Abstract

We commonly label moral violations in terms of ‘disgust’, yet it remains unclear whether metaphorical expressions linking disgust and morality are genuinely shared at the cognitive/neural level. Using transcranial magnetic stimulation (TMS), we provide new insights into this debate by measuring motor-evoked potentials (MEPs) from the tongue generated by TMS over the tongue primary motor area (tM1) in a small group of healthy participants presented with vignettes of moral transgressions and non-moral vignettes. We tested whether moral indignation, felt while evaluating moral vignettes, affected tM1 excitability. Vignettes exerted a variable influence on MEPs with no net effect of the moral category. However, in accordance with our recent study documenting reduced tM1 excitability during exposure to pictures of disgusting foods or facial expressions of distaste, we found that the vignettes of highly disapproved moral violations reduced tM1 excitability. Moreover, tM1 excitability and moral indignation were linearly correlated: the higher the moral indignation, the lower the tM1 excitability. Respective changes in MEPs were not observed in a non-oral control muscle, suggesting a selective decrease of tM1 excitability. These preliminary findings provide neurophysiological evidence supporting the hypothesis that morality might have originated from the more primitive experience of oral distaste.

中文翻译：

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对道德违规行为的愤慨抑制了舌头运动皮层：初步 TMS 证据

摘要

我们通常用“厌恶”来标记违反道德的行为，但目前尚不清楚将厌恶和道德联系起来的隐喻表达是否在认知/神经层面真正得到共享。使用经颅磁刺激 (TMS)，我们通过测量由 TMS 产生的舌头在舌初级运动区 (tM1) 上的运动诱发电位 (MEP)，为这一争论提供了新的见解。道德违规和非道德的小插曲。我们测试了在评估道德小插曲时感受到的道德义愤是否会影响 tM1 的兴奋性。小插曲对欧洲议会议员产生了不同的影响，而没有道德类别的净影响。然而，根据我们最近的研究，记录在暴露于令人作呕的食物或厌恶的面部表情的图片期间降低 tM1 的兴奋性，我们发现高度不赞成的道德违规的小插曲降低了 tM1 的兴奋性。此外，tM1 兴奋性和道德愤慨呈线性相关：道德愤慨越高，tM1 兴奋性越低。在非口服对照肌肉中未观察到 MEP 的相应变化，表明 tM1 兴奋性选择性降低。这些初步发现提供了神经生理学证据，支持道德可能起源于更原始的口腔厌恶体验的假设。tM1 兴奋性和道德愤慨呈线性相关：道德愤慨越高，tM1 兴奋性越低。在非口服对照肌肉中未观察到 MEP 的相应变化，表明 tM1 兴奋性选择性降低。这些初步发现提供了神经生理学证据，支持道德可能起源于更原始的口腔厌恶体验的假设。tM1 兴奋性和道德愤慨呈线性相关：道德愤慨越高，tM1 兴奋性越低。在非口服对照肌肉中未观察到 MEP 的相应变化，表明 tM1 兴奋性选择性降低。这些初步发现提供了神经生理学证据，支持道德可能起源于更原始的口腔厌恶体验的假设。