Source: Georgetown University Medical Center
It’s
long been believed that advancing age leads to broad declines in our
mental abilities. Now new research from Georgetown University Medical
Center offers surprisingly good news by countering this view.
The findings, published August 19, 2021, in Nature Human Behaviour,
show that two key brain functions, which allow us to attend to new
information and to focus on what’s important in a given situation, can
in fact improve in older individuals. These functions underlie critical
aspects of cognition such as memory, decision making, and self-control,
and even navigation, math, language, and reading.
“These
results are amazing, and have important consequences for how we should
view aging,” says the study’s senior investigator, Michael T. Ullman,
PhD, a professor in the Department of Neuroscience, and Director of
Georgetown’s Brain and Language Lab.
“People
have widely assumed that attention and executive functions decline with
age, despite intriguing hints from some smaller-scale studies that
raised questions about these assumptions,” he says. “But the results
from our large study indicate that critical elements of these abilities
actually improve during aging, likely because we simply practice these
skills throughout our life.”
“This
is all the more important because of the rapidly aging population, both
in the US and around the world,” Ullman says. He adds that with further
research, it may be possible to deliberately improve these skills as
protection against brain decline in healthy aging and disorders.
The
research team, which includes first author João Veríssimo, PhD, an
assistant professor at the University of Lisbon, Portugal, looked at
three separate components of attention and executive function in a group
of 702 participants aged 58 to 98. They focused on these ages since
this is when cognition often changes the most during aging.
The components they studied are the brain networks involved in alerting, orienting, and executive inhibition.
Each has different characteristics and relies on different brain areas
and different neurochemicals and genes. Therefore, Ullman and Veríssimo
reasoned, the networks may also show different aging patterns.
Alerting is characterized by a state of enhanced vigilance and preparedness in order to respond to incoming information. Orienting involves shifting brain resources to a particular location in space. The executive network inhibits distracting or conflicting information, allowing us to focus on what’s important.
“We use all three processes constantly,” Veríssimo explains. “For example, when you are driving a car, alerting is your increased preparedness when you approach an intersection. Orienting occurs when you shift your attention to an unexpected movement, such as a pedestrian. And executive function allows you to inhibit distractions such as birds or billboards so you can stay focused on driving.”
The study found that only alerting abilities declined with age. In contrast, both orienting and executive inhibition actually improved.
The
researchers hypothesize that because orienting and inhibition are
simply skills that allow people to selectively attend to objects, these
skills can improve with lifelong practice. The gains from this practice
can be large enough to outweigh the underlying neural declines, Ullman
and Veríssimo suggest. In contrast, they believe that alerting declines
because this basic state of vigilance and preparedness cannot improve
with practice.