Shifting the potential for cognitive aging
Q: What is normal cognitive aging?
A: As we get older, our thinking and memory skills tend to decline. This might affect our ability to be a good driver, manage our bank account or take medications on the correct schedule. This change, which is very common and even normal with aging, has a significant impact on our ability to maintain independence and quality of life. This decline can also be the first signs of potentially sharper declines in cognitive ability that may indicate mild cognitive impairment or Alzheimer’s disease.
Q: What is transcranial direct current stimulation?
A: Transcranial direct current stimulation, or tDCS, is a form of noninvasive brain stimulation which has been performed safely in more than 3,000 people in more than 30,000 sessions — a topic I recently researched. tDCS involves placing a pair of electrodes on the scalp, and then passing a weak electrical current — about 2 milliamps — through the scalp. It generates a tingling or prickling sensation on the scalp, but this electrical stimulation is able to safely penetrate the head and stimulate underlying brain tissue.
Q: What is cognitive training?
A: Cognitive training is a set of computerized games that challenge people in a domain of cognitive function, such as attention or how quickly we can do things, or in something like working memory. In this study, we are looking at a way to enhance the effectiveness of cognitive training because in the past, one of the problems of cognitive training is that its benefits haven’t transferred well to other areas of cognition. You may train in an area of attention or speed of processing and you get better at that task, but it doesn’t transfer to general cognitive and functional mechanisms that are important for everyday life.
Q: How does tDCS stimulation affect normal cognitive aging?A: The point of this stimulation is that it is able to facilitate the brain’s ability to form new connections, a process known as neuroplasticity. You can think of this as learning at the neuronal level. In this case, we’re not causing the neurons to fire. Instead, using a very specific set of stimulation parameters, we very subtly are preparing neurons to be more ready to fire, which allows the brain to learn more quickly and for the learning effects to sink in more deeply.
Q: How is the trial designed?
A: This will be a randomized clinical trial, and we’re enrolling 360 people into four “cells.” The cells will include cognitive training plus tDCS; a form of control for tCDS called sham stimulation plus cognitive training; educational training as a control for the cognitive training plus tDCS; and the educational control plus sham stimulation. In the trial, participants will complete 40 hours of the cognitive training or educational control over a period of three months. During this time, participants will receive either tDCS or sham stimulation. We will test their cognition and brain function before and after three months of training, and then after one year. We are using not only comprehensive assessment of neurocognitive function and functional abilities important for everyday life but also state-of-the-art MRI and spectroscopy to assess changes in brain structure, function and health.
Q: What is the goal of this trial?
A: Our idea is that if you can slow or reverse this process of normal cognitive aging, you may be able to at least postpone, if not prevent, the onset of dementia later in life. In addition, we have the potential to slow or prevent the loss of independence and functional abilities important for everyday life that occurs later in life, even in the absence of dementia. We are looking to see if we can take those who are healthy and push this decline back. Our goal with this trial is to use something that’s known to be effective — cognitive training — and then enhance that effect using noninvasive brain stimulation.
Woods’ co-principal investigators include Ronald Cohen, Ph.D., the Evelyn F. McKnight chair for clinical translational research in cognitive aging and memory in the UF College of Medicine’s department of aging and geriatric research, and Michael Marsiske, Ph.D., an associate professor in the UF College of Public Health and Health Professions’ department of clinical and health psychology. To date, this will be the largest Phase 3 National Institutes of Health clinical trial for testing the beneficial effects of tDCS. This grant is awarded under number 1R01AG054077. This grant marks the first multisite clinical trial within the McKnight Brain Research Foundation network, including collaborators from the Evelyn F. McKnight Brain Institute at the University of Arizona and the Evelyn F. McKnight Brain Institute at the University of Miami.