The human brain is basically symmetrical, split down the middle: the right cerebral hemisphere receives sensory input from and directs movement on the left side of the body, while the left hemisphere governs corresponding functions for the right side.

Symmetry only goes so far, however—there are differences, too. Yet in recent years, the two sides of the brain have come to symbolize two sides of human nature; the left brain hailed (or disparaged) as “logical,”“analytical, and “intellectual,” and the “intuitive” right brain as the avatar of emotion and creativity. A host of popular books, educational strategies, and even therapeutic interventions have ensued, promising to enhance abilities and relieve mental maladies by optimizing function on one or the other side of the cerebral cortex.

The reality is not so simple—and a good deal more interesting. And like so much in neuroscience, far from fully understood. Watch this video and learn why.

Learn more about your brain during Alzheimer’s and Brain Health Awareness Month. Video and article courtesy of The Dana Foundation.