How ageing rewires our brain

Pointing to a potentially new direction for age-related cognitive care, scientists have found more evidence that ageing brains work differently than younger brains when performing the same memory task.

The team found that younger and older adults show very different brain wave patterns when performing the same memory task. We know that our brains change over time but fully understanding how we make and recall memories as we age has been a mystery.

"Our findings are really novel as they show distinct differences in brain activity from one generation to the next. By mapping these key differences, we may be able to identify new ways to predict, diagnose and screen for cognitive decline," explained Renante Rondina from University of Toronto and Rotman Research Institute at Baycrest Health Sciences.

The findings show that rhythmic activity within the brain, including hippocampus, an area that is involved with the formation and retrieval of memories, and neocortex grey matter concerned with sight, hearing, attention and high-level thinking change with advanced age.

To reach this conclusion, scientists used MRI scans to track potential age-related differences as groups of younger and older adults performed a memory task. The median ages of the two groups were 24.8 and 65.9 years, respectively.

Past studies have shown that brain waves travelling at slower speeds tend to be important for memory while slightly faster speed brain waves play a role in our attention.

"Our study is one of the first to look at key differences between younger and older adults' brain waves as they make and recall new memories," noted Rondina in a paper published online in the journal Neurobiology of Learning and Memory.

According to him, it is remarkable to see how different the older participants' brain patterns are from the younger participants while still maintaining accuracy.

"According to the MRIs, there were minimal differences in the brain structures in the two groups yet the brain waves were very different. With additional study, these results may lead to new, more sensitive ways of screening or diagnosing cognitive decline," the authors pointed out.