August
8, 2023
A
neuroscientist explains how history, mood, and surprise can make life feel like
a slog — or go by in a blur.🌈
It’s
tempting to imagine memory as a videotape that stores and plays back the past
just as it happened. But the workings of the mind are not so simple. Memory is
more of a creative act, reconstructing the past under the often hasty and
biased influences of the present.
The
“creation” of memory doesn’t only influence what we remember, it influences our
sense of time’s duration too. Having more memories available for recall can
stretch our sense of how much time has passed, while our moods and emotions can
tune the richness of what we remember up or down.
This
all means news, current events, and the technologies that convey them (like the
internet) can influence our perception of time passing slowly or quickly, by
influencing how strongly we remember things.
But
exactly how this interaction plays out, scientists still know very little
about.
2020’s
seemingly endless brigade of big stories might’ve stretched time to feel like a
decade passed. But that stream of news was delivered to populations on
lockdown, where every day looked the same and time became something of an
undifferentiated blurry lump. How did this all influence our perception of how
much time passed?
Enter
a new paper by cognitive neuroscientist Nina Rouhani and colleagues, who
analyzed Americans’ reported memories of 2020, leveraging the dual turbulences
in news events and individual memories to learn more about how each shapes the
other.
They
found that the pandemic scrunched the distance between remembered events, like
compressing a slinky. Everything seemed closer together. In our memories, if
not in real life, time shrank. But as with most memories, there’s plenty more
to unpack.
How
the pandemic gave researchers a treasure trove of memory
Well
before the pandemic, Rouhani was busy studying how we remember surprising
events. But a lot of this work was in computer models, where modeling the
depths and complexities of human memory isn’t a perfect science. Then, as her
PhD dissertation defense began approaching, the pandemic hit, and she decided
to study memory formation in near-real time.
Timelines
of major events in 2020 are almost comically overflowing — the headline frenzy,
the tragedies, the uncertainty. It was a perfect time to study how current
events impact memory.
Rouhani
drew from a large study that was underway, which was collecting people’s
psychological and social experiences during the pandemic. It was a trove of
memories. A few times a month from April 2020 through January 2021, over 1,000
Americans were prompted by an online survey platform to report on their lives
during the pandemic.
In
addition to these monthly reports, Rouhani and colleagues collected three
memory dumps from participants across three years: 2020, 2021, and 2023. These
were prompts to tell the researchers everything they could possibly remember
during a certain time period (with approximate dates) until no more came to
mind.
These
methods filled in the individual’s side of things, but Rouhani was also
interested in the relationship between surprising collective events and
personal memories. The literature on “flashbulb memories” — as these events are
called by scientists — finds that we vividly remember the moments we first
learn of surprising events. We remember where we were, how we felt, and maybe
some other oddly particular detail or two.
The
question, then, was how to collect “collective memories,” which presents a few
challenges.
“The
challenge we face here is: Whose collective memory?” Rouhani says. “Many
different kinds of collective histories are formed, especially nowadays when
people have access to their own local ways of defining what’s happening.”
They
approximated collective memory by taking the two highest Google Trends for each
month of 2020 — from Kobe Bryant’s fatal helicopter crash to the killing of George
Floyd (the negative news bias is on full display here). Participants were asked
questions about each, from how vividly they could recall them to how far apart
they remember them being.
So
with a trove of memory data in hand, Rouhani could start to ask questions about
how all these events altered the perception of time.
Which
impacted our pandemic memories more, monotony or surprise?
Going
into the study, Rouhani and colleagues had a few sets of questions. The first
centered on duration.
Past
memory research found that surprising events create “event boundaries” in
memory. Think of the assassination of Martin Luther King Jr., or 9/11. These
events divide our pools of memory into sections. We categorize memories as
happening pre-9/11 or post, for example. Carving more boundaries into a given
passage of time can ‘stretch’ our memory of duration. According to this
hypothesis, our memory during the period of lockdowns would inflate — spreading
events to seem farther away from each other.
