The girl who feels no pain: 3 fascinating neurological disorders

This post is the first in a short series on “What I learned in my undergrad neuroscience classes.” Today, I describe a few fascinating neurological disorders.

Have you watched episodes of medical shows like Grey’s Anatomy or House and wondered where they come up with some of their disorders? Are there really people out there who feel no pain, or who only have half a brain? There are. In undergrad I took a few neuroscience classes and learned fascinating details about neurological disorders. It seems that if you want to understand how the brain works, one of the best approaches is look at what happens when parts of the brain malfunction. Although I’ve forgotten 85% of what I learned, some of the more unbelievable details have stuck with me, and I thought I’d share a few of them with you today. So without further ado, here are some of the neurological disorders that I can’t get out of my head:

Clock drawn by hemineglect patient

Hemineglect. Take a look at the world around you, do you see both hands sitting on your keyboard, are you able to see your entire computer screen? What is sitting to your left? To your right? For people with hemineglect, the answers to these questions aren’t so simple. This is a condition following brain damage (typically to the right hemisphere) in which people fail to be aware of items on the side of their visual field that is opposite to where the damage was done. In short, people with this condition just stop seeing things that are on one side of a space. So give a person with hemineglect a plate of food and they will only eat things on the right side. Give them a piece of paper, and they will only draw on one side of it. If you see a person who has only one side of his face shaved or only half his hair brushed that person may be suffering from hemineglect.  In extreme cases, people with hemineglect may not see large objects, such as a person, standing on their neglected side. 

Prosopagnosia

Prosopagnosia. Humans have an innate ability to recognize faces as, well, faces. We know when we are looking at a person as opposed to an object, and we are able to differentiate one face from another. However, it turns out that not everyone has this ability. Prosopagnosia, also known as "face blindness" can be something someone is born with, or can occur as a result of brain damage. Depending on the degree of severity, prosopagnosiacs may have trouble recognizing a familiar face, be unable to differentiate between unknown faces, or even be unable to differentiate a face from an object. In some cases, patients may not even be able to recognize their own face in the mirror. However, give them non-facial clues, such as clothing, hairstyle, or voice, and they can recognize people and distinguish between them. Faces provide us with so much information about a person, can you imagine what it must be like to find a distinctive pair of earrings more recognizable than a face?

Does this hurt?

Congenital insensitivity to pain. Some people are born without the ability to experience pain. When I learned about this disorder, my first response was a twinge of jealousy. No pain? Childbirth, here I come! But it turns out that I’m probably better off with my capacity to feel pain. How do you know to take your hand away from the fire if it doesn’t start to hurt? What keeps you from pushing yourself too hard if your body isn’t fighting back? Walk on a broken ankle? Why not! Children with this condition often suffer from serious problems because they are unaware that anything is wrong with them. So perhaps I should reappraise my pain as good and consider myself lucky.

There is also disorder in which people do not feel something if they are not looking at it. So if a man picks up a briefcase while looking at it, he is fine, but as soon as he glances away, he will drop the briefcase. This has something to do with our haptic perception but I cannot find the name of it. If you know the name, tell me in the comments!

All of these examples of what can happen when parts of our brain stop working remind me how much I take for granted… I walk, talk, see, hear, taste, touch, all without a thought about what my body and brain are able to do. Today, I think, I will focus on being appreciative that I can see both hands on my keyboard as I type. 

Do you find these disorders as fascinating as I do? Do you find one particularly intriguing or unbelievable? Have you learned about other disorders you think I’d want to know about? 

Further Reading 

• Kerkhoff, G. (2001). Spatial hemineglect in humans Progress in Neurobiology, 63 (1), 1-27 DOI: 10.1016/S0301-0082(00)00028-9
• McNeil, J., & Warrington, E. (1993). Prosopagnosia: A face-specific disorder The Quarterly Journal of Experimental Psychology Section A, 46 (1), 1-10 DOI: 10.1080/14640749308401064