Lautenbacher Stefan, Prager Martina, Rollman Gary B
Physiological Psychology, Otto-Friedrich University, Bamberg, Germany.
Somatosens Mot Res. 2007 Dec;24(4):189-201. doi: 10.1080/08990220701637638.
This study utilized the methodology of Functional Measurement theory to investigate the additivity of painful and non-painful thermally induced experiences at one body site with those produced by brief noxious and innocuous electrical stimuli at another. Forty healthy young subjects were tested, using a Peltier thermode to induce tonic pain and an electrocutaneous stimulator for presenting phasic pain, under conditions of either full attention or visual/cognitive distraction (counting numerous light signals) in order to evaluate whether the summed effects are attributable to refocused attention. Six levels of intensity were combined in a factorial design for both tonic and phasic pain. Subjects indicated the overall strength of their dual perception on a visual analog scale. Stimuli showed complex patterns of interaction. Two stimuli were generally rated as greater than one, but the summation was far from additive and greatly influenced by the intensity of the stronger stimulus, suggesting inhibitory action. In general, tonic heat pain strongly affected the perception of phasic electrocutaneous pain whereas the reverse was only partly true. Distraction had a very small effect, suggesting that the "pain inhibits pain" phenomenon attributable to diffuse noxious inhibitory controls (DNIC) is not due to attentional processes. Our data also relate to issues regarding spatial summation across dermatomes and to adaptation level effects in pain, in which a strong painful experience serves as an anchor or comparison point by which others are judged. The psychophysical findings provide a perceptual foundation for clinical phenomena in which patients face with comorbid pain disorders.
本研究采用功能测量理论方法，探究身体一个部位热诱导的疼痛和非疼痛体验与另一部位短暂有害和无害电刺激所产生体验的相加性。对40名健康年轻受试者进行测试，使用珀尔帖热电极诱发持续性疼痛，用电皮肤刺激器呈现阶段性疼痛，在全神贯注或视觉/认知分心（数大量光信号）的条件下，以评估总效应是否归因于注意力的重新聚焦。对持续性和阶段性疼痛，在析因设计中组合了六个强度水平。受试者在视觉模拟量表上指出其双重感知的总体强度。刺激显示出复杂的相互作用模式。两种刺激的总体评分通常大于一种刺激，但相加远非呈累加性，且受较强刺激强度的极大影响，提示存在抑制作用。一般来说，持续性热痛强烈影响阶段性电皮肤疼痛的感知，而反之则仅部分成立。分心的影响非常小，表明归因于弥散性有害抑制控制（DNIC）的“疼痛抑制疼痛”现象并非源于注意力过程。我们的数据还涉及关于跨皮节空间总和以及疼痛中适应水平效应的问题，其中强烈的疼痛体验充当判断其他疼痛的锚点或比较点。这些心理物理学发现为患者面临合并性疼痛障碍的临床现象提供了感知基础。
