Erasing Painful Memories With Shock Treatment

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Using electroshock therapy, scientists say it may be possible to get rid of specific emotional memories.

We’re still far from being able to blot out our latest breakup “Eternal Sunshine”-style. But research published in the journal Nature Neuroscience showed for the first time that it may be possible to manipulate human memories with physical interventions such as electricity shortly after they are recalled. The study could lead to new treatments for conditions like depression, post-traumatic stress disorder (PTSD) and even addictions— all of which can involve memories that are intrusive and potentially destructive.

The intriguing experiment involved 42 severely depressed patients who had already agreed to undergo electroconvulsive therapy (ECT), which is typically used as a last resort when all other measures have failed. Since ECT is well-known for having negative effects on recall in general — that’s why it’s reserved for only the most intractable cases— the researchers wanted to see if it might only disrupt a newly formed emotional memory, as well as lift depression.

Led by Marijn Kroes, a postdoc at the Donders Institute for Brain, Cognition and Behavior at Raboud University Nijmegen in the Netherlands, the authors first asked the participants to watch two extremely unpleasant, narrated slideshows.  One told the story of a young boy who is hit and killed by a car as he walks with his mother. The other involved two sisters, one of whom is seriously assaulted and molested by an escaped convict.

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Participants were told that the study was focused on memory, and were told to pay close attention to both the images and the stories. A week later, all were shown a partially covered version of its first slide and asked to recall just one of the stories. Then the patients were divided into three groups— two groups were given ECT immediately after recall and testing — one group was quizzed on both stories immediately after waking from the anesthesia used for the procedure while the other was tested 24 hours later. The third group simply got the cue and the test, but not ECT.

The patients who were queried just after waking remembered both stories equally well. The group that didn’t receive ECT actually remembered the story that they had been cued and tested on better— not surprisingly, since they were reminded of it.

The group tested a day later, however, was different. While they were able to remember some of the story that they hadn’t been cued to think about immediately before ECT, they couldn’t recall the one they had been primed to remember before the treatment at all.  “They performed no better than chance level,” says Kroes, “They might just as well have been guessing.”

The scientists believe that the timing of the memory testing mattered: the fact that memories could be accessed immediately, but not a day later, suggests that the effect of electricity takes time to interfere with the memory storage process.  Far from being the faithful record of the past that we like to imagine it as, memory is actually used by the brain mainly to predict the future— and this means that old memories are vulnerable to being re-written every time we access them.  Previous research showed that this time-dependent “reconsolidation” occurs in animals, but this is the first time it has been demonstrated in humans.

Hank Greely, director of the Center for Law and the Biosciences at Stanford University, who specializes in the ethics of neuroscience but was not associated with the study, notes that it’s not yet clear whether the technique would actually work for personal memories, which may be more complex, engrained and layered with emotional and other sensory characteristics that aren’t so easily manipulated—rather than those of a short slide show seen a week earlier in a lab setting. That would make a difference in how such strategies might be used to treat certain mental illnesses — while it might help those who were recently traumatized, for example, if it doesn’t affect older memories, it wouldn’t work in many cases of more established PTSD or the many other disorders  oftenrelated to childhood traumas.

Elizabeth Phelps, professor of psychology and neural science at New York University, also cautions that the participants’ overall recall of both stories wasn’t great, making the differences between the groups small.  “I think it’s interesting as a proof of concept, but I don’t think it’s necessarily going to be a robust treatment because it’s so invasive,” she says.  Phelps was not involved with this research, but Kroes has recently been hired by her lab.

Phelps and other researchers have previously used far less invasive techniques to reduce the emotional charge attached to a memory— rather than eliminating the memory itself.  For example, one study exposed participants to smells paired with shocks and then wafted the same scents into their noses as they slept.  The volunteers didn’t forget which scent was linked with the shock— but they no longer had a fear response to it. “If you could take away the fear associated with the memory and keep the memory, that would be more optimal,” she says.

Kroes plans to look next at whether having patients deliberately think about their most distressing or traumatic memories immediately before ECT would erase these memories, or at least dampen their impact and improve depression.

If that does work, the potential uses of a technique that erases personal memories raises profound ethical questions. Our memories are deeply related to our selves and many survivors of trauma get a sense of meaning and purpose from knowing what they have conquered. If negative or challenging memories are selectively removed, what would they leave behind?

“What if we wiped out all of the memories of the Holocaust?” asks Greely, “That would be terrible.  On the other hand, the suffering caused by some memories is really powerful and I would want to prioritize letting people who want to relieve their suffering, as a general matter, relieve their suffering.”

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Greely is most concerned about how such technologies would be used against people’s will. If a trauma survivor wants to erase bad memories, he thinks it should be permitted— but absolutely not required.  However, he can also envision situations in which involuntary use of memory-altering techniques might sometimes be acceptable — for example, parents might request it to protect their child from the legacy of surviving a traumatic event.

Taken to another extreme, such tactics could also be a new way to train spies and soldiers, potentially creating individuals who could commit atrocities without regret. While such professionals are already steeled to the consequences of their actions, the ability to selectively erase potentially troublesome and painful recollections would provide new levels of efficiency that might be disturbing. In legal cases, it could also raise new issues related to the reliability of witness testimony altered by such techniques.

