Contrast can aid Alzheimer's patients' vision

For more information, contact Susan Griffith, 216-368-1004 or sbg4@po.cwru.edu.

Posted 12-20-99

Researchers to find ways to aid perception of Alzheimer's, dementia patients

Click here for tips on boosting contrast for Alzheimer's patients.
Your grandmother may have told you to turn on the lights while reading. Her advice, coupled with larger print in reading materials and more contrast in the environment, may prove helpful to patients with mild and moderate forms of Alzheimer's disease and dementia.

Grover C. Gilmore, professor of psychology and director of the Department of Psychology's Perception Lab at Case Western Reserve University, and Alice Cronin-Golomb, associate professor of psychology at Boston University, have found early evidence that Alzheimer's disease (AD) and dementia patients can see and read with fewer mistakes if the print and contrast get a boost.

They will collaborate as principal investigators on a five-year, $2.8 million study, "Visual Interventions to Improve Alzheimer Cognition," funded by the National Institutes of Health, to expand their understanding of the impact of vision and motion deficits in these patients.

"This study is a project that is going to help us nail down the fundamentals of what these disorders are and permit us to build some behavioral interventions," says Gilmore.

As people age, their sensory systems begin to fail, he explains. Just as hearing aids improve hearing, the psychologists' ground-breaking research will develop ways for caregivers to help these patients augment their visual and motion perception.

Gilmore and Cronin-Golomb have been leaders in comparing how healthy individuals and patients with neuro-degenerative diseases perceive the world. The collaboration will help the researchers increase the numbers of individuals participating in their studies.

"We've had sufficient numbers for the science, but there are still questions about the outcomes in the general population and the possible existence of subgroups within the larger group," adds Gilmore. "By combining our resources, we will have the capability of doubling the number of people in our samples."

Gilmore will administer perception tests through computer-generated images developed in his lab in the basement of Mather Memorial Hall. He will look at the responses of 80 people with AD and 80 with non-AD dementia and compare their results to 80 healthy individuals to see how increasing the print size and contrast can boost vision and memory.

In normal aging, adults begin to loose their ability to distinguish the presence of objects in their environment. AD and dementia caused by strokes or other medical conditions exaggerates this loss.

Both researchers arrived at this finding through years of independent research in their labs.

Often one of the first activities these patients forego is reading because it takes them longer to read and their oral reading has many errors. "We're finding that they are having a hard time seeing the material," notes Gilmore. Giving them larger printed materials with a higher contrast improves their reading skills.

The researchers have found that these patients can pass the eye doctor's exam where the acuity of the black letters against the stark white background has a contrast level of about 80 percent, but in everyday environments where contrasts run between 40 and 50 percent, these individuals struggle to distinguish people and objects from their background environments.

"This is the hidden visual deficit that is not normally assessed," says Gilmore. It also poses many environmental dangers for those lacking this perception.

Gilmore has computer images which illustrate how the environment of his lab looks to an AD patient. To them, the lab is a murky environment with few objects standing out. When shown these images of how AD patients see the world, healthy individuals miss seeing eyeglasses on the computer and a person sitting in the shadows of the wall, for example.

When he showed these computer images of how AD patients perceive the world to neurologists during a recent Grand Round, he noted their surprise.

Another concern for these patients is their ability to navigate their environment. Gilmore wants to know whether this results from forgetfulness, or from some motion deficit in their perception.

Gilmore will give the study's participants motion perception tests via the computer and later an obstacle course in the halls under different lighting conditions to find out whether this hidden deficit exists. If it does, implications exist for modifying environments as well as assessing their ability to drive a car.

He adds that understanding this information can lead to changes in the environment where the patient's performance might be improved. "The exciting thing is that caretakers can do things to assist the patients once hidden deficits are identified," he says.

-CWRU-