From the Vault: Split Brain, Part 2

And from both sides of my intelligence, the moral and the intellectual, I've else drew steadily near to that truth, by whose partial discovery I have been doomed to such a dreadful shipwreck that man is not truly one, but truly too. Welcome to Stuff to Blow your Mind from how Stuff Works dot Com. Hey, welcome to Stuff to

Blow your Mind. My name is Robert Lamb and I'm Joe McCormick, and this is going to be part two of our two part exploration of hemisphereic collateralization and especially the split brain experiments of Roger Sperry and Michael Gazzaniga starting in the nineteen sixties. Now, if you haven't heard the last episode, you should really go check that out first.

That's gonna lay all the groundwork for what we're talking about today, right, and it will also explain why we kicked off this episode and the last episode with the reading from Robert Louis Stevenson Strange Case of Dr Jacqueline mr. Hyde from six short version is Robert Louis Stevenson thought he had another dude in there. What did he call him? The other guy? The man inside me by I know it was a different author. Uh no, it was it was me and the that other fellow, that other fellow. Yeah.

So in the last episode we discussed twentieth century research on a small group which it was a small subset of the total group of maybe fifty to a hundred or maybe a little more than a hundred people who have ever received a surgical intervention called a corpus callosotomy, which is a severing of the corpus colosum and the corpus colosum you can kind of think of as the high speed fiber optic cable that connects the two hemispheres

of the brain together. Now, the surgery was originally intended as a kind of last resort treatment for people who had terrible epileptic seizures. There are so few of these patients because now we generally have better, safer ways of treating epilepsy without such a radical surgery, right though these

individuals are still around. Yes, certainly, in the last episode we mentioned that Pinto study that looked at a couple of them in seen, And it's very possible that we have listeners out there who have received this surgery as well. And obviously we would love to hear from you if there's anything you would like to share. Oh yeah, please, if you have a split brain, email us immediately. And in fact you mentioned the more recent research. We're gonna

look at some of that research in today's episode. But what neuroscientists learned in the twentieth century from this small group of patients was truly remarkable. Beginning in the nineteen sixties and continuing up until recent years, these split brain patients have been the subject of some of the most interesting research ever on the nature of the brain, the mind,

and the self. So last time we talked about the original work of like Sperry and Gazzaniga, who discovered many fascinating things about how it's possible for one half of the brain to not know what the other half is thinking, doing, or seeing. This time we want to follow up on the subject, to explore some more recent studies and to ask questions about what these split brain studies mean for

our lives. And to start off, I wanted to mention an anecdote I came across from the neuroscientist V. S. Ramachandren that he has brought up in some of his public talks and work. He tells a story of working with one particular split brain patient who had been trained to respond to questions with his right hemisphere. Now you'll remember from our last episode that in the case of most patients, the right hemisphere of the brain cannot speak.

It might have some very rudimentary language comprehension, but generally language and especially the production of speech, is dominated by

areas of the left hemisphere. So if you're dealing with the right hemisphere of a split brain patient and you show something only to their left visual field, which connects to the right hemisphere, and you ask them about it, what often happens is that, for instance, they will not be able to say the thing you have showed them in their right brain, or even explain it in words, but they will be able to draw the image with

their left hand. Now. In the case of Ramaschandrian story, he had trained a patient in a lab at Caltech to answer questions posed directly to his right hemisphere only by pointing with his left hand to response boxes indicating yes, no, I don't know now. Of course, asking these questions directly to the left hemisphere is a lot easier because it

just processes language normally and you can just ask. But he trained the right hemisphere to respond as well, so the patient was perfectly capable of answering questions like this with either hemisphere. Are you on the moon right now? Patient says no? Are you at cal Tech? Patient says yes. But Rama Schondre and then asked the right hemisphere do you believe in God? And it says yes. And he then asked the left hemisphere, the language dominant hemisphere, do

you believe in God? And it says no. This is yet another one that immediately when I heard the story, the hair stand up on the back of my neck. I feel the I feel that the goose bumps of

of counterintuition running through me. Yeah, because I feel like, for the for the most part, I feel like a lot of us want to feel like we have a definitive answer to that question, and Queen answers like that, Now I'm probably a little weirder and that I and I imagined a lot of our listeners are like this as well, where someone asks you a questions like this and you can be a lot more wishy washy and say, well,

