通过躯体感觉系统验证电刺激：关于失匹配负波与听觉假体的观点。

文献信息

中文摘要

自然触觉会激活专门化的机械感受器，而电触觉刺激绕过这些感受器，直接使混合且不均匀的传入轴突群体去极化。这种外周编码差异是否影响大脑的预测性加工，仍是一个有待实证回答的问题。失匹配负波（MMN）是一种已确立的脑电图（EEG）自动变化检测标志物，为在无知觉混杂因素的情况下解决这一问题提供了有力工具。在同一个体健康受试者中比较自然刺激与电刺激所诱发MMN反应的躯体感觉研究，可以识别出候选机制，以便在听觉领域进行检验，因为此类设计在听觉领域本质上不可行。特别是，这些研究有助于在人工耳蜗（CI）使用者中区分设备效应与耳聋相关混杂因素。健康受试者中现有的躯体感觉证据提示，电触觉刺激所诱发的失匹配反应，其双侧整合程度低于自然触觉，尽管该证据仍仅限于一项使用oddball范式的脑磁图（MEG）研究。CI研究更为广泛，并显示特征特异性的MMN缺陷。然而，这些研究也依赖于oddball或多特征范式，从而将预测误差与感觉适应混为一谈。因此，本观点文章鼓励采用替代性MMN范式（roving、omission或local-global），以确定电刺激是否真正调动了大脑的预测机制。随着多模态刺激器的出现，躯体感觉系统提供了一个有价值的平台，用于检验电刺激是否能再现自然的预测性加工——这些见解可改进触觉神经假体和CI设备。

英文摘要

Natural touch engages specialized mechanoreceptors, while electrotactile stimulation bypasses them, directly depolarizing a mixed and non-uniform population of afferent axons. Whether this difference in peripheral encoding affects the brain predictive processing remains an open empirical question. The mismatch negativity (MMN), an established electroencephalography (EEG) marker of automatic change detection, provides a powerful tool to address this question without perceptual confounds. Somatosensory studies comparing MMN responses to natural versus electrical stimulation within the same healthy individuals can identify candidate mechanisms for testing in the auditory domain, where such designs are inherently not feasible. In particular, they can help disentangle device effects from deafness-related confounds in cochlear implant (CI) users. Existing somatosensory evidence in healthy subjects suggests that electrotactile stimulation elicits mismatch responses with less bilateral integration than natural touch, though this evidence remains limited to a single magnetoencephalography (MEG) study using an oddball paradigm. CI studies are more extensive and show feature-specific MMN deficits. However, they also rely on oddball or multi-feature paradigms that conflate prediction error with sensory adaptation. This Perspective therefore encourages the adoption of alternative MMN paradigms (roving, omission, or local-global) to determine whether electrical stimulation truly engages the brain's predictive machinery. With emerging multimodal stimulators, the somatosensory system offers a valuable platform to test whether electrical stimulation reproduces natural predictive processing-insights that can improve both tactile neuroprostheses and CI devices.