Sensory gating (SG) is a neurophysiological phenomenon whereby the response to the second stimulus in a repetitive pair is attenuated. This filtering of irrelevant or redundant information is thought to preserve neural resources for more behaviorally-relevant stimuli and thereby reflect the functional inhibition of sensory input. Developing a SG paradigm in which optimal suppression of sensory input is achieved requires investigators to consider numerous parameters such as stimulus intensity, time between stimulus pairs, and the inter-stimulus interval (ISI) within each pair. While these factors have been well defined for the interrogation of auditory gating, the precise parameters for eliciting optimal gating in the somatosensory domain are far less understood. To address this, we investigated the impact of varying the ISI within each identical pair of stimuli on gating using magnetoencephalography (MEG). Specifically, 25 healthy young adults underwent paired-pulse electrical stimulation of the median nerve with increasing ISIs between 100 and 1000 ms (in 100 ms increments). Importantly, for correspondence with previous studies of somatosensory gating, both time-domain and oscillatory neural responses to somatosensory stimulation were evaluated. Our results indicated that gating of somatosensory input was optimal (i.e., best suppression) for trials with an ISI of 200–220 ms, as evidenced by the smallest gating ratios and through statistical modeling estimations of optimal suppression. Importantly, this was true irrespective of whether oscillatory or evoked neural activity was used to calculate SG. Interestingly, oscillatory metrics of gating calculated using peak gamma (30–75 Hz) power and frequency revealed more robust gating (i.e., smaller ratios) than those calculated using time-domain neural responses, suggesting that high frequency oscillations may provide a more sensitive measure of SG. These findings have important implications for the development of optimal protocols and analysis pipelines to interrogate SG and inhibitory processing with a higher degree of sensitivity and accuracy.

中文翻译：

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更好的体感门控范式的方法论考虑：刺激间隔的影响

感觉门控 (SG) 是一种神经生理学现象，其中对重复对中的第二个刺激的反应减弱。这种对无关或冗余信息的过滤被认为可以为更多行为相关的刺激保留神经资源，从而反映感官输入的功能抑制。开发一种 SG 范式，其中实现对感官输入的最佳抑制，需要调查人员考虑许多参数，例如刺激强度、刺激对之间的时间以及每对刺激间的间隔 (ISI)。虽然这些因素已被很好地定义为听觉门控的审讯，但在体感域中引发最佳门控的精确参数却鲜为人知。为了解决这个问题，我们使用脑磁图 (MEG) 研究了在每对相同的刺激中改变 ISI 对门控的影响。具体来说，25 名健康的年轻人接受了正中神经的成对脉冲电刺激，ISI 在 100 到 1000 毫秒之间增加（以 100 毫秒为增量）。重要的是，为了与先前的体感门控研究相对应，对体感刺激的时域和振荡神经反应进行了评估。我们的结果表明，对于 ISI 为 200-220 ms 的试验，体感输入的门控是最佳的（即，最佳抑制），这可以通过最小的门控比率和最佳抑制的统计建模估计来证明。重要的是，无论是否使用振荡或诱发神经活动来计算 SG，这都是正确的。有趣的是，使用峰值伽马 (30–75 Hz) 功率和频率计算的门控振荡指标显示比使用时域神经响应计算的门控更稳健（即更小的比率），这表明高频振荡可能提供更灵敏的 SG 测量. 这些发现对于开发最佳方案和分析管道具有重要意义，以更高的灵敏度和准确性询问 SG 和抑制处理。