Visual Test Can Help Identify Early Signs of Cognitive Impairment

the Psychiatry Advisor take:

A new test has been developed that can identify whether an individual has cognitive impairment based on the speed at which the person can process visual information.

Catherine Mewborn, a doctoral candidate and the University of Georgia, and colleagues developed the test using a device that produces visual flickers to measure visual processing speed. This method can assess an individual’s level of executive cognitive abilities, including shifting attention between tasks, planning, and problem solving.

Inside the device, the light wavelengths would alternate flashing, giving the appearance of flickering. During the test, the rate of flickering was gradually increased, until it was so rapid, the subject would just see a circle of light. An individual’s critical flicker fusion measure happens when the flicker is too rapid for the person to discern, and differs from subject to subject.

Because the brain, rather than the eye, determines the fastest visual flicker that can be perceived, the critical flicker speed is an assessment of the brain’s processing speed, which plays a critical role in cognitive functioning and memory.

Participants with higher critical flicker fusion had better executive functioning, the researchers reported in the journal Archives of Clinical Neuropsychology. Older subjects had slower visual processing speed.

“The next step would be to look at these same sorts of tasks and see whether or not it could predict individuals who are beginning to show early signs of cognitive impairment, such as early signs of Alzheimer's disease,” Mewborn said in a statment.