ABSTRACT
The observation and detailed characterisation of selective impairments affecting particular cognitive areas in brain-damaged individuals can be used to inform the anatomical and functional architecture of normal cognition. Among the most striking forms of selective impairments to have been documented by neuropsychology since the mid-1980s are those that selectively affect the processing of objects from particular semantic categories while sparing objects from other categories. Most often, the semantic boundary that separates the affected categories from those that are spared distinguishes between biological and non-biological (i.e. man-made) items. In this chapter, we will review evidence from cases with category-specific visual recognition impairments that are attributable to a deficit in visual rather than semantic processing. Evidence from these studies will be used to speculate on the organisation of the visual system in the intact brain and on how this organisation interacts with the differing features of biological and non-biological semantic categories to eventually produce categorical effects in visual object recognition.
