January 05, 2017
Baycrest researchers have uncovered an important link between eye movements and the brain’s memory system that bolsters the case for using eye-tracking technology to evaluate memory problems and aid in earlier detection of dementia.
This is the first time researchers have shown a direct functional connection between the oculomotor network (the brain system controlling the eye’s movements) and the brain’s hippocampus (a structure in the brain crucial to creating memories) in healthy adults.
The study, published online in The Journal of Neuroscience, found that when the eyes view and process more details of an image, the action triggers greater brain activity within the hippocampus. When participants saw the image a second time, there was a large drop in memory activity that relates to a person’s familiarity with that image, says Dr. Zhong-Xu Liu, first author on the study and a postdoctoral fellow at Baycrest’s Rotman Research Institute (RRI).
“This neuroimaging and eye-tracking study demonstrates there could be a cyclical relationship between the eyes and memory that continually feeds information back and forth,” says Dr. Jennifer Ryan, senior investigator on the study and senior scientist at the RRI. “It seems counterintuitive to use the eyes to screen for memory problems, but these systems are so nicely coupled that it makes sense to use eye-tracking to evaluate memory.”
Previous studies have demonstrated that people with memory problems show changes in how they visually explore the world, but this basic link wasn’t demonstrated in healthy individuals until now. There are few researchers exploring the interaction between the eye and memory systems, says Dr. Ryan.
This work builds upon the team’s recent discovery of the structural link between the brain’s pathways that influence eye movements and memory, which supports their development of an eye-tracking cognitive assessment that could one day help doctors evaluate cognitive decline in clients.
Following this study, Dr. Ryan and her team will explore the relationship between these two systems within older adults to see how this functionality changes during aging.
Research for this study was conducted with support from the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council and the Canada Research Chairs Program.
Additional funding would help improve the accessibility and user-friendliness of the team’s eye-tracking cognitive test, and assist it in exploring opportunities to use eye-tracking technology as a tool to aid people in boosting their memory ability.
About Baycrest Health Sciences
Headquartered on a 22-acre campus and fully affiliated with the University of Toronto, Baycrest Health Sciences is unique in the world, combining a comprehensive system of care for aging adults and one of the world’s top research institutes in cognitive neuroscience (the Rotman Research Institute). Baycrest’s dedicated centres focus on mitigating the impact of age-related illness and impairment, and offer unmatched global knowledge exchange and commercialization capacity.
About Baycrest’s Rotman Research Institute
The Rotman Research Institute at Baycrest Health Sciences is a premier international centre for the study of human brain function. Through generous support from private donors and funding agencies, the institute is helping to illuminate the causes of cognitive decline in seniors, identify promising approaches to treatment, and lifestyle practices that will protect brain health longer in the lifespan.
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