What split-brain experiments revealed about the self

Added: 2026-05-17

[00:00:01]The behavior comes out.

[00:00:02]And then there's this little narrator up there that turns it into a story that makes us feel coherent and unified.

[00:00:10]Turns out it's a thing in the left hemisphere that does this and we called it the interpreter.

[00:00:29]Consciousness is not a linear flow of what's happening around us, but sort of a convenient narrative of what's happening around us, created for our viewing pleasure by the unconscious brain.

[00:00:43]It's a very powerful force in the human condition, and it's always trying to figure out and seek explanations for our behavior.

[00:00:57]In my early part of my career, I studied patients who had their two brains disconnected, working out the functions of each hemisphere.

[00:01:05]Test results show that speech is localized in only one half brain.

[00:01:10]Doctor Gazzaniga now reconstructs the test.

[00:01:13]We would put a question to the right non-speaking hemisphere, and it, in effect, would direct the left hand to do something.

[00:01:20]So the patient would do that. - And Joe sees two words simultaneously.

[00:01:25]Bell goes to his non-speaking right brain — Music to his speaking left brain.

[00:01:33]When asked to point to a picture of what he saw, he chooses Bell.

[00:01:37]And then we would simply say to the patient, well, why did you do that?

[00:01:40]We found out that in the left brain, there's a special system that seems to always want to explain actions and moods that we have after they occurred.

[00:01:53]Why do you pick that one?

[00:01:55]Music. - Music?

[00:01:57]There was music and bell.

[00:01:58]And it was a few minutes ago.

[00:02:00]The last time I heard any music was coming from the bells out here.

[00:02:04]Banging away.

[00:02:05]So the bells outside here.

[00:02:07]What's extraordinary is that Joe's speaking left brain concocts a plausible story of why he pointed to Bell, even when some of the other pictures more obviously represent music.

[00:02:18]We're learning and appreciating the ways in which we produce our perception, our cognition and our consciousness and all the rest of it.

[00:02:32]There's evidence that consciousness is not really what it seems to be.

[00:02:37]We feel our subjective experiences unfolding in the world around us in sort of this linear narrative in which B follows A, in which C follows B and D follows C, but in reality it seems that our conscious narrative might not be that linear.

[00:02:55]If you think of something like speech, you're probably not aware of my speech in a syllable-by-syllable, word-by-word manner.

[00:03:03]So, for example, the word mouse could mean a rodent, or it could be the mouse pad of a computer.

[00:03:09]Well if I say, "The mouse pad was beside the computer," in that case, the mouse can only be understood as a mouse pad.

[00:03:17]So it seems to be this chunking that happens, in which your unconscious mind reaches a point of analysis by sampling everything that's happening around it to deliver something a nice narrative of the world around us into our conscious mind.

[00:03:40]I think the human as a storytelling animal, as some people put it, is because the system is continually trying to keep the story coherent, even though these actions may be coming from processors going on outside of, initially, of conscious awareness.

[00:03:56]It's one of the reasons why people are different too, because people have different experiences, so they have different things they're trying to explain.

[00:04:02]So your experiences are different than my experiences and so your storyline, and we may start off with the same interpreter, but because all your experiences are different, your actual environmental experience, your temperament differences and all the rest of it, that's going to color everything in a little different way and this interpreter is going to make up a different story about it.

[00:04:20]Why does the human always seem to like fiction?

[00:04:23]Could it be that that prepares us for unexpected things that happen in our life?

[00:04:28]because we've already thought about them in our fantasy world, saw how those characters acted, and so then when we're confronted with it, we're writing it.

[00:04:35]We've sort of lived through that movie, as it were.

[00:04:38]So why do we like that stuff?

[00:04:39]Well, maybe that's a reason why we like it.

[00:04:41]And to think of all of those things, it seems to me, just to make it all richer, a richer experience.