When it comes to our memory, storing and recalling information is only half of the picture, forgetting is the other half. Forgetting is an important feature of our memory function that allows for more memory storage to take place. According to Oliver Hardt, an assistant professor at McGill University who studies memory and forgetting, “Without forgetting, we would have no memory at all,”. According to Hardt, forgetting serves as a filter for unimportant information. Forgetting happens in all species that have memory and, similar to learning, forgetting also has different types:
Intrinsic Forgetting: is an active form of forgetting that takes place when a set of cells called “forgetting cells” degrade memory traces. The mechanism of intrinsic forgetting is explained by Ronald Davis, a neuroscientist at the Scripps Research Institute in Jupiter, Florida. According to Davis, our brain cells can reverse the structural changes that resulted in the formation of a new memory. This is because cells are naturally inclined to revert to their original state before the memory was formed. However, this mechanism does not take place when a memory is identified as important so that it is not forgotten as easily.
Neurogenesis: Some researchers have shown that the formation of new neurons, or neurogenesis, is important for the formation of new memories and the degradation of old memories. Research on lab animals revealed that drugs that enhance neurogenesis help animals with learning new tasks. However, studies also demonstrate that greater neurogenesis after a memory formation can induce forgetting of previously acquired memories.
Are all of our forgotten memories completely gone? Researchers have shown that our brain cells do not fully revert to the structure they held prior to making a new memory, even after that memory is forgotten. Every new memory leaves its mark on our brains even after the memory itself is long gone.
References:
Chawla, D. S., & Quanta Magazine moderates comments to facilitate an informed, substantive. (2020, May 14). To remember, the brain must actively forget. Quanta Magazine. https://www.quantamagazine.org/to-remember-the-brain-must-actively-forget-20180724/
Image from Gitty Images.