I don't know. It depends you know, yes and no. I feel like most of us, if not all of us, we can have We can have contry contrary ideas in our mind. We can have conflicting notions that are that are vying for dominance, which me, are you asking? Yeah? Askin Jacky? L are you asking hide? You know? Hid he? You know he's he's not much of a churchgoer, but but Jackal he's there every Sunday. Yeah, but he's only there to ultimately work his way up the chain and

usurp the creator. Now Rama shonder and jokingly asks a theological question about this. He says, you know, assume the old dogma that people who have faith in God go to Heaven and people who don't go to hell? What happens when the split brain patient dies? That's a good

laugh line. But I think this question is actually more profound than it seems at first, because we may not be divine judges casting people into heaven or hell, but we are judges, and we judge and evaluate and characterize people all the time every day, as if they are some sort of essential whole. We pick out what we believe to be the salient characteristics that define a per person, like this is their character and and now we know who they are. This is their mind, this is the person.

There might be no way to get people to live and behave other than this. I mean, there might just be an inextricable part of our our personalities that we have to judge people as essential holes in this way. But I think this research should cause us to wonder about our folk beliefs about the nature of the mind

and the brain and what it means to be a person. Yeah, I mean, obviously, just to talk about judgment, we we have some severe problems with with with dealing with the idea that that that that there is not a single person over a length of time. I mean, I mean, obviously, you have people serving prison sentences for crimes that an earlier iteration of themselves committed. What do they say, I'm a different person now, and and it is true we

have all different people than than we once were. But you might in some ways also be a different person than you were a couple of seconds ago, right, Or it can be kind of a juggling back and forth. You know, I'm a different person in the morning versus uh, the afternoon. I mean, I I truly feel that, well, I mean, when it comes to questions like this, like

the theological question. The fact is, most people, I think, are probably filled with all kinds of doubts concerning whatever their beliefs about religion are, whether you believe in God or not. Either way, you probably sometimes wonder if you're wrong or you should. That's always a great exercise about anything in life, think about the possibility that you're wrong, no matter what it is exactly. But our everyday experience, of course, is that these varying states of doubt they

get somehow synthesized. Right. You roll it all up together, you say, even though whichever way I am, whether I believe in God or not, I ultimately have one way of answering that question. Most people are like this when you I mean, you might not be this way, Robert, but a lot most people would say I have an answer. Well, at the end of the day, or even just minute to minute, you your brain has to tell a story about who you are, right and for that to make sense,

there still has to be a sentence. There still has to be a story, some sort of continuation. And even if you know my story is a little more uh, you know, meandering, it's still a story, right, Yeah, Yeah, You're still narrativising yourself. You're composing a synthetic picture of who I am, and for you, I think that picture includes more ambiguity than a lot of people are comfortable with. But either way, no matter what, you're telling a story

about yourself. Yeah, and so despite your doubts, either way, you think of yourself as one whole, unified, unified person. You either believe in God or you don't, or you identify you have some narrative that's in between. You say I'm an agnostic or whatever. But this is just one

case of a generally fascinating phenomenon to ponder. What if by asking parts of our brains separately, we would think different things about all kinds of stuff, have different feelings, make different judgments, make different moral judgments, be different people. Is anyone aspect of your brain more truly authentically you than another aspect of your brain? I mean they're both

in your head right. So today this is sort of what we wanted to focus on to talk about some of these types of takeaways from split brain experiments and more recent research on split brain patients. So one really fascinating area of research we can look at is the idea of moral judgments. Robert, can I pose you a scenario and see what you think? Yes, go ahead, band or snatched me here? Okay? Oh yeah, you're taunting me with it every day. I still haven't seen it yet,

but I will. Okay, here's the scenario. Grace and her friend are taking a tour of a chemical plant. Grace goes over to the coffee machine to pour some coffee. Grace's friend asks if Grace will put some sugar in hers, and there is a white powder in a container next to the coffee machine. The white powder is a very toxic substance left behind by a scientist and deadly when ingested. The container, however, is labeled sugar, so Grace believes that

the white powder is regular sugar. Grace puts this white powder in her friend's coffee. Her friend drinks the coffee and dies. Now the question is, is what Grace did morally acceptable or not um given this scenario, I mean, it seems morally acceptable because she didn't know it was toxic. It was labeled sugar. Yeah, she was do and she

