These
posts make more sense when read in order.
Please click here for the first article in this series to enter the rabbit hole.
Following a brain injury, a man began having false memories that
were as vivid as the real thing. Suddenly his past was completely unreliable.
He couldn’t be sure that anything he remembered had actually happened.
Apparently the injury caused amnesia and his subconscious was filling in the
blank spaces with fabricated memories of what it thought might have happened.[1]
We all do this to some extent when we retrieve memories. They
are laid down fresh each time you recall them.[2]
If you don’t recall them, they deteriorate over time. This is even true for
people with amazing autobiographical memories, although to a much lesser
extent.[3]
As mentioned earlier, when we see a scene our brains break it
up into parts to process and then reconstructs it, recognizing the larger
concepts. It’s those larger concepts that are laid down in memory. This is done
by creating pathways of neurons, which alter their connections for that memory,
so that if you see a white rabbit in a waistcoat holding a pocket watch, this
memory connects the paths for “white rabbit”, “waistcoat”, “pocket watch”,
and anything else of significance using just a few of your 86 billion neurons and
their 100 to 200 trillion connections.
When we remember the scene, the process is somewhat reversed.
We start with the concepts and some salient details, then fill in the rest. Our
subconscious checks our memories for their strength and relevance, discards
what is unimportant, and fills in the gaps using our prior knowledge,
expectations, prejudices, biases, beliefs, and attitudes, so we end up
recalling some details that never happened. This is then laid down as part of
the original memory.
One of the world’s greatest
neuroscientists, Nobel laureate
Eric Kandel, explained, “Human memory reinvents itself all the time.
Every time you remember something, you modify it a little bit, in part
dependent on the context in which you recall it. That is because the brain’s
storage is not as exact as written text. It is always a mixture of many facades
of the past event: images, pictures, feelings, words, facts, and fiction—a ‘recollection’
in the true sense.”
[4]There’s no way we can tell which parts of our memories are
accurate without confirming evidence, such as photographs or videos. Even other
witnesses can get it wrong, especially if they’ve been discussing amongst
themselves or with anyone else.
People also form their memories in different ways and have
different methods of remembering. This is why two people can have different
memories of an event, even immediately afterward. This is especially evident
after they’ve had an argument. It can be as if they’re recalling two unrelated
incidents. There are individual differences in the way people remember. Some
rely on visual images, while others—roughly one to three percent of the
population who lack a mind’s eye—are unable to recall with imagery. Those that
do have a mind’s eye have it to varying degrees, with some having very vivid
visual imaginations. This affects what you remember.
A person’s emotional state can also influence how they recall
an event, with highly charged memories seeming much more vivid. In addition, we
tend to subconsciously pick out the aspects we think are more useful or
significant, casting aside whatever we feel is irrelevant.
Our memories aren’t just recorded—they are processed,
manipulated, and analyzed, passing through several stages. There’s a
controversial theory that we might have a sensory memory that holds information
for a few milliseconds before passing it on to our short-term memory.
Short-term memory roughly holds on average three to five items
or groups of items for around 18 seconds—occasionally up to 30, unless the
information is rehearsed. This stage briefly stores information. It can’t
manipulate or analyze the data.
That happens in the working-memory stage and takes place in the
prefrontal cortex of your brain. You may recall from earlier that this is also
where the higher forms of sensory processing happen and where that information
finally reaches our consciousness. Of course other specialized areas of the
brain are also involved in processing, depending on whether the information is
visual, auditory, language, or abstract, to just highlight a few. Different
people have various levels of working memory. Those with higher levels are
better at such things as communication, problem solving, and critical thinking.
Your working memory is always running, unless you’re in a coma or perhaps during
certain forms of meditation.
It is at or about this stage that visual sensory signals for
letters and numbers are re-coded as sounds for efficiency. In other words, we
remember a written phone number as we would say it, not as we see it. There are
indications that other input is similarly simplified. Details unrelated to the
task at hand are cast aside.[5]
Memories are also consolidated. Consolidation is controlled by
the hippocampus, which is roughly the size and shape of a common fully grown
seahorse. You have two of these structures in the center of your brain.
