It's no surprise that as we get older, our memory will not remain as good as it once was. But the question is…why? Does everyone develop at least a mild case of dementia? Does part of our brain deteriorate? Do we simply not have enough room for any more memories?
Heather Bailey, from Washington University in St. Louis, suggests that there is an atrophy in the medial temporal lobe in the brain. This atrophy leads to the inability to process everyday events.
For example, when you struggle to remember what you had for breakfast yesterday morning, you know it's different from lunch because you're able to chunk the events of your day properly. People with this atrophy can't do that.
This study used older individuals, some with dementia and some without, and had them watch movies of people doing everyday tasks. They had to distinguish these "chunks" by splitting the movie where they saw one task ended and a new part beginning. Later, the individuals were asked to recall the movie.
Using an MRI scan, the researchers found that those with atrophy in the medial temporal lobe did not have strong memories and they couldn't properly segment the events in the movie. They looked for the comparable size of the medial temporal lobe.
This is a big step for memory research, because now it's not simply a problem with recollection of events, but how we process/absorb that information as well.
To read more on the research, you can read the full article here.