Combined training of aerobic exercise and 3D video game to improve hippocampal and memory functions in older adults: An RCT trial

Abstract Background With the proportion of older adults rising, the progressive cognitive decline and dementia have become one of the most serious public health issues worldwide. As a result, there is a pressing need for developing effective non‐pharmaceutical intervention programs to counteract age‐related cognitive decline. Animal models robustly support that aerobic exercise can effectively improve neurogenesis and memory, whereas most of the current findings from human studies are in contrast. We speculated that two reasons may contribute to these inconsistent findings in human research. One is that hippocampal neurogenesis induced by the aerobic exercise is more likely to survive when simultaneously accompanied by cognitive stimulations, particularly when the cognitive goals are challenging. Another is that the beneficial effects from aerobic exercise are specific to hippocampal dependent memory tasks. Therefore, we designed a training program by combining aerobic cycling with 3D video game. Method We conducted a randomized controlled trial with healthy older adults randomly assigned to combined aerobic cycling and 3D video game training group (n=22), aerobic cycling group (n=23), 3D video games group (n=25), or control group (n=28). The effects of combined training on neuroplasticity (including plasma brain‐derived neurotrophic growth factor, hippocampal gray matter volume, and hippocampal‐cortical functional connectivity) and cognitive plasticity (focusing on hippocampal‐dependent memory, tested via Mnemonic Similarity Task) were examined compared with all three other groups. The training lasted four months with a frequency of twice per week, 1hour per session. Result The combined and video game training groups reported equivalent game experiences and reached similar game levels. The average and maximum heart rates were being monitored to ensure a medium exercise intensity in both combined and cycling groups. In addition self‐reported fatigue levels were equivalent in these two groups. The preliminary behavioral data analysis revealed that combined group performed better on immediate and delayed memory recall. More importantly, there was a larger effect size in pattern separation task in combined group (Cohen’s d =1.12) than in cycling (Cohen’s d =0.49) and video game (Cohen’s d =0.55) groups. Conclusion Combined aerobic exercise ‐ video game training could improve hippocampal‐dependent memory functions, which waits the MRI data analysis to further prove.