Although diagnostic interviews for cognitive impairment and memory loss have improved and are mostly reliable, researchers are looking for tests that more accurately predict the onset of various types of cognitive impairment.
With that in mind, a new method of more accurately diagnosing cognitive impairment may be on the horizon thanks to ongoing research by Stuart Zola, PhD, director of Yerkes National Primate Research Center, Emory University, and his colleagues. The researchers discovered certain behavioral tasks that are harbingers to various types of cognitive impairment, including Alzheimer's disease, which afflicts more than five million Americans at a cost estimated to approach $150 billion annually.
Using what's known as a preferential looking task, Zola was able to detect a pattern of eye movement that points to memory impairment or to normalcy when volunteers viewed specific visual stimuli.
"You watch where the person is looking when they're looking at two stimuli. In one case, the stimuli are identical," says Zola. "In the second case, the stimuli are different. When we look at the familiar stimulus and the novel stimulus preferentially, we look longer at the novel stimulus. That's because the old is familiar to us, not as interesting. The novel stimulus more significantly draws our attention and focus. People with mild cognitive impairment look at the two about equally. They're at chance both times. And that suggests that they don't remember what they saw before in the earlier part of the test," says Zola.
The test, which is featured in the current online issue of The American Journal of Alzheimer's Disease and Other Dementias, is helping researchers further understand the role of the brain structures critical to human memory.
To hear Zola's own words about his research and its intriguing details, use the player at the top left of this page or subscribe to the podcast.