Clinical and Health Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany.
Biological Psychology and Experimental Psychopathology, Charlotte-Fresenius-University, Munich, Germany.
Psychophysiology. 2024 Oct;61(10):e14639. doi: 10.1111/psyp.14639. Epub 2024 Jun 30.
Interoception, the processing of internal bodily signals, is proposed as the fundamental mechanism underlying emotional experiences. Interoceptive and emotional processing appear distorted in psychiatric disorders. However, our understanding of the neural structures involved in both processes remains limited. To explore the feasibility of enhancing interoception and emotion, we conducted two studies using high-definition transcranial direct current stimulation (HD-tDCS) applied to the right anterior insula. In study one, we compared the effects of anodal HD-tDCS and sham tDCS on interoceptive abilities (sensibility, confidence, accuracy, emotional evaluation) in 52 healthy subjects. Study two additionally included physical activation through ergometer cycling at the beginning of HD-tDCS and examined changes in interoceptive and emotional processing in 39 healthy adults. In both studies, HD-tDCS was applied in a single-blind cross-over online design with two separate sessions. Study one yielded no significant effects of HD-tDCS on interoceptive dimensions. In study two, significant improvements in interoceptive sensibility and confidence were observed over time with physical preactivation, while no differential effects were found between sham and insula stimulation. The expected enhancement of interoceptive and emotional processing following insula stimulation was not observed. We conclude that HD-tDCS targeting the insula does not consistently increase interoceptive or emotional variables. The observed increase in interoceptive sensibility may be attributed to the activation of the interoceptive network through physical activity or training effects. Future research on HD-tDCS involving interoceptive network structures could benefit from protocols targeting larger regions within the network, rather than focusing solely on insula stimulation.
内感受，即对内部身体信号的处理，被认为是情感体验的基本机制。内感受和情绪处理在精神障碍中似乎存在扭曲。然而，我们对内感受和情绪处理所涉及的神经结构的理解仍然有限。为了探索增强内感受和情绪的可行性，我们使用高清晰度经颅直流电刺激（HD-tDCS）对右侧前岛叶进行了两项研究。在第一项研究中，我们比较了阳极 HD-tDCS 和假刺激对 52 名健康受试者的内感受能力（敏感性、信心、准确性、情绪评价）的影响。第二项研究还在 HD-tDCS 开始时通过测力计循环进行了身体激活，并在 39 名健康成年人中检查了内感受和情绪处理的变化。在这两项研究中，HD-tDCS 采用了单盲交叉在线设计，有两个单独的疗程。第一项研究中，HD-tDCS 对内感受维度没有显著影响。在第二项研究中，随着身体的预先激活，内感受敏感性和信心在时间上有显著提高，而假刺激和岛叶刺激之间没有发现差异。预期的岛叶刺激对内感受和情绪处理的增强效果没有观察到。我们得出结论，针对岛叶的 HD-tDCS 并不一致地增加内感受或情绪变量。观察到的内感受敏感性增加可能归因于通过身体活动或训练效应激活内感受网络。未来涉及内感受网络结构的 HD-tDCS 研究可能受益于针对网络内更大区域的方案，而不是仅关注岛叶刺激。
