Visual Agnosia

Visual agnosia can be subdivided in object agnosias and other agnosias (Kolb and Whishaw, 2008). 

Object agnosias

There are two kinds of visual object agnosia, these are apperceptive agnosia and associative agnosia. Apperceptive agnosia is a failure of object recognition wherin the visual functions basically are not affected. The most important difficulty in this agnosia is that patients cannot form a percept about the structural characteristics of objects. Associative agnosia, however, is the impairment in the recognition of an object. But this impairment is not the result of apparent perception. In this syndrome, the patient can make drawings very well, but they have an impairment in recognizing it. It is especially associated with memory.

Other agnosias

In prosopagnosia, patients cannot recognize faces, Including their own face in a mirror. Alexia is a condition in which the patient is not capable of reading. Visuospatial agnosia are disorders of spatial perception as well as impairments in orientation. An example of this agnosia is "topographical disorientation", in which the patient cannot find his way in environments that were formerly familiar to them (Kolb and Whishaw, 2008).