Erasing Bad Memories
We've all experienced the disturbing phenomenon of having events or sights or sounds trigger unwanted reminiscences. What if you could wipe away the recollection of embarrassing moments and regrettable missteps so that you'd never have to live them all over again in your mind? Even more exciting, what if people who suffer from debilitating post-taumatic stress disorder could rid themselves of the memories that torture them? According to a study published in the journal Neuron, scientists have found not one but two ways that we can voluntarily do exactly that.
A release from the journal says that the findings may explain how individuals can cope with undesirable experiences and could lead to the development of treatments to improve disorders of memory control. Lead author Roland Benoit of the MRC Cognition and Brain Sciences Unit at the University of Cambridge in the UK said, "This study is the first demonstration of two distinct mechanisms that cause such forgetting: one by shutting down the remembering system, and the other by facilitating the remembering system to occupy awareness with a substitute memory."
Although several previous neuroimaging studies have examined the brain systems involved in "intentional forgetting", they have not revealed the cognitive tactics that people use. Benoit and his team say that both of the strategies they discovered were equally effective but that they activate distinct neural circuits. The release explains that during memory suppression, a brain structure called dorsolateral prefrontal cortex inhibits activity in the hippocampus, a region critical for recalling past events. On the other hand, memory substitution is supported by different regions, the caudal prefrontal cortex and midventrolateral prefrontal cortex—two areas of the brain involved in bringing specific memories into awareness in the presence of distracting memories.