On this page

What is agnosia? 

Agnosia (also known as primary visual agnosia, monomodal visual amnesia, and visual amnesia) is a neurological disorder characterized by an inability to recognize and identify objects or persons using one or more of the senses. This rare disorder typically results from damage to areas of your brain resulting from strokes, traumatic brain injuries, dementia, or other neurological conditions. Symptoms may vary based on the area of the brain affected: 

  • Parietal lobe: Difficulty recognizing a common object when it is placed in the hand on the side of the body opposite to the side where the brain damage occurred. But when you look directly at the object, you can identify it right away. 
  • Occipital lobe: Inability to identify familiar objects, faces, or places even when looking at them. 
  • Temporal lobe: Inability to recognize sounds, taste, or smell. 

The inability to recognize something familiar does not mean that your vision quality or thinking ability are impacted. For example, although you may not be able to recognize the object through sight, you might be able to identify the object though another sense.  

If agnosia is caused by an underlying disorder, treatment of that disorder may reduce symptoms and help prevent further brain damage. However, treatment of agnosia is symptomatic and supportive, such as rehabilitation through speech or occupational therapy.  

Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with agnosia? 

Consider participating in a clinical trial so clinicians and scientists can learn more about agnosia and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with agnosia at

Where can I find more information about agnosia? 

The following organizations and resources help people living with agnosia and their families, friends, and caregivers:

Merck Manuals Online Medical Library 

National Organization for Rare Disorders (NORD)
Phone: 203-744-0100 or 800-999-6673; 844-259-7178 Spanish

Order publications from the NINDS Catalog
The NINDS Publication Catalog offers printed materials on neurological disorders for patients, health professionals, and the general public. All materials are free of charge, and a downloadable PDF version is also available for most publications.