Abstract Feature binding is considered to be the basis for conscious stimulus perception, while anaesthetics exert a gradient effect on the loss of consciousness (LOC). By integrating these two streams of research, the present study assessed the effect of two anaesthetic agents (i.e. propofol and midazolam) on audio-spatial feature binding. We also recorded the electrophysiological activity of the frontal channels. Using pharmacokinetic simulation, we determined the effect-site concentration (Ce) of the anaesthetics at loss of response to verbal command and eyelash reflex. We subsequently adjusted Ce to 75%, 50% and 25% of Ce-LOC to achieve deep, moderate and light sedation, respectively. Behavioural results showed that moderate sedation selectively disrupted feature binding. The frontal channels showed a P3 component (350–600 ms peristimulus period) following the presentation of audio-spatial stimuli at baseline and under moderate and light sedations. Critically, the late event-related potential component (600–1000 ms) returned to the pre-activated level (0–350 ms) at baseline and under light sedation but was sustained under moderate sedation. We propose that audio-spatial feature binding may require the presence of a P3 component and its subsequent and sufficient decline, as under anaesthetic-induced moderate sedation the P3 component was sustained and featured binding was impaired.

中文翻译：

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全身麻醉药引起的中等镇静作用会破坏健康人体内持续的P3成分对音频空间特征的结合

摘要特征绑定被认为是意识刺激知觉的基础，而麻醉剂对意识丧失（LOC）起到梯度作用。通过整合这两个研究流，本研究评估了两种麻醉剂（即异丙酚和咪达唑仑）对音频空间特征绑定的影响。我们还记录了额叶通道的电生理活动。使用药代动力学模拟，我们确定了麻醉剂对口头命令和睫毛反射的反应丧失时的效应部位浓度（Ce）。随后我们将Ce调整为Ce-LOC的75％，50％和25％，以分别实现深，中和轻度镇静。行为结果表明，中等镇静作用会选择性地破坏特征结合。在基线，中度和轻度镇静下出现音频空间刺激后，额叶通道显示P3成分（350-600 ms周围刺激期）。至关重要的是，与事件相关的晚期电位成分（600–1000 ms）在基线和轻度镇静下恢复至激活前水平（0–350 ms），但在中度镇静下得以维持。我们建议音频空间特征绑定可能需要P3组件的存在及其随后的充分下降，因为在麻醉药诱导的中等镇静作用下，P3组件持续存在且特征绑定受损。在基线和轻度镇静下，与事件相关的晚期事件电位成分（600–1000 ms）返回到激活前的水平（0–350 ms），但在中度镇静下持续存在。我们建议音频空间特征绑定可能需要P3组件的存在及其随后的充分下降，因为在麻醉药诱导的中等镇静作用下，P3组件持续存在且特征绑定受损。在基线和轻度镇静下，与事件相关的晚期事件电位成分（600–1000 ms）返回到激活前的水平（0–350 ms），但在中度镇静下持续存在。我们建议音频空间特征绑定可能需要P3组件的存在及其随后的充分下降，因为在麻醉药诱导的中等镇静作用下，P3组件持续存在且特征绑定受损。