A few minutes ago, while researching about virtual worlds, I came across an article on memory. I read the whole 4 pages of it, but here are some excerpts.
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Every time we remember, it seems, we add new details, shade the facts, prune and tweak. Without realizing it, we continually rewrite the stories of our lives. Memory, it turns out, has a surprising amount in common with imagination, conjuring worlds that never existed until they were forged by our minds.
Instead of being a perfect movie of the past, psychologists found, memory is more like a shifting collage, a narrative spun out of scraps and constructed anew whenever recollection takes place.
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. “Reconsolidation suggests that when you use a memory, the one you had originally is no longer valid or maybe no longer accessible,” LeDoux says. “If you take it to the extreme, your memory is only as good as your last memory. The fewer times you use it, the more pristine it is. The more you use it, the more you change it.” 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.
Todd Sacktor, a professor of physiology, pharmacology, and neurology at the State University of New York Downstate Medical Center in Brooklyn, has found a blunter but more powerful technique that can eradicate whole categories of memory. He studies protein kinase M-zeta (PKMzeta), which is involved in memory maintenance. As calcium rushes into a memory neuron, PKMzeta is synthesized, linking up with spare glutamate receptors and dragging them to the synapse, where memory construction occurs. With more receptors at the synapse, signals are boosted and amplified and the memory persists.
When Sacktor deactivated PKMzeta with a compound called zeta-inhibitory peptide (ZIP), he got a spectacular response: total amnesia for one type of memory. Rats that had learned a day or a month before to avoid part of a platform that was rigged with electric shock forgot everything they knew about the location generating the jolt. “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.”
Certain types of memory are encoded in different brain areas, and depending on where Sacktor injects the inhibitor in his animals, he can zap away different categories of memory. In the hippocampus, he erases memory for spatial locations like the platform; in the amygdala, fear memories; in the insular cortex, memories of nauseating taste. Very rarely, Sacktor says, neurosurgeons remove nerve clusters to help disturbed psychiatric patients who do not respond to any other treatment. His research may eventually provide a way to erase memory without causing damage.
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,” he says.
None of these researchers are looking to create brain-zapped, amoral zombies—or even amnesiacs. They are just trying to take control of the messy, fragile biological process of remembering and rewriting and give it a nudge in the right direction. Brunet’s patients remember everything that happened, but they feel a little less tortured by their own pathological powers of recollection. “We’re turning traumatic memories into regular bad memories,” Brunet says. “That’s all we want to do.”----------------------------------------------------------------------------
Scary, huh? Shit, it is freakin' scary.
