健康与遗传心理学研究室知识库

认知训练和体育锻炼作为老年人干预研究中常用的训练手段被研究者们广泛接受。从当前动物研究 的 证据来看，有氧运动能够增加海马新生神经元的数量，而丰富环境和有难度的学习任务则能够提高海马新生神经元的存活率。从动物模型到人类研究，许多证据都证明多成分的联合干预对延缓衰老，提高老年人的认知能力有更好的效果。在人类研究中，有氧运动是否能够对海马及其相关记忆能力产生影响仍旧存在争议，其原因可能是单一的、缺乏认知挑战的有氧运动并不能有效引导海马可塑性并使其发挥作用。 3D视频游戏 作为一种新型的认知干预手段不仅表现出趣味性的优势，更有不同的证据证明了 3D视频游戏可以通过丰富环境刺激改善老年人的记忆及海马。因此，本 研究从多因素通过不同机制影响海马可塑性的角度出发，考察联合干预 (有氧单车 +3D视频 游戏 )是否能通过不同的机制对海马产生影响，产生比单一的有氧运动或单一的视频游戏训练更强的干预效果，更好的改善老年人的海马可塑性和记忆能力。本研究将健康的社区居住老年人分入视频游戏组(n=23)、有氧运动组(n=22)、联合干预组(n=21)与控制组(n=21)，考察持续四个月，每周两次，每次一小时的干预训练对老年人记忆及其他认知功能、血清生长因子水平以及海马结构与功能的影响。

结果发现，在健康老年人群体中同时进行有氧运动与视频游戏的联合干预是可行的。在行为结果上，三个干预组相较控制组来说都表现出了海马依赖的记忆能力的显著提升，联合干预组比单一干预组表现出了更好的干预效果，体现在对记忆改善更大的效果量以及更广泛维度上认知功能的改善。大脑结构变化的结果显示，有氧运动组与联合干预组在干预之后都出现了左侧海马体积的显著增加。左侧海马体积的变化，海马依赖的记忆能力的变化以及血液中血管内表皮生长因子(VEGF)的变化存在两两正相关，同时，VEGF的变化与有氧适能水平的变化也存在显著的正相关，这可能暗示了左侧海马灰质体积的变化是由于VEGF对神经新生的积极作用，而VEGF本身则会受到有氧运动的调制。大脑的静息态功能连接结果显示，三个干预组的海马与大脑皮层的功能连接下降，这种下降反映了海马本身工作效率的提升。游戏干预组与联合干预组还发现了腹内侧前额叶皮层(vmPFC)与后部记忆核心网络节点之间功能连接的下降，这种下降的功能连接反而提高了海马依赖的记忆成绩，可能是因为游戏训练导致老年人对先验知识的依赖减少，后部核心回想网络能够更加积极有效的对新信息进行加工，使得细节信息加工更准确。

总的来说，当前的研究结果显示，对于健康老年人，有氧运动，3D视频游戏及联合干预都是有效的干预手段，干预能够提升海马依赖的记忆 能力 及其他认知功能。有氧运动主要通过 VEGF对海马结构灰质体积的调节来产生作用，游戏则通过对大脑静息态功能网络的调节来实现记忆能力的提高。联合干预组 相比单一的干预组来说，具有更好的干预效果，表现在 对记忆提升的 更大效果量及更广泛的认知功能 改善 ，其机制可能是这种干预方式能够同时拥有对大脑灰质结构和对更广泛的静息态功能连接网络的调制。

Cognitive training and physical exercise are widely accepted as training methods in the intervention study of the elderly. Previous animal studies suggested that aerobic exercise increases the number of neurogenesis in the hippocampus, while enrichment environment and challenging cognitive learning increase the survival rate of neurogenesis. From animal models to human studies, there is plenty of evidence that multi-component intervention is better at alleviating aging and improving cognitive performance in the elderly. In human studies, whether aerobic exercise has a solid improvement effect on the memory and hippocampus plasticity remains controversial, an underlying cause might be aerobic exercise is a single form of intervention method without cognitively challenged, which could not effectively guide the hippocampal plasticity and functioning. The 3D video games exhibit not only the interesting advantages as a new intervention method, but there is also various evidence that 3D video games may enhance the memory and hippocampal plasticity of older adults due to enrichment environment. Therefore, the present study from the perspective of multiple factors affects hippocampal plasticity through different mechanisms, exploring whether the combined training (aerobic cycling+3D video game) could have more benefits than the single aerobic exercise training or the single 3D video game training, to be more specific, whether the combined training could better improve the hippocampal plasticity and memory in the old adults. In the present study,healthy older adults were assigned to the 3D video games group (n=23), aerobic cycling group (n=22), combined aerobic cycling and 3D video game training group (n=21) or control group (n=21). The effects of combined training on hippocampal-dependent memory, peripheral growth factor, hippocampal gray matter volume, and hippocampal-cortical resting-state functional connectivity were examined compared with all three other groups. The training lasted four months with a frequency of twice per week, 1hour per session.

The combined training method was feasible in healthy elderly. Behavioral data analysis revealed that all the three training groups showed significant improvement in hippocampal-dependent memory function compared with the control group. More importantly, there was a larger effect size on the improvement of hippocampal-dependent memory function and more dimensional cognitive function improved in the combined training group than in the cycling training group or the video game training groups. Structural brain results showed that both the cycling training group and the combined training group experienced a significant increase in left hippocampal volume after the training. In addition, the change of vascular endothelial growth factor (VEGF) was significantly positively correlated with the change of left hippocampal volume, which may indicate that the change of left hippocampal gray matter volume is due to the positive effect of VEGF on neurogenesis. There was also a significant positive correlation between the changes of VEGF and the changes of aerobic fitness, which might indicate that VEGF was modulated by aerobic exercise. The results of the resting-state functional connections showed a decrease in the functional connections between the hippocampus and the cerebral cortex in the three training groups, which reflected an increase in the work efficiency of the hippocampus. Combined training group and video game training group also found decreased connectivity between the ventromedial prefrontal cortex (vmPFC) and the core network nodes related to memory recollection, the decline of functional connectivity indeed improves the hippocampus-dependent memory performance. The mechanism behind this may be the game training reduce the dependence on the prior knowledge in the elderly, and the core network of memory can be more effective to process the new information, make the memory of details more accurate.

Overall, the current findings suggest that in healthy older adults, aerobic exercise training, 3D video games training, and combined training are effective training that improves hippocampal-dependent memory and other cognitive functions. Aerobic exercise plays a role mainly through the regulation of volume of the hippocampus, while video game training can improve memory ability through the regulation of the resting-state functional network. Compared with the single training group, the combined training group had a better training effect. The mechanism may be that this combined training mode can simultaneously modulate the brain gray matter structure and the widely resting-state functional connection network.