BACKGROUND Past studies have shown that pain memories are often inaccurate, a phenomenon known as mnemonic pain bias. Pain memories are thought to play an important role on how future pain is felt. Recent evidence from our laboratory suggests that individuals who exaggerate past pain display increased superior temporal gyrus (STG) activity during the encoding of experimental painful stimulations, suggesting that this brain structure plays an important role in pain memories. OBJECTIVE /hypothesis. To determine whether a virtual lesion paradigm, targeting the STG during pain encoding, can affect long-lasting pain memories. We hypothesized that interfering with the activity of the STG would attenuate mnemonic bias. METHODS Randomized double-blind study with two parallel groups. Participants received either sham (n = 21) or real (n = 21) transcranial magnetic stimulation (TMS - virtual lesion paradigm) over the STG during pain encoding (milliseconds after the administration of a painful stimuli). Pain intensity and unpleasantness were evaluated using a visual analog scale (VAS; 0 to 10) immediately after the painful event, and at recall, 2 months later. The mnemonic pain bias (calculated by subtracting the pain scores obtained at recall from the pain score obtained during encoding) was compared between the two groups for both pain intensity and unpleasantness. RESULTS Participants in both groups did not differ in terms of age and gender (real TMS = 27 years ± 9, 43% female; sham TMS = 25 years ± 4, 49% female; p > 0.64). The mnemonic bias related to pain intensity was similar in both groups (p = 0.83). However, the mnemonic bias related to pain unpleasantness was lower in the real TMS group (p = 0.04). CONCLUSIONS Our results provide the first evidence that the STG, is causally involved in the formation of biased memories of pain unpleasantness.

中文翻译：

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在疼痛编码过程中干扰上颞回的活动可防止疼痛记忆的夸张：一项使用单脉冲经颅磁刺激的虚拟损伤研究。

背景技术过去的研究表明，疼痛记忆常常是不准确的，这种现象被称为记忆性疼痛偏向。疼痛记忆被认为在感觉未来疼痛方面起着重要作用。来自我们实验室的最新证据表明，夸大过去的疼痛的人在实验性疼痛刺激的编码过程中表现出较高的颞回（STG）活动，表明这种大脑结构在疼痛记忆中起重要作用。目标/假设。要确定在疼痛编码过程中针对STG的虚拟病变范例是否会影响持久的疼痛记忆。我们假设干扰STG的活性会减轻记忆的偏见。方法采用两个平行组的随机双盲研究。在疼痛编码期间（给予疼痛刺激后数毫秒），参与者在STG上接受了假（n = 21）或真实（n = 21）经颅磁刺激（TMS-虚拟病变范例）。在疼痛事件发生后立即以及在两个月后的回忆中，使用视觉模拟量表（VAS； 0至10）评估疼痛强度和不适感。比较两组记忆力偏倚（通过从编码过程中获得的疼痛评分中减去召回时获得的疼痛评分来计算），以比较两组患者的疼痛强度和不适感。结果两组参与者的年龄和性别均无差异（实际TMS = 27岁±9，女性为43％；假TMS = 25岁±4，女性为49％； p> 0.64）。两组与疼痛强度有关的记忆偏倚相似（p = 0.83）。然而，在真正的TMS组中，与疼痛不适相关的记忆偏倚较低（p = 0.04）。结论我们的研究结果提供了第一个证据，表明STG因果关系到疼痛不愉快的偏见的形成。