New memory principle may help treat psychological trauma

Everyone has stored in his brain at least one traumatic experience, such as the death of a loved one, a horrific road accident, a terrorist attack, or a Holocaust experience. Now Israeli neurobiologists, working on rats and fish, have discovered a new principle that guides memory dynamics and may make eventually make it possible for people to intentionally erase or at least dim specific memories from their minds without affecting the other ones.

A team of neurobiologists at Rehovot's Weizmann Institute of Science headed by Prof. Yadin Dudai have published their findings in Thursday's issue of the prestigious journal Science. Their discovery is regarded as an important step towards reaching the goal of wiping out or dimming unpleasant memories.

Every memory that humans and lower animals acquire undergoes a "ripening" process (called consolidation) immediately after it is formed. In this process, it becomes impervious to outside stimulation or drugs that would obliterate it. Until recently, the accepted theory was that for each separate item of memory, consolidation occurs just once, after which time the window that allows for "memory erasing" closes usually about an hour or two after the memory is acquired.

But recently, evidence came to light that a memory is open to disruption for a short period following each time this memory is recalled. If this is true, it would be possible to recall a memory and immediately after the act of remembering activate a "memory eraser" and wipe it out, even though years may have passed since the original memory was formed.

Research into the subject carried out in leading labs around the world produced indecisive results: In some cases it was found possible to erase old memories upon recall, while in others no evidence for this was found.

But Dudai and colleagues have now identified a new principle guiding the activity of the brain's memory systems that sheds light on how memories are recalled and stabilized. It can also explain the puzzling discrepancies in the findings. This principle points to the conditions in which the recalled memory becomes re-sensitized to the activity of the "memory erasers."

Bits of information are stored in memories, each with many associations some of which conflict with others. For instance, a certain food can bring up memories delicious or distasteful; in another example, an individual can be remembered in pleasant or unpleasant contexts. When we next taste the food or see the person, all of the associated memories are called up in the blink of an eye, but in the end, only one of those memories will become dominant and determine the reaction to the recollection.

This memory will decide whether we will eat the food or reject it, or whether we will smile at our acquaintance or ignore him. Dudai's team found that only the recalled memory that won the competition for dominance was re-exposed to the time window of sensitivity to memory erasers, and it is this memory that must consolidated once again before being reinstalled in the long-term memory. In other words, the winner, in the appropriate circumstances, may lose all: The stability of the recalled memory is inversely correlated with its dominance. Their discovery is likely to assist in the future in developing new methods of wiping out unwanted memories, and thus of treating some kinds of psychological trauma.

Research that deals with the physical basis of the processes and mechanisms of memory, especially those that involve chemical or other intervention, relies on animal subjects. The Weizmann team chose rats and fish because they are especially suited for this type of research. The rats learned to remember flavors; the fish learned to remember flashes of light, and in both instances, the animals were trained to associate them with conflicting memories. That is, the tastes were sometimes good and sometimes bad, and the light sometimes signaled danger and sometimes didn't.

In both species, it was possible to show that the dominant memory that which won out over other associated memories and determined subsequent behavior was the only one that could be erased by giving the appropriate drug within a few minutes of the memory's recall. The closer we get to the "basic hardware" of memory, the more similarities exist between different animals, including humans, and this fact paves the way to the possibility that certain drugs found to be effective in eliminating memories in animals will also work on humans.

To: SJackson; Yehuda; Nachum; Paved Paradise; Mr. Mojo; Thinkin' Gal; Bobby777; adam_az; Alouette; ...

2 posted on 08/23/2003 6:05:29 PM PDT by yonif ("If I Forget Thee, O Jerusalem, Let My Right Hand Wither" - Psalms 137:5)

this fact paves the way to the possibility that certain drugs found to be effective in eliminating memories in animals will also work on humans.

Scheesh ! They could have learned as much from a country song. "I've been drinking her off my mind..."

4 posted on 08/23/2003 6:17:02 PM PDT by SSN558 (Be on the lookout for Black White-Supremacists)

and it is this memory that must consolidated once again before being reinstalled in the long-term memory.

There is a theory that the presence of high adrenaline is all that is needed to incorporate a memory. I don't think I needed seeing those planes flying into the World Trade Center more than once to ever forget it.

If memory can be affected, maybe in a while we will all be able to learn Kung Fu the way Neo did.

Which leads to interesting problems. You could learn things by having your memory downloaded but there are things you can only learn from experience. You could learn the moves but would you also be able to learn how to integrate your moves into a strategy that evaluates the strengths and weaknesses of each adversary ? Could you learn the moves and still be a lazy slacker who never finishes anything ?

"Their discovery is regarded as an important step towards reaching the goal of wiping out or dimming unpleasant memories"

. . .bad as memories can be; seems,nonetheless, a counterproductive goal.

Forget the Holocaust?

10 posted on 08/23/2003 8:09:30 PM PDT by Wild Thing (Prayers for our troops, Israel and the IDF ! Support the troops fighting Terrorists !)

There is a Christian Counseling technique that is very successful. Take the memory and in your heart and mind, take it to the Cross and lay it there. Then pray for cleansing of the mind. It works very well. If the memory does come back, the sting is gone and what is remembered is laying it in the Lord's hands.

This could be a very bad idea. We learn things from our memories, people who simply forget unpleasent things will never grow, and never learn who to avoid unpleasent memories in the first place.

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