Agnosia is a rare disorder characterized by an inability to recognize and identify objects, persons, sounds, shapes, or smells, while the specific sense is not defective nor is there any significant memory loss.

People with agnosia may have:

  • Difficulty recognizing the geometric features of an object
  • Difficulty recognizing a face
  • May be able to perceive the geometric features but not know what the object is used for
  • May not know whether a face is familiar or not

Agnosia can be limited to one sensory modality such as vision or hearing. For example, a person may have difficulty in recognizing an object as a cup or identifying a sound as a cough.

Agnosia can result from:

  • Strokes
  • Dementia
  • Developmental disorders
  • Other neurological conditions

It typically results from damage to specific brain areas in the occipital or parietal lobes of the brain. Some forms of agnosia have been found to be genetic. People with agnosia may retain their cognitive abilities in other areas.

Agnosia can compromise quality of life. Treatment is generally symptomatic and supportive. The primary cause of the disorder should be determined in order to treat other problems that may contribute to or result in agnosia. In some cases, occupational therapy or speech therapy can improve agnosia, depending on its cause.