Yang Qin, Qu Xiujuan, Sheng Can, Zhao Xing, Chen Guanqun, Wang Xiaoni, Li Yuxia, Du Wenying, Wang Xiaoqi, Sun Yu, Li Xiaobo, Niu Haijing, Han Ying
Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China.
Beijing Normal University, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing, 100875, China.
Neuroimage. 2025 Aug 1;316:121305. doi: 10.1016/j.neuroimage.2025.121305. Epub 2025 Jun 6.
Transcranial photobiomodulation (tPBM), as a novel non-invasive neurostimulation technique, has shown the compelling potential for improving cognitive function in aging population. However, the potential mechanism remains unclear. Neuroimaging studies have found that tPBM-induced physiological changes exist in both targeted and non-targeted brain areas, suggesting the necessity of understanding the modulation mechanism from the perspective of the whole brain level.
This randomized, single-blind, sham-controlled crossover study aimed to investigate the hypothesis that tPBM improved working memory in healthy older adults through the mechanism of optimizing the properties of the resting-state functional brain networks.
A total of 55 right-handed healthy older adults were randomly assigned to sham tPBM session group or active tPBM session group. After a washout interval, they were assigned to the opposite intervention session. Each session included the following: active or sham tPBM application with a 1064-nm laser to the left forehead; before and after, resting-state functional near-infrared spectroscopy (fNIRS) measurements; and the digital n-back task. Differences in accuracy and reaction time of the n-back task, and changes in functional connectivity and graph metrics of the brain networks were investigated and compared between the active and sham tPBM sessions. In addition, correlations between tPBM-induced changes in functional brain networks, and the n-back task were examined.
The results showed that compared with the sham tPBM session, the accuracy and reaction time during 3-back task significantly improved in the active tPBM session. In addition, the global efficiency, local efficiency, nodal efficiency, and functional connectivity significantly increased in the active tPBM session, particularly in the frontoparietal areas. Importantly, the altered 3-back accuracy was positively correlated with the changes of functional connectivity and nodal efficiency mainly in left prefrontal cortex in those who had increased 3-back accuracy in the active tPBM session.
This study suggests that tPBM may serve as an effective tool to improve working memory in older adults through the modulation of resting-state functional brain network properties. Investigations in large-scale samples are needed to further validate the findings of this study.
经颅光生物调节（tPBM）作为一种新型非侵入性神经刺激技术，已显示出改善老年人群认知功能的巨大潜力。然而，其潜在机制仍不清楚。神经影像学研究发现，tPBM诱导的生理变化存在于目标脑区和非目标脑区，这表明有必要从全脑水平的角度理解调节机制。
本随机、单盲、假对照交叉研究旨在探讨tPBM通过优化静息态功能脑网络特性的机制改善健康老年人工作记忆的假设。
共55名右利手健康老年人被随机分配到假tPBM治疗组或主动tPBM治疗组。经过洗脱期后，他们被分配到相反的干预组。每个治疗组包括以下内容：用1064纳米激光对左侧前额进行主动或假tPBM治疗；治疗前后进行静息态功能近红外光谱（fNIRS）测量；以及数字n-back任务。研究并比较了主动和假tPBM治疗组之间n-back任务的准确性和反应时间差异，以及脑网络功能连接性和图论指标的变化。此外，还研究了tPBM诱导的功能脑网络变化与n-back任务之间的相关性。
结果显示，与假tPBM治疗组相比，主动tPBM治疗组在3-back任务期间的准确性和反应时间显著提高。此外，主动tPBM治疗组的全局效率、局部效率、节点效率和功能连接性显著增加，特别是在额顶叶区域。重要的是，在主动tPBM治疗组中3-back准确性提高的受试者中，改变的3-back准确性与主要在左侧前额叶皮层的功能连接性和节点效率变化呈正相关。
本研究表明，tPBM可能通过调节静息态功能脑网络特性，作为改善老年人工作记忆的有效工具。需要进行大规模样本研究以进一步验证本研究结果。
