Help me, brain-science LJ!

[drwex]

I know I had this conversation not long ago, but I can't remember who I had it with...

bluegargantua linked to this Time article on consciousness. In it, the author Steven Pinker references a series of at-the-time startling results from surgery on the corpus callosum. In short, the surgery was used for a brief time in history on patients with severe epilepsy. These days we have 'better' drugs and don't generally go about whacking apart large parts of peoples' brains because we can't figure out what else to do.

Anyway, the startling bit about this was that post-operative study of these patients revealed that our experience of unitary consciousness was, well, an illusion. In particular, people whose brain halves had been split from each other demonstrated that each half had a complete and coherent consciousness, often with a radically different personality than the commonly experienced consciousness. When I was an undergrad I remember reading, for example, about one of these patients whose dominant brain still loved his fiancee but when the other half was queried (*) it was found that this personality HATED the woman.

Problem: I can't find the original research reporting results on the split personality patients. I first read it on paper now long gone from my possession. Searching online has been fruitless. Even specialized sources like Google Scholar are just chock full of things I don't want. Pinker, of course, doesn't reference original source - he's not doing a scholarly publication after all. It's just accepted fact for people who study consciousness and yet virtually unknown to the general public.

So... HELP! I want to find and re-read these original studies, and I'm completely failing.

(*) It turns out you have to do some tricks to query the non-language half of the brain. Generally you cover one eye and communicate largely by pictures and pointing with the appropriate hand. If you let the patient use the other hand, the language/dominant personality tends to take over.

Comments

[intuition-ist.livejournal.com]

hm, googling for "pinker split personality corpus callosum" yielded a reference to:

"Nobel prize winner R Sperry's research concentrated on what happens when parts of the corpus callosum, which connects left and right hemisphere, is cut.... Perhaps the most intriguing split brain research was with a patient of another pair of split brain researcher, Michael Gazzaniga and Joseph LeDoux, who had some limited language facilities in his right brain. This patient show marked preferences in responses from the two hemispheres. When asked, "What do you want to do?" the left hemisphere replied "draftsman", but the right hemisphere (using scrabble letters) replied "automobile race".
The overall results of Sperry's research can be summarised by his quote: "Everything we have seen indicates that the surgery has left these people with two separate minds. That is, two separate spheres of consciousness".

with a further reference to R.W. Sperry, Brain bisection and consciousness, in How the Self Controls Its Brain, ed C. Eccles. Springer-Verlag, New York, 1966.

(from http://www.singsurf.org/brain/rightbrain.html)

also, a tantalizing sentence: "When a surgeon takes a knife and cuts the corpus callosum (which joins the two cerebral hemispheres), the mind is split in two and in some sense the body is inhabited by two selves." from The Blank Slate, the Noble Savage, and the Ghost in the Machine (a 1999 lecture at Yale by Stephen Pinker)

also, Gazzaniga, M.S. 1998. The split brain revisited. Scientific American 279(1):50--55. A review of studies on patients whose separated cerebral hemispheres act as two semi-independent selves.

[r-ness.livejournal.com]

great, induced MPD/DID. that's all we need.

(Thanks for the pointer!)

[drwex]

Great stuff! I think that different-preferences patient might be the one I'm remembering.