Just as there are many changes in one’s physical capabilities as one ages, so some cognitive abilities begin to decline as early as the 30s, while some others continue to grow. It is critical to recognize that there are tremendous individual differences, not only in the maximum level one’s abilities achieve in young adulthood but also in the speed with which cognitive capabilities decline in later adulthood. Given that caveat, vocabulary tends to increase until the mid-50s and is among the cognitive abilities most resistant to decline. Declines in speed in completing mental tasks, reasoning and memory loss generally occur at about the same rate. To put these changes in perspective, the average person in her or his 20s scores at about the 75th percentile on speed reasoning and memory tests. In contrast, people in their 70s score near the 20th percentile on these tasks.
Modern neuroscience has a great deal to say about how mental (and physical) activity keeps our brains from becoming walnut-sized. Let us start with the central maxim of neuroscience that the mind and all our mental functions are solely functions of the neurons (i.e., the individual “nerve” cells) of our brain. Readers may remember from their school days that our brain’s neurons are connected to each other through synapses—the tiny gaps between the sending end of one neuron and the receiving end of the next. The picture in many of our minds from those early texts is that when the impulse from one neuron reaches that synapse, it causes chemicals to be released (called neurotransmitters) that cause the second neuron to “fire” an impulse.
It looks so simple in basic textbooks on this topic, but consider facts: first, that there are about 10 to 100 billion neurons in a human brain; second, that a typical neuron in the brain’s cortex is connected through synapses to 10,000 (and up to 100,000) other neurons, and thus the total number of synapses in the brain is between 10 and 100 trillion. Written out in digits, the smaller of those last two numbers is 10,000,000,000,000. (A third equally astonishing fact that is interesting, but not relevant to our main theme here, is that each cortical neuron fires spontaneously about five times per second—so a tremendous amount of neural activity is occurring all the time, and most of it is not relevant to neural information transmission—just “neurons having fun.”)
Of many important structures within the brain, consider the hippocampus. The hippocampus is the brain structure responsible for the formation (but not the storage) of some aspects of memory, including especially learning of special relationships and “episodic” learning—remembering the time and place where we learned things. This “time and place” aspect of learning is important, because a damaged hippocampus may still allow us to learn things such as how to play checkers or to dislike our neighbor, but not remember where or when we learned checkers or why we dislike the neighbor.
Another fascinating thing about the hippocampus, besides its great name and crucial role in episodic and spatial memory, is that it seems to be the most “plastic” or changeable area of the brain. Some of those changes are not good, as the hippocampus shrinks in substantial ways as we age, accounting in part for why older individuals sometimes quickly forget the names of people introduced at a dinner party. However, the hippocampus also shrinks in people suffering from post-traumatic stress disorder, or in response to other forms of chronic stress, and it shrinks dramatically with depression.
The great thing, though, is that the plasticity of the hippocampus is a two-way street, with hippocampal expansion occurring with recovery from depression and even (apparently) hippocampal volume increases resulting from mental activity that involves substantial learning of new relationships (and, not so incidentally, from physical exercise, too). Those changes in volume can be studied in live humans with magnetic resonance imaging of the brain (MRIs). Intuitively it would be easy to conclude that changes in hippocampal volume result from neurons dying off or being regenerated. While substantial dying and regeneration of neurons does indeed occur in the human hippocampus (yes, regeneration even in adults), neural volume changes in the hippocampus are due largely to the number of synapses between neurons decreasing or increasing. Some of the most compelling evidence for stimulation-induced hippocampal expansion comes from studies of London cabbies who must prepare for a required examination, training intensively for a year by studying the layout of the streets of London and the surrounding areas. MRI results showed an increase in the mass of the hippocampus of the cabbies as a result of preparing for the exam.
These changes in people’s cognitive abilities as they age take on special significance when viewed in the light of the increasing percentage of the population, both nationally and in Nebraska, of people 65 and older. Nationally, in 2000 12.4 percent of U.S. citizens were 65 or older. By 2010 that will rise to 13 percent and by 2030 that percent is projected to jump to 19.7 percent. In Nebraska, the percent of the population of people 65 and older is projected to grow from 13.6 percent in 2000 to 13.8 percent in 2010 and 20.6 percent in 2030. With the increasing number of individuals 65 and older, it is critical to consider ways in which such cognitive declines can be mitigated.
