Abstract：
A new functional deficit caused by a stroke can be understood as a situation of uncertainty that has to prompt deficit discovery and subsequent incorporation into an altered self-perception. Anosognosia for visual field deficits is frequent after stroke. For hemiplegia, patients\' performance in a riddle test provided evidence that the inability to generate and adjust beliefs in face of uncertainty contributes to anosognosia for hemiplegia. In this prospective study, the same riddles are used in patients with homonymous hemianopia due to a first-ever stroke in the posterior cerebral artery territory and in an age-matched control cohort. The riddles create a situation of uncertainty that is resolved with five successive clues which progressively delimit the target word. After each clue, patients have to guess the target word and rate their confidence in the answer\'s correctness. Patients were tested once during the hospital stay. According to the Bisiach score for anosognosia, 12 out of 29 patients were unaware of their visual field deficits. All patients with anosognosia for hemianopia had right hemisphere lesions. Patients with and without anosognosia did not differ significantly in global cognitive impairment, mental flexibility or memory function. Importantly, patients with anosognosia showed higher confidence ratings than patients without anosognosia and controls in the first two clues (situations of uncertainty). This was demonstrated by a significant interaction effect in a mixed ANOVA with the factors group (anosognosia, nosognosia, controls) and riddle clues. An exploratory lesion subtraction analysis showed a high proportion of deficit unawareness in patients with lesions in the right fusiform and (para)hippocampal gyri. Our findings suggest that overconfidence in situations of uncertainty might contribute to the appearance of anosognosia for hemianopia. Because this has been demonstrated before in anosognosia for hemiplegia, we suggest that overconfidence is a supra-modal contributor to deficit unawareness.
摘要：
由中风引起的新的功能缺陷可以理解为一种不确定性的情况，这种情况必须促使缺陷发现并随后纳入改变的自我感知中。中风后经常发生视野缺损的失语症。偏瘫,患者在谜语测试中的表现提供了证据，证明在面对不确定性时无法产生和调整信念会导致偏瘫的失认症。在这项前瞻性研究中，同样的谜语也适用于大脑后动脉区域首次卒中导致同义偏盲的患者和年龄匹配的对照组.谜语创造了一种不确定性的情况，通过五个连续的线索来解决，这些线索逐渐界定了目标单词。在每个线索之后，患者必须猜测目标单词，并评估他们对答案正确性的信心。在住院期间对患者进行了一次测试。根据Bisiach失认症的评分,29名患者中有12名不知道他们的视野缺损。所有因偏盲而患有失语症的患者均有右半球病变。患有和不患有失语症的患者在总体认知障碍方面没有显着差异，心理灵活性或记忆功能。重要的是,在前两条线索(不确定情况)中,失认症患者的信心评分高于无失认症患者和对照者.这通过混合方差分析与因子组(失认症，失认症,控件)和谜语线索。探索性病变减影分析显示，右梭形和（旁）海马回病变的患者缺乏意识的比例很高。我们的发现表明，在不确定的情况下过度自信可能会导致偏盲的失语症的出现。因为这已经在偏瘫的失认症中得到了证明，我们认为，过度自信是导致赤字无意识的超模式因素。