But before that happens, says Kroes, he and others will have to learn much more about how the brain makes, stores and recalls memories. His results suggest that it may be possible to selectively delete some memories from our brains, but more work will be needed to understand what happens to the space that those missing memories leave behind.

4 comments
BrianCh16
BrianCh16

It's already possible to eliminate a past traumatic memory, and it can be done without pumping electricity through someone.  Instead, tapping on specific acupuncture points while focusing on those past traumas can be remarkably effective.  Two such techniques are the Emotional Freedom Technique (EFT) and Thought Field Therapy (TFT).  

I suffered severe PTSD many years ago when I witnessed an accidental death up-close and personal.  Over the years, I sought help because I suffered from frequent flashbacks and depression.  But talk therapy didn't help me, nor did the drugs I was prescribed for anxiety and depression.  

Someone I knew back then suggested EFT, and although I felt it sounded new-age and stupid, I was desperate enough to try it.  Now, the memory doesn't trouble me at all; in fact, I can describe it in detail to someone else without feeling any discomfort.  

I'm grateful that researchers are working to help people with PTSD, but it saddens me that suffering patients will be convinced to undergo electric shock treatment when there is a non-invasive alternative that works very well.

Tablo31
Tablo31

Hey man, after I read your comment I became interested so I decided to look up EFT but the thing is I only found articles and stuff that only discredited it and affirmed it it just a pseudoscientific method. The thing is, me too, have spend years in trying to relieve my pain caused by a traumatic situation. So I wanted to ask, how much time it took you to start feeling relieve and how long has it been since you tried this technique and how long has it last the effect on you. I'm really skeptic because it's been years since I've trying to find relieve to my situation but I can't seem to find it.

BrianCh16
BrianCh16

@Tablo31  

(Sorry for the long response.)

I'll answer your last part first.  I successfully ended my PTSD issue a year or so ago.  My flashbacks which plagued me for years are now gone (and still gone), as are the associated anxiety and depression issues it caused.  It took well over a year of doing EFT to get the full amount of relief that I wanted; I wasn't always doing it correctly, and I was a little slow to figure things out.      

Given how well it worked for me, I can only speculate as to why some (were they professionals? You didn't say who.) would write that EFT is not legitimate.  Since many mainstream researchers are skeptical of anything associated with acupuncture, I find myself wondering if they would even bother testing EFT in a thorough manner, since they would likely think "this is probably a waste of time" and "it can't possibly work, anyway!"    


EFT isn't horribly complicated, but it's not idiot-proof, either.  With deeper emotional issues, some finesses in the general EFT method are often required; that's something people doing a study may not know how to do --- or want to do.  My own issues were only partially helped through the standard method; ultimately, I had to look online to find a variation that another EFT practitioner came up with (which she dubbed "Slow EFT"), and only by using that did I fully conquer my "demons".

Gary Craig (creator of EFT) has often talked about how successful use of EFT requires one to "tune in" to the problem:  in other words, not just calmly verbalizing it, but making a conscious effort to remember as much as possible how the pain and trauma FELT AT THE TIME.  For the tapping to work, the painful memory needs to be briefly re-imagined again.  You didn't indicate where you read the critical viewpoints of EFT, but I read one article a couple years ago which claimed to show that EFT doesn't work, and they didn't even do the method correctly.  For one, they made no reference whatsoever to having their subjects "tune in" and visualize their traumas.

And let's be honest ---- in this day and age of scientific advances, it's hard for many to believe that something so simple could be highly effective.  For decades, mental health professionals have become accustomed to the belief that relief from PTSD can only come through therapy over a very long period of time, and with very hard work.  Understandably, they probably feel very offended when someone suggests there's a much easier and faster way, and they tend to roll their eyes.  And then they would probably immediately rule it out without taking a hard look at it.

Through my many years of therapy, I constantly wondered how much therapists, although well-intentioned, REALLY understood or knew about severe PTSD ---- or if they had ever experienced it themselves.  Their advice always seemed kind of impotent:  they would often naively tell me there's no logical reason to hold on to the pain (no kidding!), and then they would look genuinely confused when that approach didn't work and I kept having flashbacks.  I rarely felt as if I, or my issues, were being taken seriously.

We should also note that medical science hasn't always taken the straightest path between two points.  Remember the people who you said "discredited" EFT?  The fact that doctors would even look seriously at electroshock therapy shows that there's still a great deal about PTSD that they don't understand.  Over two centuries ago, doctors resisted handwashing for years, even after evidence showed that it decreased death rates in some fields of medicine.  And despite decades of work in pain medicine, doctors are still struggling mightily to explain what causes it in the first place, and how to effectively treat it.  

Modern medicine has provided many benefits, but it has hardly been without some sizable failures along the way.

Whether you try EFT or go with entirely different approaches, I wish you the absolute best.  Whatever route you choose, don't give up; for years, I thought my life was over, and I'm glad I was wrong.