Believe it or not, clues about your risk of Alzheimer's disease might be found in tiny purple characters called Greebles.
People who are unable to tell which shape is the odd one out in a series of images could be more at risk of developing the brain disease in future, according to new research from scientists at the University of Louisville.
In the April 2017 study, researchers found that participants who were genetically more at risk for the disease struggled to spot subtle differences in an image of Greebles, despite being perfectly able to detect minor changes in people's faces.
Emily Mason, PhD, the lead author of the study and a postdoctoral associate in the Department of Neurological Surgery, said in a statement:
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. 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.
Odd One Out
For the study, a group of 57 participants were asked to complete a series of "odd man out" tasks. They were shown sets of four images depicting real-world objects, human faces, scenes, and Greebles, and in all of the sets, one image was slightly different from the other three.
The genetically at-risk participants performed similarly to those participants who were not genetically at-risk for Alzheimer's when it came to objects, faces, and scenes. But with the Greebles, the at-risk group scored lower than their control counterparts.
Dr. Mason said in the statement:
Most people have never seen a Greeble and Greebles are highly similar, so they are by far the toughest objects to differentiate. 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.
It's important to note that this is a small study, and it doesn't show a link between test results and having Alzheimer's — it shows a link between test results and having a gene that indicates higher risker of having Alzheimer's in the future. In the end, much more research needs to be done, and Dr. Mason said she would like to see further studies conducted to determine whether the individuals who performed poorly on the test actually develop Alzheimer's in the future.
"The best thing we could do is have people take this test in their 40s and 50s and track them for the next 10 or 20 years to see who eventually develops the disease and who doesn't," she said.
Can You Spot the Difference?
So, what is the correct answer — which Greeble is different from the rest, and how? In the example given above, image four is the odd Greeble out because its horns and arms are shaped ever-so-slightly different from the rest.