Event Review: Cognitive Plasticity in Adulthood
• Max Planck Society
• German Center for Research and Innovation (GCRI)
Demographic change poses a serious challenge to Western nations. As society faces longer life expectancies and lower birth rates, older adults are becoming an increasingly influential force. As a result, aging is emerging as a key area of scientific research, with cognitive decline as one of the most pressing issues currently under examination. Scientists are not only studying diseases affecting the brain, but also ways to enhance cognitive performance in general. Topics in question include: Why do some older adults perform at higher cognitive levels than others? And how do our habits and environments influence age-related cognitive trajectories? On January 28, 2015, aging experts from the Max Planck Institute for Human Development in Germany and Columbia University in New York City convened at the German Center for Research and Innovation to address these issues during a panel discussion on “Cognitive Plasticity in Adulthood.”
After Dr. Joann Halpern, Director of the German Center for Research and Innovation, introduced the evening’s topic and speakers, Prof. Dr. Ulman Lindenberger, Director of the Center for Lifespan Psychology at the Max Planck Institute for Human Development, presented on the aging brain ‘in vitro’, i.e. as measured in a laboratory and through tests. Prof. Dr. Lindenberger began by providing a general introduction to human cognitive aging. “75 is the new 55,” he stated, summarizing a study that compared 75-year-old Berliners across the historical time frames of 1990 to 1993 and 2010 to 2013. While longitudinal studies like this show a trend towards adults being able to maintain their cognitive abilities on a high level at older ages, a substantial difference in cognitive performance between individuals nevertheless exists. In particular, some older adults show considerably less cognitive decline than others. So what contributes to these differences and furthermore, how can individuals work to retain high levels of cognitive ability into old age?
One field that can be studied in order to shed light on this question is cognitive plasticity, which describes the brain’s capacity to change in structure and behavior. It is thought to be a key factor for promoting successful cognitive aging. According to Prof. Dr. Lindenberger, plasticity is elicited by a mismatch between ‘supply’ and ‘demand’. Supply refers to the available cognitive capacity and demand refers to the cognitive capacity needed to perform a certain task.
Such a mismatch, for example, occurs during the learning process. Demand does not match supply because the individual does not yet possess the cognitive abilities required for performing said task. Because plasticity is triggered by this kind of supply-demand mismatch, Prof. Dr. Lindenberger explained that plasticity is not possible without exerted effort. It requires continuous training over time in order to be successful. Additionally, the mismatch has to be within the brain’s range of flexibility for it to induce plastic change. This means that the task has to be learnable and geared to the individual’s cognitive abilities. For example, it would not be sensible for a person who only has knowledge of high school math, acquired 30 years ago, to be presented with tasks requiring more advanced mathematics. If the supply-demand mismatch is within the brain’s range of flexibility, however, then cognitive plasticity can be successful, as studies have shown.
Following Prof. Dr. Lindenberger’s presentation on the aging brain ‘in vitro’, Dr. Ursula Staudinger, Director of the Robert N. Butler Columbia Aging Center of Columbia University, focused on the plasticity of cognitive aging ‘in vivo’. The ‘in vivo’ perspective studies cognitive aging as it happens in the “real world” and how these findings relate back to results from analyses in the lab. As a consequence, Dr. Staudinger’s definition of plasticity is a bit broader. She explained that plasticity ‘in vivo’ denotes the modifiability of human development, which not only encompasses the brain, but also other organs as well as our physiology, culture, and behavior.
Dr. Staudinger then addressed widespread stereotypes about aging. While older adults are often thought to be forgetful, slow, unable to learn new tasks and skills, or even demented, they are also highly regarded for being wise, experienced, and knowledgeable. Dr. Staudinger continued by pointing out that findings from her cognitive aging laboratory match these stereotypes. As Prof. Dr. Lindenberger previously explained, some older adults maintain a high cognitive capacity as they age while others experience a significant decline. Similar to Prof. Dr. Lindenberger, Dr. Staudinger is also interested in uncovering why this difference exists and how adults can compensate for cognitive decline. While researching cognitive plasticity ‘in vitro’ is one approach, another focuses on the study of cognitive plasticity ‘in vivo,’ which she proceeded to describe in more detail.
Dr. Staudinger stated that cognitive and personality plasticity seems to be linked to a “challenge it or lose it” principle. This principle refers to the scientific assumption that if cognitive abilities are not exercised and challenged, they will begin to decline. “Our brain is a very curious thing and it needs to be stimulated,” Dr. Staudinger explained. In addition, she noted that studies have shown that the more complex these challenges are across a span of time, the better the cognitive performance in old age will be. Taking up her earlier argument of prevalent stereotypes about older adults, Dr. Staudinger added that these images of aging in our socio-cultural environments shape how society perceives older adults as well as how they see themselves. She therefore argues for changes in societal structures that better integrate older adults and encourage them to keep challenging their cognitive abilities.
Dr. Staudinger and Prof. Dr. Lindenberger then proceeded to field questions from the audience. The evening’s moderator, Dr. Halpern, oversaw the discussion, which included questions about the implications of cognitive plasticity for retirement as well as the impact of early childhood education for making a difference later in life.