In April of 2006, when I was 19, I suddenly started getting painful headaches. Over the course of several weeks, they increased in intensity until the pain was unbearable. I saw a neurologist, and he ordered some tests including an MRI series.
Thankfully, the MRIs showed nothing wrong, and we later found the cause of the headaches to be my murderous car emitting carbon monoxide into the cabin. But one good thing did come out of the whole experience: I now have a complete series of MRIs showing my real, actual brain. I'd like to show them to you (and maybe try to remember some random neuroanatomy facts).
Nuclear magnetic resonance imaging has always fascinated me. It works on a completely subatomic level: an MRI machine creates an intensely powerful magnetic field which causes the protons in hydrogen atoms (from water) throughout the body to realign toward the magnets within the scanner. The field is then briefly disrupted and the protons snap back to their original orientation. While moving back, they vibrate and release energy which is detected by sensors.
A computer then processes the sensor data through a mathematical operation called a Fourier transform. Once this has completed, it is possible to visualize the differences in hydrogen atom density throughout the part of the body in the scanner. Eventually, the data is cleaned up and detailed pictures, like the ones below, are created.
Let's get to the images. Below are 22 sagittal (vertical) cross-sections. Image 1 shows my right cheek and image 22 shows my left cheek.
At its core, it is the "artful" hemisphere. Abstract thinking, intonation and rhythm of language, artistic ability, and the perception of joy from music are centered here. The right hemisphere specializes in thinking about big picture ideas and overarching themes holistically instead of linearly.
Inside my skull, you can see the wrinkling black lines of the sulci (dark indented areas) and the gyri (the lighter protrusions) in the folds of brain matter.
I've always liked the cerebellum, which is a bulbous structure at the back of the brain. Though it is an evolutionarily old part of the brain, it regulates complex and important body systems like overall balance, eye movement and blinking, and some aspects of motor control. When the motor cortex decides to move, the cerebellum manages the hugely complex combination of muscles required to perform the movement.
Image 11 shows the perfect center of the sagittal plane between the left and right hemispheres, right between the eyeballs.
Each hemisphere is almost totally independent and essentially has a mind of its own. They communicate across a large bundle of axonal fibers called the corpus callosum. Except for this bundle of neurons, the two hemispheres are physically separated.
In severe cases of epilepsy, the corpus callosum is sometimes cut to reduce seizures. The result is fascinating; two totally separate minds emerge. A researcher can show an apple to only the right hemisphere (by showing it only to the left eye) and although the person intuitively knows the object is an apple, he cannot name it because the right hemisphere can't communicate with the language centers of the brain in the left hemisphere.
The left hemisphere tends to be logical, literal, and optimized for linear analytical thought. Primary language centers of the brain, including Broca's and Wernicke's areas, are usually located here. Broca's area produces language and Wernicke's area specializes in understanding language.
One of my favorite neurological conditions, Wernicke's aphasia (receptive aphasia), sometimes presents itself when there is damage to Wernicke's area (and nearby regions). A person with this disorder can speak with perfect syntax and rhythm while outputting random nonsense words instead of the ones they are trying to say. For example, someone with this condition might say:
"I called my mother on the television and did not understand the door. It was too breakfast, but they came from far to near. My mother is not too old for me to be young." -- A patient with Wernicke’s Aphasia
For a long time, I thought my calling was in medicine. I studied biology extensively and started at an undergraduate cognitive neuroscience program. Ultimately, I dropped out to pursue design. It was a hard decision to make.
Sometimes, when I read about interesting new research in neuroscience, I wonder what would have happened if I had continued studying medicine. Who knows? At least I know what lurks inside my head. •
-d
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Coming soon