Memory — our way of encoding, storing, and retrieving information — is a complicated thing. Short term vs. long term, explicit vs. implicit, recall vs. recognition… there’s a lot involved. Rather than trying to catalogue all those nuts and bolts, let’s take a look at some of the scientific community’s more, ahem, memorable memory findings.
Confidence and Accuracy
As reported by the New Yorker, an Emory University study asked psychology students to recount their memories of January 28, 1986, the day the Challenger exploded — once the day after the disaster occurred, and once again over 2 years later.
Comparing questionnaire answers in the fall of 1988, researchers found that many students’ later recollections were far from accurate. “When the psychologists rated the accuracy of the students’ recollections for things like where they were and what they were doing, the average student scored less than three on a scale of seven. A quarter scored zero.”
That, by itself, isn’t all that surprising — 2½ years is plenty of time for a memory to fade and change. What is surprising is how confident the students were that they were remembering the day correctly. “[W]hen the students were asked about their confidence levels, with five being the highest, they averaged 4.17. Their memories were vivid, clear—and wrong. There was no relationship at all between confidence and accuracy.”
Next time you say “I can remember it like it was yesterday,” you might very well be wrong.
Remembering What You “Learn” During Sleep
According to the the Guardian, researchers in the 1950s claimed that sleep learning was “probably impossible.” Turns out that qualifier was a wise inclusion.
A 2012 study cited in the same Guardian article found participants “were more likely to correctly play a melody in a musical video game (similar to Guitar Hero) if the tune had been previously played to them during the slow-wave stage of a 90-minute nap.” This points to the possibility of subconscious sleep learning.
Another study tasked participants with learning a “visuo-spatial two-dimensional object-location task” — that is, they were asked to memorize specific card pairings in a 5 by 5 grid. As they studied the cards, an odor was released into the room (an “unfamiliar slightly negative smell”). Afterwards, the group went to sleep for 40 minutes, during which time the researchers re-released the odor in 30-second intervals.
Participants were also tested in a control condition. In this repeated version of the experiment, no odor was released.
In both versions of the experiment, after everyone was awake again, the group was asked to learn an “interference object-location task.” That means they had to memorize new card pairings. 30 minutes after that, they were tested to see if they could remember the original pairings.
The findings? During the initial (odor) test, participants remembered 84.18 (± 4.68)% of the original card pairings. During the control (no odor) test, they only remembered 60.80 (±4.24)% of the pairings. This suggests that your memory can be helped (in a Pavlovian way) by certain stimuli during sleep.
As the Challenger experiment made clear, we’re capable of remembering important events incorrectly. Would you believe we also sometimes remember events that never even occurred — including crimes we didn’t commit?
Findings from a 2014 study suggest that it’s possible to generate false memories of committing a crime. All it takes is a few rounds of suggestive interviewing: “After three interviews, 70% of participants were classified as having false memories of committing a crime (theft, assault, or assault with a weapon) that led to police contact in early adolescence and volunteered a detailed false account.”
These confessions apparently contained “complex descriptive and multisensory” details — just like real memories.
Okay, so maybe memory isn’t just complicated — it’s downright mysterious. The results of these studies suggest that our brains work in very unexpected ways (unexpected even for the “experts”). It’s possible you’ll hear about some wild new finding before you even have a chance to start misremembering the ones in this post.