Edgcumbe Daniel R, Rivolta Davide, Nitsche Michael A, Thoma Volker
School of Psychology, University of East London, London, United Kingdom.
School of Psychological, Social and Behavioural Sciences, Faculty of Health and Life Sciences, Coventry University, United Kingdom.
Heliyon. 2024 Aug 13;10(16):e36078. doi: 10.1016/j.heliyon.2024.e36078. eCollection 2024 Aug 30.
Anodal transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (DLPFC) has shown to have effects on different domains of cognition yet there is a gap in the literature regarding effects on reflective thinking performance.
The current study investigated if single session and repeated anodal tDCS over the right DLPFC induces effects on judgment and decision-making performance and whether these are linked to working memory (updating) performance or cognitive inhibition.
Participants received anodal tDCS over the right DLPFC once (plus sham tDCS in a second session) or twice (24 h apart). In the third group participants received a single session of sham stimulation only. Cognitive characteristic measures were administered pre-stimulation (thinking disposition, impulsivity, cognitive ability). Experimental tasks included two versions of the Cognitive Reflection Test (numeric vs verbal-CRT), a set of incongruent base-rate vignettes, and two working memory tests (Sternberg task and n-back task). Forty-eight participants (mean age = 26.08 ± 0.54 years; 27 females) were recruited.
Single sessions of tDCS were associated with an increase in reflective thinking performance compared to the sham conditions, with stimulation improving scores on incongruent base rate tasks as well as marginally improving numeric CRT scores (compared to sham), but not thinking tasks without a numeric component (verbal-CRT). Repeated anodal stimulation only improved numeric CRT scores. tDCS did not increase working memory (updating) performance. These findings could not be explained by a practice effect or a priori differences in cognitive characteristics or impulsivity across the experimental groups.
The current results demonstrate the involvement of the right DLPFC in reflective thinking performance which cannot be explained by working memory (updating) performance or general cognitive characteristics of participants.
经颅直流电刺激阳极（tDCS）作用于右侧背外侧前额叶皮层（DLPFC）已显示出对不同认知领域有影响，但关于其对反思性思维表现的影响，文献中存在空白。
本研究调查单次和重复的右侧DLPFC阳极tDCS是否会对判断和决策表现产生影响，以及这些影响是否与工作记忆（更新）表现或认知抑制有关。
参与者接受一次右侧DLPFC阳极tDCS（第二次实验接受伪刺激）或两次（间隔24小时）。第三组参与者仅接受一次伪刺激。在刺激前进行认知特征测量（思维倾向、冲动性、认知能力）。实验任务包括两个版本的认知反思测试（数字版与文字版-CRT）、一组不一致的基础概率案例以及两个工作记忆测试（斯特恩伯格任务和n-back任务）。招募了48名参与者（平均年龄=26.08±0.54岁；27名女性）。
与伪刺激条件相比，单次tDCS与反思性思维表现的提高相关，刺激提高了不一致基础概率任务的得分，并略微提高了数字版CRT的得分（与伪刺激相比），但对无数字成分的思维任务（文字版CRT）没有影响。重复阳极刺激仅提高了数字版CRT的得分。tDCS没有提高工作记忆（更新）表现。这些发现无法用练习效应或实验组间认知特征或冲动性的先验差异来解释。
目前的结果表明右侧DLPFC参与了反思性思维表现，这不能用工作记忆（更新）表现或参与者的一般认知特征来解释。
