Drawing disorders

I'm studying for finals tonight, and I finished going through my notes for my Visual Neurophysiology class for the entire semester. These last few weeks w have been discussing brain disorders and how they affect vision. It's actually super interesting. If you've ever read anything by Oliver Sacks, you are pretty familiar with what can happen.

Anyway, I made a list of 5 disorders that can be manifested by asking a patient to sketch a picture. And to help me study, I thought I would sketch some examples here on my blog for you all. Now you can say that you studied Visual Neurophysiology with me!

1. Apperceptive agnosia. If you have this, you can't understand what you are looking at, but you can still draw objects from memory. If asked to draw the sketch on the left, you would draw something like this on the right:

2. Associative agnosia. If you had this, you can draw objects extremely well, but you have no idea what they are until you touch or smell them. So if you were asked to draw the apple, it would be very accurate, but you would have no idea what it was that you drew.

3. Simultagnosia. If you had this, you can understand bits of pieces of what you see, but you can't pull it all together to understand the "Gestalt" of that thing. So you would say that you see a leaf, stem, and a round thing, and a small white reflection, but you wouldn't say you see an apple.

4. Constructional apraxia. If you had this, you know you're looking at an apple, but you can't draw it well. And I don't mean that you just draw things badly. I mean it looks really bad. This is common in people with Alzheimers.

5. Unilateral neglect. This one is really interesting. If you have this, you neglect half of whatever symmetrical object you're looking at. Men with this often shave only half of their face, or only put on one shoe. You might think that your left arm isn't even yours.