You are undoubtedly aware of the maxim “use it or lose it.” While it is typically applied to physical capabilities and exercise, there is growing evidence that it also applies to cognitive skills. Just as reductions in the hippocampus can be reversed, the same may be true for other areas of the brain. It is important to note that, just as no amount of physical exercise will bring a senior to levels of physical capacity that exceed their young adult potential, so mental activity as a senior will not add IQ points to those engaging in such mental exercise. However, at a minimum, the mental activity stimulated by lifelong learning will help to keep us mentally sharp and delay the decline in cognitive capacity.
Opportunities for physical exercise for seniors are growing as new health clubs and fitness centers open. In 2005, the number of such facilities nationally grew by 14 percent. The comparable national data for programs offering comparable cognitive exercise are less readily available; however, in Nebraska, there are many opportunities available for seniors to continue to learn and make use of their cognitive skills to “use it and not lose it.”
Many colleges offer special learning programs aimed at mature adults. For example, each of the three undergraduate campuses of the University of Nebraska offer such programs. The University of Nebraska-Kearney’s (UNK) program is referred to as Senior College of Central Nebraska and operates as a partnership between UNK and several area institutions. The Institute for Lifelong Learning at the University of Nebraska-Omaha (UNO) will begin offering classes this winter.
However, the longest running lifelong learning program within the University of Nebraska system is the Osher Lifelong Learning Institute (OLLI) at the University of Nebraska-Lincoln (UNL) that traces its roots to 1992 when Sharing Across Generations (SAGE) was begun in the Division of Continuing Studies (DCS) by Dr. Deanna Eversoll, then director of evening programs. SAGE continued until 2002 when budget cuts eliminated DCS. Through the determination of Dr. Eversoll and the dedicated volunteers who had been a part of SAGE, and an alliance with the Nebraska Alumni Association, SAGE was able to survive until 2003, when a one-year grant was received from the Bernard Osher Foundation of San Francisco. (The Osher Foundation, founded by successful businessman Bernard Osher, has a major emphasis on promoting lifelong learning. Currently, there are 121 OLLIs located in 48 states.)
Two requirements of the grant were a change in name to OLLI and affiliation with an accredited college. Thanks to strong support from Dean Marjorie Kostelnik, OLLI became a component of the College of Education and Human Sciences. Following five annual grant renewals, in fall 2008, a major endowment grant was received from the Osher Foundation that will provide significant support for OLLI and the 624 persons who were members in 2006–07.
The core of OLLI’s offerings is six-week courses, which cover a wide variety of topics, ranging from the arts (Stitch in Time: International Quilt Study Center and Museum), humanities (Irish Poetry), current events (Lessons from the 2008 Presidential Election), as well as how-to courses (Beginning Violin: Suzuki). Last year OLLI offered 72 courses during the academic year in five six-week sessions. While courses are organized only in response to member interest, the actual instruction is offered by many university faculty, including many who are OLLI members, and other professionals from the local community.
Because OLLI is largely run by volunteers, members also have the opportunity to explore “new careers” through participating as volunteers in OLLI’s organizational structure, assuming responsibility for curriculum development, marketing, membership and support activities. Members may take leadership positions through organizing or teaching courses, serving on committees or organizing tours. For example, OLLI provides individuals, who have never had a career in education the opportunity to develop curriculum.
OLLI also offers the opportunity to participate in educational trips, such as a recent one to Washington, D.C., to visit major sites, including war memorials, as a follow-up to a course on World War II. A similar tour of Chicago is planned for this coming spring.
Belonging to OLLI also offers special opportunities, such as an extended tour of the new facilities at Memorial Stadium or a private meeting with Sen. Chuck Hagel. Members are also entitled to discounts at the University Bookstore and several artistic events on campus. In short, OLLI offers a number of opportunities to “enhance your hippocampus.”
If your goal is to enhance your quality of life as you mature, to work out cognitively and physically on a regular basis, then UNL’s OLLI, UNK’s Senior College and UNO’s Institute for Lifelong Learning are three options. Interested individuals should look for the OLLI advertisement in this edition of Prairie Fire.
Persons interested in exercising their mind are welcome at the OLLI open house on Jan. 11, 2009, from 1:30–3:00 at the Champions Club west of Memorial Stadium. For more information on the programs mentioned in this article, please visit the following Web sites:
University of Nebraska-Kearney’s Senior College of Central Nebraska:
www.unk.edu (search for Senior College)
University of Nebraska-Omaha’s Institute for Lifelong Learning:
University of Nebraska-Lincoln’s Osher Lifelong Learning Institute: