Body integrity dysphoria (BID), a long-lasting desire for the amputation of physically healthy limbs, is associated with reduced fMRI resting-state functional connectivity of somatosensory cortices. Here, we used fMRI to evaluate whether these findings could be replicated and expanded using a task-based paradigm. We measured brain activations during somatosensory stimulation and motor tasks for each of the four limbs in ten individuals with a life-long desire for the amputation of the left leg and fourteen controls. For the left leg, BID individuals had reduced brain activation in the right superior parietal lobule for somatosensory stimulation and in the right paracentral lobule for the motor task, areas where we previously found reduced resting-state functional connectivity. In addition, for somatosensory stimulation only, we found a robust reduction in activation of somatosensory areas SII bilaterally, mostly regardless of the stimulated body part. Areas SII were regions of convergent activations for signals from all four limbs in controls to a significantly greater extent than in subjects with BID. We conclude that BID is associated with altered integration of somatosensory and, to a lesser extent, motor signals, involving limb-specific cortical maps and brain regions where the first integration of body-related signals is achieved through convergence.

中文翻译：

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渴望健康截肢的个体的大脑异常：体感、运动还是两者兼而有之？基于任务的 fMRI 判决

身体完整性烦躁 (BID) 是对身体健康四肢截肢的长期愿望，与体感皮层的 fMRI 静息状态功能连接减少有关。在这里，我们使用 fMRI 来评估是否可以使用基于任务的范式来复制和扩展这些发现。我们测量了 10 个终生希望截肢左腿的个体和 14 个对照组的四个肢体在体感刺激和运动任务期间的大脑激活。对于左腿，BID 个体在用于体感刺激的右侧顶上小叶和用于运动任务的右侧旁中央小叶中的大脑活动减少，我们之前发现这些区域的静息状态功能连接性降低。此外，仅针对体感刺激，我们发现双侧体感区域 SII 的激活显着减少，主要与受刺激的身体部位无关。区域 SII 是来自对照组所有四个肢体的信号的收敛激活区域，其程度显着高于 BID 受试者。我们得出结论，BID 与体感和运动信号的整合改变有关，涉及肢体特异性皮层图和大脑区域，其中身体相关信号的第一次整合是通过收敛实现的。