Remarkable news on the memory-erasure front. A team led by Elizabeth Phelps at New York University has published a report in Nature this week about a technique for wiping out unpleasant associations by taking advantage of a psychological process known as reconsolidation. A good deal of research has gone on lately into the erasure of unpleasant memories, with the goal of treating people suffering from anxiety and PTSD, but so far the focus has been on using drugs, as I’ve described earlier.
This kind of emotional memory is processed in the amygdala, a crucial hub for coordinating the brain’s response to danger. Fear memories can be problematic because, unlike the conscious, “explicit” memories that are formed via the hippocampus — things like the name of a friend, or the number of pints in a gallon — they do not fade with time in the same way. As I write in Chapter 10 of Extreme Fear:
The amygdala’s memory system retains frightening associations permanently. If you’ve been bitten by white dog, your amygdala will never forget. But the memory can get overlaid by a positive or neutral association. If you later buy a friendly white dog, say, and spend day after day associating your pet with harmless fun, in time your fear of white dogs will be overlaid by a suppressing response generated by the medial prefrontal cortex. Your amygdala isn’t forgetting that white dogs are dangerous, but you’ve laid a new memory on top of it, like a linoleum floor over a trap door. The old unconscious fear connection remains, encoded subconsciously in the amygdala. Under stress, the buried fear can spontaneously reemerge.
In her study, Phelps explored the effect on extinction of reconsolidation, an intriguing effect in which a memory that has been recalled into consciousness becomes temporarily malleable and subject to change. Previous experimenters have administered drugs, such as the beta-blocker propranalol, during the reconsolidation phase, and found that this can help erase painful memories. Phelps’ experiment was designed to see whether a similar effect could be obtained without the use of drugs. And the surprising answer was yes.
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Filed under: Research, Uncategorized, amygdala, Anxiety, extinction training, Extreme Fear, fear, phobia, reconsolidation