Laura has recently experienced what her doctors call a “bilateral posterior vascular abnormality.” This resulted in some brain damage. While her rehabilitation has gone well, she has been left with some strange, specific visual difficulties.
As she described the problems to her doctors, Laura was clearly uncomfortable with the conversation. When asked why, she said, “I’m sorry, but it looks to me like your lips are just hopping up and down. It’s very distracting. I hope you don’t mind if I just close my eyes while we talk.”
After being told that this was all right, Laura went on to tell of how she sometimes felt like she was a blind person. “I can’t pour tea anymore unless I have my finger in the cup … otherwise I can’t tell when the tea has reached the rim and I end up with hot tea in my lap! If I watch it pour from the pot, all I see is something like an icicle that goes from the spout to my cup. And what’s more, the tea doesn’t look right anymore; everything is just yucky and colorless … a nasty grey.”
When asked about her everyday life, Laura seemed quite dejected. “I can’t go anywhere by myself. If I have to go where there are crowds of people I just feel like I’m in some kind of horror movie. People just disappear and suddenly reappear right in front of me … and I never see them move! It’s terrifying! And what’s more … I almost got run over by a car yesterday …. Somebody had to grab me before I stepped out into traffic. I swear I thought they had all stopped!”
Standard neuropsychological testing yielded no deficits in her reading or writing abilities. She could recognize objects well, and showed no problems with complex movements.
Strangely enough, her world has also become “washed out” and “colorless.” Not only did her tea look colorless, but people appeared to have nasty grey skin, foods were unappealing (everything appeared grey, dead, and tasteless), and she could no longer imagine things in color.
Questions
- What condition or conditions (there may be more than one possibility) are being described in this case?
- What brain area or area(s) may be involved? Be sure to consider which visual stream is involved. Is there a specific hemisphere that is affected? How do you know?
- How should these brain areas function normally? What could be causing this dysfunction?
- What do the assessments and their results tell you about this person’s abilities and condition?
Remember to document your sources!
Originally published at http://www.sciencecases.org/mini_perception/2Laura.asp
Copyright © 1999–2009 by the National Center for Case Study Teaching in Science. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.
