By Daniel, ESL Educator & Everyday Curiosities Writer
In 1986, on the morning after the space shuttle Challenger exploded, a group of first-year college students wrote down how they had heard the news. Where were they? Who told them?
Two and a half years later, the psychologists Ulric Neisser and Nicole Harsch asked the same students, now seniors, the same questions. The new stories often didn’t match the ones written the morning after. Out of 40 students, 11 changed their answers to every question. Yet most stayed highly confident.
Some moments feel burned into our minds while whole months of ordinary life vanish. And even the burned-in moments may not be as solid as they seem.
Quick answer: Your brain doesn’t record everything like a camera. What stays depends mostly on whether you paid attention, how strongly you felt something, how much time has passed, and what happens in the hours and nights afterward. Strong emotion makes a memory feel vivid and certain, but that feeling is not proof that it’s accurate.
Four things that decide what sticks
1. Did you actually notice it?
Memory starts with attention. In a classic 1979 study, the researchers Nickerson and Adams asked Americans to draw a penny from memory. Most had seen pennies countless times, but their drawings put features in the wrong places or added details from the other side of the coin. In a later study, Alan Castel and his colleagues at UCLA asked people who worked in a building where the nearest fire extinguisher was. Most couldn’t say, even though they found one in a few seconds when they looked.
Seeing something many times is not the same as noticing it. Often the brain stores only the gist and fills in the rest later.
2. Did it make you feel something?
The neuroscientist James McGaugh has spent decades studying why “some events are remembered well while other events are remembered poorly, if at all.” A big part of the answer is emotion.
When something exciting, frightening or upsetting happens, your body releases stress hormones such as adrenaline and cortisol. These act on the amygdala, a small, almond-shaped part of the brain. McGaugh and his colleague Larry Cahill explain that the amygdala doesn’t store the memory itself. Instead, it signals other areas, such as the hippocampus, to store this experience more strongly.
Timing matters. In animal studies, adrenaline improved memory when it was given shortly after learning. In a 1994 human study, people who took propranolol, a drug that blocks some effects of adrenaline, lost the usual memory boost for an emotional story. So a memory isn’t finished when the event ends. It keeps “setting,” like concrete, in the hours that follow.
3. How long ago was it?
In 1885, the German psychologist Hermann Ebbinghaus published the first careful experiments on forgetting. He tested only himself. He memorized lists of nonsense syllables such as “WID” and “ZOF,” and then measured how much faster he could relearn each list after different delays.
The result became known as the forgetting curve. Forgetting is very fast at first and then slows down. In 2015, the researchers Murre and Dros repeated the experiment with one volunteer and found results similar to Ebbinghaus’s.
That is why an ordinary Tuesday disappears. Nothing about it was emotional or special, and you never thought about it again. It simply slid down the curve.
4. Did you sleep on it?
Sleep is not just rest for memory. In a major 2013 review, Björn Rasch and Jan Born described over a century of research showing that sleep helps us keep what we’ve learned. During sleep, especially deep slow-wave sleep, the brain seems to reactivate recent memories, gradually moving them from the hippocampus into longer-term storage in the cortex.
Sleep also seems to be choosy. A 2015 review by Gordon Feld and Susanne Diekelmann notes that it tends to favor memories that matter to us, such as emotional ones or information we know we’ll need. The details are still debated, but the basic idea is well supported.
Why vivid doesn’t mean correct
In 1977, the psychologists Brown and Kulik used the term flashbulb memories for those sharp memories of hearing shocking news. They suggested the brain had a special “print now” system for such moments.
Later research disagrees. On the day after the September 11, 2001 attacks, Jennifer Talarico and David Rubin at Duke University asked 54 students to describe how they heard the news. They also asked about a recent ordinary event. They then retested the students after 1, 6 or 32 weeks.
Both kinds of memory changed over time at about the same rate. But only the ordinary memory felt weaker. The 9/11 memories stayed vivid, and the students stayed confident in them. The researchers titled their paper “Confidence, not consistency, characterizes flashbulb memories.”
So emotion does help an event get remembered at all. You’re unlikely to forget that it happened. But the small details around it, such as where you were and who told you, can quietly change while still feeling perfectly clear.
A small thing to try tonight
- Before bed, spend two minutes remembering three moments from today in detail: what you saw, heard and felt. Recalling a memory on purpose, then sleeping on it, may help it last.
- When something important happens, write a few lines about it within a day. Years later, compare the note with what you “remember.” Like the Challenger students, you may be surprised.
Useful words from this story
- vivid: very clear and bright in your mind (“a vivid memory”)
- the gist: the main idea, without the details
- flashbulb memory: a very sharp memory of where you were when you heard surprising news
- consolidate: to make something stronger and more stable; for memory, to store it more firmly
- sleep on it: to wait until the next day before deciding something
You might also like: Why Do Some Smells Bring Back Memories So Strongly? and Why Does Time Seem to Move Faster as We Get Older?
A Note from Daniel
I wrote this article for anyone who has ever wondered why some memories stand out while others disappear. Memory often seems mysterious, but science offers helpful insights into how it works. I hope this article helps make memory a bit easier to understand and encourages you to notice more in everyday life.
Sources
- Neisser, U. and Harsch, N. “Phantom flashbulbs: False recollections of hearing the news about Challenger.” In Affect and Accuracy in Recall, Cambridge University Press, 1992. cambridge.org
- Craik, F. and Jacoby, L. “What Are Flashbulb Memories?” The MIT Press Reader. thereader.mitpress.mit.edu
- Talarico, J. M. and Rubin, D. C. “Confidence, not consistency, characterizes flashbulb memories.” Psychological Science, 2003. scholars.duke.edu
- “Memory Science and the Kennedy Assassination.” APS Observer, Association for Psychological Science. psychologicalscience.org
- McGaugh, J. L. “‘Significance and Remembrance’ Revisited.” APS Observer, 2015. psychologicalscience.org
- Cahill, L. and McGaugh, J. L. “Mechanisms of emotional arousal and lasting declarative memory.” Trends in Neurosciences, 1998. utdallas.edu (PDF)
- Castel, A. D., Nazarian, M. and Blake, A. B. “Attention and Incidental Memory in Everyday Settings.” The Handbook of Attention, MIT Press, 2015. castel.psych.ucla.edu (PDF)
- Crump, M. J. C. “Memory I” (on Ebbinghaus and the Murre & Dros replication). Cognition open textbook. crumplab.com
- Murre, J. M. J. and Dros, J. “Replication and Analysis of Ebbinghaus’ Forgetting Curve.” PLOS ONE, 2015. doaj.org
- Rasch, B. and Born, J. “About sleep’s role in memory.” Physiological Reviews, 2013. citedrive.com
- Feld, G. B. and Diekelmann, S. “Sleep smart: optimizing sleep for declarative learning and memory.” Frontiers in Psychology, 2015. frontiersin.org
Stay curious, and the ordinary will start to speak. — Daniel