I vividly remember the moment my late lab partner, Xu Liu, and I first met.
Illuminated, it felt as if the neurons responsible for some of our memories were breathing life into those thoughts again. We stimulated groups of neurons in the hippocampus of mice, positing that these neurons serve as the physical foundation of memories, or engrams. Little did we realize, we were delving into one of neuroscience’s most thrilling frontiers: the potential to modify memories themselves.
The term “memory manipulation” might evoke unsettling imagery of erased histories and deceitful implants. However, within the lab, the reality is much more serene and optimistic. The very discovery that enables us to activate or deactivate memories in mice is also guiding us on how to heal our brains, including methods for diminishing trauma
memory and enhancing the fading
elements, allowing us to rebalance the emotions associated with our memories
we carry.
Over the last decade, this research has unveiled three significant principles. First, memories are adaptable during their storage, recall, and restoration. Second, they are situated across various regions in the brain rather than being localized to one area. Finally, memories can be artificially implanted within the brain. Each principle reshapes our understanding of what “memory editing” signifies.
During memory formation, brain cells collaborate and strengthen their connections. This process can be either enhanced or hindered by varying stimulation patterns. Brain stimulation through implanted electrodes or magnetic pulses can facilitate navigation in a
virtual environment. Substances like medications, hormones, and even tiny amounts of sugar can bolster the brain’s ability to stabilize new experiences. Moreover, exercise promotes the development of new neurons, thereby enhancing the health of the hippocampus and the brain overall
body. Conversely, overstimulation of memory circuits may lead to a decline in memory strength
leading to degradation; inhibiting the molecules that fortify these connections can weaken them further.
Memories can also be altered at the moment of recollection, temporarily rendering them unstable, thus creating opportunities to adjust them before they are stored once more. Therapists are already utilizing this “window of reintegration” in assisting individuals grappling with phobias and trauma. In our studies involving animals, the repeated reactivation of distressing memories is enough to
dull their emotional impact. Additionally, reactivating positive memories during periods of stress can completely overshadow negative emotions. In one
rat study, a week of “positive memory reactivation” alleviated depression-like symptoms for over a month.
Given that memories are distributed throughout the brain, they are highly resilient. Damage to a specific region will likely not erase the entire experience; instead, the brain finds alternative pathways to access memories through
multiple “drafts”. This redundancy provides hope for treating Alzheimer’s disease. If we can reinforce the pathways to the intact memories, we might restore fragments of our identity previously deemed lost. Thus, memory manipulation isn’t about altering who we are; it’s about forging new pathways back to our true selves.
Like any significant medical development, from pacemakers to transplants, this concept raises ethical considerations. Our aim is to alleviate suffering to improve overall well-being. It’s about assisting veterans in easing the grip of flashbacks, aiding individuals in recovery to dissociate cravings from triggers, and helping those with Alzheimer’s to grasp the names of loved ones.
Learning to reshape memories responsibly can foster healing. Each time a memory is revisited, the brain is already in editing mode. Today’s science is just beginning to uncover the rules guiding this process. As I recall fleeting memories with Xu, I envision not science fiction, but a future in which scientific knowledge and memory converge to become foundational to mental health.
Steve Ramirez. I am the author of How to change your memory: One neuroscientist’s quest to change the past.
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Source: www.newscientist.com
