Errante Antonino, Rossi Sebastiano Alice, Ziccarelli Settimio, Bruno Valentina, Rozzi Stefano, Pia Lorenzo, Fogassi Leonardo, Garbarini Francesca
Department of Medicine and Surgery, University of Parma, Parma 43125, Italy.
MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy.
Brain Commun. 2022 Feb 11;4(1):fcac032. doi: 10.1093/braincomms/fcac032. eCollection 2022.
The brain mechanisms underlying the emergence of a normal sense of body ownership can be investigated starting from pathological conditions in which body awareness is selectively impaired. Here, we focused on pathological embodiment, a body ownership disturbance observed in brain-damaged patients who misidentify other people's limbs as their own. We investigated whether such body ownership disturbance can be classified as a disconnection syndrome, using three different approaches based on diffusion tensor imaging: (i) reconstruction of disconnectome maps in a large sample ( = 70) of stroke patients with and without pathological embodiment; (ii) probabilistic tractography, performed on the age-matched healthy controls ( = 16), to trace cortical connections potentially interrupted in patients with pathological embodiment and spared in patients without this pathological condition; (iii) probabilistic '' tractography on two patients without and one patient with pathological embodiment. The converging results revealed the arcuate fasciculus and the third branch of the superior longitudinal fasciculus as mainly involved fibre tracts in patients showing pathological embodiment, suggesting that this condition could be related to the disconnection between frontal, parietal and temporal areas. This evidence raises the possibility of a ventral self-body recognition route including regions where visual (computed in occipito-temporal areas) and sensorimotor (stored in premotor and parietal areas) body representations are integrated, giving rise to a normal sense of body ownership.
正常身体所有权感出现的脑机制可从身体意识选择性受损的病理状况入手进行研究。在此，我们聚焦于病理体现，这是一种在脑损伤患者中观察到的身体所有权障碍，患者会将他人的肢体误认成自己的。我们基于扩散张量成像采用三种不同方法，研究这种身体所有权障碍是否可归类为一种分离综合征：（i）在有和没有病理体现的大量中风患者样本（n = 70）中重建分离图谱；（ii）对年龄匹配的健康对照者（n = 16）进行概率性纤维束成像，以追踪在有病理体现的患者中可能中断且在无此病理状况的患者中未中断的皮质连接；（iii）对两名无病理体现患者和一名有病理体现患者进行概率性纤维束成像。这些趋同结果显示，弓状束和上纵束的第三分支是出现病理体现的患者中主要受累的纤维束，表明这种状况可能与额叶、顶叶和颞叶区域之间的分离有关。这一证据提示存在一条腹侧自我身体识别路径，该路径包括视觉（在枕颞区计算）和感觉运动（存储在前运动区和顶叶区）身体表征整合的区域，从而产生正常的身体所有权感。
