The presence of above-chance unconscious behavioral responses following stimulus presentation to the blind hemifield of hemianopic patients (blindsight) is a well-known phenomenon. What is still lacking is a systematic study of the neuroanatomical bases of two distinct aspects of blindsight: the unconscious above chance performance and the phenomenological aspects that may be associated. Here, we tested 17 hemianopic patients in two tasks i.e. movement and orientation discrimination of a visual grating presented to the sighted or blind hemifield. We classified patients in four groups on the basis of the presence of above chance unconscious discrimination without or with perceptual awareness reports for stimulus presentation to the blind hemifield. A fifth group was represented by patients with interruption of the Optic Radiation. In the various groups we carried out analyses of lesion extent of various cortical areas, probabilistic tractography as well as assessment of the cortical thickness of the intact hemisphere.

All patients had lesions mainly, but not only, in the occipital lobe and the statistical comparison of their extent provided clues as to the critical anatomical substrate of unconscious above-chance performance and of perceptual awareness reports, respectively. In fact, the two areas that turned out to be critical for above-chance performance in the discrimination of moving versus non-moving visual stimuli were the Precuneus and the Posterior Cingulate Gyrus while for perceptual awareness reports the crucial areas were Intracalcarine, Supracalcarine, Cuneus, and the Posterior Cingulate Gyrus. Interestingly, the proportion of perceptual awareness reports was higher in patients with a spared right hemisphere. As to probabilistic tractography, all pathways examined yielded higher positive values for patients with perceptual awareness reports. Finally, the cortical thickness of the intact hemisphere was greater in patients showing above-chance performance than in those at chance. This effect is likely to be a result of neuroplastic compensatory mechanisms.

在对偏盲患者的盲半场（盲视）进行刺激后，出现超乎意料的行为反应是一种众所周知的现象。仍然缺乏对盲视性两个不同方面的神经解剖学基础的系统研究：无意识的偶然机会表现和可能相关的现象学方面。在这里，我们测试了17名偏盲患者，完成了两项任务，即显示给有视力或盲人半视野的视觉光栅的运动和方向辨别。我们根据有无机会无意识歧视的存在将患者分为四组，无论有无或没有知觉报告以向盲人半场进行刺激。第五组的患者是视光中断的患者。

所有患者的病灶主要但不仅限于枕叶，其范围的统计学比较分别提供了无意识机会性表现和知觉意识报告的关键解剖学基础的线索。实际上，在区分运动的和不运动的视觉刺激方面，对胜过表现至关重要的两个区域是足前神经节和后扣带回，而就知觉意识而言，关键区域是骨内钙蛋白，超骨钙素，角膜肌，以及后扣带回。有趣的是，右半球幸存者的知觉意识报告比例更高。至于概率性的胎儿影像学检查，所有有知觉意识报告的患者所检查的途径均产生较高的阳性值。最后，表现出机会较高的患者的完整半球皮层厚度要大于偶然者。这种作用可能是神经塑性补偿机制的结果。