A senior couple playing with a jigsaw, a way to promote cognitive health Photo: TUCHONG

Population aging presents a serious challenge to China. According to statistics, at the end of 2021, people aged 65 and older made up over 14% of China’s total population, marking the country’s transition into an aged society. As individuals age, cognitive functions, including information processing speed, executive functions, memory, and decision-making, gradually decline. If this decline occurs more rapidly than expected for one’s age or education level, it may indicate mild cognitive impairment (MCI) or even Alzheimer’s disease. Age is the most significant risk factor for dementia. For example, the incidence of dementia among people aged 60 is about 1%, and it doubles every five years thereafter. By age 95, this proportion rises to 50%.

Fortunately, the brains of older adults retain a certain degree of plasticity. At present, a well-established theory in academia, known as the “scaffolding theory,” posits that the human brain has a built-in “scaffold” whose structure and functions gradually degenerate with age. However, with appropriate training and intervention, it may be possible to repair the damaged scaffold to a certain extent. For example, a declining neural pathway in the scaffold can be strengthened through targeted training, or a new compensatory pathway can be developed. Our research is grounded in this scaffolding theory.

This article introduces four recent research projects conducted by our team. The first two studies explore methods to slow cognitive decline in healthy older adults as part of normal aging. The latter two focus on the prevention and treatment of Alzheimer’s disease. Among them, the third study investigates early detection and warning and intervention of MCI, while the fourth study develops cognitive stimulation therapy for patients with mild to moderate dementia.

Delaying cognitive aging

Cognitive training and physical exercise are the two most important methods to improve the brain’s cognitive functions. Animal studies have found that aerobic exercise can promote the regeneration of hippocampal neurons, while cognitive training can preserve new neurons’ functions. As such, combining aerobic exercise and cognitive training is even more effective in enhancing functions of the brain. Inspired by animal studies, we conducted further empirical research on healthy olderly people at the community level.

The first study explored the effects of combining aerobic exercise and video game training on memory and hippocampal plasticity among the elderly. Participants were divided into four groups: the control group, the game training group, the aerobic cycling group, and a group receiving both video game and aerobic cycling training. The results revealed that, compared to the control group, the other three intervention groups—especially the group receiving both types of training—showed improvements in hippocampus-dependent memories. At the structural level of the brain, similar to findings of animal studies, we found that exercise induced structural plasticity in human brains as well. Both the aerobic cycling group and the combined training group reported increases in left hippocampal volumes after training. Cognitive training promoted changes in the brain’s functional plasticity, as both the game training group and the combined training group reported enhanced functional connectivity of the default network.

Study Two further explored the impact of comprehensive intervention integrating cognitive training, physical exercise, and psychological counseling aimed at promoting physical and mental health among the elderly, as well as functions of the brain. Psychological counseling was integrated into the training, given the strong link between cognition and emotions revealed in psychology. The research design included four groups: the control group, the cognitive training group, the cognitive and physical exercise group, and the comprehensive training group receiving cognitive training, physical exercise, and psychological counseling. The findings revealed that the combination of cognitive and physical exercise exerted the most significant effect on maintaining and improving cognitive functions. What is more noteworthy, however, is that the comprehensive training group reported significant improvements in multiple aspects including cognition, social interaction support, and physical health. In addition, a significant correlation was found between the training effect and the age effect, as data gained through MRI scans suggested that the brain functions of the elderly participants exhibited signs of becoming “younger” after training.

The results of these two studies suggest that combining cognitive training, physical exercise, and psychological counseling can effectively slow cognitive aging and promote rejuvenation of brain function in older adults.

Prevention and intervention

The increasingly serious aging problem has drawn attention to pathological cognitive decline, with neurodegenerative diseases posing significant societal challenges. To address this, our team sought strategies for the early identification and effective intervention of individuals at high risk of cognitive impairment at the community level.

Specifically, Study Three investigated a stratified mechanism for the early detection and comprehensive intervention of MCI. In order to better serve the community, we designed a multi-layered and multi-dimensional early warning system aimed at identifying high-risk groups as early as possible. This system is sensitive, accurate, easy to implement, and economical. Its effectiveness has been verified and it has been granted a patent. For elderly individuals identified as high risk for cognitive impairment, we conducted a comprehensive intervention that included cognitive training, physical exercise, psychological counseling, and lifestyle management. At the end of the nine-month intervention, participants reported significant improvements in both objective cognitive function and subjective cognitive abilities. A one-year follow-up confirmed that the improvements in subjective cognitive abilities and lifestyles were maintained. To ensure that these studies can truly help the communities, we also developed a series of practical intervention manuals and supporting electronic products.

Study Four broadened the scope from olderly people with MCI to patients with mild to moderate dementia. Given the lack of non-drug treatments for this specific group in China, our team developed a cognitive stimulation therapy tailored to accommodate Chinese cultural elements. While the design philosophy of this therapy is consistent with traditional cognitive stimulation therapies, it was adapted to better suit the local context and has been successfully implemented in numerous nursing homes. Preliminary results demonstrate that the therapy was effective in improving overall cognition functions and memory, while reducing caregiver burden.

Research on brain mechanisms has always been central to the study of aging societies. Initiatives like the China Brain Project and the recent Sci-Tech Innovation 2030 have continually advanced brain science and brain-inspired artificial intelligence, deepening our understanding of brain mechanisms. Although psychology is primarily based on mesoscopic research, it can extend its research breadth and depth to the micro and macro levels through cooperation with related disciplines. In the future, research into the mechanisms concerning normal and pathological aging of the human brain will be more thorough and comprehensive.

Understanding the brain’s working mechanisms lays the foundation, and a scientific approach to brain protection is the ultimate goal. By focusing on applying our research findings to practical outcomes, our results will contribute towards the goal of slowing the progression of dementia proposed by the Healthy China Action Plan. Additionally, we have also proposed incorporating brain health examinations for people aged 65 and above into the public health system, making it mandatory rather than optional.

In conclusion, deepening the research on brain and mental health mechanisms and translating these findings into practice are among the most important directions for aging research in China, and will play a vital role in building healthier societies.

Li Juan is a research fellow from the Institute of Psychology at the Chinese Academy of Sciences.