Memories are stored in the hippocampus and the neocortex—the gray matter outer
layer of the brain. Consolidation is where the hippocampus moves memories
around between itself and the neocortex, reorganizing and stabilizing them,
while putting them in long-term storage. This is done through repetition and
rehearsal, which alters the proteins in the network of neurons. The process can
take minutes or many hours. In a subtype of consolidation, the process can take
years or decades.
Interestingly, the hippocampus and neocortex work in opposite
ways. In the hippocampus, the neurons are synchronized and fire together,
ensuring different parts of the memory are linked, while those in the neocortex
are kept separate so they are processed as elements and aren’t retrieved all at
once.[6]
It’s thought that memories are reduced to their gist during
consolidation so that the more significant points are retained. For example, if
you know that hermit crabs are not crabs, you probably won’t remember where you
learned that or the other details you learned with it.
This causes problems when you hear something that you know is
false from an unreliable source. When the memory is stored, the source and details
are stripped away and sometimes you can even forget that you knew it was a
false in the first place.
Political candidates often rely on this when they use negative
advertising. They know you probably won’t believe their lies when you hear
them, but if they’re shocking enough, the gist will stick in your memory and
later you may not remember your source or even that you knew it was a lie, and
you could end up remembering it as being truthful. Unfortunately this has been
found to generate more votes than positive advertising, which is why you see so
much negative advertising, and it’s one reason why some of the worst candidates
get elected.
We currently divide long-term memories into about six types
that are associated with different parts of the brain—two of which involve the
memories we’re conscious of. An example of subconscious memories would be
knowing where to place your fingers when typing or playing the piano. While you
may be curious about the types of long-term memories, listing them here would just
bore you, so I’ll move on. Feel free to research them on your own, if you like...as
with any of this. Memory formation is very complex and I’ve barely touched on
it here.
As is often the case in nature, these divisions of memory
actually blend together. We artificially create categories to make it easier
for us to understand.
Now, the memories also have to be retrieved. This is done in
several different ways and there are different things that can affect it. In
general, it’s thought that during recall the hippocampus activates the gist and
then calls out to the neocortex for the details,[7]
all within a fraction of a second.
A Convincing Mirage
Many people wrongly think of the brain as a memory vault that
stores everything and it sits there even if we can’t recall it—we just have to
figure out a way to retrieve these long-stored memories.
We have all had trouble recalling things, and we’ve all had
something remind us of something from the past we hadn’t thought of in years,
much like Marcel Proust’s famous Madeleine cookie. Sigmund Freud expanded on
this suggesting traumatic memories could
be stored and remain inaccessible unless they are re-accessed by a trigger or
in therapy. He later abandoned the idea, but some therapists and a few
researchers carried it on.[8] It seems logical, but the preponderance of researchers
and studies say there’s no evidence of this and it goes against what we know
about how memory works.[9]
This is a huge field of study in psychology and in the center of it is
Elizabeth Loftus, one of the top experts on false memories, having conducted
over 200 experiments with more than 20,000 subjects.[10]
The tricky thing is
that false memories can be easily created through leading questions by a
therapist or police interrogator without any of the parties being aware of it.
In addition, tests show hypnosis is very effective at converting fantasies,
imagination, and even suggestions into fake memories that are even more
convincing than the real thing.[11]
False memories in general tend to be strong and can even cause symptoms of
PTSD, as has been seen in those who claim to have been abducted by aliens.
If someone suddenly remembers something in great detail, that’s
a red flag indicating it’s a false memory. Memory just doesn’t work like that.
It has to be reinforced in order to retain its strength.
False memories are not
just parts of memories—they can be the entire memory. This became a real
problem during the 1980s and 90s during the Satanic child abuse scare that
swept across the U.S., resulting in many false accusations and trials, such as
those against the McMartin Preschool in Manhattan Beach, California.
Strangely many of the
McMartin accusations were so outlandish it’s hard to believe the authorities
took them seriously. Along with raping children for years unnoticed, the
teachers were accused of sacrificing a baby in a church, using a baseball bat
to beat a horse to death, cutting up animals, forcing the children to drink
blood, and flying through the air dressed as witches. In spite of this, the
trial carried on for years and no one was ever found guilty of anything. Still,
many lives were severely damaged.
