False Memories Occur Amongst Superior Memory

False Memories Occur Even Among Those with Superior Memory:

False Memories Occur Even Among Those with Superior Memory

False Memories Occur Even Among Those with Superior Memory

 

Some people have the unique talent of being able to remember daily details of their lives from decades past.

But surprising new research finds that even among this select group of memory experts, false memories occur at about the same frequency as among those with average memory.

False memories are the recollection of an event, or the details of an event, that did not occur. UC Irvine psychologists and neurobiologists created a series of tests to determine how false information can manipulate memory formation.

In their study they learned that subjects with highly superior autobiographical memory preformed similar to 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.

“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.”

Patihis works in the research group of world-renowned psychologist Dr. Elizabeth Loftus, who pioneered the study of false memories and their implications.

Persons with highly superior autobiographical memory (HSAM, also known as hyperthymesia) – have the astounding ability to remember even trivial details from their distant past. This includes recalling daily activities of their life since mid-childhood with almost 100 percent accuracy.

The lead researcher on the study, Patihis believes it’s the first effort to test malleable reconstructive memory in HSAM individuals.

Working with neurobiology and behavior graduate student Aurora LePort, Patihis asked 20 people with superior memory and 38 people with average memory to do word association exercises, recall details of photographs depicting a crime, and discuss their recollections of video footage of the United Flight 93 crash on 9/11. (Such footage does not exist.)

These tasks incorporated misinformation in an attempt to manipulate what the subjects thought they had remembered.

“While they really do have super-autobiographical memory, it can be as malleable as anybody else’s, depending on whether misinformation was introduced and how it was processed,” Patihis said.

“It’s a fascinating paradox. In the absence of misinformation, they have what appears to be almost perfect, detailed autobiographical memory, but they are vulnerable to distortions, as anyone else is.”

Phobias memories passed down from ancestors

Phobias may be memories passed down in genes from ancestors:

Phobias may be memories passed down in genes from ancestors

Phobias may be memories passed down in genes from ancestors

 

Memories can be passed down to later generations through genetic switches that allow offspring to inherit the experience of their ancestors, according to new research that may explain how phobias can develop.

Scientists have long assumed that memories and learned experiences built up during a lifetime must be passed on by teaching later generations or through personal experience.

However, new research has shown that it is possible for some information to be inherited biologically through chemical changes that occur in DNA.

Researchers at the Emory University School of Medicine, in Atlanta, found that mice can pass on learned information about traumatic or stressful experiences – in this case a fear of the smell of cherry blossom – to subsequent generations.

The results may help to explain why people suffer from seemingly irrational phobias – it may be based on the inherited experiences of their ancestors.

So a fear of spiders may in fact be an inherited defence mechanism laid down in a families genes by an ancestors’ frightening encounter with an arachnid.

Dr Brian Dias, from the department of psychiatry at Emory University, said: “We have begun to explore an underappreciated influence on adult behaviour – ancestral experience before conception.

“From a translational perspective, our results allow us to appreciate how the experiences of a parent, before even conceiving offspring, markedly influence both structure and function in the nervous system of subsequent generations.

“Such a phenomenon may contribute to the etiology and potential intergenerational transmission of risk for neuropsychiatric disorders such as phobias, anxiety and post-traumatic stress disorder.”

In the study, which is published in the journal of Nature Neuroscience, the researchers trained mice to fear the smell of cherry blossom using electric shocks before allowing them to breed.

The offspring produced showed fearful responses to the odour of cherry blossom compared to a neutral odour, despite never having encountered them before.

The following generation also showed the same behaviour. This effect continued even if the mice had been fathered through artificial insemination.

The researchers found the brains of the trained mice and their offspring showed structural changes in areas used to detect the odour.

The DNA of the animals also carried chemical changes, known as epigenetic methylation, on the gene responsible for detecting the odour.

This suggests that experiences are somehow transferred from the brain into the genome, allowing them to be passed on to later generations.

The researchers now hope to carry out further work to understand how the information comes to be stored on the DNA in the first place.

They also want to explore whether similar effects can be seen in the genes of humans.

Professor Marcus Pembrey, a paediatric geneticist at University College London, said the work provided “compelling evidence” for the biological transmission of memory.

He added: “It addresses constitutional fearfulness that is highly relevant to phobias, anxiety and post-traumatic stress disorders, plus the controversial subject of transmission of the ‘memory’ of ancestral experience down the generations.

“It is high time public health researchers took human transgenerational responses seriously.

“I suspect we will not understand the rise in neuropsychiatric disorders or obesity, diabetes and metabolic disruptions generally without taking a multigenerational approach.”

Professor Wolf Reik, head of epigenetics at the Babraham Institute in Cambridge, said, however, further work was needed before such results could be applied to humans.

He said: “These types of results are encouraging as they suggest that transgenerational inheritance exists and is mediated by epigenetics, but more careful mechanistic study of animal models is needed before extrapolating such findings to humans.”

It comes as another study in mice has shown that their ability to remember can be effected by the presence of immune system factors in their mother’s milk

Dr Miklos Toth, from Cornell University in New York, found that chemokines carried in a mother’s milk caused changes in the brains of their offspring, affecting their memory in later life.

Scientists capture memories being made

Scientists capture the first image of memories being made:

Scientists capture the first image of memories being made

The ability to learn and to establish new memories is essential to our daily existence and identity; enabling us to navigate through the world. A new study by researchers at the Montreal Neurological Institute and Hospital (The Neuro), McGill University and University of California, Los Angeles has captured an image for the first time of a mechanism, specifically protein translation, which underlies long-term memory formation. The finding provides the first visual evidence that when a new memory is formed new proteins are made locally at the synapse – the connection between nerve cells – increasing the strength of the synaptic connection and reinforcing the memory. The study published in Science, is important for understanding how memory traces are created and the ability to monitor it in real time will allow a detailed understanding of how memories are formed.

When considering what might be going on in the brain at a molecular level two essential properties of memory need to be taken into account. First, because a lot of information needs to be maintained over a long time there has to be some degree of stability. Second, to allow for learning and adaptation the system also needs to be highly flexible.

For this reason, research has focused on synapses which are the main site of exchange and storage in the brain. They form a vast but also constantly fluctuating network of connections whose ability to change and adapt, called synaptic plasticity, may be the fundamental basis of learning and memory.

“But, if this network is constantly changing, the question is how do memories stay put, how are they formed? It has been known for some time that an important step in long-term memory formation is “translation”, or the production, of new proteins locally at the synapse, strengthening the synaptic connection in the reinforcement of a memory, which until now has never been imaged,” says Dr. Wayne Sossin, neuroscientist at The Neuro and co-investigator in the study. “Using a translational reporter, a fluorescent protein that can be easily detected and tracked, we directly visualized the increased local translation, or protein synthesis, during memory formation. Importantly, this translation was synapse-specific and it required activation of the post-synaptic cell, showing that this step required cooperation between the pre and post-synaptic compartments, the parts of the two neurons that meet at the synapse. Thus highly regulated local translation occurs at synapses during long-term plasticity and requires trans-synaptic signals.”

Long-term memory and synaptic plasticity require changes in gene expression and yet can occur in a synapse-specific manner. This study provides evidence that a mechanism that mediates this gene expression during neuronal plasticity involves regulated translation of localized mRNA at stimulated synapses. These findings are instrumental in establishing the molecular processes involved in long-term memory formation and provide insight into diseases involving memory impairment.

This study was funded by the National Institutes of Health, the WM Keck Foundation and the Canadian Institutes of Health Research.