was following a request. Yeah, so you are answering the question the way almost all adult adults tend to answer these questions, that what matters is the intention of the person doing the action. Uh So let me pose it another way. Same scenario. Grace and her friend or at a coffee. They're getting coffee at the chemical plant. Now it turns out that the white powder in the container is just sugar and it's fine, but it is labeled toxic. So Grace believes that the white powder is a toxic substance,

but she's wrong. She puts it in her friend's coffee. It's actually just sugar. Her friend drinks it. Is what is what Grace did morally acceptable? Well, I would say it is forbidden because she attempted to poison a friend, exactly right. So yeah, this is how I would answer as well. This is how almost all adults tend to

answer these questions. The fact is that in general, adults tend to think that intentions are highly morally relevant, so they usually say that a person who accidentally poisons a friend of theirs with no intent to harm them is not morally blame worthy, but somebody who intends to poison a friend, even if they fail at doing so, is

morally blameworthy. And of course, like you know, there are many aspects that you see this put into practice around the world, and like legal injustice systems, a person is punished a lot more for trying to hurt someone on purpose than for hurting them by accident, though often sometimes they are still held responsible for hurting somebody growth negligent situation, you know. Uh, And that's like a middle category, right like if you didn't mean to hurt somebody, but you

were doing something really reckless, send it hurt them. That's sort of like a middle culpability level, right like if you stored the toxic white powder next to the sugar and she just didn't look closely enough, like you really should you know that this place has as sugar and toxic poison. You should you should know to check which one you're scoop Getting lumps out of right, But we wouldn't think that Grace should have expected there to be

poisoned right next to the coffee machine, right. And on the other hand, Grace, you can't expect Grace to just expect people to be trying to poisoning her all the time like they're they're they're certain cultural expectations in place here exactly. But the weird thing is not everyone answers

scenarios this way. For example, previous research, including by the Swiss psychologist Jean piage Uh and others later, has found that young children and pj found this was up to about the age of nine or ten, tend to attribute moral guilt and deservingness of punishment in exactly the opposite way.

They assigned guilt based on the active consequences of the action rather than to the knowledge or intentions of the agent, meaning that many young children will suggest that if Grace means to put sugar in her friend's coffee but accidentally poisons her friend, she is naughty. But if she tries to poison her friend and the poison doesn't work, she's fine. Well that sounds totally believable. I mean, I now that

it's pointed out like that. You know, I can see I can see various aspects of that popping up in just raising a child, you know, where where they're gonna they're gonna going to jump to this conclusion. You know it certainly not with poisoning, but with just sort of

the everyday minutia that fills your life. Well, they don't reason this way every time, Like sometimes intentions seem salient to them, but generally the rule is after about age ten, almost nobody ever thinks that accidentally harming someone is worse

than intending to harm them and not harm in failing. Yeah, but this, I mean that I've seen this with my son though, where like he'll do something accidentally and then he's really hard on himself for having for for quote, being bad or having you know, done something bad and you have to reassure him you know this was you know, there was an accident, but you know it's all cool. Well,

this is a fascinating phenomenon on its own. I mean, before we even get to how this applies to the split brain experiments for example, you know, I went back, I was like, is this really true? So I was reading some of Pj's work on this question from a book of his. And so here's one of the scenarios he describes when interviewing young children. Okay, the first one is, uh this, uh about this little boy named John, Robert, do you want to read about John? Sure? A little

boy who is called John is in his room. He has called to dinner. He goes into the dining room. But behind the door there was a chair, and on the chair there was a tray with fifteen cups on it. John couldn't have known that there was all this behind the door. He goes in the door, knocks against the tray, Bang, go the fifteen cups and they all get broken. All right. Here's the other scenario. Once there was a little boy

whose name was Henry. One day when his mother was out, he tried to get some jam out of the cupboard. He climbed up onto a chair and stretched out his arm, but the jam was too high up and he couldn't reach it and have any But while he was trying to get it, he knocked over a cup. The cup fell down and broke. Ah. So, yeah, we have a situation where John was just going about normal everyday. How stuff he didn't know where some stuff was. Yeah, and it stuff got broken. But Henry is trying to do

