Critics, mathematicians, scientists and busybodies want to classify everything, marking the boundaries and limits... In art, there is room for all possibilities. -- Pablo Picasso
Once, right after I had given an assignment for a drawing class, a student asked me which side of her brain she should use to make the drawing. I suggested she use whatever she had. Another student with whom I'd worked for a while, and knew to be right-handed, started drawing with her left hand in order to use the right side of her brain (which controls the left side of the body). She took things literally.
It got me to thinking about this sides-of-the-brain thing, a genuinely innovative idea from neuroscience, which, like so many valid scientific insights, got reified, oversimplified and misinterpreted by popular psychology. The book Drawing from the Right Side of Your Brain, wildly popular and in print since 1979, was loosely based on cerebral hemisphere research of the 1960's. All of a sudden people started copying drawings upside-down and looking around for a gestalt. Pretty much everything the book says would have already been known and taught by any decent drawing teacher, but getting millions of people to draw when they didn't think they could was remarkable.
A quick surf of the web reveals the following characteristics and capacities of the two sides of your brain:
Left Brain | Right Brain
Reality-based | Imaginative
Symbolic | Geometric
Mimetic | Risk-taking
Measuring | Spatial relations
Dexterity of the human right hand | Inventive
Planning | Concrete
Pattern perception | Perception of shapes and sizes
Conscious, externally-focused attention | Process ideas simultaneously
Looking at differences and distinctions | Sees relationships
Analytical | Synthesizing
Detail-orientation | Looks at the "big picture"
Enjoys observing | Sees more than one way of looking at things
Organizing information | Abstraction of qualities
Communicative | Gestural
(You are also told that if you happen to be a teacher, you're left-brained; if you can explain your opinions in words, you're left-brained; if you bother to read a how-to book, you're left-brained; better put away that Drawing from the Right Side of Your Brain book).
Drawing, or participating actively in any of the arts, demands the entirety of ourselves -- these undertakings engage bodily, intellectual, analytical and emotional capacities. The act of perception itself -- making sense of what you see -- and the subsequent complex process of interpreting and translating to paper what you observe, are extraordinarily active and consuming tasks, and they require your whole brain. Drawing, like musical ability, is not a single ability, but a set of abilities, working simultaneously.
Let's stop calling ourselves right- or left-brained, bad at art, bad at math; we share every capacity, albeit to varying degrees. Categorizing yourself just gets you off the hook. Leaving the arts to artists is like leaving exercise to athletes -- you can do it, it's good for you, and no one should fault you for not making a living at it.
In a recent study, David Navon of the University of Haifa asked brain-damaged patients to copy a picture in which 20 small copies of the uppercase letter A were arranged to form the shape of a large capital H: "Patients with damage to the left hemisphere often make a simple line drawing of the H with no small A letters included; patients with damage to the right hemisphere scatter small A letters unsystematically all over the page." The two hemispheres of our brain, working in tandem, see both the small A's and the big H. So use whatever you've got.