Scientists from McGill University have just published the results of their study into the possible causes of memory decline in middle aged people, and what constitutes healthy ageing of our brains. Their research, which was published in a recent edition of the online journal NeuroImage, suggests that the decline in our memory may all be down to changes in our brain’s focus when it forms and retrieves memories.
If you’re 40 or over, you’ve probably already experienced times where you’ve found it difficult to remember details such as names and where you put your keys. This inability to remember such things usually begins in early midlife, in other words from the 40s onwards. Now researchers believe that rather than being a decline in our brain function, these memory problems are down to how the brain focuses during memory formation and retrieval.
The McGill team, led by Natasha Rajah, the Director of the Brain Imaging Centre at the university, suggests that this reorientation of the brain’s focus may have an impact on our day-to-day life, particularly when you’re trying to remember details such as where you parked your car when you were out shopping.
Currently scientists believe that the changes in the brain that we see with dementia arise years before the actual symptoms are seen. With this in mind, many research projects concentrate on trying to discover what constitutes normal and abnormal changes as the brain ages. However, not much is known about what happens to our brains as we reach middle age, and how this relates to changes in later life. The team at McGill aimed to find out more about this through their research.
For their study, the team showed a series of images of faces to 112 healthy adults, aged between 19 and 76. The participants then had to recall whether the image appeared on the left or the right of the screen, and whether it appeared towards the beginning or the end of the test. As the participants answered these questions, the researchers analysed which part of their brains were being activated by using functional MRI scans.
From their analysis they found that young adults activated their visual cortex as they recalled the images. However, older and middle-aged adults didn’t exhibit the same level of visual cortex activation; their brains relied on their medial prefrontal cortex to retrieve the information, the part of the brain that’s used to process information about your own life and introspection. However, Rajah says that this shouldn’t necessarily be seen as a brain impairment, but that it may simply reflect what people class as important information as they age.