A research has shown that cognitively normal people who have a genetic predisposition for Alzheimer’s disease (AD) have more difficulty distinguishing among unique graphic characters called Greebles.
The study findings have the potential to help doctors detect signs of Alzheimer’s disease decades before symptoms become apparent.
“Right now, by the time we can detect the disease, it would be very difficult to restore function because so much damage has been done to the brain,” said Emily Mason from the Department of Neurological Surgery at the University of Louisville, who led the study.
“We want to be able to look at really early, really subtle changes that are going on in the brain. One way we can do that is with cognitive testing that is directed at a very specific area of the brain,” she added.
Alzheimer’s disease (AD) is a progressive, irreversible neurodegenerative disease characterised by declining memory, cognition and behaviour.
Mason identified test subjects age 40-60 who were considered at-risk for AD due to having at least one biological parent diagnosed with the disease. She also tested a control group of individuals in the same age range whose immediate family history did not include AD.
The at-risk and control groups performed at similar levels for the objects, faces and scenes. For the Greebles, however, the at-risk group scored lower in their ability to identify differences in the images.
Individuals in the at-risk group correctly identified the distinct Greeble 78 per cent of the time, whereas the control group correctly identified the odd Greeble 87 per cent of the time.
“Most people have never seen a Greeble and Greebles are highly similar, so they are by far the toughest objects to differentiate,” Mason said. “What we found is that using this task, we were able to find a significant difference between the at-risk group and the control group. Both groups did get better with practice, but the at-risk group lagged behind the control group throughout the process.”
The research was recently published online in the prestigious Journal of Alzheimer’s Disease.