健康与遗传心理学研究室知识库

内感受是有机体对身体内部信号的感知、解释、整合和调节的过程。内感受在成瘾行为的发展和维持中起着重要作用，药物滥用导致内感受功能在行为、外周和中枢等不同层面的受损，而内感受功能受损又会反过来加重成瘾者异常的物质使用。成瘾者在戒断过程中通常会伴随着焦虑、抑郁情绪以及强烈的心理渴求，而内感受能力与情绪和渴求密切相关，对当前身体状态的迟钝感知可能放大身体预测误差，并可能对成瘾者的情绪、渴求和用药行为产生一系列负面影响，那么提高成瘾者对当下的内感受感知能力是关键。

经皮耳廓迷走神经刺激（transcutaneous auricular vagal nerve stimulation，taVNS）是调节有机体内感受的重要神经调控方法。目前taVNS 在内感受和成瘾干预方面的相关研究较少，需要补充一些临床对照研究。在已有研究中，taVNS 的效应量都不是很大，这可能和 taVNS 的刺激频率有关，需要选择适合的 taVNS 刺激频率才可能达到最佳效果。因此本研究目的是想要探索高频刺激是否比中频刺激更能促进身体对当下内感受的感知能力；成瘾者的内感受能力和健康人群的差异如何，迷走神经刺激是否可以通过提高成瘾者的内感受能力来缓解负性情绪和降低渴求。

研究一招募 28 名健康的大学生被试，探究不同频率（0hz、25hz 和100hz）的 taVNS 对内感受的外周神经系统活性、内感受行为任务、身体的主观感觉报告以及情绪的影响，确定最适合的 taVNS 刺激参数。结果表明：（1）在外周神经系统活性方面，25hz 和 100hz 的 taVNS 都可以显著激活迷走神经刺激的活性，即心率变异性显著降低，和基线相比，100hz 刺激期间降低的效果比25hz的更显著；此外，100hz 在刺激后也显著降低，提示我们100hz 还有显著的延续效应。（2）在内感受行为任务表现方面，100hz 比 25hz 在提高内感受准确性上效果更好，即与基线相比，100hz 的 taVNS 刺激之后的内感受准确性显著升高。（3）在正负性情绪方面，在 0hz 和 100hz 的 taVNS 刺激之后正性情绪显著降低，25hz 对正性情绪没有影响，三种频率的刺激对负性情绪都没有影响。（4）在身体感知觉的主观报告方面，和基线以及刺激后相比，100hz 的taVNS 在刺激期间的手心汗液和脚心汗液自我感知显著升高，提示我们刺激期间显著促进手心汗液和脚心分泌的自我感知，心跳速度感知在刺激期间也有增强的趋势，而呼吸和唾液分泌无明显变化。身体感知报告属于内感受敏感性的主观报告，100hz 的 taVNS 在刺激期间可以显著增强内感受敏感性。总之，100hz 的taVNS对内感受的外周神经系统活性、内感受任务表现以及身体的主观感知的增强效果更好。

研究二招募 35 名成瘾者（住院酒精依赖患者和吸烟者），将其匹配分成taVNS 组和对照组，进行为期一个月的干预，用问卷法观察taVNS 干预对内感受、情绪和心理渴求的影响，对所有被试的这三个方面在干预前，干预2 周末和干预 4 周末进行评定，其主要观察指标包括身体知觉问卷、酒精渴求问卷、吸烟渴求量表、汉密尔顿抑郁和焦虑量表；同时通过采取生态瞬时评估方法进行每日追踪，收集 taVNS 组和对照组在干预 1 个月期间的情绪和心理渴求情况，探讨 taVNS 对成瘾者的影响。结果表明：（1）在内感受敏感性方面，与基线相比，taVNS 组在干预之后的内感受敏感性显著提高；（2）在情绪和渴求方面，问卷结果和生态瞬时评估的结果都显示，taVNS 干预对渴求和情绪没有显著影响。（3）对内感受敏感性、情绪和渴求在干预 1 个月前后的问卷量表的差值进行相关分析，整体相关性分析结果表明，内感受敏感性和抑郁情绪在干预1个月前后的差值为呈现显著负相关关系，进一步分组相关性分析发现，在情绪方面，实验组中，内感受敏感性和抑郁、焦虑情绪的变化呈现显著的负相关关系，但是在对照组中没有差异，这提示我们迷走神经刺激可能加强了内感受变化与抑郁、焦虑情绪变化之间的联系，在渴求方面，在实验组中，内感受敏感性和渴求的变化的相关性边缘显著，但这提示我们 taVNS 可能在提高身体内感受敏感性的同时也唤醒了对药物的特异性身体感觉。

综上所述，本研究探讨了不同频率的 taVNS 对内感受的影响，发现100hz的 taVNS 对内感受的增强效果最好，然后使用 100hz 的taVNS 在成瘾人群中进行一个月的干预，发现 100hz 的 taVNS 可以显著提高成瘾者的内感受敏感性，且内感受敏感性的变化和抑郁、焦虑情绪的变化呈显著负相关关系，为后续100hz 的 taVNS 在临床上的干预提供一定的参考。

Interoception is the process by which the body perceives, interprets, integrates, and regulates internal signals. It plays a crucial role in the development and maintenance of addictive behaviors. Substance abuse leads to impaired interoception at various levels一behaviorally, peripherally, and centrally, which, in turn, can exacerbate abnormal substance use in addicts. Addicts often experience anxiety, depressive moods, and intense psychological cravings during withdrawal. Since interoception is closely linked with emotions and cravings, a dull perception of the current bodily state could magnify body prediction errors and potentially have a series of negative impacts on addicts' emotions, cravings, and drug use behaviors. Thus, enhancing addicts' perceptive ability towards current interoception is key.