In a letter to the
California Supreme Court, Richard J. McNally, Harvard University’s Director of
Clinical Training in the Department of Psychology, wrote, “The notion that
traumatic events can be repressed and later recovered is the most pernicious
bit of folklore ever to infect psychology and psychiatry. It has provided the
theoretical basis for 'recovered memory therapy'—the worst catastrophe to
befall the mental health field since the lobotomy era.”[12]
Many studies have
shown how easy it is to alter someone’s memories and create false ones,
especially using hypnosis. It was a key feature in many cases of supposed past
lives, future lives, extraterrestrial abductions, “satanic abuse”, and court
cases where innocent people were sent to prison for decades based on faulty
eyewitness testimony, only to be eventually proven innocent by DNA and other
objective tests.
When it comes to who we are, our past plays a big role and for
that we largely rely on our memories. A person with amnesia feels unmoored and
adrift in the world. It’s our memories that anchor us. We think of our memories as an indelible record of our lives and
experiences, both reliable and unchangeable, but they’re not. Unfortunately our memories are often flawed,
from being missing altogether, to being unreliable or altered, to being
completely false.
One study suggested to more than 400 people that they had done
certain things during their childhood, such as flying in a hot air balloon or
disrupting a wedding, and then had them imagine the event several times. None
of these things ever happened, but by the end of the study about half of the
participants believed they had. Those suggestions had created false memories.[13]
There are many ways scientists artificially alter and create
memories. It one interesting study, researchers were able to alter memories in
mice while they were replaying and laying down their memories during sleep.
When a neuron that was active when the mouse was at a particular location in a
maze became active during sleep, they stimulated the mouse’s pleasure center.
The next time the mouse was placed in the maze, it ran straight to that spot,
even though nothing had actually happened there.[14]
British and American scientists were able to give fruit
flies false memories of a disagreeable event that never happened just by
causing 12 neurons to fire.[15]
Our memories can be modified by suggestions, our imagination,
our desires, lack of sleep, or our own embellished stories. Trying to jog
someone’s memories by suggesting possibilities or showing them photographs can
alter their memories. Just asking leading questions can give someone false memories.[16]
Actually, asking them any questions at all can change their memories. People
can also subconsciously modify their memories to match those of others because
of subtle social pressures. In addition, watching someone else do something can
form the memory that they did it themselves.[17]
Elizabeth Loftus had this happen to herself. Thirty years after
her mother had drowned while on vacation at her uncle Joe’s house, her uncle
reminded her that she was the one who found the body floating in the pool. Up
to this point, Loftus’s memories of that day had been vague and she didn’t
recall seeing her mother’s body, but over the next couple of days the memories
slowly coalesced into vivid detail—the emergency vehicles, the flashing lights,
and the stretcher with the body wrapped in a white blanket.
Then her uncle called saying he’d made a mistake. His memory
turned out to be wrong. On checking around he found that it was actually
Loftus’s aunt who had found her mom. Loftus hadn’t been at the scene after all.
She wrote, “When my memory was revealed as a false creation, I
experienced a strange yearning for the crisp colors and narrative drive of my
invented story-truth. That elaborate but completely fabricated memory comforted
me with its detail and precision, its utter lack of ambiguity. At least I knew
what happened that day; at least my memory had a beginning, a middle, and an
end; at least it all hung together. When it was gone, all I had left were a few
somber details, a lot of empty spaces, and an aching, endless grief.”[18]
Lost on Shifting Sands
Memories aren’t dots and spaces on a hard disk, they’re pathways
in squishy tissues that are alive and constantly changing. They’re renewing
themselves, while being influenced by the fluctuating chemicals that make them
up. Sometimes only the gist of the memory is retained, with a bias towards
semantic overviews.[19]
Our memories are also being pruned for efficiency, deleting memories in the
process. This happens throughout our lives, but it’s particularly noticeable at
about the age of seven when most of us lose the majority of our childhood
memories, particularly those before the age of four. Known as childhood
amnesia, this greatly reduces the number of our memories, but strengthens the
details of those that remain and can place them in context.[20]
It’s not just old memories that are affected, it can happen
immediately. For example, in 2015 David Baril was shot by a policeman on Eighth
Avenue in Manhattan. Immediately after the incident one eyewitness told a The New York Times reporter that Baril
was fleeing officers when he was gunned down, while another witness said he was
in handcuffs when he was shot. Both memories were wrong. Surveillance footage
and photographs showed that Baril was chasing a female officer, swinging a
hammer at her head when he was shot. He was handcuffed later. Such
misremembering is very common and police are used to receiving conflicting
statements.[21]
One study suggests that false memories can arise faster than
the blink of an eye—within 42 milliseconds to be exact[22]—while
another one indicates that on a particular task there can be an error rate between
20% and 30% within three seconds, which increases from there, with indications
the errors are top-down mistakes most likely caused by the subjects’ expectations.[23]
In other words, as you are experiencing something, you might already be
creating false memories of what is happening, influencing your perception of
what’s taking place.
