Until recently, the only way to reliably predict Alzheimer’s Disease was to wait until the symptoms became tragically obvious. A new test, developed at Emory University’s Yerkes National Primate Research Center, may offer a way to predict the onset of Alzheimer’s without waiting for full dementia or enduring significant inconvenience.

The Yerkes test revolves around the observation that Mild Cognitive Impairment (MCI) is correlated enough with Alzheimer’s Disease that it can be used as a predictor. The test focuses on one of the principle symptoms of MCI- difficulty remembering if something is new or has been seen before.  As MCI is by its definition mild, such memory problems may be difficult for observers, and especially the patient themselves, to detect. However, the Yerkes researchers developed a system that tracks minute eye-movements.

The eye-movement system presents subjects with a series of images, two at a time. Eventually, the image pairs begin to contain one new and one previously seen image. Normal subjects rapidly shift their view to the new image, giving the old one much less attention. Subjects with MCI move their eyes between the two images more equally because they do not have solid memories of the old images and must reanalyze the details each time. 

The quick and easy assessment of MCI is crucial because 10-15% of these cases become Alzheimer’s Disease each year. An eye-movement test is incredibly simple to take and could be installed in homes so that elderly users have only to look at a few dozen images, without using any computer skills, and they will be warned when they have entered the earliest stages of dementia.