Nearly 36 million people worldwide are estimated to currently have dementia. That number is expected to almost double every 20 years. Researchers are working diligently to find better, more accurate methods for earlier diagnosis.
According to recently published research from the Franklin College of Arts and Sciences’ psychology department, scientists may be one step closer to a better biomarker for earlier detection of mild cognitive impairment, the leading predictor of dementia and Alzheimer’s disease in older adults.
Stephen Miller, a psychology professor and director of the Bio-Imaging Research Center, along with former graduate student Carlos Faraco, used fMRI brain scans-scans that give researchers not only a visual picture of the structure of the brain but also information about blood flow within the brain-to test the working memory of adults with normal healthy adult brains against those showing signs of mild cognitive impairment. The research was recently published in the journal Neuropsychologia.
While researchers have looked at stored memory in terms of mild cognitive impairment and dementia research, working memory is a relatively new area of research in the fMRI research realm.
Initial results from the study show hyperactivity in the lateral temporal lobes, the area of the brain associated with working memory. Hyperactivity here means that the brain is exerting more energy to complete a task, which may be a biomarker for developing dementia.
“Broadly, we’re interested in finding more ways to identify people at risk for developing dementia,” Miller said. “So, one of the ways that’s been developed over the last few years is identifying a group of individuals who seem to be at higher risk for developing dementia based on early, relatively subtle signs of cognitive difficulties.”
Researchers have been using fMRI brain scans for some time now to look at parts of the brain that are associated with stored memory, mainly the medial temporal lobes and the hippocampus. However, Miller’s team decided to look at the part of the brain that is associated with working memory-the lateral temporal lobes.
Human brains use working memory to hold a piece of information, manipulate it and memorize it until it’s time to be used, all within a relatively short amount of time. Remembering and dialing a telephone number after someone calls it out orally, despite a small distraction like the doorbell ringing, is an example of working memory in use.
To test working memory, Miller and his research partners tested both older adults with mild cognitive impairment and older adults with normal functioning brains using a series of complex working memory tasks. They tasked participants with using working memory in two tasks-clicking on the correct color dot and remembering a sequence of letters-with one working memory task interrupting the next. At the end of the tasks, participants then had to recall information from those tasks.
Researchers then used scans to examine brain activity when participants were completing working memory tasks and at the end when participants were recalling information.
The findings, he said, could lead to better biomarkers for dementia, as other studies using fMRI scans testing stored memory are more difficult to read due to their placement next to sinus air passages that often makes imagery blurry.
While Miller admits that other researchers need to replicate this research and further test the hypothesis, the initial results from this study suggest that fMRI scans of the temporal lobes could give doctors earlier diagnostic tools someday.