1)安徽医科大学生物医学工程学院,合肥 230032;2)合肥综合性国家科学中心人工智能研究院,合肥 230026;3)中国科学院生物物理研究所认知科学与心理健康全国重点实验室,北京 100101
安徽省卫生科研项目(AHWJ2024Aa20259)资助。
1)School of Biomedical Engineering, Anhui Medical University, Hefei 230032, China;2)Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei 230026, China;3)State Key Laboratory of Cognitive Science and Mental Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
This work was supported by a grant from the Health Research Program of Anhui (AHWJ2024Aa20259).
目的 经颅聚焦超声(transcranial focused ultrasound,tFUS)作为一种具有前景的无创神经调控技术,能够以高空间特异性调节神经活动。然而,在缺乏外部周围感觉输入的情况下,tFUS对初级体感觉皮层(primary somatosensory cortex,S1)的刺激能否可靠地诱发有意识的触觉感知,目前尚不明确。本研究旨在探讨通过靶向S1刺激诱发手部相关触觉知觉的可行性,并进一步探究作为关键时间参数的超声持续时间(sonication duration,SD)如何影响该知觉反应的一致性。本研究结果有望为优化人类体感觉调控中的tFUS参数提供实证依据。方法 48名健康成年人参与了本研究,并被分配到两个实验中。实验1包括24名参与者,初步考察S1的tFUS刺激能否诱发与手相关的触觉。该实验包含两个子实验,即实验1a和实验1b,各招募12名受试者,其中,实验1a采用针对双侧S1的随机化有效刺激方案,评估诱发对侧触觉感知的基本可行性,而实验1b则采用交替半球设计,结合真刺激和假刺激,验证tFUS诱发感觉的特异性。实验2招募了另外24名参与者,并采用真假刺激双探头设计,控制可能源于探头与头皮接触的空间触觉线索。系统测试了5个SD条件,包括200、400、600、800和1 000 ms,评估刺激持续时间如何影响行为反应。主要行为结果指标为感知一致率,该指标根据对侧触觉定位的准确性进行量化。结果 在实验1中,91.7%的受试者在真实tFUS刺激期间报告了可靠的手部相关触觉感觉,包括麻木、刺痛或类似的触觉体验。真实刺激下的对侧定位准确率显著高于0.50的偶然水平(P<0.05)。相比之下,假刺激下的表现与偶然水平无异,这表明,所观察到的触觉反应主要由针对S1的真实tFUS刺激诱发,而非来源于非特异性刺激线索。在实验2中,400和1 000 ms条件下的感知一致率显著高于偶然水平(P<0.05),而在200、600和800 ms条件下未达到显著水平。进一步的两两比较显示,400和1 000 ms条件下的感知一致率显著高于200 ms条件(P<0.05)。结论 对S1进行tFUS刺激可在没有外周感觉输入的情况下引发明显的手部相关触觉,这表明利用靶向皮层超声刺激诱导有意识的体觉感知是可行的。这种感知效应的可靠性受SD的影响,该参数对行为反应的产生及其一致性具有重要的调控作用。在测试的各种条件下,400 ms可能提供了产生稳定触觉感知的一个理想时间窗口,而刺激时间过短可能不足以产生一致的反应。这些发现凸显了体觉网络对超声调制的敏感性,并为tFUS在无创感觉增强和皮层功能映射中的应用提供了有价值的参数指导。
Objective Transcranial focused ultrasound (tFUS) has emerged as a promising noninvasive neuromodulation technique capable of modulating neural activity with high spatial specificity. However, whether tFUS stimulation of the primary somatosensory cortex (S1) can reliably evoke conscious tactile perception without external peripheral sensory input remains unclear. Therefore, this study examined the feasibility of inducing hand-related tactile perception through targeted S1 stimulation and further investigated how sonication duration (SD), a key temporal parameter, influences the consistency of this perceptual response. The findings may provide empirical evidence for optimizing tFUS parameters in human somatosensory modulation.Methods Forty-eight healthy adults participated in the study and were assigned to two experiments. Experiment 1 included 24 participants and was designed to preliminarily examine whether S1-targeted tFUS could evoke hand-related tactile sensations. This experiment comprised two sub-experiments, Experiment 1a and Experiment 1b, with 12 participants in each. Specifically, Experiment 1a used a randomized active stimulation protocol targeting the bilateral S1 to assess the initial feasibility of inducing contralateral tactile perception, whereas Experiment 1b employed an alternating hemispheric design incorporating both active and sham stimulation to verify the specificity of the tFUS-induced sensations. Experiment 2 enrolled another 24 participants and used a real-sham dual-probe design to control for spatial tactile cues that might arise from probe-scalp contact. Five SD levels, including 200, 400, 600, 800, and 1 000 ms, were systematically tested to evaluate how stimulation duration influenced the behavioral response. The primary behavioral outcome was the perceptual consistency rate, quantified according to the accuracy of contralateral tactile localization.Results In Experiment 1, 91.7% of participants reported reliable hand-related tactile sensations during active tFUS stimulation, including numbness, tingling, or similar sensory experiences. Contralateral localization accuracy under active stimulation was significantly higher than the 0.50 chance level (P<0.05). In contrast, localization performance under sham stimulation did not differ from chance, suggesting that the observed tactile responses were mainly induced by active S1-targeted tFUS stimulation rather than nonspecific stimulation cues. In Experiment 2, perceptual consistency rates significantly exceeded the chance level under the 400 and 1 000 ms SD conditions (P<0.05), whereas no significant effect was observed at 200, 600, or 800 ms. Pairwise comparisons further showed that the 400 and 1 000 ms conditions produced significantly higher perceptual consistency rates than the 200 ms condition (P<0.05).Conclusion tFUS stimulation of S1 can elicit distinct hand-related tactile sensations without peripheral sensory input, demonstrating the feasibility of using targeted cortical ultrasound stimulation to induce conscious somatosensory perception. The reliability of this perceptual effect was modulated by sonication duration, indicating that temporal stimulation parameters play an important role in shaping both the occurrence and consistency of behavioral responses. Among the tested conditions, 400 ms appeared to provide a favorable temporal window for generating stable tactile perception, whereas excessively short stimulation may be insufficient to produce consistent responses. These findings highlight the sensitivity of somatosensory networks to ultrasonic modulation and provide useful parameter guidance for the application of tFUS in noninvasive sensory enhancement and cortical functional mapping.
陈煦煦,奚欢君,梁振,王波,赵旭东.初级体感觉皮层进行经颅聚焦超声刺激可诱发手部触觉感知:超声持续时间的影响△,[J].生物化学与生物物理进展,2026,53(7):1942-1952 CHEN Xu-Xu, XI Huan-Jun, LIANG Zhen, WANG Bo, ZHAO Xu-Dong. Transcranial Focused Ultrasound Stimulation of the Primary Somatosensory Cortex Evokes Hand Tactile Perception: The Effect of Sonication Duration△,[J]. Progress in Biochemistry and Biophysics,2026,53(7):1942-1952
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