The Problems We Face in Retrieving Memories ‚Äî Part 3
For all we know about human memory, there are even more mysteries to uncover. In the first installment of our memory series, we explored how memories are created but we also revealed the lack of certainty around how those memories are stored. In the follow up post, we covered the different factors that affect which memories are stored but discovered a range of variables that impact the quality of those memories. Now, we'll dive deeper into what happens to those memories that have been successfully stored. Are they saved in mint condition, like files to a hard drive, or are they corrupted?
Flashbulb memories are those that we recall with a crisp vividness.
Since the 1970s, the most significant memory research has focused on memory retrievalÔøΩ mainly the concept of flashbulb memories. Flashbulb memories are those that we recall with a crisp vividness. They're the moments in which we learn about a national or global tragedy. Throughout history, prior generations have shared stories about where they were and what they were doing when they learned about JFK's assassination or the death of Princess Diana or the Challenger explosion. They can recall every detail from the kind of coffee they were drinking to the channel they were watching. These autobiographical, and often emotional, memories are so sharp that we hardly ever question their accuracy. But flashbulb memory research has challenged that notionÔøΩ that the specificity of these memories doesn't always stand the test of time.
Researcher Jennifer Talarico conducted one of the most high-profile and jarring studies on the subject. During 9/11, she was a Duke University grad student, and she saw a silver lining in the tragedy with a unique opportunity to study flashbulb memories. The next day, Sept. 12, she and her adviser interviewed undergrad students with 54 questions about how they learned of the attacks. They also asked about one autobiographical memory from the prior weekend.
Next, they separated the study participants into smaller subgroups and asked the same questions either one week later, one month later, or seven months later. As more time passed, the participants were just as passionate about their vivid memories, but there was one problemÔøΩ the details changed. At the one-week mark, they were very few inconsistencies. But over 30 days and 7 weeks, there were significant differences in the details that were first recorded and the new memories. Despite how vivid those memories still seemed to the participant, they weren't accurate.
Flashbulb memory studies reveal moments where memory retrieval fails. On the surface, it doesn't seem incredibly significant. Though the undergrad students may not recall every single detail, they still connect with their original emotions and understand the gravity of the event. Yet still, there's more at stake than simply forgetting a minute detail. This cognitive failure can have greater consequences.
Memory Retrieval and the Law
Back in 1984, a college student's memory retrieval failure led to the wrongful imprisonment of an innocent man. North Carolina college student Jennifer Thompson-Cannino was raped in her apartment. After reporting the incident to police, she was asked to draw a composite sketch of the suspect. Based on that sketch, Thompson-Cannino was shown six photos of men who matched what she'd drawn. She narrowed down the field to two men, studied those photos for no more than 5 minutes, and selected Ronald Cotton's mug shot. Cotton was sentenced to life in prison. He served over 10 years of his sentence before being exonerated of the charges through DNA tests.
Years later, in a New York Times editorial, Thompson-Cannino wrote that she was "completely confident" she'd identified the right man. But clearly, she hadn't. For her, memory retrieval had failed her and cost an innocent man 10 years of freedom.
In another instance, a Georgia man, Troy Davis, was executed for the shooting death of a police officer. 7 of 9 eyewitnesses identified Davis as the shooter but all recanted their testimony at a later date. The unreliability of these eyewitness accounts was not considered as a reason for overturning Davis' conviction.
Memory researcher Elizabeth Loftus has made a career of exposing flaws in eyewitness testimony. Also in 1984, she testified on behalf of Joseph Pacely, a man who'd been wrongfully accused of rapeÔøΩ a case that was eerily similar to that of Cotton's. She argued that fear and stress impaired the accuser's ability to correctly identify her attacker. And because of this testimony, centered on memory retrieval, Pacely was acquitted. Pacely was the 101st person she'd testified for. And she's spent the greater part of four decades documenting the fallibility of the human memory, especially as it relates to crimes and court procedures. Her work is starting to have a greater impact on the justice system. In 2013, a New Jersey Supreme Court ruled that jurors should be briefed on the inaccuracies of human memory.
Chronic stress causes difficulties with spatial memory, the ability to relate objects and recall locations. It also permanently changes the makeup of your brain.
Loftus' work and testimonies raise an important point. Past studies have shown that memories tied to deep emotions increase the probability that the memory will become permanent. But if that deep emotion is stress or fear, it could seriously impact the accuracy of the memory. Chronic stress causes difficulties with spatial memory, the ability to relate objects and recall locations. It also permanently changes the makeup of your brain. Acute stress can even impair these functions in the moment. In rare instances, acute stress has heightened these functions. But Loftus' research, along with cases like those of Davis and Cotton, has shown that more often than not, stress doesn't work in favor of accurate memories.
Another memory researcher, Elizabeth Phelps, served on a committee for the National Academy of Sciences in 2015. The goal of the committee was to suggest changes in eyewitness testimony processes based on recent discoveries concerning emotional memory. The committee made several recommendations, including using the process of "blinded" eyewitness identification, in which a person would be shown photographs of potential suspects without any other identifying information. If observed, the committee's recommendations could change the way the American justice system handles criminal cases. Concerning our general memory, Phelps suggested we err on the side of caution, in an interview with The New Yorker. "The more we learn about emotional memory, the more we realize we can never say what someone will or won't remember given a particular set of circumstances," she said.
This isn't to say that we can't trust any of our memories, as there are certainly many accuracies. Each of us dearly holds sets of memories about positive experiences or growth experiences that have shaped our lives. And we should continue to hold them dearly. But it's also important to know that they may not always be as they seem. However, we can view this less as a bug of our brain's hard drive and more like a feature.
Think of the types of memories that are typically skewedÔøΩ ones that are impacted by stress or fear. Odds are, these memories are negative, and perhaps we're forgetting them as a means of moving forward. Forgetting negative memories, or even inaccurately recalling them, can aid the process of forgiveness, for ourselves and others. A failure to forget can actually have negative consequences, and may play a role in conditions like PTSD. Thus, a memory retrieval "failure" isn't always a bad thing. It's possible that, in some instances, memory failure really isn't a failure at all but a subconscious coping mechanism to help with our personal healing. Like so many other aspects of memory and the human brain, the study of memory loss and retrieval is richly layered with complexity.
In the last and final post of our memory series, we'll explore ways to keep those memories sharp for the long haul.