Abstract：
We present a comprehensive review of the rare syndrome visual form agnosia (VFA). We begin by documenting its history, including the origins of the term, and the first case study labelled as VFA. The defining characteristics of the syndrome, as others have previously defined it, are then described. The impairments, preserved aspects of visual perception, and areas of brain damage in 21 patients who meet these defining characteristics are described in detail, including which tests were used to verify the presence or absence of key symptoms. From this, we note important similarities along with notable areas of divergence between patients. Damage to the occipital lobe (20/21), an inability to recognise line drawings (19/21), preserved colour vision (14/21), and visual field defects (16/21) were areas of consistency across most cases. We found it useful to distinguish between shape and form as distinct constructs when examining perceptual abilities in VFA patients. Our observations suggest that these patients often exhibit difficulties in processing simplified versions of form. Deficits in processing orientation and size were uncommon. Motion perception and visual imagery were not widely tested for despite being typically cited as defining features of the syndrome - although in the sample described, motion perception was never found to be a deficit. Moreover, problems with vision (e.g., poor visual acuity and the presence of hemianopias/scotomas in the visual fields) are more common than we would have thought and may also contribute to perceptual impairments in patients with VFA. We conclude that VFA is a perceptual disorder where the visual system has a reduced ability to synthesise lines together for the purposes of making sense of what images represent holistically.
摘要：
我们对罕见综合征视觉形式失认症（VFA）进行了全面审查。我们首先记录它的历史，包括这个词的起源，第一个案例研究标记为VFA。该综合征的定义特征，正如其他人之前定义的那样，然后描述。损伤，保留的视觉感知方面，并详细描述了21例符合这些定义特征的患者的脑损伤区域，包括哪些测试用于验证关键症状的存在或不存在。由此,我们注意到患者之间的重要相似性以及明显的差异.枕叶损伤（20/21），无法识别线条图(19/21)，保留的色彩视觉（14/21），视野缺损(16/21)是大多数病例的一致性区域.我们发现，在检查VFA患者的感知能力时，区分形状和形式作为不同的构造是有用的。我们的观察表明，这些患者在处理简化形式时经常遇到困难。加工方向和尺寸的缺陷并不常见。尽管通常被引用为综合征的定义特征，但运动知觉和视觉图像并未得到广泛的测试-尽管在所描述的样本中，运动知觉从未被发现是一个缺陷。此外，视力问题(例如，视力低下和视野中存在半尖牙/暗点瘤）比我们想象的更常见，也可能导致VFA患者的知觉障碍。我们得出的结论是，VFA是一种感知障碍，其中视觉系统出于理解图像整体代表的目的而将线条合成在一起的能力降低。
