Visual Agnosia

Visual Agnosia

VISUAL AGNOSIA

Agnosia is the general term given to a variety of recognition disorders thought to occur at later stages of processing; in other words, beyond the level of basic sensory mechanisms such as vision and acuity.
The disorder can occur at the level of the perception of a stimulus, or at the level at which meaning is assigned to a correctly perceived cue.
Although these disorders often overlap with each other as well as with other disorders such as aphasia, and are often hard to distinguish in an absolute manner, there are basic characteristics that have been established for each subtype.
Several of these subtypes are apperceptive agnosia, the inability to correctly perceive objects, associative agnosia, the inability to assign meaning to a correctly perceived stimulus, and mirror agnosia, the inability to differentiate between real and reflected objects.