We know that long-term memory is fallible, and now it seems short-term memory can’t be relied on either, if you are trying to recall an event that doesn’t match your expectations
By Jason Arunn Murugesu
5 April 2023
Memory is not as secure as you might think
Jan Hakan Dahlstrom/Stone RF/Getty Images
You can misremember something just seconds after it happened, reframing events in your mind to better fit with your own preconceptions. Our brains probably do this in an effort to make sense of the world in line with our expectations, even if that isn’t helpful all of the time.
Marte Otten at the University of Amsterdam in the Netherlands and her colleagues wanted to tease out the relationship between prior expectations and short-term memories. “We already know that long-term memory is fallible, we just wanted to find out if we could determine the specific ways in which short-term memory is fallible also,” she says.
The team conducted several experiments on more than 400 people that all involved showing the participants random letters arranged in a circle on a computer screen.
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In the simplest form of this experiment, the participants were shown the letters for a quarter of a second before the screen went blank. After a gap of 3 seconds, a box appeared where one of the letters had been for half a second, followed immediately by a different circle of letters for half a second.
The participants were asked to recall which letter from the original circle had been in the position held by the box on the screen. Crucially, some of the letters were flipped, which Otten calls “pseudo-letters”. The participants were explicitly warned about these flipped letters and told not to mistake them for real ones.
After recalling the letters, the participants were asked to rate their confidence in each answer. The team focused its analysis on the most confident participants, in order to weed out random guesses.