Our Two Separate Brains

“In test situations [presenting odors to split brain patients], where the speechless right hemisphere is made to know the correct answer, and then hears the left dominant hemisphere making obvious verbal mistakes, the patient may frown, wince, or shake his head. It is not simply a way of speaking to say that the right hemisphere is annoyed by the erroneous vocal responses of the other.”     

~Julian Jaynes

Comment: Today we are looking at the subject of the separate abilities and functions of the right and left hemispheres.

Dr. Jill Bolte Taylor is a neuroanatomist who suffered a stroke on the left side of her brain at the age of 37. In her book, My Stroke of Insight, she tells the story of her experiences, beginning with the excruciating pain in her head on the morning of the stroke, and continuing through her eight-year journey to full recovery from the hemorrhage. She describes what it is like to lose all the abilities of her left hemisphere, which include auditory perception, language comprehension, speech, and linear cause-effect calculations. She is left only with the processes and abilities of the right hemisphere. Her book provides an insightful and beautiful description of right hemispheric activities – its capacities in perceiving energetic experiences in the present moment, and anything that can be considered non-verbal communication.

In a recent interview she summarizes:

“When you look at the brain, the two hemispheres – the right and left hemispheres – are completely separate from one another. All you have to do is cut that corpus callosum and we have two completely separate brains. At the same time, each half of the brain has what we call the limbic system, and the limbic system is our ability to place affect or feeling on information coming in through our sensory systems. So that is our emotional system. And when you look at the two hemispheres, they each have a limbic system. When I had the hemorrhage in the left hemisphere, all of my old emotions evaporated. So my experience of fear, my experience of anger, my experience of sadness – all of that – disappeared. And part of that was because I wasn’t saying those things to myself that would normally stimulate that circuitry. So I wasn’t saying things to myself that made me angry; so I wasn’t running my anger circuitry, because the language center was offline that would say things to me that would trigger that circuitry. But that didn’t mean that I didn’t experience emotions in the present moment, because the right hemisphere is all about the present moment in the information processing. So I was still capable of having a full experience in the present moment. And in the absence of my negative emotions, I personally had this total sense of euphoria.”

The abilities and processes in the right hemisphere are less accessible to us because that side of the brain has been shown to have very limited or no ability to communicate linguistically. So its mysterious doings are a subject of many studies and controversies. Jill Taylor’s book provides a rare and more complete view into the life of the right hemisphere through her experience of complete loss of left hemisphere function.