something he shouldn't and then accidentally break something. But here then, PJ includes a little transcript of a dialogue with a six year old boy named Geo about these stories. Robert, do you want to be Geo? I'll be the child? Yes? Okay, have you understood these stories? Yes? What did the first boy do? He broke eleven cups? And the second one he broke a cup by moving roughly? Why did the swan break the cups because the door knocked them in the second he was clumsy when he was getting the

jam the cup fell down? How did Geo become Richard O'Brien? Okay? No, sorry? Going on? Is one of the boys naughtier than the other? The first is because he knocked over twelve cups? If you were the daddy, which one would you punish most? To one who broke twelve cups? Why did he break them? The door shut too hard and knocked them. He didn't do it on purpose? And why did the other boy break a cup? He wanted to get the jam. He moved too far, the cup got a broken. Why did

he want the jam? Because he was all alone? Because his mother, wasn't there have you got a brother, no, a little sister. Well, if it was you who had broken the twelve cups when you went into the room and your little sister had broken the one cup while she was trying to get the jam, which of you would be punished most severely? Me? Because I broke more within one cup. Robert. First of all, I'm gonna give a rave view to your creepy child voice. That was

like a beau, a full riff raff French geo. I think I was trying to go for like a Damian child or something. But you know, Richard O'Brien is still pretty good. It's all for you riff raff. But this is illuminating. This shows, Uh, this shows how the six year old is thinking about these two scenarios in applying judgment. Yes, almost no adult reasons this way right right, So this on its own is fascinating to me. Why this discrepancy in the moral reasoning of children and adults? And what

causes the change? You know? POJ says the change tends to happen somewhere in late childhood, you know, somewhere between like uh, like seven and nine or ten. This change really takes over and people still and the children start reasoning about moral intentions and moral knowledge as opposed to

just the objective outcomes. Uh. One issue I think that plays into this maturation process in moral judgments is of course going to be the development of the sophistication of theory of mind, and theory of mind of course is the ability to understand that others have into mental states

and imagine what those states are. But this clearly can't be the only factor, because most children develop theory of mind by around age five or so, and a significant number of them think outcomes matter more than intentions for guilt until around age nine or so, So there must be something else happening also, so they're able to either able to contemplate other mind states, and yet they're still sticking to this. Uh, this this harsh form of judgment. Yeah.

And again, to be clear, not in every case, because sometimes children will seem to think intentions matter, but they clearly they they default to this far more than adults would. Now, there's one reason to think that, of course, theory of mind is important for making a mature moral judgments the

kind adults make based on knowledge and intentions. For the obvious reason that when you make a judgment considering a state of mind, including the knowledge and intentions of the person who broke the cups or put the powder in the coffee or whatever, you need to imagine their state of mind, like you have to have that in your rain in order to evaluate whether they were guilty or not.

And so in like two thousand and eight two thousand nine, researchers named Leanne Young and Rebecca Sacks used neuroimaging to find evidence that when you try to ascribe beliefs and intentions to other people, essentially when you practice theory of mind and you're thinking about other minds, it involves processes that are lateralized their primarily on one side of the brain,

specifically in the right temporal parietal junction or TPJ. And in a two thousand nine study, Young and Sacks found that uh temporal parietal junction activity in the right hemisphere only appeared when people tried to assess the moral significance of things like accidental harms when you hurt somebody but you didn't mean to. So if I tell you a story about Jeffrey accidentally knocking somebody into the Grand Canyon and then I ask you to think about whether Jeffrey

did something morally wrong or not. Whatever thinking you use to answer that question will probably we involve the t PJ on the right side. But oh, what if the part of your brain that's getting that's interacting with the language that poses this question to you, cannot retrieve information

from the lateralized TPJ the right side the brain. Yes, so we're gonna look at the two thousand tens study from Neuropsychologia called Abnormal Moral Reasoning and Complete and partial calisotomy Patients by Miller, Senate, Armstrong, Young, King, Pagi, Fabri, Polinara,

and Gazanaga. So the authors begin by looking at the state of affairs we just talked about, uh, with the you know, the localization in the right hemisphere of this part of the brain that's used in imagining other minds and making judgments about something like the intentions of somebody

in reference to moral guilt and the right quote. These findings suggest that patients with disconnected hemispheres would provide abnormal moral judgments on accidental harms and fail old attempts to harm, since normal judgments in these cases require information about beliefs and intentions from the right brain to reach the judgmental processes in the left brain. So they ran a test. They used six split brain patients who have had either a partial or total sectioning of the corpus colosum and

compared that with twenty two normal control subjects. Now verbally, so what they did is verbally out loud conducted interviews posing moral judgment scenarios like the sugar or poison story we talked about with Grace, but also other ones like it uh. They conducted these interviews verbally, asking the subjects about whether different types of action in the scenario were morally acceptable or not. And remember, of course, which hemisphere of the brain is the one primarily responsible for speech.

