The science of memory
By Jill Pease
During his more than 25 years of Alzheimer’s disease research, Glenn E. Smith, Ph.D., has seen a dramatic shift in the way scientists view the condition.
Alzheimer’s was long considered an unstoppable progression towards dementia in which patients go through a steady decline, forgetting the names of loved ones, losing the ability to perform daily activities and eventually experiencing a complete loss of independence. But research from Smith, the chair of the college’s department of clinical and health psychology, and others, has demonstrated that dementia may not be a foregone conclusion for many people. Now scientists are looking beyond the question of how to slow cognitive decline to ask, “Can we prevent dementia?”
Among the pieces of evidence that point to this possibility is a study by Smith and colleagues that tracked memory function in older adults over a period of years until death. Several participants consented to autopsy and researchers were surprised to discover that the brains of 15 to 20 percent of these people had the plaques and tangles characteristic of Alzheimer’s disease, yet those individuals exhibited no signs of dementia in life. Smith also points to findings of the Framingham Heart Study, which has been studying the health of Framingham, Mass., residents since 1948. With each generation of older adult participants, the rate of dementia has decreased.
“There’s no reason to think biology has changed,” said Smith, who joined the faculty from the Mayo Clinic in Rochester, Minn., last fall under UF’s preeminence initiative. “What has changed are the risk factors. In the same way that getting people to quit smoking or change their diets has had an impact on heart disease, stroke and cancer, it’s reasonable to think a public health approach to dementia can have some success. That is the grand scale of what we’re trying to pursue.”
Looking for early signs
In the 1990s, Smith and fellow researchers at the Mayo Clinic developed tests to recognize the earliest signs of memory problems in older adults, a condition they called mild cognitive impairment. Their diagnostic criteria have been cited more than 7,000 times in the research literature and influenced the Diagnostic and Statistical Manual of Mental Disorders. But at the same time the diagnosis was gaining wide acceptance, the team’s work had its critics, Smith said.
“We were being reasonably criticized by some people, especially general practitioners, who said, ‘Well, you still can’t do anything for these people, so why diagnose them even earlier?’” Smith said. “In essence, why traumatize them even longer?”
But Smith believed that it was possible for patients to take action to prevent or delay memory loss and he looked to interventions being used to help patients with traumatic brain injury as a guide. Several treatment programs had had success with training patients to habitually use calendars and take notes to compensate for memory problems.
“The first thing we needed to do was blow up the idea that just because someone is going to get worse, doesn’t mean you shouldn’t help them,” said Smith, drawing a comparison between dementia and his father’s pancreatic cancer.
“We knew he was going to die of pancreatic cancer and yet we tried many things to help him in the interim between his diagnosis and death. Why we think Alzheimer’s patients aren’t entitled to that same best effort has always perplexed me. So we undertook this endeavor with the idea that we want to help people be as independent as possible for as long as possible.”
Improving habit memory
Smith developed a program at Mayo called Healthy Action to Benefit Independence & Thinking, or HABIT, that uses patients’ procedural, or habit memory, to teach or strengthen the use of calendar and note taking. Procedural memory is the kind of memory that prompts drivers to push in the clutch when driving a standard transmission vehicle, for example, without conscious thought. It is also a memory system that is largely intact during mild cognitive impairment.
“We recognized the value of the mild cognitive impairment diagnosis is that people can still acquire new skills even if they couldn’t remember that they are acquiring them,” Smith.
HABIT combines the calendar and note taking training with other interventions that have shown success in improving cognitive function, including computerized brain fitness training, group therapy, yoga and wellness education. Patients who have recently been diagnosed with mild cognitive disorder and a partner attend 50 hours of HABIT programming over a 10-day period.
Studies of HABIT’s impact have shown that six months after treatment, participants are still functioning as well as they did when they started the program. Smith and his colleagues are currently conducting a comparative effectiveness trial of the individual components of the HABIT program to determine their effect on daily function, cognition, quality of life, mood and self-efficacy in patients and caregivers. The study is supported by a more than $2 million grant from the Patient-Centered Outcomes Research Institute.
Building cognitive reserve
Findings from HABIT and the study of older adults who had pathological changes associated with Alzheimer’s but no symptoms of dementia, as well as many other studies, demonstrate the importance of cognitive reserve, Smith said. A lifetime of mentally stimulating experiences, including educational, occupational and leisure activities, can help the brain resist damage that can come with aging.
“That’s one of our challenges, getting people to engage in active coping and not merely sit back and wait for the pill that is, right now, nowhere in the pipeline,” Smith said.
At UF, Smith is exploring ways to offer HABIT-like programs locally and at the state level through networks such as the state’s memory disorders clinics.
“I think people still get this diagnosis of mild cognitive impairment and are told that there’s nothing we can do,” Smith said. “I’m driven by the possibility that we can eliminate that exchange from happening in health care.”
Maintaining brain health
It is a question Glenn E. Smith, Ph.D., receives frequently: What can I do on my own to maintain cognitive function with age?
“First and foremost, make sure you’re being physically active,” Smith said. “The most solid cognitive research is on physical exercise.”
Exercise should be intense enough to modestly raise heart rate and respiration. For older adults, yoga, as used in the HABIT program, is vigorous enough to fit the bill.
Brain games can be valuable, but challenge yourself, Smith said.
“If you want to do things like Sudoku and crossword puzzles, don’t just be happy to finish them, but set goals for getting faster and faster because then you’re improving your processing speed, one of the forms of memory, along with working memory, that decline with age.”
And finally, consistently use tools like note taking and calendars to build habits.
“Start engaging in these behaviors so religiously that even if you start to decline in your cognitive function, just out of the force of habit, you continue to do them,” Smith said. “So you don’t have to think, ‘It’s Tuesday, do I have bridge club or not?’ When it’s Tuesday and time for bridge club it’s so routine that you get up and put on your coat.”