Temporary split brain


This is a science-fictional idea, but strikingly probable. You are probably aware the brain is split into two halves, joined by a nerve bundle called the corpus callosum. People with severe epilepsy have had the callosum severed, and ended up having two brains in one body. A left brain controlling the right half, and a right brain controlling the left half. The left brain can speak and can lie, the right brain can write with the left hand to communicate. Until experimenters tried to communicate with each half, the people were unaware they were sharing their body with another half-brain. You can read more details if you were unaware.

Anyway, on to the idea. It seems plausible one could apply a temporary anesthetic to the corpus callosum, and temporarily split a person into two brains. Today that might require drastic steps like brain surgery. In the future it's not hard to imagine a specialized drug or highly targetted drug delivery or nanobots to temporarily numb and disable the zone, without too much shutdown of adjacent tissue.

One could even imagine recreational use if it were safe and simple. It would be quite something to learn just what happens when you are split into two and then re-integrated, and how the reformed whole you would remember the two split experiences. Would your left and right half have a conversation? What would they talk about? How long could you persist in this state before it became difficult to reintegrate? How long after the cutoff would you be cogent enough to do all this (one presumes the cutoff might be a bit of a shock.)

Imagine an SF story where one half of the protagonist's brain decides it doesn't want to re-integrate with the other half, and takes steps to assure this...


A similar procedure is apparently used for diagnosing epilepsy patients (among others). Do a Google search for "Wada test," which involves using a fast-acting anesthetic to put one hemisphere to sleep while the other side remains active. Not quite the same as selectively targeting the corpus callosum, but not so different, either.

Take it a step in the other direction... I have an enlarged corpus callosum. It's four times the size of an average person's, or "freakishly big" as one doctor termed it. It creates a whole new set of problems and theories...

Regarding the Wada test, and this vector of curiosity, you might want to check out Patricia Churchland's Neurophilosophy:

"Unacquainted with the hazards of the procedure, I once asked if it would be possible for me to undergo a left-sided Wada test. My objective was simple enough; I wanted to see what it was like to have an inactive LH and to find out whether, with only the RH active, there is still awareness, experience, thinking, and so on. I reasoned that even if my RH was mute, once the amytal had worn off, the RH should be able to transfer memories to the LH and the LH could then report. And of course I expected that "yes-no" questions concerning my conscious states could be put to me during the procedure - for example, "Are you aware in the usual way of what is going on?"

As a number of neurologists have explained, the plan was ill conceived. First, the procedure carries risks one would not normally take simply for the sake of science. Sometimes a piece of plaque is dislodged from teh arterial wall and plugs a blood vessel. Second, I was told I would not get what I was after in any case, because patients typically have only confused and scanty recollections of the events during the test, regardless of which hemisphere is suppressed. As Bryan Kolb described it, they tend to give confabulated answers to questions, and they appear unable to recollect even such striking things as the paralysis to one arm. Even their descriptions of mood and feelings during the test are at variance with the behavior observed by the researchers."

hi, about 22 years ago, I thought that if you could use nanotech to temporairilly disable your memory so that, if you were a director, you could make a movie and then disable that memory of the movie from your brain, so you could go see the movie with other people and you could discuss the movie with them since you all had not seen it so that later, you could analize what you thought of the movie from an unbiased point of view wo you could go back and "imrove" the movie once you had regained your memories of making it.

Re: split-brain sci-fi

"Distraction" by Bruce Sterling is a good one.

And of course, "A Scanner Darkly"
by Phillip K. Dick.

more recommended reading:

_Peace on Earth_ by Stanislaw Lem.

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