How Memories Can Be Modified and Manipulated

By Dov Michaeli, MD, PhD | Published 4/15/2018 0

Memory manipulation brain and eraser

We intuitively feel that we exercise free will in our decision-making. But as neurobiologists have suggested, this is a bit illusory. They have shown that circuits in different regions of the brain are activated fractions of a second before we consciously make a decision. This phenomenon may reflect the fact that decisions are not made in a vacuum. They are made in the context of our previous experiences and the observed brain activity is a reflection of the subconscious retrieval and organization of the relevant memories into a coherent framework that will affect, if not pre-determine, a conscious decision.

But, you might argue, we still own that decision; it is based on our own memories and experiences. So in a way, it was generated within us, not imposed or influenced by somebody else; in other words, it is pretty close to our understanding of “free will”. Well, not so fast.


What makes a memory?

Memories can be individual, unadulterated by external influences. For instance, I can vividly remember the smells of my mother’s kitchen when she was baking cheese blintzes. I can also remember how delicious they were. And I recall the pangs of regret after (alas, not while) devouring a dozen of them. These memories were generated by me; nobody generated them for me, nor altered them after the fact. If I see blintzes on the restaurant menu, all those memories are going to feed into the decision I make about whether to order one (or a dozen).

But I also have memories that I am not so sure are truly unadulterated or even purely factual. These are the kind of memories that have been generated but then altered by social influences. I loved my high school history teacher. But I gradually changed my memory of him because whenever I got together with my classmates, their memories were of a pretty unappealing character. In a word, I conformed to the prevailing memory.

Social psychologists distinguish two types of social conformity. If other people’s memory agrees with yours but updates and reinforces yours, you accept it as your own. This is called private conformity. But there is another type of social conformity. You are totally confident that your memory is accurate and at variance with the others, but under social pressure, you conform to the group’s memory. This is called public conformity. Interestingly, private conformity tends to be long-lasting, whereas public conformity tends to be short-lived, or transient.

You can now see how our memories may not be truly individual. They are subject to social influences, some positive (they correct factual errors and omissions), and some negative (they manipulate the memory of facts to conform to the “accepted” version, regardless of veracity). This is not just an exercise in theoretical psychology. It has important social implications.

Remember the wave of “recovered memories” stories of child abuse? They provided newspapers with sensational stories and lawyers with fat fees, but not before the claimed psychological basis was shown to be largely bogus.

Or how about the eyewitness testimonies that are still being obtained under police or prosecutor pressure? The profound effects of social conformity on our personal and social lives demand that it be examined rigorously, using the latest scientific tools available.


The neurobiology of social conformity

A recent controversy flared up about special prosecutor Robert Mueller’s statement that Russian intelligence operatives tried to influence the 2016 election results by sowing discord in our political discourse. The Russian operation began about four years ago, well before Mr. Trump entered the presidential race, a fact that he quickly seized upon in his own defense:

Russia started their anti-US campaign in 2014, long before I announced that I would run for President,” he wrote on Twitter. “The results of the election were not impacted. The Trump campaign did nothing wrong—no collusion!

Really? What does science say about the potential impact?

A group of investigators from the neurobiology department of the Weizmann Institute in Israel studied the brain “signature” of social conformity. They used fMRI to record the brain activity of 30 adults who viewed a documentary-style movie and then were tested on their memories of the movie over a 2-week period. The researchers intentionally tried to induce memory errors in some subjects by telling them what others recalled about the movie; they exposed other subjects to randomized “recollections”.

The researchers observed greater neural activation in the hippocampus for items that showed persistent memory errors (private conformity) than for items that displayed transient errors (public conformity). They were also able to distinguish between conformity elicited by social influences (being exposed to other people, or at least their faces) and conformity produced by nonsocial methods (being exposed to computer-generated responses to questions on a test).

The investigators observed strong activation of the amygdala in subjects who displayed social conformity (responding when influenced by other people’s responses). In contrast, they observed less activation in subjects displaying nonsocial conformity (responding to computer-generated responses). This finding mirrored behavioral data suggesting that greater conformity occurred under social pressure.


Memory manipulation

The major importance is social. For the first time, it demonstrated that the way social pressure affects our memory is literally etched in our mind—it activates new pathways. For instance, the amygdala has never been known to be involved in memory. Their involvement in memory-under-social-pressure is surprising (they have been known to be primarily involved in controlling emotions). It opens new possibilities in understanding psychological states such as cognitive dissonance and conflicts of conscience.

But there is another aspect to this study. The other side of the social conformity coin is memory manipulation. We have already mentioned it in relation to psychotherapists, police, and lawyers. But there are bigger manipulators, more insidious and dangerous: think propaganda machines of political parties, think totalitarian regimes rewriting history.

In the 1920’s, there was hardly any antisemitism in Germany. The Jewish population was in the center of the cultural and economic life of the country. Goebbels’ propaganda machine, through incessant repetition of “the big lie” planted in the collective German mind a new bogus memory. The Soviets distorted historical facts and used the Goebbels’ tactic to manipulate their own masses. And without getting overly political, one doesn’t have to dig deep to find the same tactics being used in our country, attempting to manipulate people’s collective memory.

Mark Twain’s pithy aphorism that

“A lie can travel halfway around the world while the truth is putting on its shoes”

is true, but incomplete. Who, or what is at fault?

A major new study published in the journal Science finds that false rumors on Twitter spread much more rapidly, on average than those that turn out to be true. Interestingly, the study also finds that bots aren’t to blame for that discrepancy. People are.

The paper, authored by scholars at the MIT Media Lab, analyzed an enormous data set of 126,000 rumors that were spread on Twitter between 2006 and 2017, generating tweets from more than 3 million different accounts. Specifically, they looked at claims that were subsequently evaluated by major fact-checking organizations and found to be either true, false, or some combination of the two.

They found that false rumors traveled “farther, faster, deeper, and more broadly than the truth in all categories of information,” but especially politics. On average, it took true claims about six times as long as false claims to reach 1,500 people, with false political claims traveling even faster than false claims about other topics, such as science, business, and natural disasters.

Medicine has taught us that in order to effectively combat a disease we need to gain a detailed knowledge of its inner workings. Likewise, I believe that scientific understanding of the mechanisms underlying our social interactions may help in creating a healthier society. The Israeli paper and the MIT paper are important first steps in this journey.

More by this author: How Did We End Up in a Post-factual World?

This post was originally published August 2011. It was updated by the author on March 11, 2018.


Dov Michaeli, MD, PhD

Dov Michaeli, M.D., Ph.D. (now retired) was a professor and basic science researcher at the University of California San Francisco. In addition to his clinical and research responsibilities, he also taught biochemistry to first-year medical students for many years.

During this time he was also the Editor of Lange Medical Publications, a company that developed and produced medical texts that were widely used by health professionals around the world.

He loves to write about the brain and human behavior as well as translate knowledge and complicated basic science concepts into entertainment for the rest of us.

He eventually left academia to enter the world of biotech. He served as the Chief Medical Officer of biotech companies, including Aphton Corporation. He also founded and served as the CEO of Madah Medica, an early-stage biotech company that developed products to improve post-surgical pain control.

Now that he is retired, he enjoys working out for two hours every day. He also follows the stock market, travels the world, and, of course, writes for TDWI.