Jill Bolte Taylor is a neuroanatomist who specializes in the postmortem investigation of the human brain. She is affiliated with the Indiana University School of Medicine and is the national spokesperson for the Harvard Brain Tissue Resource Center. Jill Bolte Taylor got a research opportunity few brain scientists would wish for: She had a massive stroke, and watched as her brain functions — motion, speech, self-awareness — shut down one by one. An astonishing story.
I grew up to study the brain because I have a brother who has been diagnosed with a brain disorder: schizophrenia. And as a sister and later, as a scientist, I wanted to understand why is it that I can take my dreams, I can connect them to my reality, and I can make my dreams come true. What is it about my brother’s brain and his schizophrenia that he cannot connect his dreams to a common and shared reality, so they instead become delusion?
So I dedicated my career to research into the severe mental illnesses. And I moved from my home state of Indiana to Boston, where I was working in the lab of Dr. Francine Benes, in the Harvard Department of Psychiatry. And in the lab, we were asking the question, “What are the biological differences between the brains of individuals who would be diagnosed as normal control, as compared with the brains of individuals diagnosed with schizophrenia, schizoaffective or bipolar disorder?”
So we were essentially mapping the microcircuitry of the brain: which cells are communicating with which cells, with which chemicals, and then in what quantities of those chemicals? So there was a lot of meaning in my life because I was performing this type of research during the day. But then in the evenings and on the weekends, I traveled as an advocate for NAMI, the National Alliance on Mental Illness. But on the morning of December 10, 1996, I woke up to discover that I had a brain disorder of my own. A blood vessel exploded in the left half of my brain. And in the course of four hours, I watched my brain completely deteriorate in its ability to process all information. On the morning of the hemorrhage, I could not walk, talk, read, write or recall any of my life. I essentially became an infant in a woman’s body.
If you’ve ever seen a human brain, it’s obvious that the two hemispheres are completely separate from one another. And I have brought for you a real human brain. So this is a real human brain.
This is the front of the brain, the back of brain with the spinal cord hanging down, and this is how it would be positioned inside of my head. And when you look at the brain, it’s obvious that the two cerebral cortices are completely separate from one another. For those of you who understand computers, our right hemisphere functions like a parallel processor, while our left hemisphere functions like a serial processor. The two hemispheres do communicate with one another through the corpus collosum, which is made up of some 300 million axonal fibers. But other than that, the two hemispheres are completely separate. Because they process information differently, each of our hemispheres think about different things, they care about different things, and, dare I say, they have very different personalities.