BOOST PERCEPTION Research Group, Department of Psychology, University of Bologna, Bologna, Italy.
Maugeri Clinical Scientific Institutes, IRCCS of Castel Goffredo, Mantova, Italy.
J Neurosci Res. 2022 Nov;100(11):1987-2003. doi: 10.1002/jnr.25109. Epub 2022 Jul 22.
The ability to discriminate between one's own and others' body parts can be lost after brain damage, as in patients who misidentify someone else's hand as their own (pathological embodiment). Surprisingly, these patients do not use visual information to discriminate between the own and the alien hand. We asked whether this impaired visual discrimination emerges only in the ecological evaluation when the pathological embodiment is triggered by the physical alien hand (the examiner's one) or whether it emerges also when hand images are displayed on a screen. Forty right brain-damaged patients, with (E+ = 20) and without (E- = 20) pathological embodiment, and 24 healthy controls underwent two tasks in which stimuli depicting self and other hands was adopted. In the Implicit task, where participants judged which of two images matched a central target, the self-advantage (better performance with Self than Other stimuli) selectively emerges in controls, but not in patients. Moreover, E+ patients show a significantly lower performance with respect to both controls and E- patients, whereas E- patients were comparable to controls. In the Explicit task, where participants judged which stimuli belonged to themselves, both E- and E+ patients performed worst when compared to controls, but only E+ patients hyper-attributed others' hand to themselves (i.e., false alarms) as observed during the ecological evaluation. The VLSM revealed that SLF damage was significantly associated with the tendency of committing false alarm errors. We demonstrate that, in E+ patients, the ability to visually recognize the own body is lost, at both implicit and explicit level.
自身和他人身体部位的辨别能力可能会在大脑损伤后丧失，例如患者会将他人的手误认为自己的手（病理性身体归属）。令人惊讶的是，这些患者不会使用视觉信息来区分自己的手和他人的手。我们想知道这种受损的视觉辨别能力是否仅在生态评估中出现，即当病理性身体归属被物理上的他人手（检查者的手）触发时，或者当手的图像显示在屏幕上时是否也会出现。我们让 40 名右脑损伤患者（有 [E+] = 20 名，无 [E-] = 20 名）和 24 名健康对照组接受了两项任务，其中采用了描绘自我和他人手的刺激。在隐性任务中，参与者判断两个图像中的哪一个与中央目标匹配，控制组中会出现自我优势（对自我刺激的表现优于他人刺激），但患者组中不会。此外，E+ 患者的表现明显低于对照组和 E- 患者，而 E- 患者与对照组相当。在显性任务中，参与者判断哪些刺激属于自己，与对照组相比，E- 和 E+ 患者的表现最差，但只有 E+ 患者会将他人的手错误地归为自己的手（即错误警报），这与生态评估中观察到的情况一致。VLSM 显示，SLF 损伤与犯错误警报错误的倾向显著相关。我们证明，在 E+ 患者中，自身身体的视觉识别能力在隐性和显性水平上都丧失了。
