Agnosia is a condition that impairs a person’s sensory receptors due to an injury or tumor in the brain
• Hearing (auditory) agnosia — the inability to identify objects through sound, such as a buzzing doorbell
• Taste (gustatory) agnosia — the inability to identify objects through taste, such as sweet or salty
• Smell (olfactory) agnosia — the inability to identify scents correctly
• Sight (visual) agnosia — the lack of perception or inability to identify objects through sight
Consider a man with a curious form of agnosia who could not properly perceive objects and images with his eyes. Instead, he could only identify a person or object by a notable feature, a recognizable sound, or if he could feel it in his hands. He had visual agnosia from the look of things, and his brain had found a way around the disability to arm him with alternatives with which he could observe his environment. But the problem was he couldn’t perceive something if he couldn’t hear, smell, or touch it; so much so that upon examination at the neurologist’s, he motioned to leave but couldn’t find his hat and grabbed onto his wife’s head instead.
Other forms of the condition include prosopagnosia, anosognosia, and somatosensory agnosia. But the most common is visual agnosia, and its sufferers are rid of their sight but still able to see, albeit in part. This summary describes the various forms of this type of mental illness and how to heal from them.