It's the left. So if you're having a verbal interview with somebody, their left hemisphere is sort of like it's like the gatekeeper right that will in most cases be dominating the input and output of the brain you're interacting with,

since the input and output is all spoken words. So if you have to give your answers in words coming from your left hemisphere and it can't communicate very well with your right hemisphere or at all with your right hemisphere, which is the home of an important part of the brain that used to think about the knowledge and intentions of other people. Your verbal answers on subjects requiring this kind of knowledge may very well be impaired, and the results,

it turned out, supported this hypothesis. The control subjects, the people without split brains, they tended to judge just like we did earlier. Like they judged based on intentions, well, did grace mean to harm somebody or not? And that was the mainly salient thing. The split brain patients did so far less consistently, more often judging based purely on outcomes, the way many young children did and pj's work, and also to supplement their experiment, they tested two of the

split brain patient's ability to detect hypothetical faux pause. For example, a person quote telling somebody how much they dislike a bowl while forgetting that the person had given them that

bowl as a wedding present. Uh. And of course, the idea is that a person who's unable like if you're unable to give spoken answers involving the theory of mind function localized in the right TPJ, you will find it significantly harder to detect a faux paw which requires you to think about other minds, and the split brain difference

held true here. Out of tin faux pause, they said, patient VP successfully detected only six and patient j W correctly identified only four, whereas control subjects all identified a hundred of the faux pause. So when they were given a scenario like that and asked did something awkward happen

normal people? They detected every time. In fact, one of the things that I would say our brains are most highly suited for is detecting social awkwardness and stuff, right, Yeah, And it is interesting to notice this emerging in younger or children too, you know, like you see this kind of awareness coming online, you know where they're able to identify faux pause as opposed to just be like the master of folk pause. Well do you ever notice I wonder if like adolescence and teenage years are kind of

an error. It's like it's a time when you were almost like hyper aware of social awkwardness. Does that ring true to you? Um to a certain extent? But I don't know. I've run into some teens who I mean, there are a lot of different types of brains out there, but I mean I've run into some teams that that definitely have a lot of social awkwardness or or definitely

walk into a lot of faux pas. So I don't know. Well, I mean, just because you are awkward doesn't mean you're not aware of awkwardness, right, Yeah, certainly awkwardness does seem to define that buried in one's life. That would be that might be something to come back to. I know we've done episodes in the past on the teenage brain, in the particular aspects of the team age brain. I wonder if there's a if there's an entire episode on

the science of awkwardness. Well, I think we should take a quick break and then when we come back we can discuss this study a little more than alright, we're back, all right. So we've just discussed this study about split brain patients and moral judgments and found that split brain patients, at least in this one study, made moral judgments based on outcomes rather than on intentions, more like children sometimes do instead of the way that adults normally do. Um,

And this is fascinating. Now, of course, we should acknowledge some potential drawbacks of this experiment. Like all split brain studies, by necessity, it's a small sample, right, you know, there aren't that many of these people out there, and even a smaller subset of them want to participate in experiments like this, But so it's almost on the scale of anecdote, so you have to be careful about drawing strong conclusions

from the results. Also, there are some other detailed complications in the study, such as questions about why the effect also manifested impartial calisotomy patients, so when the authors had not expected it to they thought it would only appear in the full calisotomy patients. And then also about where the exact side of decoding the beliefs of others is located. Maybe it's not exactly the TPJ but more anterior to it.

Uh So that's some peripheral issues. But nevertheless, if we tentatively accept these results like how fascinating, and it leads

to these questions like here's one. You know we discussed in the last episode that despite the radical nature of the surgery that cuts the corpus colossum and the amazing neurological anomalies that can arise from it under lab conditions, generally most patients and patient families report totally normal functionality no major changes in personality or behavior after the surgery. If it's changing their moral reasoning in in this kind

of way, how could that be possible? I mean yeah, because certainly from your own standpoint, I mean, you were if you're moral compass has changed than you I mean, you can't see the forest for the trees, right, But but you're gonna be surrounded by other people who would be able to identify the change. But presumably yeah, you would think so, I mean if there is actually a change.