But
then, there was the monotony. Lockdowns imposed a sameness on our daily
activities, where the lack of changing context could muddle everything into a
compressed memory of time. “If you think about the processes you’re using when
thinking about subjective time perception,” Rouhani said, “one of them is the
number of memories. When you go on vacation and come back it feels like a
century has passed.” That’s because changing scenery leads to more memories. “So
it feels longer,” she said, “and lockdowns did the opposite of that.”
Just
as astronomers measure cosmic expansion by tracking the growing distance
between galaxies, Rouhani and colleagues looked at the subjectively reported
distances between big news events, and found evidence that the compression
hypothesis wins out. When recalling events during Covid, participants
remembered them as being closer together than when they recalled events of
similar distance before or after the pandemic. The sense of time, in other
words, shrank.
A
separate set of hypotheses focused on emotion. Especially charged events,
whether positive or negative, tend to be easier to recall. But during negative
times, chronic stress tends to block memory formation. Rouhani explained that
in clinical disorders like depression or PTSD, memory is often blunted. While
you may have plenty of flashbacks or ruminations, the details blur, and your
ability to reconstruct the particulars fades.
The
study analyzed the reported memories to find any links between emotional states
and memory. Their results confirmed that bad moods lead to a greater volume of
memory recall, especially for those who scored high on markers of depression or
PTSD. But the blurring effect was also confirmed — while they recalled more
memories, the actual quality of memory was worse.
“Having
strong negative emotions can improve your memory,” Rouhani said. “But if you
enter into this chronic state of trauma or depression, it removes the
specificity of those memories.”
There’s
also a wrinkle here: Despite the higher volume of memory recall among those
most emotionally impacted by the pandemic, the fabric of memory still grew
closer together across all participants, and perceived time compressed in
memory.
Using
the past to heal the future
If
the pandemic feels like a blur, or if details don’t readily come to mind, the
study helps explain why. Learning more about these flourishes of memory gives
us a fuller perspective on the relationship between the worlds our minds
conjure and the experiences they reflect.
But
the research has more to offer. How we remember the past can provide clues as
to the ways stressful or anxious memories may continue to distort our present,
or even how we envision the future.
It’s
tempting to let stressful memories, like low points from the lockdowns, remain
as Rouhani found them: blurred, compressed, and behind us. But “not having
specific markers of your past can lead to many external events that trigger
trauma-related emotions, generating repetitive, crippling memory,” she said.
In
other words, lack of detail in remembering one’s stressful past raises the odds
that it may show up and haunt the present. But the good news is that you can
flip this all around. Since memory is always recreated on the fly, it’s always
open to reinterpretation. Intentionally remembering the past in more vivid
detail — called episodic memory induction — can untangle its hold on the
present, and even expand our ability to imagine alternative, brighter futures.
All that’s required is a focus on recalling specific details from stressful
memories in the past, meaning you can take your pick of journaling, talking
with a friend or therapist, or just remembering on your own.
While
the study of emotion’s effects on memory is already well established, we’re
still in the very early days of understanding how time perceptions can get
distorted. This study suggested that monotony may have a greater impact than
surprising news stories (i.e. flashbulb memories), but do some forms of
monotony carry more weight than others?
For
example, the study suggests that the extended sameness of our lockdown days
compressed how we remember the time. But sameness can come in a variety of
forms — physical environments, activities, moods. “If we go through 10
different emotions during a day versus 10 different geographic locations,”
Rouhani mused, “how do those two contribute to my time perceptions? Do they
affect it the same or differently?”
She’s
not yet sure. “Memory is biased in such unintuitive but consistent ways,” she
says. It will take further research to figure out.
The
stakes of understanding memory may be on the rise. We’re on the brink of a new
era of brain-machine interfaces that will likely throw a new set of questions,
functions, and biases around memory into the mix.
“There’s
a lot of really exciting new work that’s applying collective memory to
cognitive science, but it’s rather new still,” Rouhani said. “In terms of open
questions, I could go on forever. There’s so much more that’s unanswered.”
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