What's it like to have your brain split in half?

Via Cognitive Daily

Here's a fascinating video featuring split-brain researcher Michael Gazzaniga. The patient had his corpus callosum severed as a treatment for severe epilepsy. The treatment terminated nearly all communication between his brain's right and left hemispheres.

Since language is primarily processed in the left hemisphere, the patient can't name items on the left side of his field of vision (remember, the brain is "flipped" relative to the body parts it senses and controls). But he can draw pictures of them, and then he can look at the pictures and name them.

That's a nice snippet, but a commenter to the above cog daily post points out a different intriguing link to a Scientific American Frontiers program called Pieces of Mind. 54 mins, online here. It too has Joe and his surgically clipped Callosum, along with Dartmouth neuro-scientist Gazzaniga, but it also delves approachably into broader cognitive stuff:

There's some on emotions as "post-it" notes helping to affix memories, a concept we've talked about around here lots, and quite relevant to media-criticism of news framing and presentation. There's a segment on memory being malleable, changeable, suggestable, foolable.


In one place, 7:30 mins into the program, Joe's left brain is shown the word "stool," his right is shown "toad." We get to see him try to do unsuccessfully on paper what most of us do instantly--mentally doodle--associate two into one: the mushroom. He draws an amphibian on a seating device.

Imagine, the Corpus Callosum makes visual puns and double-take jokes possible. In other words, appears to aid contextual knowledge and nuance and reduce cognitive friction. (As an aside, it's apparently larger in women than men, smaller in autism sufferers - link to CC size and autism study.) The show ends with the development of language specialization and how it moves from a whole brain activity in children, when the most basic associations are being built, to its leftward migration after 4-5 years of age.

Still, for me, the sorting and synthesizing, pattern-matching and 'play-writing' (creative and dream) aspects are quite interesting, not to mention heads made of cukes, cabbage and carrots...

The Corpus Callosum joins L/R somewhat like a central switch or system integrator--a big trunk of nerves between hemispheres. And recognizing faces are the domain of the Right Brain. We know this matters for infant bonding, recognizing friend or foe and determining our behavioral response to the people we encounter. But if naming things is the domain of the left, and seeing the role of the right, and a healthy Corpus Collosum allows them to compare notes, what happens when we see faces made from collages of fruit and vegetables? The answer's at 10:00 mins in.

The phrase "sleep on it" in the context of a difficult challenge seems to have real legs. August Kekulé, a father of organic chemistry and discoverer of the structure of long-chain molecules said he fell asleep in front of the fire while pondering how carbon atoms linked. While napping, he supposedly dreamed of the flames dancing, circling and overlapping each other like snakes eating their tails. Hey!--maybe the molecules were rings not sticks. Yes, they were.

The program doesn't mention the ring thing, but does examine the subconscious' power in helping cognition and even exam study. (See 36:00) Dreams appear to help us sort out and synthesize complex or conflicting information a la Kekulé. In many cases, dreams can be the result of our brain left alone to it's own interior inputs--our skull as it's own Altered States sensory deprivation tank--because during sleep most of our senses are on standby: eyes closed, quiet room, stillness. During this time, the mental movies of us doing impossible things like floating in flight or talking with animals or leg-wrestling Cleopatra, all these appear to be our higher cognitive functions trying to thread some sense into a storm of signals washing up from our more primitive centers such as the R-Complex and Amygdala. The desire for a narrative and structure, so strong in our left brain and neocortex, causes our very-at-rest cognition to weave a "sensible" story out of what appears to be nonsensical, unrelated impulses and snips of info. From this we get Carbon atoms, and maybe sleeper movie hits, Reeses Cups, talking geckos and pet rocks.

Okay I've rambled too much. Take a look at the show sometime. Next, maybe we dig up a test on whether we have a Male- or Female-tending brain.