Ngetich Ronald, Li Wenjuan, Jin Donggang, Zhang Junjun, Jin Zhenlan, Li Ling
Key Laboratory for NeuroInformation of Ministry of Education, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, Center for Psychiatry and Psychology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
Neuroreport. 2021 Jun 9;32(9):808-814. doi: 10.1097/WNR.0000000000001666.
Previous studies have shown that visuospatial working memory (VSWM) plays a key role in the encoding and processing of visuospatial information. More importantly, there is evidence suggesting the role of frontal and parietal cortical areas in VSWM and especially, the influence of the frontal cortex in regulating goal-directed behavior. However, the functional role of the right dorsolateral prefrontal cortex (rDLPFC) in visuospatial working memory is still unclear. Here, we noninvasively modulated the rDLPFC activity using continuous theta-burst stimulation (cTBS), with the vertex as the control site. Our study aimed to investigate the effects of cTBS over rDLPFC on working memory task (2- and 4-back) performance. Working memory performance was assessed at the baseline and after stimulation. We observed that the working memory performance as measured by discriminability index was impaired after cTBS over rDLPFC in 2-back task, whereas 4-back task performance was not significantly affected. More so, there was no effect on performance after cTBS over the vertex, suggesting a functional role of rDLPFC in VSWM. Our findings demonstrate the involvement of the rDLPFC in VSWM as well as the load-dependent effect of working memory performance. Taken together, our work constitutes a useful addition to the literature and underscores the effectiveness and efficiency of noninvasive brain stimulation in modulating neuro-cognitive activity.
先前的研究表明，视觉空间工作记忆（VSWM）在视觉空间信息的编码和处理中起着关键作用。更重要的是，有证据表明额叶和顶叶皮质区域在VSWM中发挥作用，特别是额叶皮质在调节目标导向行为方面的影响。然而，右侧背外侧前额叶皮质（rDLPFC）在视觉空间工作记忆中的功能作用仍不清楚。在此，我们以头顶作为对照部位，使用连续theta爆发刺激（cTBS）对rDLPFC的活动进行非侵入性调节。我们的研究旨在探究rDLPFC上的cTBS对工作记忆任务（2-back和4-back）表现的影响。在基线和刺激后评估工作记忆表现。我们观察到，在2-back任务中，rDLPFC上进行cTBS后，以辨别指数衡量的工作记忆表现受损，而4-back任务表现未受到显著影响。更重要的是，在头顶进行cTBS后对表现没有影响，这表明rDLPFC在VSWM中具有功能作用。我们的研究结果证明了rDLPFC参与VSWM以及工作记忆表现的负荷依赖性效应。综上所述，我们的工作为文献增添了有用内容，并强调了非侵入性脑刺激在调节神经认知活动方面的有效性和效率。
