Posts Tagged ‘Claire Wilson’

Memory Special: Can You Trust Your Memories?

November 29, 2018

The title of this post is the same as the title of a Feature article by Clare Wilson. in the 27 October 2018 issue of the “New Scientist.” There have been many previous healthy memory blog posts on the research of Elizabeth Loftus. Wilson writes, “NO ONE has done more than Elizabeth Loftus to expose the fallibility of human memory. In the 1990s, amid growing panic over claims of satanic child sex abuse rings, the psychologist showed how easy it is for people to develop false memories of events that never happened. All it took was repeatedly being asked to imagine them. At the time, this was a common psychotherapy technique to recover supposed repressed memories.”

Over the last three decades, Loftus, now at the University of California, Irvine has become well known for her work as an expert witness in legal cases. Her continuing research on the fallibility of eyewitness testimony has taken fresh importance in the era of fake news, the Me Too movement and digital image manipulation.

Clare Wilson asks, “The Me Too movement has led to a surge in historic claims of sexual assaults. Do you think some of these could be based on false memories?

Dr. Loftus responded, “It is possible, We have to accept that when there are two people whose versions of an event are different, the man’s version may not be the truth or, alternatively maybe the woman’s version is not the truth. We have to look for other sources of evidence to corroborate either person. But right now, at the height of “Me Too”, people are not as interested in hearing you talk about false accusations as they might have been a year ago. The pendulum has swung too far in the direction of automatically believing the accuser. It used to be too far the other way.

Clare Wilson, “But we know most abuse cases are not successfully brought to trial…

Dr. Loftus responds, “I absolutely see what you’re saying. But as an expert witness on memory, I see a different subset of cases to the ones that most people see. I see the most contentious ones. I hate the idea people will try to point to all the false memory work and use it to deny guilt when they’re truly guilty. I think that probably sometimes happens and it’s just going to be a cost. I don’t know what we can do to stop that.”

Clare Wilson, “What other memory problems has your research shed light on?”

Dr. Loftus responds, “We have been doing some work on the phenomenon called memory blindness. Say that someone is being interviewed after witnessing a crime. They tell you that person was wearing a green jacket. Later on you tell them they told you the jacket was brown. We’re exploring the extent to which people even notice you fed back a different answer from the one you actually gave. Often they don’t. We think this can be a problem in cases where the police are writing out a statement. They say, ‘Here’s what you told me.’ What if there are errors contained in it? It can happen. We are showing that people can fail to detect them and be influenced by them.”

Clare Wilson, Can we misremember our feelings as well as facts?

Dr. Loftus responds, The evidence would suggest so. Another study we’re doing is we take you through a difficult task and ask you to rate your anxiety. I tell you that I rated it at 40 when you really rated it at 60. People often don’t detect you gave them the wrong rating and they start to feel less anxious about the task. When they look back, it was less awful for them. You could do this with kids when they go to the dentist. A former student of mine did some research with kids at a dental clinic, and she got them to remember less fear and pain, and they also behaved better at the next visit.

Clare Wilson, So there could be benefits to fallible memories?

Dr. Loftus responds, “If your kid had a traumatic but minor experience, rather than dwelling on the negatives, it might be better instead to talk them up. To say: “You were so brave, you hardly cried.” It is generally a little easier to plant a positive memory than a negative one. We don’t know why, it just empirically seems to be the case.”

Clare Wilson, Is there any evolutionary reason why memory is so unreliable?

Dr. Loftus responds, “One benefit is that when errors creep in, you can fix them and update memories with true information. Another is that some errors make you feel bette about yourself. These are called prestige-enhancing distortions. A common example is people remembering voting in elections they didn’t vote in, because they like to think of themselves as civic-minded. Sometimes it gets people into trouble, like in “stolen valor cases”, when someone famous says they were a brave soldier on the battlefield and it turns out they were really behind a desk on that day.”

Clare Wilson, So most of the time it is a harmless delusion?

Dr. Loftus responds, “If these kinds of prestige-enhancing distortions aren’t caught, it does allow people to feel better about themselves. People with depression don’t have them as much as everyone else. Such people are sadder but wiser. This is just a correlation, so we don’t know if the lack of prestige-enhancing memory distortions is causing the depression. But it does suggest another possible upside to the untenability of our memories. If there are costs, there have got to be some benefits.”

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How the Cognitive Reserve Works

December 22, 2017

There have been many previous healthy memory posts informing its readers that there are people who die with brains filled with amyloid plaque and neurofibrillary tangles, but who never exhibited any of the cognitive or behavioral symptoms of Alzheimer’s. About one-third of the people who die without cognitive problems have had the plaques and tangles that define Alzheimer’s Disease. It is believed that intellectual stimulation builds this cognitive reserve. HM has advanced the notion that it is specifically Daniel Kahneman’s System 2 processing that largely builds this cognitive reserve.

The question is what is the cause or causes of this cognitive reserve? Jeremy Herskowitz at the University of Alabama at Birmingham and his colleagues studied brain samples from 41 people. They had either beta-amyloid plaques but not symptoms, plaques and symptoms, or no plaques or symptoms. The team took close-up pictures of the samples, then used software to trace the physical shape of the brain cells and their connections or synapses. This technique allowed the team to visualize the first neuron of a pair that make up a synapse. This neuron sends out small buds known as spines which connect with projections from other neurons. Each synapse exists where a spine links to a projection. The spines of people who were Alzheimer’s resistant were longer than those from the other groups (Annals of Neurology, dos.org/cgfx).

Synapses are where signals pass from one neuron to another. Herskowitz says “the longer spines might make the synapse more effective in this role. Or new spines might be growing outwards to generate more synapses to replace those destroyed by plaques and tangles.” Herskowitz goes on to say,”It’s possible that the spines are reaching out to maintain the synaptic connections. They are putting themselves out there to catch a new one.”

Michael Valenzuela at the University of Sydney says that this finding may not be the only explanation. Brain imaging studies suggest that people who are resistant to Alzheimer’s may compensate for damage by using different parts of their brain. It should also be noted that these explanations are not mutually exclusive. They could both be operative.

The news here is that we have reasonable explanations as to what accounts for this cognitive reserve. However, it has long be expected that this cognitive reserve is built by cognitive activity. HM further postulates that it is System 2 processing of Kahneman’s ilk that is primarily responsible for the cognitive reserve.

So live a healthy lifestyle, stay cognitively engaged, and foster growth mindsets for a health memory.

This post is based on an article by Claire Wilson titled “Elongating your brain cells could ward off Alzheimer’s in the News & Technology section of the 25 November 2017 issue of the New Scientist.

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