Rhudy Jamie L, Grimes Jeffrey S, Meagher Mary W
Department of Psychology, University of Tulsa, Tulsa, Oklahoma 74104, USA.
J Pain. 2004 Oct;5(8):458-68. doi: 10.1016/j.jpain.2004.08.001.
Prior research indicates that exposure to fear-inducing stimuli inhibits finger withdrawal to sudden onset and high intensity radiant heat in humans. Although withdrawal latencies to intense heat are thought to reflect changes in spinal nociceptive processing, supraspinal measures are needed to determine whether pain perception is altered. The present study used gradual onset and low intensity radiant heat to induce a finger withdrawal response that depends on supraspinal processes. After baseline pain threshold tests, 57 healthy human participants were randomly assigned to 1 of 2 groups. In the fear group, participants received 3 brief shocks. In the neutral group, participants did not receive shock. Results suggest that finger withdrawal latencies to low intensity heat were increased after shock presentation, providing additional evidence that fear reduces pain on a measure that is influenced by supraspinal processes. Both self-report and physiological (skin conductance level, heart rate, and blood pressure) measures of emotion confirmed that the intended affective states were induced. Finger temperature was unaffected by emotion manipulations; thus, skin cooling does not appear to mediate increased withdrawal latencies. These findings provide additional evidence that fear not only inhibits spinal nociceptive reflexes, it also inhibits supraspinal measures of pain.
From a clinical perspective, these data suggest that patients who experience intense fear in response to unpredictable threatening events will show a reduction in pain perception.
先前的研究表明，暴露于诱发恐惧的刺激会抑制人类对突然出现的高强度辐射热的手指回缩反应。虽然对强烈热刺激的回缩潜伏期被认为反映了脊髓伤害性处理的变化，但需要进行脊髓以上水平的测量来确定痛觉是否改变。本研究使用逐渐增加强度和低强度的辐射热来诱发一种依赖于脊髓以上水平过程的手指回缩反应。在进行基线疼痛阈值测试后，57名健康人类参与者被随机分配到2组中的1组。恐惧组的参与者接受了3次短暂电击。中性组的参与者未接受电击。结果表明，电击呈现后，对低强度热的手指回缩潜伏期增加，这进一步证明了恐惧会在一种受脊髓以上水平过程影响的测量中减轻疼痛。情绪的自我报告和生理测量（皮肤电导率水平、心率和血压）均证实诱发了预期的情感状态。手指温度不受情绪操纵的影响；因此，皮肤冷却似乎并未介导回缩潜伏期的增加。这些发现进一步证明，恐惧不仅会抑制脊髓伤害性反射，还会抑制脊髓以上水平的疼痛测量。
从临床角度来看，这些数据表明，因不可预测的威胁事件而经历强烈恐惧的患者会表现出痛觉降低。
