You might wonder why your memories fade after a while. Can you remember all the details of your childhood, for instance? Probably not; most people just remember a few important events like birthdays or family trips. But, what causes these ‘blips’ in memory over the years?
Scientists believe they have found the answer. A team of researchers at the Universities of Glasgow and Birmingham investigated why memories fade. They sought to understand what information we retain in our memories, and what details we lose. Many theories have been presented over the years. But scientists believe that they finally struck gold with this study.
The study, published May 26, 2021, in Nature Communications, discovered that our memories become less vibrant and detailed over time. Only the gist, the main point, gets preserved in our minds. Everything else becomes fuzzy as time wears on.
Scientists also found that the ‘gistification’ of our memories gets boosted when we recall recent experiences frequently.
How This Knowledge of Why Memories Fade Over Time Can Prove to Be Helpful
This research could help with many facets of life and job fields. For instance, it could reveal important information about the nature of memories in people with PTSD. The study could also have implications in the repeated questioning of eye-witness testimonies. Finally, it could improve memory recall when studying for exams.
It’s important to remember that our memories don’t always match up with reality. In other words, over time, our memories get distorted. When this happens, we may reconstruct them as we see fit; however, in reality, something much different may have occurred. Experts suggest that the contents of a memory could actually change every time we recall it.
However, until now, scientists have had difficulty measuring how our memories differ from the original experiences. They’ve also met challenges in figuring out how memories become transformed over time. So, this is a groundbreaking study when it comes to why, and how, memories fade.
Here’s what the scientists discovered about memories in the study
For this study, the researchers developed a simple task using a computer. It measures how quickly people can recall certain aspects of visual memories when asked to do so. The volunteers learned word-image pairs for the memory task. Later, they had to recall different elements of the image when prompted with the word to test the quality of their memories.
Participants had to indicate, as quickly as possible, certain details about the image. Researchers asked them to recall if the image was colored or greyscale (a perceptual detail). They also asked volunteers whether the image showed an animate or inanimate object (a semantic element).
Volunteers performed these tests immediately after learning the word-image pairs and also after two days. Reaction time patterns revealed that volunteers recalled meaningful, semantic elements faster than the surface, perceptual ones.
Julia Lifanov, the lead author of the study from the University of Birmingham, said:
“Many memory theories assume that over time, and as people re-tell their stories, they tend to forget the surface details but retain the meaningful, semantic content of an event. Imagine reminiscing about a pre-COVID dinner with a friend — you realize that you cannot recall the table décor but know exactly what you ordered, or you remember the conversation with the bartender, but not the color of his shirt. Memory experts call this phenomenon ‘semanticization’.”
Prof Maria Wimber, the senior author on the study from the University of Glasgow, said: “The pattern towards recollection of meaningful semantic elements we demonstrate in this study indicates that memories are biased towards meaningful content in the first place — and we have shown in previous studies that this bias is clearly reflected in brain signals too.
“Our memories change with time and use and that is a good and adaptive thing. We want our memories to retain the information that is most likely to be useful in the future when we encounter similar situations.”
Other findings from the study about why memories fade
Researchers discovered that people tend to pull more from semantic memory content as time wears on. Also, with repeated remembering, this semantic memory bias grows stronger. When the volunteers performed the test after two days, they had slower reaction times to perceptual-detailed questions.
However, when a group of subjects repeatedly viewed the images, it brought about different results. There was a much smaller gap between the detail-rich and concept-based memories. This makes sense because the researchers didn’t give them an opportunity for the memories to fade. Therefore, the images were fresher in their minds, in contrast to the other group being tested.
This study may help researchers better understand how memories affect health in the future. For example, with post-traumatic stress disorder, patients often have intrusive, traumatic memories. They also tend to over-generalize these experiences to new situations. This research could provide scientists with a tool to analyze these maladaptive changes in the brain.
The findings may also help experts understand how frequent interviews may create bias in eyewitness memories. Also, asking witnesses to repeatedly recall the same event can lead to inaccuracies. This study about why memories fade could prove highly relevant to this field.
Finally, the research demonstrates that studying before an exam can improve your memory of meaningful information. Especially when followed by rest or sleep, testing yourself prior to an exam can help boost memory.
Final thoughts on why memories fade over time, according to science
The latest research on why memories fade provides exciting new insight into how our brains work. The scientists found that over time, people tend to skew the details of their memories. They also can only remember certain events, usually the most traumatic or exciting ones. However, until now, researchers had no way of measuring this recall bias, and how the memories transform over time.
In the study, they found that people tend to remember the meaningful parts of memories. This happens so that our brains can adapt in the future when we encounter similar situations. The team hopes the study can help in areas such as PTSD research, eyewitness interviews, and studying for exams.
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