Agnosias are sensory modality specific, usually classified as<unk> , auditory, or tactile.<unk>  refers to a subtype of<unk>  agnosia, which was labeled by Lissauer (1890), as an inability to connect the<unk>  percept (mental representation of something being perceived through the senses) with its related semantic information stored in memory, such as, its name, use, and description. This is distinguished from the<unk>  apperceptive form of<unk>  agnosia, apperceptive<unk>  agnosia, which is an inability to produce a complete percept, and is associated with a failure in higher order perceptual processing where feature integration is impaired, though individual features can be distinguished. In reality, patients often fall between both distinctions, with some degree of perceptual disturbances exhibited in most cases, and in some cases, patients may be labeled as integrative agnostics when they fit the criteria for both forms.<unk> s are often category-specific, where recognition of particular categories of items are differentially impaired, which can affect selective classes of stimuli, larger generalized groups or multiple intersecting categories. For example, deficits in recognizing stimuli can be as specific as familiar human faces or as diffuse as living things or non-living things. An agnosia that affects hearing, auditory sound agnosia, is broken into subdivisions based on level of processing impaired, and a semantic-associative form is investigated within the auditory agnosias.
Associative visual agnosia
Apperceptive agnosia
Cortical visual impairment
Integrative agnosia
Visuospatial dysgnosia
Asomatognosia
Autotopagnosia
Auditory verbal agnosia