Neuroscientists Shed Light on the Benefits of “Forgetting” in New Study
Neuroscientists have made a groundbreaking discovery that challenges our understanding of forgetting. According to their research, forgetting might actually be a form of learning that facilitates flexible behavior in dynamic environments. The implications of this finding are far-reaching, particularly for conditions like Alzheimer’s disease.
In the past, scientists have proposed that changes in memory retrieval stem from environmental feedback and predictability. Rather than being a flaw, forgetting may be an intentional characteristic of the brain, allowing it to adapt to ever-changing surroundings. To investigate this concept further, a team of neuroscientists conducted a series of experimental studies.
Published in the prestigious journal Cell Reports, their initial findings provide strong evidence to support the idea that forgetting is not necessarily a bad thing. The team focused on a type of forgetting called “retroactive interference,” which occurs when different experiences that happen close together cause the forgetting of recently formed memories.
In their study, mice were asked to associate a specific object with a particular context or room. However, when competing experiences were introduced, the mice forgot these associations. The researchers genetically labeled the brain cells responsible for storing these memories, known as engrams, and tracked their activation and functioning after forgetting occurred.
Using a technique called optogenetics, the researchers found that stimulating the engram cells with light retrieved the seemingly lost memories in various behavioral situations. Additionally, when the mice were exposed to new experiences related to the forgotten memories, the engrams were naturally rejuvenated.
Dr. Tomás Ryan, the lead author of the study and an Associate Professor at Trinity College Dublin, explained, “It is increasingly becoming clear that the memories themselves are still there, but the specific ensembles are not activated, and so the memory is not recalled. It’s as if the memories are stored in a safe, but you can’t remember the code to unlock it.”
Dr. Livia Autore, the Irish Research Council Postgraduate Scholar who spearheaded the research, added, “Our findings here support the idea that competition between engrams affects recall and that the forgotten memory trace can be reactivated by both natural and artificial cues, as well as updated with new information.”
The implications of this study are significant, particularly for individuals with Alzheimer’s disease. Understanding that “natural forgetting” can be reversible in certain circumstances provides new avenues for research and potential therapeutic interventions.
The study was funded by various organizations, including the European Research Council, the Canadian Institute for Advanced Research, the Irish Research Council, and the Science Foundation Ireland.
Further investigations are underway to explore the mechanisms underlying forgetting and its potential applications in the treatment of memory-related disorders.