The cerebral integration of somatosensory inputs from multiple sources is essential to produce adapted behaviors. Previous studies suggest that bilateral somatosensory inputs interact differently depending on stimulus characteristics, including their noxious nature. The aim of this study was to clarify how bilateral inputs evoked by noxious laser stimuli, noxious shocks, and innocuous shocks interact in terms of perception and brain responses. The experiment comprised two conditions (right-hand stimulation and concurrent stimulation of both hands) in which painful laser stimuli, painful shocks and non-painful shocks were delivered. Perception, somatosensory-evoked potentials (P45, N100, P260), laser-evoked potentials (N1, N2 and P2) and event-related spectral perturbations (delta to gamma oscillation power) were compared between conditions and stimulus modalities. The amplitude of negative vertex potentials (N2 or N100) and the power of delta/theta oscillations were increased in the bilateral compared with unilateral condition, regardless of the stimulus type (P < 0.01). However, gamma oscillation power increased for painful and non-painful shocks (P < 0.01), but not for painful laser stimuli (P = 0.08). Despite the similarities in terms of brain activity, bilateral inputs interacted differently for painful stimuli, for which perception remained unchanged, and non-painful stimuli, for which perception increased. This may reflect a ceiling effect for the attentional capture by noxious stimuli and warrants further investigations to examine the regulation of such interactions by bottom–up and top–down processes.

来自多个来源的体感输入的大脑整合对于产生适应性行为至关重要。以前的研究表明，双边体感输入的相互作用取决于刺激特征，包括它们的有害性质。本研究的目的是阐明有害激光刺激、有害冲击和无害冲击引起的双侧输入如何在感知和大脑反应方面相互作用。该实验包括两种条件（右手刺激和双手同时刺激），其中传递痛苦的激光刺激、痛苦的电击和非痛苦的电击。知觉、体感诱发电位（P45、N100、P260）、激光诱发电位（N1、N2 和 P2）和事件相关的光谱扰动（delta 到 gamma 振荡功率）在条件和刺激方式之间进行了比较。与单侧条件相比，双侧负顶点电位（N2 或 N100）的幅度和 delta/theta 振荡的功率增加，无论刺激类型如何（P  < 0.01)。然而，疼痛和非疼痛冲击的伽马振荡功率增加（P  < 0.01），但疼痛激光刺激没有增加（P  = 0.08）。尽管在大脑活动方面存在相似性，但对于疼痛刺激（感知保持不变）和非疼痛刺激（感知增加），双侧输入的交互作用不同。这可能反映了有害刺激对注意力捕获的天花板效应，并需要进一步调查以检查自下而上和自上而下过程对此类相互作用的调节。