Agnosia
is the loss of the ability to recognize objects, the perception of the senses being intact.
Classification according to the sensory area affected
Auditory agnosia (Psychic Deafness), can be:
- Global: Global psychic deafness.
- Partial: For noise; Amusia (for music); Verbal deafness (for phonemes).
Visual agnosia .- “This term encompasses a series of perceptual function disorders that concern discrimination, identification and recognition, through the visual channel only, of objects, faces and their representations, significant or non-significant forms of spatial data, there being no other elemental disorder of vision, or deficit of higher mental functions, at least to a sufficient degree to account for the disturbances. following types:
- Agnosias for inanimate objects and for images
- Agnosias for animated objects, and for physiognomies (prosopagnosia)
- Agnosia for colors
- Agnosia for graphic symbols (alexia agnosica)
- Spatial agnosias
Visual agnosia, for things, people (prosopoagnosia), situations, images, symbols, colors.
- It can be: disorder in spatial perception; spatial data manipulation disorder; topographic memory disorder.
- Alexia agnosica (problems in recognizing graphic signs of language).
Tactile agnosia .- “Inability to recognize objects through touch in the absence of primary sensory disorders. According to Delay’s classic description , three degrees of identification are distinguished:
- Of the most elementary aspects such as surface, temperature, size (hylognosia)
- Of the three-dimensional configuration (morphognosia)
- Recognition of the object (stereognosia) “
Can be:
- Primary: Amorphognosia (does not recognize forms); Ahylognosia (does not recognize materials).
- Secondary: Tactile asymbolism (does not recognize objects).




