Health and Medical News and Resources

General interest items edited by Janice Flahiff

Recalling happier memories can reverse depression

Recalling happier memories can reverse depression 

From the 17 June 2015 MIT news release

MIT neuroscientists have shown that they can cure the symptoms of depression in mice by artificially reactivating happy memories that were formed before the onset of depression.

The findings, described in the June 18 issue of Nature, offer a possible explanation for the success of psychotherapies in which depression patients are encouraged to recall pleasant experiences. They also suggest new ways to treat depression by manipulating the brain cells where memories are stored. The researchers believe this kind of targeted approach could have fewer side effects than most existing antidepressant drugs, which bathe the entire brain.

“Once you identify specific sites in the memory circuit which are not functioning well, or whose boosting will bring a beneficial consequence, there is a possibility of inventing new medical technology where the improvement will be targeted to the specific part of the circuit, rather than administering a drug and letting that drug function everywhere in the brain,” says Susumu Tonegawa, the Picower Professor of Biology and Neuroscience, director of the RIKEN-MIT Center for Neural Circuit Genetics at MIT’s Picower Institute for Learning and Memory, and senior author of the paper.

Memory control

In 2012, Tonegawa, former MIT postdoc Xu Liu, Ramirez, and colleagues first reported that they could label and reactivate clusters of brain cells that store specific memories, which they called engrams. More recently, they showed that they could plant false memories, and that they couldswitch the emotional associations of a particular memory from positive to negative, and vice versa.

In their new study, the researchers sought to discover if their ability to reactivate existing memories could be exploited to treat depression.

To do this, the researchers first exposed mice to a pleasurable experience. In this case, all of the mice were male and the pleasurable experience consisted of spending time with female mice. During this time, cells in the hippocampus that encode the memory engram were labeled with a light-sensitive protein that activates the neuron in response to blue light.

After the positive memory was formed, the researchers induced depression-like symptoms in the mice by exposing them to chronic stress. These mice show symptoms that mimic those of human sufferers of depression, such as giving up easily when faced with a difficult situation and failing to take pleasure in activities that are normally enjoyable.

However, when the mice were placed in situations designed to test for those symptoms, the researchers found that they could dramatically improve the symptoms by reactivating the neurons that stored the memory of a past enjoyable experience. Those mice began to behave just like mice that had never been depressed — but only for as long as the pleasant memory stayed activated.

July 17, 2015 Posted by | Medical and Health Research News, Psychiatry, Psychology, Uncategorized | , , , , , , , , | Leave a comment

[News article] People can be induced to remember crimes they never committed | Ars Technica

People can be induced to remember crimes they never committed | Ars Technica.

Implanting a false memory of committing a crime is easier than you think.

2383172328_a708fee546_zAlejandro Mejía Greene (flickr user: ·júbilo·haku·)

From the 26 January 2015 article

The idea that memories are not as reliable as we think they are is disconcerting, but it’s pretty well-established. Various studies have shown that participants can be persuaded to create false childhood memories—of being lost in a shopping mall or hospitalized, or even highly implausible scenarios like having tea with Prince Charles.

The creation of false memories has obvious implications for the legal system, as it gives us reasons to distrust both eyewitness accounts and confessions. It’s therefore important to know exactly what kinds of false memories can be created, what influences the creation of a false memory, and whether false recollections can be distinguished from real ones.

A recent paper in Psychological Science found that 71 percent of participants exposed to certain interview techniques developed false memories of having committed a crime as a teenager. In reality, none of these people had experienced contact with the police during the age bracket in question.

A number of tactics were used to induce the false memory. Social pressure was applied to encourage recall of details, the interviewer attempted to build a rapport with the participants, and the participants were told that their caregivers had corroborated the facts. They were also encouraged to use visualization techniques to “uncover” the memory.

In each of the three interviews, participants were asked to provide as many details as they could for both events. After the final interview, they were informed that the second memory was false, and asked whether they had really believed the events had occurred. They were also asked to rate how surprised they were to find out that it was false. Only participants who answered that they had genuinely believed the false memory, and who could give more than ten details of the event, were classified as having a true false memory. Of the participants in the group with criminal false stories, 71 percent developed a “true” false memory. The group with non-criminal false stories was not significantly different, with 77 percent of participants classified as having a false memory. The details participants provided for their false memories did not differ significantly in either quality or quantity from their true memories.

This study is only a beginning, and there is still a great deal of work to be done. There are a number of factors that couldn’t be controlled for but which may have influenced the results.

 

 

January 28, 2015 Posted by | Uncategorized | , , | Leave a comment

[Journal Article] People with highly superior powers of recall also vulnerable to false memories

From the 20 November 2013 Science 360 News Service

People who can accurately remember details of their daily lives going back decades are as susceptible as everyone else to forming fake memories, UC Irvine psychologists and neurobiologists have found. In a series of tests to determine how false information can manipulate memory formation, the researchers discovered that subjects with highly superior autobiographical memory logged scores similar to those of a control group of subjects with average memory. “

Finding susceptibility to false memories even in people with very strong memory could be important for dissemination to people who are not memory experts. For example, it could help communicate how widespread our basic susceptibility to memory distortions is,” said Lawrence Patihis, a graduate student in psychology & social behavior at UC Irvine. “This dissemination could help prevent false memories in the legal and clinical psychology fields, where contamination of memory has had particularly important consequences in the past.”

More on this finding from the UC Irvine press release

 

November 20, 2013 Posted by | Psychiatry | , , , | Leave a comment

   

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