What Is Agnosia?

There are a variety of brain disorders that affect up to 1 billion people worldwide! At the United Brain Association, our mission is to find a cure and end these life-altering and sometimes fatal disorders. In this blog, we want to examine at one of these rare and complicated disorders known as Agnosia. So what is Agnosia? Sometimes called visual amnesia, or visual agnosia, this perplexing neurological brain disorder impacts the brain so that the person affected by it cannot recognize physical objects or people and sometimes sounds. This rare disorder is typically the result of damage to the occipital or parietal portion of the brain due to stroke, dementia, various neurological conditions, or developmental disorders. While agnosia symptoms are most commonly visual in nature, these symptoms can also include tactile and auditory impairment.

What is Agnosia? Understanding This Disorder’s Impact on the Brain

Agnosia is considered a communication disorder due to its impairment of visual and auditory processing. These symptoms affect areas of the brain that handle visual and motor information, spatial processing, and attention processes. It is caused by damage to areas of the brain that handle these processes, including the posterior parietal cortex and occipito-temporal areas. These areas of the brain are responsible for processing sensory information, including auditory and body part perception.

The parietal lobe of the brain and its functions by Interactive Biology

There are a variety of forms of agnosia. Most commonly, patients are affected by visual recognition symptoms, however, the inability to recognize objects or people based on sound or touch is also possible. Below are the three most common forms of agnosia and how they may affect a patient.

• Visual Agnosia – Despite having fully functioning memory, vision, and language, patients experiencing visual agnosia symptoms are unable to recognize objects, even if it’s an item they may have used routinely for long periods. In many cases, the individual may be able to recognize the object by touching it or hearing a sound it makes. Another more specific version of this impairment comes in the form of prosopagnosia, or face blindness. This means the patient cannot identify or process facial features to recognize an individual but may be able to identify the person when they speak or by how they walk. Prosopagnosia is not always caused by neurological damage, and has been observed in people born with the disorder.
• Auditory Agnosia – The inability to recognize sounds, despite having no hearing impairments is another form of agnosia. Word deafness, or verbal auditory agnosia, is the inability to process specific words, despite the ability to speak, write, and read. Another form of auditory agnosia is non-verbal auditory agnosia, a disorder that makes the patient unable to recognize sounds, while still being able to speak and understand words.
• Tactile Agnosia – Tactile agnosia is the inability to recognize objects through touch. Oftentimes, the individual can identify these objects through smell or sight.

Face Blindness – Video from CBS News

Living with Agnosia – Agnosia Symptoms and Treatment

While the symptoms of all varieties of agnosia seem as though they would be easy to spot, they can present themselves in subtle ways that laymen may not observe immediately. Being unable to recognize an object or a person may, at first, seem like a silly mistake. Or hearing a noise that may seem unfamiliar to someone while those around them clearly remember the sound’s source doesn’t seem too alarming. Below are a few examples of symptoms that may indicate one form of agnosia or another.

• Being unable to recognize objects in a variety of forms. This means that the individual sees an object, but can’t identify it in its physical form, but may be able to recognize it in a drawing, or from another angle.
• Being able to draw, or describe a familiar object, but unable to say what that object is.
• Being able to describe a person or face, and even sometimes describing their relation to the individual, but being unable to identify the person by name when seeing them in person.
• Being unable to differentiate types of music or sounds from one another. Examples include being unable to name common and popular music styles or identifying music pieces from the individual’s favorite artist.
• Being unable to identify familiar buildings or locations well known to the individual. This means the individual may describe a location and even identify it on a map, but when in that physical location they don’t recognize it.

Treatment for agnosia starts with ruling out other disorders, cognitive dysfunctions, or illness that may impact the neurological processes to those areas of the brain that process sensory information. If these types of occurrences are identified, medical care providers can begin by addressing those disorders or illnesses and hopefully reverse the effects of agnosia on their patients. If these root cause issues are ruled out, further tools like brain imaging and advanced testing to diagnose agnosia can take place to pinpoint the areas of the brain affected.

Once the type of agnosia is identified and diagnosed, medical professionals can move toward treatment methods. In many cases, treatment includes exercises in memory, lip-reading, and helping patients learn how to use alternative identification processes to help deduce the person, sound, or object they are attempting to remember. Unfortunately, most treatments are only to assist the patient in coping with their diagnosis and learning to live with their condition. A variety of therapies are available to assist patients in overcoming the day to day challenges their agnosia may present them with.

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