Tale of Two Brains
The truth behind the right-brain-left-brain debate, and how the ubiquitous bit of pop science wisdom came about.
Right-brained people are supposed to be artistic and spontaneous, while left-brainers are literal and analytical; in other words, Captain Kirk and Spock. This ubiquitous bit of pop science wisdom came out of Nobel Prize-winning neurology, and it spawned the bestseller "Drawing on the Right Side of the Brain."
But does the story of the two brains stand up? "Studio 360's" Dave Johns tries to find out.
In the 1960s, surgeons developed a radical new way to treat patients with severe epilepsy -- they would cut the corpus callosum, a thick cable of nerves that connects the left and right halves of the brain. These so-called split-brain patients made fascinating research subjects.
Joe Hellegy is a neuroscientist at the University of Southern California: "In a normal person, the information can be quickly processed and spread to both sides; but in the split-brain patients that sharing of information is greatly impaired, and might even be eliminated. And so for the first time you could look at the competence of each hemisphere in isolation."
It wasn't long before a Caltech neuroscientist named Roger Sperry figured out a way to do just that. His experiments took advantage of the fact that the right side of the brain controlled the left side of the body, and vice versa. Some of the differences Sperry saw was dramatic.
Hellegy: "So you flashed a word to the left hemisphere, the person could tell you what it is; you flashed the word to the right hemisphere, they'll tell you quite correctly they didn't see anything. The right hemisphere has almost no ability to actually produce overt speech."
But the research also showed that the right side was actually better than the left at visual and spatial tasks. Sperry won a Nobel Prize for his work.
In the late 70s, a woman named Betty Edwards wrote a book called "Drawing on the Right Side of the Brain." It drew heavily on Sperry's research. Edwards taught drawing classes too, and they're still run today by her son, Brian Bomeisler.
Bomeisler: "It turns out ... from Roger Sperry himself, that the left hemisphere is competitive and likes to stay on task. The left hemisphere ... doesn't want you to draw at all, it doesn't want to lose control like that. So it will find multiple ways of tricking you out of it -- it will say something like, 'well I've got to clean up the house' or 'I've got to mow the lawn' or something like that. But the right hemisphere is sort of nudging the left hemisphere, saying 'come on, let's have some fun, let’s do a drawing.'"
"Drawing on the Right Side of the Brain" became a best seller, and helped popularize the notion that the right brain is the source of human creativity. Editorialists began to declare that tomorrow's problems required creative, right-brained solutions. Advocates accused the educational system of catering to the left brain, and called for more art in public schools.
Roger Sperry himself complained that society discriminated against the non-verbal right hemisphere. Suddenly, two blobs of brain matter had become a kind of neurological odd couple, crammed together in their cranial apartment.
So how do you draw on the right side of the brain? Many of the techniques are meant to get around the left brain's tendency to draw objects in a preconceived way. So instead of say drawing an easel, Beaumont has his students draw the negative spaces surrounding the easel, which the left brain doesn't recognize.
Joe Hellegy says imaging studies actually suggest the hemispheres work together on visual perception. The right side pays closer attention to overall patterns, while the left focuses more on detail. But he says Bomeisler's techniques are helpful: "We come equipped to analyze things, to categorize things, to verbalize things, and I do believe that techniques which force us out of that are likely to be helpful in teaching people to be more attentive to shadings and lines that are actually there."
There's good evidence that forcing yourself to think in new ways is a powerful educational technique. It can literally change the brain's wiring, according to David Sulzer, a Columbia neuroscientist: "Essentially anything you learn -- learning how to play the piano, or learning how to throw a ball, or using a tool, especially if they're a little difficult at first -- are forcing you, and engaging you, and essentially making new synaptic pathways."
According to Sulzer, having success at a new skill, such as drawing, produces a spike in the neurotransmitter dopamine, and that pleasure surge reinforces the neuro pathways involved. That's how the brain remembers what it learns.
Alice Flaherty is a neurologist at Harvard Medical School. She studies creative drive, and its flip side, writers block. She says creative drive is mediated by a relationship between the brain's temporal and frontal lobes. In other words, the front and back of the brain are just as important as the right and left: "What the right-brain, left-brain model is relatively good at is predicting what parts of the brain are involved in what particular domains of creativity -- whether it's art and music or literature -- they're not so good at talking about creative drive, for example, and it turns out drive is way more important than talent. In fact, there's some fair amount of evidence that over an IQ of about 115, increasing your IQ doesn't really help your creativity, there's like a threshold. What's really important is drive."
PRI's Peabody Award-winning "Studio 360 with Kurt Andersen" from WNYC is public radio's smart and surprising guide to what's happening in pop culture and the arts. Each week, Kurt Andersen introduces you to the people who are creating and shaping our culture. Life is busy — so let "Studio 360" steer you to the must-see movie this weekend, the next book for your nightstand, or the song that will change your life.