notice is that almost all of them will be memories of an emotional nature: perhaps a particularly frightening experience of being separated from your parents, or almost being hit by a car on the street. Also notice, however, that your recall of these detailed memories is no longer accompanied by the same degree of emotion that was present at the time of the experience. You have not forgotten the memory, but you have cast off the emotional charge, or at least a significant amount of it. You can accurately relive the memory, but you do not regurgitate the same visceral reaction that was present and imprinted at the time of the episode.”

(Note: An exception to the soothing balm of REM sleep dreaming is the condition of post-traumatic stress disorder [PTSD], which Dr. Walker discusses later in the chapter. REM sleep dreaming is important to the reduction of PTSD symptoms, but additional factors are involved, which will not be addressed in this blog). 

Continuing this lengthy, but necessary excerpt, Dr. Walker writes:

“The theory argued that we have REM-sleep dreaming to thank for this palliative dissolving of emotion from experience. Through its therapeutic work at night, REM sleep performed the elegant trick of divorcing the bitter emotional rind from the information-rich fruit. We can therefore learn and usefully recall salient life events without being crippled by the emotional baggage that those painful experiences originally carried….That was the theory, those were the predictions; next came experimental test, the results of which would take a first step toward falsifying or supporting both.

We recruited a collection of healthy young adults and randomly assigned them to two groups. Each group viewed a set of emotional images while inside an MRI scanner as we measured their emotional brain reactivity. Then, twelve hours later, the participants were placed back inside the MRI scanner and we again presented those same emotional images…During these two exposure sessions, separated by twelve hours, participants also rated how emotional they felt in response to each image.

Importantly, however, half of the participants viewed the images in the morning and again in the evening, being awake between the two viewings. The other half of the participants viewed the images in the evening and again in the morning after a full night of sleep….

Those who slept in between the two sessions reported a significant decrease in how emotional they were feeling in response to seeing those images again. In addition, results of the MRI scans showed a large and significant reduction in reactivity in the amygdala, that emotional center of the brain that creates painful feelings. Moreover, there was a reengagement of the rational prefrontal cortex of the brain after sleep that was helping maintain a dampening brake influence on emotional reactions. In contrast, those who remained awake across the day without the chance to sleep and digest those experiences showed no such dissolving of emotional reactivity over time. Their deep emotional brain reactions were just as strong and negative, if not more so, at the second viewing compared with the first, and they reported a similarly powerful reexperiencing of painful feelings to boot….

As the theory predicted, it was the dreaming state of REM sleep–and specific patterns of electrical activity that reflected the drop in stress-related brain chemistry during the dream state–that determined the success of overnight therapy from one individual to the next. It was not time, therefore, time per se that healed all wounds, but instead it was time spent in dream sleep that was providing emotional convalescence.”

One, final important caveat. Citing the exquisite dream research of Dr. Rosalind Cartwright at Rush University in Chicago, Dr. Walker adds: “it (is) not enough to have REM sleep, or even generic dreaming, when it comes to resolving our emotional past….,but dreaming of a very specific kind: that which expressly (involves) dreaming about the emotional themes and sentiments of the waking trauma. It (is) only that content-specific form of dreaming that (allows movement) forward into a new emotional future, and not be enslaved by a traumatic past.”

So, what might be the possible implications of REM sleep dreaming, (if any) to Eye Movement Desensitization & Reprocessing (EMDR) therapy?

My website is replete with information about EMDR therapy; from a separate web page, to official websites, to specific blog posts. Borrowing an excerpt from my May 1, 2016 post:

“(EMDR therapy) was developed in the 1980s by psychologist Francine Shapiro, PhD. As with many discoveries, Dr. Shapiro made the chance observation that eye movements can reduce the intensity of disturbing thoughts, under certain conditions. This humble beginning launched years of experimental and clinical research, and has now evolved into one of the leading and most recognized treatments for trauma throughout the world. My succinct description of EMDR to clients goes something like this: ‘Research suggests that when distressing events are paired with bilateral stimulation—visual, tactile, and/or auditory—there is the potential that those events will be desensitized and reprocessed.’ Although no one knows how any form of psychotherapy works neurobiologically in the brain, EMDR appears to be similar to what occurs naturally during dream or REM (rapid eye movement) sleep. Therefore, EMDR therapy can be thought of as a physiologically based therapy that helps a person see disturbing material in a new and less disturbing way.”

Now, 30 years later, independent sleep studies—like Matthew Walker–offer support for Shapiro’s ideas: that directed eye movements can stimulate the same processes that occur in REM sleep. Dr. Shapiro (2018) writes:

“Despite this evidence that REM can support forms of memory and emotional processing critical for trauma recovery, there is currently no direct evidence that EMDR induces similar processing during the waking state. However, Strickgold (2002) has posited direct neurobiological correlates between EMDR- and REM-state functions and has also posited appropriate tests of this hypothesis….Strickgold (2002) proposed that the repetitive redirection of attention in EMDR processing induces changes in regional brain activation and neuromodulation similar to those produced during REM sleep. Activation of these systems may simultaneously shift the brain into a memory-processing mode similar to that of REM sleep, facilitating the integration of traumatic memories into associative cortical networks.”

Robert Strickgold, PhD (cited above) is not only Professor of Psychology at Harvard Medical School, and Director of the Center for Sleep and Cognition in Boston, Massachusetts, he is also Matthew Walker’s “mentor…longtime collaborator and friend” at Harvard Medical School.

Conclusion? Independent sleep research suggests that the most common form of bilateral stimulation used in EMDR therapy—side-to-side eye movements—can stimulate the same processes that occur in REM sleep.

Bill Bray, Colorado Springs, CO

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