Back in junior high school health class, we were told that the brain has two different hemispheres — the left and the right. The left brain, the textbook stated, is responsible for language, math, and science, logic and rationality. The right brain was the artistic one, the creative half of the brain. But that’s not quite true. Neuroimaging and experiments on patients with split brains and brain damage to only one hemisphere have allowed a much more detailed, and fascinating, accounting of how the two parts interact with the world, and how they combine to become a unified consciousness (and, in some cases of mental disorders, how they occasionally don’t). Iain McGilchrist has combined scientific research with cultural history in his new book The Master and His Emissary: The Divided Brain and the Making of the Western World to examine how the evolution of the brain influenced our society, and… More…

 

With all of its variables and mysteries, sleep (like the weather) provides for an endless source for small talk. How did you sleep, and did you get enough? Was it hard to fall asleep, or hard to wake up? Did you dream, and what about?

It’s unclear why, but people need sleep to survive. Insects, fish, and animals need it, too, but some less and others more, some hibernating for months. Sometimes sleep eludes people, no matter how tired they are, and other times the well-rested can’t stop themselves from nodding off throughout the day. People dream, but often can’t remember what about, or they dream the same thing over and over and over again.

Sleep is fascinating, and not just to regular people, but also to scientists who can now use technology like fMRI and modern biochemical… More…