Researchers from two of the U.S. states with the fastest-growing populations of older adults will partner on a study of a possible intervention for preventing, halting or reversing age-related cognitive decline.
The University of Arizona, the University of Florida and the University of Miami have been awarded a five-year, $5.7 million grant from the National Institute on Aging to study whether a combination of computer-based cognitive training exercises and direct electrical stimulation to the brain can help improve cognitive functioning in older adults.
The work may provide new insights into how to prevent or combat cognitive decline associated with normal aging, and in turn could improve quality of life for the world's rapidly growing population of older adults.
The UA will receive $1.47 million for the project, which is being led by the University of Florida. All three institutions involved in the research are home to Evelyn F. McKnight Brain Institutes, funded by the Evelyn F. McKnight McKnight Brain Research Foundation, which is dedicated to studying age-related memory loss.
Gene Alexander, professor of psychology, neuroscience and physiological sciences, and a member of the UA's Evelyn F. McKnight Brain Institute, will lead the work done at the UA.
The multi-institutional study will look at the combined effect of two techniques: the delivery of computer-based cognitive training exercises, and a method known as transcranial direct current stimulation, in which a weak electrical current is delivered via electrodes to the front of the brain.
Previous research has shown that cognitive training can have lasting beneficial effects. However, it is less clear whether and how those effects translate to a person's functioning in everyday life — something researchers hope to explore further in the current study.
Researchers also want to find out if electrical stimulation can amplify the benefits of cognitive training alone.
"We're interested in understanding why some people age well and some don't, and to help develop ways to intervene to enhance cognitive function as people age," Alexander said. "We hope at the end of the study to be able to assess whether there's a real benefit from combining these techniques and whether the combination is better than either one alone."
Researchers will recruit 360 adults between ages 65 and 90 with no significant cognitive impairment or neurodegenerative disease for the randomized clinical trial, which will have 120 participants at each site. Over a 12-week period, some participants will undergo only cognitive training, some only transcranial direct current stimulation and some the combination. Another control group will be tasked with watching and responding to educational videos.
Those receiving both the cognitive training and transcranial direct current stimulation will be asked to complete a series of computer-based visual tasks designed to improve various aspects of their cognitive functioning. As they complete the tasks, an electrical current will directly stimulate the areas of the brain believed to be most important in the cognitive abilities being evaluated.
Researchers will look at whether using transcranial direct current stimulation to boost the brain's plasticity — or its ability to change — results in optimal benefit from the cognitive training.
"We are learning that the brain is not static but rather dynamic and we can continue to have beneficial changes in the brain as we age, and the idea is to see if we can stimulate that," Alexander said. "We think that this combination of direct current stimulation with cognitive training may augment the benefits and enhance the structural and functional changes that we see in the brain."
All study participants will complete a battery of tests to assess their memory, language, visual spatial skills, attention and everyday functioning abilities at the start of the study, after 12 weeks and at a one-year follow-up visit. Researchers also will use state-of-the-art neuroimaging techniques to assess the structure and function of participants' brain at each of those time points.
"Studying age-related cognitive decline is critical, especially at a time when people worldwide are living longer," Alexander said.
From 2025 to 2050, the older population is projected to almost double to 1.6 billion globally, according to the U.S. Census Bureau.
"As we age, we often experience changes in aspects of our memory, our ability to attend to things, and our ability to problem-solve. These kinds of changes are common, and they can cause real concern and reduce our quality of life, interfering with our ability to function at our best," Alexander said. "So we think it's really important to be able to understand the mechanisms underlying these changes and the kinds of things we can do to enhance cognitive performance as we age, to prevent decline from occurring."
Alexander's collaborators at the UA are John Allen, University Distinguished Professor of psychology, cognitive science and neuroscience and a member of the BIO5 Institute; Alex Hishaw, assistant professor of neurology and psychiatry; and Ted Trouard, professor of biomedical engineering, associate professor of radiology and member of the BIO5 Institute and the Evelyn F. McKnight Brain Institute.