Groundbreaking study reveals older adults can improve brain power, defying cognitive aging decline

Cognitive training interventions, which involve targeted computer tasks or strategy training, have shown immediate increases in trained abilities but limited evidence of gains in non-trained abilities.

In contrast, cognitive engagement interventions that involve real-world skills, such as photography or piano playing, have demonstrated cognitive gains in older adults. However, evidence of longer-term maintenance or improvements in cognitive gains is scarce, with only a small number of studies investigating long-term effects.

To address this gap, a team led by Rachel Wu, Associate Professor of Psychology at the University of California, Riverside, has examined whether learning multiple new real-world skills simultaneously results in long-term improvements in cognitive abilities.  

Interesting Engineering (IE) spoke to Rachel Wu to discuss the team's research. Speaking of her motivation behind the study, she said, "One of my long-term goals is to create optimal learning environments for all learners across the lifespan. This study investigates how we could do that with older adults."

Wu's lab at UC Riverside, The CALLA Lab, is focused on this very issue. Her team is working on understanding the mechanisms of cognitive growth and decline in learning and attention over the human lifetime.

Setting the stage

Previous research by Wu has focused on the potential of real-world skill learning to promote long-term cognitive gains in older adulthood. Based on her previous study, the team proposed a novel theory suggesting that older adults can experience significant cognitive improvement by participating in enriched learning environments reminiscent of childhood experiences. 

Their theory emphasizes six key factors, open-minded input-driven learning, individualized scaffolding, serious commitment, a growth mindset, a forgiving environment, and learning multiple skills simultaneously. Wu's previous work, which aimed to replicate the findings using a larger sample size, highlights the decline in rich learning environments after young adulthood.

With this foundation in place, Wu's new research aims to observe long-term cognitive outcomes over the course of one year. The study focused on executive functions (cognitive control, inhibition, and flexibility), working memory, and verbal episodic memory.

Cognitive abilities were assessed in two separate trials conducted with older adults. The assessments were carried out for one year following their participation in an intensive multi-skill learning intervention. The first trial involved a smaller feasibility sample, while the second aimed to replicate the findings using a larger sample size.

Two studies, one goal

The research involved two separate intervention studies conducted with older adults. Study 1 involved six participants (67% female) whose mean age was 66.33 years. Study 2 included 27 participants (67% female), whose mean age was 69.44 years.

"Participants were recruited separately for the different research groups. Through advanced statistical analyses, we accounted for the baseline cognitive abilities. In addition, we investigated the change in their cognitive abilities over time relative to where they started," explained Wu.

"In our study, many factors, such as age, education level, and socioeconomic status, were included in the analysis. However, our sample sizes were relatively small, so it may be difficult to detect differences based on these factors," continued Wu.

In Study 1, participants underwent a 15-week intervention in which they learned how to use an iPad, paint, and speak Spanish. They attended 2-hour classes for each skill every week and an additional hour of lecture or discussion on relevant topics.

Study 2 had a similar design and procedure as Study 1 but with a few differences. Participants had a 12-week intervention and were assigned three of the five available classes (Spanish, photography, iPad operation, drawing, and music composition). They were also given the option to enroll in additional classes. They followed the same assessment schedule as the participants in Study 1.

"We chose skills that were challenging and not something participants could easily learn on their own within a week or so. Many of these skills take years, even decades, to master. Participants also had little to no prior experience with these skills," said Wu, explaining the thought process behind choosing the skills for the intervention.

A baseline assessment was conducted six weeks before the intervention for participants in both studies. Cognitive assessments were conducted at various time points: pre-test, mid-point, post-test, and three-month, six-month, and one-year follow-ups.

Lasting cognitive improvements that defy time

The team used linear-mixed effects models to analyze the data from the studies. 

Significant enhancements in executive function, as indicated by a cognitive composite score, were observed from the pre-test to the 6-month and 1-year follow-up in both studies. Notably, those in the first study exhibited more pronounced improvements. 

The observed improvements were primarily attributed to improvements in cognitive control abilities, including attention control, inhibitory control, working memory, and cognitive flexibility.

Verbal episodic memory, evaluated through the Rey Auditory Verbal Learning Test (RAVLT), exhibited significant improvement at the 3- and 6-month follow-up periods compared to the baseline and pre-test scores in both studies.

However, while no significant changes were found in working memory scores for Study 1, Study 2 showed significant improvements at the 3-month, 6-month, and 1-year follow-up. Overall, there were cognitive improvements across all three measures over a one-year period.

When asked about any unexpected or surprising findings from the study, Wu said, "We were surprised to see how much participants continued improving after the end of the intervention. Typically, follow-up studies for cognitive interventions with older adults show that participants return to baseline within a few months."

Implications for aging and cognitive health

Contrary to previous research, which often showed a dissipation of cognitive intervention effects over time, this study revealed sustained improvements in cognitive function up to a year following the learning intervention.

These long-term improvements are rare in the cognitive intervention literature and provide new insights into the potential for cognitive enhancement in older adults. "It demonstrates the potential of older adults when provided with an enriched learning environment. I hope these findings encourage those who design education and training programs to consider how their programs could further provide optimal learning environments," said Wu hopefully.

Due to the multifaceted nature of the intervention, there are many possible explanations for the sustained improvements in cognitive functions. Is it the participants' dedication to skill development? Or is it the social component of learning a skill? Or whether some other activities or personal experiences are enhancing cognition? We don't exactly know.

We also asked if another crucial thing to think about is whether or not cognitive progress may differ based on the skill, level of difficulty, and quantity of abilities being learned. "Absolutely," says Wu.

"The difficulty level is dependent on one's prior experience, and therefore, the type of skill that may yield the best cognitive changes can vary from person to person. In terms of the number of skills being learned, research has been showing that variety for skill learning matters, as does frequency," she continued.

Identifying the active ingredients that drive the overall intervention effect requires further investigation, with this research setting the stage for that.

Future research and practical applications

The research establishes that cognitive abilities can improve and be sustained as you get older. This can be used to develop various programs to help people as they age. "Our research provides a recipe for potentially helpful ingredients for learning during older adulthood. In addition, our research counters negative stereotypes that older adults can't learn new skills," explained Wu.

Though Wu's work is significant in helping to break the stereotypes around cognitive growth in older adults, future studies are required to understand the factors that contribute to the gains. Additionally, future studies should include a larger sample size and more diversity to account for factors like levels of stress, dietary differences, etc.

Learning is a central ability for many living things, and Wu expresses her interest in exploring more about it.

"I would like to explore how learning is an important privilege. Learning is important when adapting to changes in the environment, such as learning to use new online platforms during the pandemic. But learning is also a privilege because it requires a great deal of support. I would [also] like to explore how much of the cognitive decline that we currently see in older adults can be accounted for by the fact that learning is an important privilege," Wu concluded."