Psychologist Deryn Strange at the John Jay College of Criminal
Justice, told the Times, “That’s the
hard thing to get our heads around.[...] It is surprising to the average person
how quickly memories can be distorted.”[24]
Yet jurors still tend to consider eyewitness testimony dependable
evidence, when in fact it’s been shown to be quite unreliable and it has led to
many convictions of innocent people. Of 375 convictions overturned by DNA and
examined by the U.S. Innocence Project, 69%—more than two-thirds—involved
misidentification by eyewitnesses. And 29% involved false confessions, many by
suspects who were convinced during interrogations that they were guilty, when
they actually were innocent—a strange phenomenon in itself, since you’d think
people would know whether they were guilty or not, but your memories can be
manipulated.[25]
Scientists can easily alter many people’s memories, getting
them to unknowingly change their eyewitness accounts, and even get people to
identify the wrong culprit.[26]
It’s actually not that difficult. And once a memory has been altered, you can’t
change it back.
Thousands of studies have revealed flaws in eyewitness
statements and out of the roughly 74,000 eyewitness identifications, there are
indications that about a third of them are wrong. Those in law enforcement are
now, in the 2020s, beginning to alter their methods to correct this.[27]
It also turns out that people with highly superior
autobiographical memory—who can tell you what they ate and what the weather was
like on any particular date, even a decade or more ago—have just as many false
memories as the rest of us.
People are confident they can recognize their own false
memories, but experiments show they do just as well by flipping a coin.[28]
The more confident someone is in their false memories, the more convincing they
are when they retell these memories and the more people will believe them, which
is particularly bad when it comes to eyewitness testimony.
In highly emotional situations, we tend to focus on a few
details, such as the gun, so miss other things. And because it’s emotional,
those details tend to be more vivid, increasing your confidence in your memory.
But...
If you ask someone who remembers 9/11 where they were when they
first heard about the attack, they have a good memory of it. Psychologists at
New York University surveyed 24 subjects who were in New York City at the time,
interviewing them a week after the attack, a year later, and after three years.
The consistency between the first and second surveys was only 63%. This dropped
to 57% by the third year. Concerning their emotions at the time, they were only
40% consistent a year after the attack. So by year three, the consistency was
just over 50%, yet they were confident their memories were accurate.[29]
Another study with 700 subjects came up with similar results.[30]
Some researchers believe many, perhaps even most, of our
memories are false or distorted in some way. Julia Shaw of London South Bank University and the author
of The Memory Illusion: Why You May Not Be
Who You Think You Are, said, “The question isn’t whether our memories are
false, it’s how false are our memories. Complex and full false memories (of
entire events) are probably less common than partial false memories (where we
misremember parts of events that happened), but we already naturally fill in so
many gaps between pieces of memories and make so many assumptions, that our
personal past is essentially just a piece of fiction.[...] I am convinced that
no memories are to be trusted. I am confident that we create our memories every
day anew, if ever so slightly.”[31]
Go to my index of posts to see more.
If you'd like to comment, please email me at John@AWondrousWorld.com.
Click here for the next article in this series:
Bright Summer Days
[2]
A.C. Holland and E.A. Kensinger, “Emotion
and autobiographical memory”, Physics of Life Reviews, 7(1), 2010, pp.
