recollections frequently surfaced with the help of recovered-memory therapy techniques like hypnosis and guided imagery, in which patients are encouraged to visualize terrible experiences.
Cognitive scientists suspected that some of these memories were bogus, the unwitting product of suggestion by the therapist.
::: memory tools altering our memories - bias of what is thought more vital in the recollection of the memory - e.g. visual data over other sensorial data included in the memory file? :::
http://discovermagazine.com/2009/jul-aug/03-how-much-of-your-memory-is-true/article_view?searchterm=memory&b_start:int=1
Spurred on by the controversy over recovered memory, other cognitive scientists found that false memory is a normal phenomenon
Even harrowing memories—the so-called flashbulb memories that feel as if they have been permanently seared into the brain—are not as accurate as we think. Less than a year after a cargo plane crashed into an Amsterdam apartment building in 1992, 55 percent of the Dutch population said they had watched the plane hit the building on TV. Many of them recalled specifics of the crash, such as the angle of descent, and could report whether or not the plane was on fire before it hit. But the event had not been caught on video. The “memory” shared by the majority was a hallucination, a convincing fiction pieced together out of descriptions and pictures of the event.
memory is more like a shifting collage, a narrative spun out of scraps and constructed anew whenever recollection takes place.
Nader tweaked a standard method used in fear research, in which rats are trained to associate a tone with an electric shock to the foot. The animals quickly learn that the sound is bad news. If they hear it weeks later, they freeze in fear. It is an easy way for the experimenter to know that they remember what took place. Nader trained some rats, then played the tone again 14 days later, prompting them to remember. He also simultaneously injected them with a protein-synthesis inhibitor, which prevents new memory from forming by prohibiting alteration at the synapses. According to the standard model of memory, the chemical should have no effect since the memory of the tone has already consolidated. In reality, the treated rats’memory disappeared. When Nader sounded the tone again later, the animals did not freeze. LeDoux was won over by this simple but powerful demonstration, he showed that reactivating a memory destabilizes it, putting it back into a flexible, vulnerable state. >>>>> Memory constantly rewritten/reconstructed - Re-consolidation teasing out the reconsolidation process molecule by molecule. Nader’s group found that the NMDA glutamate receptor—which solidifies memory—also is involved in destabilizing it. A group led by Sue-Hyun Lee at Seoul National University demonstrated that proteins must be actively dismantled to destabilize a memory, more evidence that the old memory is actually changed as it is recalled. “I felt more detached from it,” she says. “I felt that I was relating a narrative rather than describing something right in front of me right now.” After the study was over, the flashbacks returned, though with less intensity. For her, the only real cure was time.Six-session treatments with a total of 12 doses of propranolol have shown better results. Collaborating with Harvard psychiatrist Roger Pitman, who was the first to try propranolol for post-traumatic stress, the McGill group has treated about 45 PTSD patients, ranging from soldiers to rape victims. Most had been suffering for years. But after the longer treatment, their symptoms declined by half and stayed that way even six months afterward. They still remember what happened, but it is less disturbing. “They say: ‘I’m not thinking about it as much. It just doesn’t bother me as much anymore,’?” Brunet says. As a group, they are considered to be in remission. The researchers must still prove that the improvement will last. If it does, it could offer rare hope to millions of people with PTSD, a disorder from which only a third completely recover. >>> tools for constructing memory>>> emphasisng certain perts of the memory?>>> Anxiety, acquired phobias, and addiction are increasingly described as disorders of emotional memory, overly powerful fear memory, for example, can crystallize into a phobia, in which a relatively safe experience like flying in a plane is inextricably linked to a feeling of extreme danger, No matter how the phobic person tries, his emotional memory refuses to update itself to incorporate reassuring information. A treatment that restores his emotional memory to a flexible state http://discovermagazine.com/2009/jul-aug/03-how-much-of-your-memory-is-true/article_view?searchterm=memory&b_start:int=2 Addiction is another kind of pathological remembering, but in this case the memory is pleasurable. drugs of abuse enlist the amygdala and the brain’s reward centers to forge unforgettable memories of pleasure. Anything connected to the bliss reawakens the memory, in the form of craving.you are suffering from reminiscence, from an emotional memory memory might be constantly revamped As you replay these memories, you reawaken and reconsolidate them hundreds of times. Each time, you replace the original with a slightly modified version. Eventually you are not really remembering what happened; you are remembering your story about it. your memory is only as good as your last memory. The fewer times you use it, the more pristine it is. We’ve all had the experience of repeating a dramatic story so many times that the events seem dead, as if they came from a novel rather than real life. This might be reconsolidation at work. the flexibility of memory might be functional—an advantage rather than a bug in the brain. Reconsolidation might be how we update our store of knowledge, by making old memories malleable in response to new information. “When you encounter a familiar experience, you are remembering the original memory at the same time, and ?the new experience somehow gets blended in. From the perspective of survival, constructive memory is an asset. It allows you to pull together scraps of information to simulate the future on the fly. Facing something new, we want to link the novel information with memories to better interpret the situation. If the side effect is a few mistakes memory and imagination are two sides of the same coin. Like memory, imagination allows you to put yourself in a time and place other than the one we actually occupy. remembering and imagining mobilize many of the same brain circuits. “When people are instructed to imagine events that might happen in their personal future and then to remember actual events in the past, we find extensive and very striking overlap in areas of brain activation,” he says. Other researchers have found that people with severe amnesia lose their ability to imagine. Without memory, they can barely picture the future at all. When calcium floods a neuron as a memory is formed, it turns on an enzyme called CaMKII (calcium/calmodulin-dependent protein kinase). Among many other things, the enzyme responds to signals from NMDA receptors, leading to more receptor activity and stronger signaling throughout the network of cells. protein kinase M-zeta (PKMzeta), which is involved in memory maintenance,“You inhibit the PKMzeta and those glutamate receptors float away very, very fast,” he says. “As a result, the memory is lost—very, very fast.” The implications are staggering. If stored memories were inscribed in the brain, it is hard to imagine how flipping one chemical switch could erase them so quickly. “It really is a paradigm shift in how people think about long-term memories,” Sacktor says. In the old view, erasure should cause permanent brain damage as the synapses are ripped apart. Instead, Sacktor’s rats’ brains remain intact. Once the ZIP treatment wears off, the animals behave and even learn normally again. “It’s like wiping a hard disk http://discovermagazine.com/2009/jul-aug/03-how-much-of-your-memory-is-true/article_view?searchterm=memory&b_start:int=3 Nader and Brunet’s studies suggest much more benevolent possibilities. If he had received reconsolidation therapy, Carrey’s character would not have forgotten Winslet’s. He simply wouldn’t care that much about her anymore. He would be able to look at his failed relationship as if through the wrong end of a telescope. What is on the other side is still visible, but it is tiny and far away. >>> army veterans - easing memory from war - (PTSD study with a new, $6.7 million grant from the U.S. Army,) LeDoux’s lab has figured out a way to trigger reconsolidation without drugs to weaken memory, simply by carefully timing the sessions of remembering. “The protocol is ridiculously simple,” LeDoux says. >>> Tools to help people with dementia and other memory loss problems retain important memories. digital applications that ultalise physical sensorial data to reate memory stimulating experience?
No comments:
Post a Comment