Transcutaneous auricular vagal nerve stimulation (taVNS) is an essential neural regulatory method for modulating bodily interoception. Presently, there is a scarcity of research related to taVNS in interoception and addiction intervention, necessitating additional clinical controlled studies. In existing research, the effect size of taVNS is not very large, which may relate to the stimulation frequency of taVNS. Choosing a suitable taVNS stimulation frequency is crucial to achieve optimal effects. Therefore, this study aims to explore whether high-frequency stimulation is more effective than mid-frequency stimulation in enhancing bodily perception of current interoception; how interoceptive abilities differ between addicts and a healthy ulation, and whether vagal nerve stimulation can alleviate negative emotions and reduce cravings by enhancing interoceptive abilities in addicts.

Study 1 recruited 28 healthy university students to explore the effects of different frequencies (OHz, 25Hz, and 100Hz) of taVNS on peripheral nervous system activity related to interoception, interoceptive behavioral tasks, subjective reports of bodily sensations, and emotions, and to identify the most suitable taVNS stimulation parameters. The results indicated that: (1) In terms of peripheral nervous system activity, both 25Hz and 100Hz taVNS can significantly activate vagal nerve stimulation activity, with heart rate variability significantly reducing more during 100Hz stimulation than during 25Hz; furthermore, 100Hz significantly reduces post-stimulation, indicating a significant sustained effect. (2) In terms of interoceptive behavioral task performance, 100Hz is more effective than 25Hz in improving interoceptive accuracy, as interoceptive accuracy significantly increases after 100Hz taVNS stimulation compared to baseline. (3) In terms of positive and negative emotions, positive emotions significantly decrease after OHz and 100Hz taVNS stimulation, 25Hz has no effect on positive emotions, and no stimulation frequency affects negative emotions. (4) In terms of subjective reports of bodily perception, compared to baseline and post-stimulation, 100Hz taVNS significantly increases self-perception of palm and sole sweating during stimulation, indicating significant promotion of self-perception of palm and sole sweating during stimulation; heart rate perception also tends to increase during stimulation, while respiration and saliva secretion do not change noticeably. Subjective reports of bodily perception pertain to subjective reports of interoceptive sensitivity, and 100Hz taVNS can significantly enhance interoceptive sensitivity during stimulation. In summary, 100Hz taVNS has better enhancing effects on peripheral nervous system activity related to interoception, performance in interoceptive tasks, and subjective perception of the body.

Study 2 recruited 35 addicts (hospitalized alcohol-dependent patients and smokers) and the addicts was then matched and split into a taVNS group and a control group for a one-month intervention, observing the effects of taVNS intervention on interoception, emotion, and psychological cravings using questionnaires, and evaluating these three aspects in all subjects before the intervention, at the end of intervention weeks 2 and 4, with the main observation indicators including the body perception questionnaire, alcohol craving questionnaire, smoking craving scale, and Hamilton depression and anxiety scale. Concurrently, using the ecological momentary assessment method for daily tracking, data on emotional and psychological craving conditions were collected from both the taVNS and control groups during the one-month intervention period, exploring the effects of taVNS on substance dependents. The results showed that: (1) In terms of interoceptive sensitivity, compared to baseline, interoceptive sensitivity significantly increased after the intervention in the taVNS group; (2) In terms of emotion and craving, both questionnaire results and the ecological momentary assessment results showed that taVNS intervention had no significant effect on cravings and emotions. (3) A correlational analysis was conducted on the differences in questionnaire scales for interoceptive sensitivity, emotion, and craving before and after a one-month intervention. The overall correlational analysis results showed that there was a significant negative relationship between the changes in interoceptive sensitivity and depressive emotions before and after the intervention. Further grouped correlational analysis found that, in terms of emotion, in the experimental group, interoceptive sensitivity showed a significant negative relationship with depressive and anxious emotions, but there was no difference in the control group. This suggests to us that vagal nerve stimulation might have strengthened the connection between changes in interoception and changes in depressive and anxious emotions. Regarding cravings, in the experimental group, the enhancement of interoceptive sensitivity is edges related to the enhancement of cravings, it hints to us that taVNS might also awaken specific bodily sensations related to drugs while increasing bodily interoceptive sensitivity.

In conclusion, this study explored the effects of taVNS at different frequencies on interoception and found that taVNS at 100Hz demonstrated the most potent enhancement effect on interoception. Subsequently, employing 100Hz taVNS in a one-month intervention among individuals with addiction, it was found that 100Hz taVNS could significantly increase the sensitivity of interoception among addicts. Furthermore, the changes in interoceptive sensitivity were significantly negativelycorrelated with changes in depressive and anxious emotions, providing a certainreference for subsequent 100Hz taVNS interventions clinically.