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CBC The Nature Of Things (2018.10.28) The Memory Mirage
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| 1.11 GiB | 1 | 0 | 63 |
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| CBC-TheNatureOfThings.20181028.TheMemoryMirage.1280x720.mp4 | 44m8s | 1280x720 | AVC | AAC |
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We cherish our memories. They tell us who we are. They help us recall our first love affair, where we had dinner last week. And what else happened there.
Or do they?
Memory is under heavy scrutiny by a new generation of scientists — and they’re posing an uncomfortable question: Can we trust what we remember about our lives?
Just as we often recall someone’s name incorrectly, scientists say we can misremember critical personal events, catastrophes and even crimes we think we saw or committed.
Recent studies are questioning the fragile unreliability of the human memory — with enormous implications for justice, psychology and our sense of who we are. Says psychologist Julia Shaw: “Every memory you’ve ever had is full of distortions and errors.”
We will look at the implications in:
Eyewitness testimony
DNA evidence has already overturned almost 350 criminal cases in the U.S. — people who spent an average of 14 years in jail,” says Iowa State University cognitive psychologist Gary Wells. “Three-quarters of these convictions were based almost entirely on eyewitness testimony that was mistaken.”
Jennifer Thompson was raped at knifepoint when she was a university student. During the traumatic event, she focused on memorizing details of her attacker so she could pick him out of a line-up. She accused Ronald Cotton, confident that he was the one who assaulted her. 11 years later, DNA evidence cleared Cotton and proved Jennifer wrong.
Hundreds of studies have now shown there is almost nothing more unreliable than an eyewitness who thinks they remember they saw. Yet tens of thousands of people are indicted every year because a witness has picked them out of a lineup. According to Wells, until laws are changed, a frightening number of people will continue to be mistakenly arrested.
Flashbulb memories
We all have crystal-clear memories of where we were and what happened on specific dates such as 9/11 — or JFK’s murder. Events which seem seared on our brains are called “flashbulb memories” because we practically see them in our mind like pictures illuminated by flashbulbs.
We have great confidence in these memories — but we are mostly wrong, says NYC neuroscientist Elizabeth Phelp. Her studies show that flashbulb memories erode over time just like fading memories of birthdays and love affairs. If our memories are so wrong, while convinced we are so right, some scientists now pose an even more extraordinary question: Can we deliberately create false memories?
False memories
In studies, people have been led to remember all kinds of false things: a supposed beach vacation, or being lost in a mall as a child. It’s known as “memory-hacking,” and it’s proving remarkably easy to do.
In 2015, Dr. Julia Shaw and colleagues tried to convince a group of 60 UBC students they had each committed a crime when they were younger — a crime which never took place. An astonishing 70 per cent of subjects came to believe the story, often adding details and embellishments to make the fake event seem even more real.
As scientists discover our memories are vulnerable to change and malleable to our experiences, is it possible that traumatic memories could be “replaced” with healthy ones to deal with issues like depression and PTSD?
According to Julia Shaw, “Memory is largely an illusion. All our memories are essentially false.” But she goes on to say: “We should all accept our clumsy, flimsy memories because that’s what makes us human.”
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Another article about our faulty memories worth reading:
https://www.cbc.ca/natureofthings/features/partial-recall-why-we-cant-tr...
Partial recall: Why we can’t trust our own memories
By Graham Duggan
How well do you remember your family vacations from when you were young? How about your first date, or learning to ride a bike? Do you know where you were when you heard about the 9/11 attacks or the death of Princess Diana? You are likely nodding your head — "yes, I remember very clearly."
Chances are, you’re wrong.
In the Nature of Things documentary The Memory Mirage, scientists explain just how much our memories can deceive us. We used to think that our experiences were recorded in our brains like a videotape which we could play back. However, we’re finding that memories are more often written in water — meaning our life experiences probably didn’t happen exactly how we remember them.
We can’t even remember key events in our own lives
Why do two people remember the same event differently? New science is showing us how our memories are vulnerable to change over time.
In the days following 9/11, cognitive neuroscientist Elizabeth Phelps surveyed over 3,000 subjects, asking them what they recalled about that day — where they were, who were they with, and how they heard the news. One year later, she asked them the same questions, and again at 3 and 10 years on. After just one year, many of the answers changed. When first asked, a subject was perhaps in a café with a friend when they heard the news. The following year, they were certain they were alone at home.
These are called "flashbulb" memories — shocking experiences that are stored vividly in our brains, capturing the context and emotional reaction to the event. However, apart from the central incident itself, the other details of the memory are easily altered.
Each time we recall a memory, we only remember the last time we recalled that memory. And each time we pull up a memory, we may introduce new details that never occurred in real life.
Eyewitness testimonies are often wrong
When it comes to solving crimes, police have traditionally relied on eyewitness accounts to catch criminals — who better to finger a criminal? But researchers featured in The Memory Mirage show just how wrong we can be when relying on memories, even minutes after the event.
When Jennifer Thompson was assaulted at the age of 22, she was confident she identified the guilty man after carefully memorizing every detail of her attacker. After spending 11 years in prison, the convicted man, Ronald Cotton, was proven innocent through new DNA evidence — Thompson had identified the wrong person.
Incorrect memories from eyewitnesses may have led to the wrongful convictions of thousands of innocent people across North America. Through DNA analysis, 350 criminal cases have been overturned, and in 245 of those cases, eyewitnesses had ID’d the wrong person.
All of our memories are vulnerable to change, especially in their early stages. That means that the memories of eyewitnesses can be quickly altered through positive reinforcement during the investigative and judicial process. Police can inadvertently implant false details in eyewitness memories that weren’t there at the time of the crime.
Following his release, Cotton worked together with Thompson to pass legislation requiring reforms to eyewitness testimony. They succeeded in North Carolina, and since then, twenty other states have followed. Canada has had similar guidelines since 2001, but they’re not always used.
Inception is real — false memories are easy to implant
With growing evidence of how memories can trick us, researchers have tried bold new experiments to find out if they could implant a false memory and have someone believe it was true.
Canadian scientist Julia Shaw suggested to her subjects, UBC university students that they had a minor run-in with police as teenagers, incidents that never happened in real life. Of course, they didn’t remember the event at first, but when offered a "guided imagery technique," said to help retrieve lost memories, the students began to reveal details. By their third interview, 70% of the students recalled the fake incident, some describing it in detail.
MRI scans show that false memories are indistinguishable from real ones. As far as the brain is concerned, the false memory actually happened.
Faulty memories make us happier
It’s clear that the human brain is wired to forget details. But why?
Researchers report that people diagnosed with depression may remember negative experiences more accurately than the rest of us. But remembering both the good and the bad can negatively affect emotion and poison the present. Memories that can be reshaped allow us to reinterpret negative events with positive outcomes. It appears that forgetting the details helps protect our mood and self-esteem.