Help me, brain-science LJ!
Jan. 23rd, 2007 03:05 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
drwexI know I had this conversation not long ago, but I can't remember who I had it with...
![[livejournal.com profile]](https://www.dreamwidth.org/img/external/lj-userinfo.gif)
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.
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.
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2007-01-23 08:21 pm (UTC)no subject
Date: 2007-01-23 08:21 pm (UTC)Will say, though (from my own vague and uncited recollections of this research, back in the day) that while "our experience of unitary consciousness was, well, an illusion" strikes me as a very apt summary of the results, "each half had a complete and coherent consciousness" is a bit more troublesome a claim, though I understand where you're getting it from. It's one thing to demonstrate there isn't one-and-only-one "consciousness" in my brain... it's harder to demonstrate that there's exactly two, or anything else quite that neat.
Oh, and also:
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.
You know, taken out of context, that sentence grows more entertaining with each rereading.
no subject
Date: 2007-01-23 09:11 pm (UTC)no subject
Date: 2007-01-23 09:28 pm (UTC)no subject
Date: 2007-01-23 09:29 pm (UTC)no subject
Date: 2007-01-23 09:32 pm (UTC)Right, and some of what interested me was the connection between this research and research into multiple personality disorder (back then called schizophrenia). The reason for picking the number two was that there were two personalities with which the researchers could reliably communicated. One had half the brain, one eye, one side of the body and the speech centers. The other had the other half.
taken out of context, that sentence grows more entertaining with each rereading.
Thank you, I spent some time constructing it for maximal entertainment value.
no subject
Date: 2007-01-23 09:33 pm (UTC)Pinker's "How the Mind Works", Dennet's "Consciousness Explained", and
many books by Michael Gazzaniga. Also this recent book by a fellow
with an Indian-sounding name that starts with R; slipping my memory at
the moment.
no subject
Date: 2007-01-23 09:33 pm (UTC)no subject
Date: 2007-01-23 09:34 pm (UTC)no subject
Date: 2007-01-23 09:36 pm (UTC)no subject
Date: 2007-01-23 10:31 pm (UTC)read
blindsight.
one of the main charectors has had that surgery
and another is ... a multiple personality....
and it gets weirder and better.
some of the best hard science fiction I have ever read.
I hate the man - because - I know I will NEVER be as good a story teller as he is.
go go go
read rifters as well.
no REALLY.
no subject
Date: 2007-01-23 11:07 pm (UTC)Curse You.
Date: 2007-01-23 11:34 pm (UTC)Which means I have to pay my library fines, which I was hoping to put off.
Although it looks fantastic. Warped, twisted, unhealthy, but fantastic.
The most interesting hard SF I have read to date I think has got to be David Gerrold's "War Against the Chtorr" series, on the off-chance you haven't seen it.
Fines paid.
Book ordered.
no subject
Date: 2007-01-24 12:07 am (UTC)Strauss, E. (1998, May). Writing, speech separated in split brain. Science pgs. 280-287
Sperry, R. (1992). Some effects of disconnecting the cerebral hemispheres. Science. vol. 217, pgs 1223-6.
Baynes, K., Elisassenk, JC. Lutsep, HL & Gazzaniga, MS (1998, May). Modular organization of cognitive sysems marked by interhemispheric integration. Science, vol 280, pgs 902-905
Hope that helps. I believe there is also a recent article (ummm New York Times? or Psychology Today?) that discusses brain operations and the renewal of severing the CC for severe epilepsy. What they are doing now is not a complete cut, but a partial cut maintaining some pathway in the back I believe.
Re: Curse You.
Date: 2007-01-24 12:07 am (UTC)I've been reading all of his books
and
monster island
on line...
oops...
;-D
no subject
Date: 2007-01-24 12:29 am (UTC)"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.
no subject
Date: 2007-01-24 12:44 am (UTC)(Thanks for the pointer!)
no subject
Date: 2007-01-24 04:52 am (UTC)no subject
Date: 2007-01-24 05:28 am (UTC)The split-brain course I took at the University of Chicago used, as its main text (besides Fundamentals of Human Neuropsychology), Springer & Deutsch's Left Brain, Right Brain. My copy was published in 1981, or I'd pass it on to you; it's been through several editions since, though, and Amazon has at least a fifth edition published in '97 or '98. I'd recommend a search for "brain asymmetry" to find research that's newer still.
no subject
Date: 2007-01-24 03:19 pm (UTC)"DUAL MENTAL FUNCTIONING IN A SPLIT-BRAIN PATIENT", R. JOSEPH, Journal of Clinical Psychology (not sure of vol/issue, sorry). Also has a ton of references, including:
Puccetti, R. (1981). The case for mental duality: Evidence from split-brain data and other considerations.
Behavioral and Brain Sciences, 4, 93-123.
The earliest reference is
AKELEITIS, A. J. (1945). Studies on the corpus callosum. IV. Diagnostic dyspraxia in epileptics following partial and complete section of the corpus callosum. American Journal of Psychiatry, 101, 594-600.
Which startled me because I didn't realize the procedure was that old. If a major study was published in '45 then the procedure has to have been used well before that.
Some of the recent papers I've read in the past day have taken care to point out that the studied population often had significant socio-behavioral dysfunctions prior to surgery either due to the severe epilepsy or to underlying conditions of which the seizures were a symptom. Therefore it's not clear how much can be attributed to the surgical procedure and how much to underlying conditions.
The literature is HUGE. Even narrowing to the field I actually care about there's a mountain of relevant stuff. I doubt I'll ever re-find that original undergrad paper.
no subject
Date: 2007-01-24 04:28 pm (UTC)no subject
Date: 2007-01-25 03:31 pm (UTC)no subject
Date: 2007-01-25 07:17 pm (UTC)no subject
Date: 2007-01-26 02:58 pm (UTC)