Wischnewski Miles, Berger Taylor A, Opitz Alexander
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States.
Imaging Neurosci (Camb). 2024 Jan 25;2. doi: 10.1162/imag_a_00078. eCollection 2024.
Numerous studies have demonstrated the beneficial effects of anodal prefrontal transcranial direct current stimulation (tDCS) on working memory. However, a large variability exists in the applied tDCS parameters and working memory outcome measures. Using a meta-modeling approach, we investigated the relationship between tDCS electric fields in the left prefrontal cortex and improvements in working memory performance. Using this approach, a vector of outcome measures is correlated with the tDCS-related electric fields across several studies. These performance-electric field correlations (PEC) are calculated for each spatial location of the grey matter. Extracting 354 data points from 67 studies, we compared the spatial maps of tDCS effects on I) working memory accuracy and speed (regardless of working memory type and time of assessment), II) verbal and visuospatial working memory (regardless of performance measurement and time of assessment), and III) performance during and after stimulation (regardless of performance measurement and working memory type). We found that accuracy improves when anodal tDCS is applied to inferior frontal regions (Brodmann area 47) while working memory speed benefits from stimulation to dorsolateral and anterior prefrontal areas (Brodmann areas 9/10). Furthermore, the beneficial effects of left prefrontal tDCS are exclusive to verbal working memory, with no improvements in visuospatial working memory. We also observed region-specific effects only for task performance during, but not after, stimulation. The results of this study elucidate the causal involvement of prefrontal regions in working memory and can help guide tDCS placement for therapeutic application in disorders that involve working memory deficits.
众多研究已证明阳极前额叶经颅直流电刺激（tDCS）对工作记忆有有益影响。然而，所应用的tDCS参数和工作记忆结果测量存在很大差异。我们采用元建模方法，研究了左前额叶皮质中tDCS电场与工作记忆表现改善之间的关系。使用这种方法，在多项研究中，将一组结果测量值与tDCS相关电场进行关联。针对灰质的每个空间位置计算这些性能-电场相关性（PEC）。我们从67项研究中提取了354个数据点，比较了tDCS对以下方面影响的空间图谱：I）工作记忆准确性和速度（无论工作记忆类型和评估时间），II）言语和视觉空间工作记忆（无论性能测量和评估时间），以及III）刺激期间和之后的表现（无论性能测量和工作记忆类型）。我们发现，当阳极tDCS应用于额下回区域（布罗德曼区47）时准确性提高，而工作记忆速度则受益于对背外侧和前额叶前部区域（布罗德曼区9/10）的刺激。此外，左前额叶tDCS的有益效果仅针对言语工作记忆，视觉空间工作记忆没有改善。我们还仅在刺激期间而非刺激后观察到任务表现的区域特异性效应。本研究结果阐明了前额叶区域在工作记忆中的因果作用，并有助于指导tDCS在涉及工作记忆缺陷的疾病治疗应用中的放置。