88–131, https://doi.org/10.1016/j.plrev.2010.01.006.
And Kathleen McGowan, “Out of the Past”, Discover Magazine, July/August 2009, pp.
30-37, and with an added note as Kat McGowan, “Past Imperfect”, July 31, 2010, https://www.discovermagazine.com/mind/past-imperfect,
and just the first part of the article as “How Much of Your Memory Is True?”,
August 2, 2009, https://www.discovermagazine.com/mind/how-much-of-your-memory-is-true.
And Helen
Phillips, “Mental blocks”, New Scientist,
no. 3111, February 4, 2017, and as “Spotless mind: Manipulating the brain to rewrite
memories”, February 1, 2017, https://www.newscientist.com/article/mg23331110-700-spotless-mind-manipulating-the-brain-to-rewrite-memories/.
[3]
Erika Hayasaki, “How Many of Your Memories Are Fake?”, The Atlantic, November 18, 2013, https://www.theatlantic.com/health/archive/2013/11/how-many-of-your-memories-are-fake/281558/.
And Michael Dhar, “Mind Maze: How Your Memory Deceives
You”, Live Science, October 25, 2014,
https://www.livescience.com/48451-how-your-memory-deceives-you.html.
[4]
Steve Ayan interview with Eric Kandel, “Speaking of Memory”, Scientific American Mind, Oct./Nov.
2008, p. 17.
[8]
Joshua Kendall, “Forgotten Memories of
Traumatic Events Get Some Backing from Brain-Imaging Studies”, Scientific American, April 6, 2021, https://www.scientificamerican.com/article/forgotten-memories-of-traumatic-events-get-some-backing-from-brain-imaging-studies/.
And Jessica
Hamzelou, “The mysterious memory gap”, New
Scientist, no. 3355, October 9, 2021, pp. 44-49, and as “Repressed
memories: The dangerous idea we can’t seem to forget”, October 6, 2021, https://www.newscientist.com/article/mg25133551-000-repressed-memories-the-dangerous-idea-we-cant-seem-to-forget/.
[9]
An excellent overview on recovered memories can be found in Heidi Sivers,
Jonathan Schooler, and Jennifer J. Freyd, “Recovered Memories” in Vilayanur
Ramachandran, ed., Encyclopedia of the
Human Brain, New York, NY: Academic Press, 2002, vol. 4, pp. 169-84.
Also Julia Shaw, The Memory Illusion, London: Random
House Books, 2016.
[10]
See the extensive work done by psychologist Elizabeth Loftus with at least 18
books and more than 250 scientific articles, including her book with Katherine Ketcham, The Myth of Repressed
Memory, New York City: St. Martin’s Press, 1994.
[11]
For related information, but on an interesting tangent, see Michael Nash,
“What, if Anything, is Regressed About Hypnotic Age Regression?”, Psychological Bulletin, 1987, vol. 102,
no. 1, pp. 42-52.
And Ian Stevenson, “A Case of the Psychotherapist’s
Fallacy: Hypnotic Regression to ‘Previous Lives.’”, American Journal of Clinical Hypnosis, 36(3), 1994, pp. 188–193, https://doi.org/10.1080/00029157.1994.10403068.
And R. A. Baker, “The Effect of Suggestion on Past-Lives Regression”. American Journal
of Clinical Hypnosis, 25(1), 1982, 71–76, https://doi.org/10.1080/00029157.1982.1040.
And Nathan Israeli, “Experimental study of hypnotic
imagination and dreams of projection in time: I. outlook upon the remote future—extending
through the quintillionth year,”, Journal
of Clinical and Experimental Hypnosis, 1:2, 1953, pp. 49-60, https://doi.org/10.1080/00207145308409817,
https://www.tandfonline.com/doi/abs/10.1080/00207145308409817.
[12]
Richard J. McNally, Amicus Curiae (Friend of the Court) brief to the justices
of the California Supreme Court, June 3, 2005, https://www.religioustolerance.org/rmtmcnally.htm.
