What Is Agnosia?
Agnosia is a word which means “not knowing” or “ignorance”. It’s meaning is not just limited to the inability to understand something completely. It refers to being unable to recognize or identify with any degree of certainty. A person may have no idea what someone else looks like, but they are sure that it isn’t them!
Visual Agnosia Treatment:
The first step towards treating visual agnosia is understanding its cause. There are several theories about why some people cannot recognize others’ faces, while other people do not experience such problems. Some believe that the problem lies in our brain’s ability to distinguish between similar shapes and colors; others say it lies in how we process images. These two theories are still very much up for debate, so there is no one right answer yet.
One thing that all these theories agree upon is that the condition occurs when we see something familiar to us and then try to make sense of it. For instance, if I saw my grandmother for the first time, I would probably think she was a beautiful woman with long blond hair wearing a red dress. However, after seeing her picture many times over the years, I might start thinking she looked different than what I remembered. In reality, she looks the same as she always has- I’ve just built up an image of what she looks like in my head.
If I saw someone who was the opposite of what I thought my grandmother looked like, I would not be able to recognize her as her.
This happens with objects as well as people. For example, most children can’t tell the difference between a football and a basketball. They aren’t familiar with either, so they wouldn’t be able to recognize them if they saw them. As they get older and start playing sports, they learn what a football and a basketball look like, so it becomes easier for them to tell them apart.
If a person with visual agnosia was given an orange scarf and a purple one, she might think that both of them were purple. She might also be unable to tell the difference between a hat and a pair of gloves.
Visual agnosia is not an all-encompassing disorder; it only affects a small part of your life. For instance, someone with this condition might be able to recognize people just fine, but not be able to tell the difference between a hat and a glove. Someone else might only have trouble recognizing faces. It all depends on the person and how the condition manifests.
It also worsens over time, so someone who just develops the condition might not experience many problems, but someone who’s had it for years will experience considerable difficulties.
Sources & references used in this article:
Visual agnosia by MJ Farah – 2004 – books.google.com
Agnosia, apraxia, aphasia: Their value in cerebral localization by JM Nielsen – 1946 – pure.mpg.de
Perception and action in ‘visual form agnosia’ by AD Milner, DI Perrett, RS Johnston, PJ Benson… – Brain, 1991 – academic.oup.com
Agnosia for faces (prosopagnosia) by H Hecaen, R Angelergues – Archives of neurology, 1962 – jamanetwork.com
Associative visual agnosia by AB Rubens, DF Benson – Archives of Neurology, 1971 – jamanetwork.com
Visual form agnosia: A specific defect in visual discrimination by DF Benson, JP Greenberg – Archives of Neurology, 1969 – jamanetwork.com
Face agnosia and the neural substrates of memory by AR Damasio, D Tranel… – Annual review of …, 1990 – annualreviews.org