Examining the mechanisms underlying crossmodal interaction between nociceptive and visual stimuli is crucial to understand how humans handle potential bodily threats in their environment. It has recently been shown that nociceptive stimuli can affect the perception of visual stimuli, provided that they occur close together in external space. The present study addresses the question whether these crossmodal interactions between nociceptive and visual stimuli are mediated by the visually perceived proximity between the visual stimuli and the limb on which nociceptive stimuli are applied, by manipulating the presence vs. absence of visual feedback about the position of the stimulated limb. Participants performed temporal order judgments on pairs of visual stimuli, shortly preceded by nociceptive stimuli, either applied on one hand or both hands simultaneously. The hands were placed near the visual stimuli and could either be seen directly, seen through a glass barrier, or hidden from sight with a wooden board. Unilateral nociceptive stimuli induced spatial biases to the advantage of visual stimuli presented near the stimulated hand, which were greater in the conditions in which the hands were seen than in the condition in which vision was prevented. Spatial biases were not modulated by the presence of the glass barrier, minimizing the possibility that the differential effect between the vision and no-vision conditions is solely due to the presence of the barrier between the hands and the visual stimuli. These findings highlight the importance of visual feedback for determining spatial mapping between nociceptive and visual stimuli for crossmodal interaction.

中文翻译：

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看到或不看到你的手在哪里。关于手部位置的视觉反馈对伤害性和视觉刺激之间相互作用的影响。

检查伤害性和视觉刺激之间跨模式交互的潜在机制对于了解人类如何处理环境中潜在的身体威胁至关重要。最近的研究表明，伤害性刺激可以影响视觉刺激的感知，前提是它们在外部空间中靠得很近。本研究解决了伤害性和视觉刺激之间的这些交叉模式交互是否由视觉刺激与施加伤害性刺激的肢体之间的视觉感知接近度介导的问题，通过操纵关于位置的视觉反馈的存在与缺失受刺激的肢体。参与者对成对的视觉刺激进行时间顺序判断，紧接着是伤害性刺激，无论是单手涂抹还是双手同时涂抹。手被放置在视觉刺激附近，可以直接看到，通过玻璃屏障看到，或者用木板隐藏起来。单侧伤害性刺激引起空间偏差，以在受刺激的手附近呈现视觉刺激的优势，在看到手的条件下比在阻止视觉的条件下更大。空间偏差不受玻璃屏障的影响，最大限度地减少了视觉和无视觉条件之间的差异效应完全是由于手和视觉刺激之间存在屏障的可能性。