[13]
University of Warwick, “Half of people believe fake facts, ‘remember’ events
that never happened”, ScienceDaily,
December 7, 2016, www.sciencedaily.com/releases/2016/12/161207101433.htm,
citing Alan Scoboria, Kimberley A. Wade, D. Stephen Lindsay, Tanjeem Azad,
Deryn Strange, James Ost, and Ira E. Hyman, “A mega-analysis of memory reports
from eight peer-reviewed false memory implantation studies”, Memory, 2016; 1, https://doi.org/10.1080/09658211.2016.1260747.
See also Maryanne Garry and Matthew P. Gerrie, “When
Photographs Create False Memories”, Current
Directions in Psychological Science, vol. 14, no. 6, December 1, 2005, pp.
321-325, https://journals.sagepub.com/doi/abs/10.1111/j.0963-7214.2005.00390.x,
https://doi.org/10.1111/j.0963-7214.2005.00390.x.
And Elizabeth
F. Loftus, “Creating False Memories”, Scientific
American, vol. 277, no. 3, September 1997, pp. 70-75, https://www.scientificamerican.com/article/creating-false-memories/.
[14]
Jessica Hamzelou, “New memories implanted in mice while they sleep”, New Scientist, March 9, 2015, https://www.newscientist.com/article/dn27115-new-memories-implanted-in-mice-while-they-sleep/,
citing Gaetan de Lavilléon, Marie Masako Lacroix, Laure
Rondi-Reig & Karim Benchenane, “Explicit memory creation during
sleep demonstrates a causal role of place cells in navigation”, Nature
Neuroscience, 2015, vol. 18, pp. 493–495, https://www.doi.org/10.1038/nn.3970.
[16]
Elizabeth F. Loftus, “Leading questions and eyewitness report”, Cognitive Psychology, vol. 7, no. 4,
1975, pp. 560–572.
[17]
Association for Psychological Science, “False memories of self-performance result
from watching others’ actions”, ScienceDaily,
September 14, 2010, http://www.sciencedaily.com/releases/2010/09/100914131006.htm, citing Isabel Lindner, Gerald
Echterhoff, Patrick S.R. Davidson, and Matthias Brand, “Observation Inflation:
Your Actions Become Mine. Psychological”, Science,
2010; 21: 1291-1299 https://doi.org/10.1177/0956797610379860.
[18]
Dr. Elizabeth Loftus and Katherine Ketcham, The Myth of Repressed Memory,
New York City: St. Martin’s Publishing Group, 1996, pp. 39-40.
[19]
University of Birmingham. “Memory details fade over time, with only the main
gist preserved”, ScienceDaily, May
26, 2021. www.sciencedaily.com/releases/2021/05/210526085058.htm,
citing Julia Lifanov, Juan Linde-Domingo, and Maria Wimber, “Feature-specific
reaction times reveal a semanticisation of memories over time and with repeated
remembering”, Nature Communications,
2021; 12 (1), https://doi.org/10.1038/s41467-021-23288-5.
[20]
Tiffany O’Callaghan, “FAQ: Why Can’t We Remember
Being Babies?”, New Scientist, no.
3201, October 27, 2018, p. 35, and as “Memory FAQ: Answers to the common
questions that baffle us all”, October 24, 2018, https://www.newscientist.com/article/mg24032011-500-memory-faq-answers-to-the-common-questions-that-baffle-us-all/.
[25]
Innocence Project, “DNA Exonerations in the United States”, 2022, https://innocenceproject.org/dna-exonerations-in-the-united-states/.
And Association for Psychological Science. “People can
be convinced they committed a crime that never happened”, ScienceDaily, January 15, 2015. https://www.sciencedaily.com/releases/2015/01/150115102835.htm,
citing J. Shaw and S. Porter. “Constructing Rich False Memories of Committing
Crime”, Psychological Science, 2015, https://doi.org/10.1177/0956797614562862.
[29]
Tali Sharot, Elizabeth A. Martorella, Mauricio R. Delgado, and Elizabeth A.
Phelps, “How personal experience modulates the neural circuitry of memories of
September 11”, PNAS, vol. 104, no. 1,
January 2, 2007, https://doi.org/10.1073/pnas.0609230103,
