Electric Field Strength From Prefrontal Transcranial Direct Current Stimulation Determines Degree of Working Memory Response: A Potential Application of Reverse-Calculation Modeling?
Electric Field Strength From Prefrontal Transcranial Direct Current Stimulation Determines Degree of Working Memory Response: A Potential Application of Reverse-Calculation Modeling?
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DOI：
10.1111/ner.13342
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发表时间：
2020-12-14
期刊：
影响因子：
2.8
通讯作者：
George, Mark S.
中科院分区：
文献类型：
--
作者：
Caulfield, Kevin A.;Indahlastari, Aprinda;George, Mark S.
背景经颅直流电刺激（tDCS）的工作记忆是一个诱人的治疗，但有混合evidence to date.Objectives我们测试了电场强度均匀2 mA剂量对工作记忆的影响，从prestimulation到poststimulation。其次，我们统计评估了一种个体化tDCS剂量的反向计算方法及其对皮层电场归一化的影响。材料和方法我们对28名健康老年人的数据集进行了电场建模（15名女性，平均年龄= 73.7，SD = 7.3），在三盲设计中，在双侧背外侧前额叶皮质（DLPFC）上接受10次主动2 mA tDCS（N = 14）或假tDCS（N = 14）。我们在左侧和右侧DLPFC的感兴趣区域（ROI）处，在高于中位数的条件下，从活动2 mA（N = 7）开始的高电场（N = 7），低于中位数的条件下，从活动2 mA（N = 7）开始的低电场（N = 14），以及假手术（N = 14），评估了N-back任务中电场强度和工作记忆变化之间的关系。然后，我们确定了个性化的反向计算剂量，以产生组平均电场，并测量了均匀的2 mA剂量与个性化的反向计算剂量在相同的ROIs.Results工作记忆改善前至后tDCS之间的电场方差显着高于中位数的电场从活跃的2 mA条件下，在左侧DLPFC（混合方差分析，p = 0.013）。此外，反向计算建模显著降低了两个ROI的电场方差（Levene检验; p < 0.001）。结论来自均匀2 mA剂量的左侧DLPFC的较高电场似乎可以驱动tDCS的工作记忆改善。从反向计算建模的个体化剂量显着减少在皮层的电场变化。总而言之，使用反向计算建模在参与者的皮层产生相同的高电场，可能会在未来产生更有效的tDCS治疗工作记忆。
Background Transcranial direct current stimulation (tDCS) for working memory is an enticing treatment, but there is mixed evidence to date.Objectives We tested the effects of electric field strength from uniform 2 mA dosing on working memory change from prestimulation to poststimulation. Second, we statistically evaluated a reverse-calculation method of individualizing tDCS dose and its effect on normalizing electric field at the cortex.Materials and Methods We performed electric field modeling on a dataset of 28 healthy older adults (15 women, mean age = 73.7, SD = 7.3) who received ten sessions of active 2 mA tDCS (N = 14) or sham tDCS (N = 14) applied over bilateral dorsolateral prefrontal cortices (DLPFC) in a triple-blind design. We evaluated the relationship between electric field strength and working memory change on an N-back task in conditions of above-median, high electric field from active 2 mA (N = 7), below-median, low electric field from active 2 mA (N = 7), and sham (N = 14) at regions of interest (ROI) at the left and right DLPFC. We then determined the individualized reverse-calculation dose to produce the group average electric field and measured the electric field variance between uniform 2 mA doses vs. individualized reverse-calculation doses at the same ROIs.Results Working memory improvements from pre- to post-tDCS were significant for the above-median electric field from active 2 mA condition at the left DLPFC (mixed ANOVA, p = 0.013). Furthermore, reverse-calculation modeling significantly reduced electric field variance at both ROIs (Levene's test; p < 0.001).Conclusions Higher electric fields at the left DLPFC from uniform 2 mA doses appear to drive working memory improvements from tDCS. Individualized doses from reverse-calculation modeling significantly reduce electric field variance at the cortex. Taken together, using reverse-calculation modeling to produce the same, high electric fields at the cortex across participants may produce more effective future tDCS treatments for working memory.