The ability to recognize what we perceive can be altered in function or reduced. Agnosia is a recognition disorder in charge of a sensory mode without the concurrence of disorders of sensitivity, language or intelligence. A prerequisite for diagnosing agnosia is the absence of significant levels of aphasia and dementia.
The lesions responsible for agnosia are located in the parietal, temporal and occipital lobes, and affect the associative areas adjacent to the primary sensory areas. The corpus callosum may also often be involved.
Clinically, suspicion of agnosia should arise in people who react to some environmental stimuli as if they were blind or deaf, while they react normally to different stimuli from the same sensory field. However, there are multiple types of agnosia which we will see together in this Psychology-Online article, along with its symptoms and possible treatments.
visual agnosia
Visual agnosia is inability to recognize objects normally perceived through vision. Several types of visual agnosias are described in relation to the category of unrecognized stimuli. Let’s see which ones:
- Object agnosia: The person cannot tell the name and use of an object by sight, but can do so correctly by touching it, listening to the sound, or breathing in the smell. Sometimes, she can describe the physical characteristics of the object, without being able to identify it (associative agnosia). Other times even analytical description is impossible (apperceptive agnosia).
- Color agnosia: the person is not able to name colors, put them in increasing order of luminosity, match equal colors or assign the appropriate color to a common object.
- Agnosia of the faces or : the person does not recognize the faces of family members, sometimes not even the reflection in a mirror. Recognition can be done through particulars (glasses, mustaches), the way they dress, the sound of the voice.
- Agnosia of written words or alessia.
- Balint syndrome: It is not exactly a visual agnosia, but rather an opening of the gaze that causes difficulties in exploring the visual field.
auditory agnosia
Auditory agnosia is inability to recognize common noises, musical sounds and spoken language, in the absence of deafness. Next, we will see the different types of auditory agnosia:
- Noise agnosia: inability to identify the origin of characteristic noises such as the ringing of a bell, flowing water, animal sounds, etc.
- Agnosia of musical sounds or amusia: inability to recognize songs and the sounds of different instruments.
- Spoken language agnosia: it is pure verbal deafness, described in aphasias.
Tactile agnosia
Tactile agnosia is inability to identify an object by palpation with eyes closed, even being able to describe its physical characteristics such as shape, size and surface. The disorder depends on a lesion of the contraateral parietal lobe, and must be distinguished from , in which the person does not identify the palpated object because he or she does not perceive its spatial characteristics, while elementary sensitivities are preserved.
This disorder has no localizing value, and can occur in the presence of lesions of the sensory pathways at the level of the brainstem or bone marrow.
- Amorphognosia: the person does not recognize the shape and dimensions of the object in their hand.
- Asymmetric touch: inability or difficulty to name that object through touch. Tactile agnosia itself.
- Ailognosia: with touch, the person does not understand the material with which the object is made, nor the weight, nor the temperature.
Spatial agnosia
The term spatial agnosia indicates the inability to correctly analyze and use spatial dataFor example, locating objects with respect to the body or between them, appreciating distance, direction, etc.
The unilateral spatial agnosia It is of great clinical interest and is known as hemisphere neglect, which consists of a degree of indifference to stimuli coming from one side of space. It is generally evident in the spontaneous behavior of people who, for example, write and draw on only half of the page or when copying a figure reproduce only half of the pattern.
Somatoagnosia
Somatoagnosia refers to disorders in the perception of one’s own body. Different types of agnosia are distinguished regarding the body pattern, which can be unilateral or bilateral.
- Autotopoagnosia: consists of the difficulty of indicating the parts of one’s own body and that of another.
- Digital agnosia: it is the impossibility of indicating and naming the fingers of one’s own and other people’s hands.
Treatment of agnosia
It can have a significant impact on the daily lives of those affected, as well as their families, friends and colleagues. In general, the most recommended agnosia treatments are:
- Treatment of the direct cause of agnosia: whenever possible it is treated, for example, with surgery and/or antibiotics for brain abscess, surgery and/or radiotherapy for brain cancer.
- Speech therapy or occupational therapy: Rehabilitation treatment through speech therapy or occupational therapy can help patients learn to compensate for their deficits.
This article is merely informative, at Psychology-Online we do not have the power to make a diagnosis or recommend a treatment. We invite you to go to a psychologist to treat your particular case.
If you want to read more articles similar to Types of agnosia: symptoms and treatmentwe recommend that you enter our category.
Bibliography
- Quartesan, R. (et al.) (2009). Manual of Psychiatry. Perugia: Morlacchi Editore.
- Pazzaglia, P. (2010). Neurological Clinic. Rome: Società Editrice Esculapio.