Why do people with Alzheimer's remember old memories?
Why--and how--does someone with Alzheimer’s remember old memories while new memories fade?
Navigating the journey of a loved one’s memory loss to Alzheimer’s can be quite difficult, particularly understanding why some memories fade while older memories may be resurrected. A common question is why--and how--does someone with Alzheimer’s remember old memories while new memories fade? Though the workings of the brain can still be mysterious in many ways, research has suggested a few reasons.
The best explanation is that Alzheimer’s affects recent memories first, debilitating retention of new information. Memories of childhood or from long ago are well encoded since the person has had longer to process and remember specific events. In contrast, when Alzheimer’s symptoms start to show, think of “Last in, first out.” It can be difficult for a person with dementia to remember something from 20 minutes ago.
More technically speaking, new experiences or memories register in the part of the brain called the hippocampus, which sends the memory to the brain’s “storage bank.” When Alzheimer’s develops, the hippocampus is one of the first areas to be affected. Because that area of the brain can’t remember a new memory or person, the hippocampus can’t assist in "retrieving" the memory from the storage bank. These new memories also don’t have as much emotional attachment to them, as other memories stored in a different area of the brain, which suggests why it’s so difficult to retain a new memory.
Alzheimer’s affects the brain in such a way that even those long-term memories will fade over time as well.
For more information:
- Dementia Resources
- Videos: Doctors answer dementia questions
- Memory care and dementia frequently asked questions