Farah M J, Feinberg T E
Department of Psychology, University of Pennsylvania, Philadelphia 19104, USA.
Semin Neurol. 1997 Jun;17(2):145-52. doi: 10.1055/s-2008-1040924.
Disturbances of visual perception after brain damage provide clues to understanding consciousness and the brain. In this article we review six visual disorders in which perception and consciousness are dissociated as a result of brain damage: blindsight, implicit shape perception in apperceptive visual agnosia, covert recognition of faces in prosopagnosia, unconscious perception in neglect and extinction, implicit reading in pure alexia, and implicit object recognition in associative visual agnosia. We consider these six disorders from the standpoint of three main schools of thought concerning consciousness and the brain, namely a localized system for consciousness, consciousness as a state of integration, and consciousness as a property of graded representation. The findings suggest that these syndromes do not share a single mechanism and that it is conceivable that more than one explanation will be necessary both within and across syndromes. We conclude on the basis of the current evidence that it is unlikely that any single brain system is necessary for conscious awareness of perception that does not play a role in perception as well.
脑损伤后视觉感知障碍为理解意识与大脑提供了线索。在本文中，我们回顾了六种因脑损伤导致感知与意识分离的视觉障碍：盲视、统觉性视觉失认症中的隐性形状感知、面孔失认症中的面孔隐性识别、忽视和消退中的无意识感知、纯失读症中的隐性阅读以及联想性视觉失认症中的隐性物体识别。我们从关于意识与大脑的三种主要思想流派的角度来考量这六种障碍，即意识的局部系统、作为整合状态的意识以及作为分级表征属性的意识。研究结果表明，这些综合征并非共享单一机制，而且在综合征内部和跨综合征的情况下，可能需要不止一种解释。基于当前证据，我们得出结论：对于感知的意识觉知而言，不太可能存在任何一个在感知中不发挥作用的单一脑系统是必要的。
