Background

Deficient cognitive control (CC) over emotional distraction is a central characteristic of borderline personality disorder (BPD). Reduced activation of the left dorsolateral prefrontal cortex (dlPFC) has been linked to this deficit. This study investigates whether it is possible to ameliorate CC deficits via anodal tDCS over the left dlPFC in BPD. Furthermore, we investigate whether the extent of CC impairment influences how well one responds to tDCS.

Methods

The effect of a single-session tDCS (1 mA for 20 min, reference electrode on the contralateral mastoid bone) to the left dlPFC (F3) on the CC of patients with BPD (N = 20) and healthy control participants (HCs, N = 20) was examined in a double-blinded, balanced randomized, sham-controlled crossover trial. A delayed response working memory task with negative, neutral and positive pictures presented during the delay period was conducted to assess CC. Stimulation was applied simultaneously with the task.

Results

Negative pictures caused prolonged response times as compared to a control condition in patients with BPD and HCs. Anodal tDCS to the left dlPFC did not significantly reduce this interference effect in the overall sample. Further analyses showed, however, that participants with impaired CC profited the most from anodal tDCS. In the subgroup of participants who actually showed an interference effect we found the expected significant amelioration of CC under tDCS.

Conclusions

The present study demonstrates that anodal tDCS applied to the left dlPFC improves deficient CC. Thereby, base-level performance moderates tDCS effects. Hence, tDCS might be suitable to support behavioral trainings to enhance CC specifically in people whose impairments in CC are comparably high.

中文翻译：

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边缘性人格障碍中对情绪的挑战性控制-tDCS研究

背景

情绪分散的认知控制不足（CC）是边缘性人格障碍（BPD）的主要特征。左背外侧前额叶皮层（dlPFC）的激活减少与这种缺陷有关。这项研究调查了是否有可能通过BPD中左dlPFC上的阳极tDCS改善CC缺陷。此外，我们调查了CC损伤的程度是否会影响人们对tDCS的反应程度。

方法

单次tDCS（1 mA持续20分钟，对侧乳突骨上的参比电极）到左dlPFC（F3）对BPD患者（N = 20）和健康对照参与者（HCs，N = 20）在双盲，平衡随机，假对照交叉试验中进行了检查。进行了延迟反应的工作记忆任务，其中在延迟期间显示了负面，中性和正面图片，以评估CC。刺激与任务同时进行。

结果

与对照组相比，在BPD和HCs患者中，负片导致响应时间延长。左侧dlPFC的阳极tDCS并未显着降低整个样品中的这种干扰效应。然而，进一步的分析表明，CC受损的参与者从阳极tDCS获益最大。在实际上表现出干扰作用的参与者亚组中，我们发现tDCS下CC的预期显着改善。

结论

本研究表明，将阳极tDCS应用于左dlPFC可改善CC不足。因此，基本级别的性能可减轻tDCS的影响。因此，tDCS可能适合支持行为培训，以专门针对CC损伤相对较高的人群增强CC。