Editing Semantic memory (section)

==== Impairment categories ====
Category-specific semantic deficits tend to fall into two different categories, each of which can be spared or emphasized depending on the individual's specific deficit. The first category consists of animate objects, with animals being the most common deficit. The second category consists of inanimate objects with two subcategories: fruits and vegetables (biological inanimate objects), and artifacts being the most common deficits. The type of deficit does not indicate a lack of conceptual knowledge associated with that category, as the visual system used to identify and describe the structure of objects functions independently of an individual's conceptual knowledge base.<ref name=":0" />

Most of the time, these two categories are consistent with case-study data. However, there are a few exceptions to the rule. Categories like food, body parts, and musical instruments have been shown to defy the animate/inanimate or biological/non-biological categorical division. In some cases, it has been shown that musical instruments tend to be impaired in patients with damage to the living things category despite the fact that musical instruments fall in the non-biological/inanimate category. However, there are also cases of biological impairment where musical instrument performance is at a normal level. Similarly, food has been shown to be impaired in those with biological category impairments. The category of food specifically can present some irregularities though because it can be natural, but it can also be highly processed, such as in a case study of an individual who had impairments for vegetables and animals, while their category for food remained intact.<ref name=":0" />