<unk> s are generally attributed to anterior left temporal lobe infarction (at the left inferior temporal gyrus), caused by ischemic stroke, head injury, cardiac arrest, brain tumour, brain hemorrhage, or demyelination. Environmental toxins and pathogens have also been implicated, such as, carbon monoxide poisoning or herpes encephalitis and infrequent developmental occurrences have been documented. The separate streams of the<unk>  processing system. The ventral "what" stream is in purple and the dorsal "where" stream is in green. Most cases have injury to the occipital and temporal lobes and the critical site of injury appears to be in the left occipito-temporal region, often with involvement of the splenium of the corpus callosum. The etiology of the cognitive impairment, as well the areas of the brain affected by lesions and stage of recovery are the primary determinants of the pattern of deficit. More generalized recognition impairments, such as, animate object deficits, are associated with diffuse hypoxic damage, like carbon monoxide poisoning; more selective deficits are correlated with more isolated damage due to focal stroke. Damage to the left hemisphere of the brain has been explicitly implicated in the<unk>  form of<unk>  agnosia. Goldberg suggested that the<unk><unk>  form of agnosia results from damage to the ventral stream of the brain, the occipito-temporal stream, which plays a key role in object recognition as the so-called "what" region of the brain, as opposed to the "where," dorsal stream.
Associative visual agnosia
Apperceptive agnosia
Cortical visual impairment
Integrative agnosia
Visuospatial dysgnosia
Asomatognosia
Autotopagnosia
Auditory verbal agnosia