Kuehne Maria, Heimrath Kai, Heinze Hans-Jochen, Zaehle Tino
Department of Neurology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.
PLoS One. 2015 May 18;10(5):e0127061. doi: 10.1371/journal.pone.0127061. eCollection 2015.
Attitude to morality, reflecting cultural norms and values, is considered unique to human social behavior. Resulting moral behavior in a social environment is controlled by a widespread neural network including the dorsolateral prefrontal cortex (DLPFC), which plays an important role in decision making. In the present study we investigate the influence of neurophysiological modulation of DLPFC reactivity by means of transcranial direct current stimulation (tDCS) on moral reasoning. For that purpose we administered anodal, cathodal, and sham stimulation of the left DLPFC while subjects judged the appropriateness of hard moral personal dilemmas. In contrast to sham and cathodal stimulation, anodal stimulation induced a shift in judgment of personal moral dilemmas towards more non-utilitarian actions. Our results demonstrate that alterations of left DLPFC activity can change moral judgments and, in consequence, provide a causal link between left DLPFC activity and moral reasoning. Most important, the observed shift towards non-utilitarian actions suggests that moral decision making is not a permanent individual trait but can be manipulated; consequently individuals with boundless, uncontrollable, and maladaptive moral behavior, such as found in psychopathy, might benefit from neuromodulation-based approaches.
对道德的态度反映了文化规范和价值观，被认为是人类社会行为所特有的。在社会环境中产生的道德行为受包括背外侧前额叶皮层（DLPFC）在内的广泛神经网络控制，该脑区在决策中起重要作用。在本研究中，我们通过经颅直流电刺激（tDCS）来研究DLPFC反应性的神经生理调节对道德推理的影响。为此，我们在受试者判断艰难的道德个人困境的适当性时，对左侧DLPFC进行阳极、阴极和假刺激。与假刺激和阴极刺激相比，阳极刺激导致个人道德困境的判断向更多非功利性行动转变。我们的结果表明，左侧DLPFC活动的改变可以改变道德判断，因此在左侧DLPFC活动和道德推理之间建立了因果联系。最重要的是，观察到的向非功利性行动的转变表明，道德决策不是一种固定的个人特质，而是可以被操纵的；因此，患有如精神病态中发现的无节制、无法控制和适应不良的道德行为的个体，可能会从基于神经调节的方法中受益。