So uh. And and also like, yeah, you think that moral judgments sort of go to the heart of a person's personality, right, like that that is your character, that is who you are as a person, or at least how you think about that subject. Right. You would think there would be anecdotes out there about like, yeah, my uncle had this surgery and then his like his his political ideology changed afterwards, or yeah you have been something to that effect. But we have not seen that in

referenced in any of these studies. So, if these results from this two thousand ten studies are sound, what accounts for the discrepancy here? And the authors they posit three possible answers. One is, well, maybe there are profound personality changes in split brain patients that have gone unnoticed or unreported.

They don't think this is very likely because quote, most reports from family members suggest no changes in mental functions or personality, and early studies that thoroughly tested patients pre and postoperatively reported no changes in cognitive functioning. So they feel pretty robustly that these patients in their day to day lives are not really changed. The other possibility as well. Maybe it's just because the judgment tasks here have no

relevance to real life. But I mean, we use judgments like this all the time, like did somebody mean to do something that? That seems like something that comes up every day? Yeah, I mean I jokingly brought up Bandersnatch the Town Adventure Black Mirror episode on Netflix earlier, But like I I found myself in watching that, like having to make choices about moral choices for the character. I found myself very uncomfortable with with choices that that I

found morally reprehensible, even though it's just purely hypothetical. It's just a story, right, all right? What else do we have? What other possible answers? Well, the third possibility is what the researchers think is probably the case, which is that even though this impairment is manifested in the lab, in reality it somehow gets compensated for somehow in daily life.

Other brain regions and functions or alternative processes kick in to counteract whatever is causing people to give these unusual answers in the lab condition. The brain finds a way, yes, so what would it be, Well, what about a version of something not exactly but something like the system one versus system to schema. Of course, now, of course we can remind people what the system one in the system to themes are. Well, it's like, basically like the different

ways of dealing with the threat of the tiger. There's the way of dealing with the tiger by avoiding it and not going to the places where the tiger is, and then there's the way of dealing with the tiger where you have to fight it re flee from it. So I think we'd have the order inverted there. But yeah, so like system too is generally considered to be like low deliberate, methodical, logical thinking about how to solve problems, whereas system one is fast, reactive, intuitive, implicit right punch

the tiger in the nose and run for it. And we need both for life. I mean, system to reactions might be less likely to give us erroneous results. But you don't have time to use system to thinking on everything. You know, you're trying to get through life. Most of the time. You need to make quick judgments that are not overly concerned. You know, you can't overthink, like which foot I'm gonna put in front of the other right now? Right? Yeah, So so you've got to be prepared for either tiger,

the distance tiger or the close tiger. And so maybe the idea here is that the right TPJ is somehow necessary for making fast implicit system one type decisions about judging more, you know, the moral valance of an action and imagining theory of mind. But that you can if you can't do that, you can somehow do the same thing. It just takes longer, and it's is a more difficult, deliberate process that the brain has to go through if it can't rely on this brain region that does does

this fast for you normally the author's right quote. If the patients do not have access to the fast implicit systems for ascribing beliefs to others. Their initial automatic moral judgments might not take into account beliefs of others, but you know, they're slow reason deliberate thinking system can compensate,

it can kick in. Then again, I mean, I wonder how this, if this is the case, and we'll discuss this a little more, how this wouldn't manifest in normal life, because I feel like we use the fast intuitive system one type process to make morally relevant judgments all the time. I mean, we're constantly making sort of unfair moral judgments about things that would not you know, they're not using the kind of reasoning that you would sit down and

deliberate about. Think about how often you get mad at somebody because they do something accidentally, and if you were forced to stop and think about it, you're like, Okay, no they didn't, they didn't mean to do that. There's no reason to morally blame them. You just get mad in the moment and you're just like, why are you in my way? Or why did you do that? Yeah? Yeah, totally.

This is you know, this like the the other split brain experiments we're looking at, though it reminds me of say, if you're watching a three D film and you have the glasses on, and then you take the glasses off, and you you you see that there is there's there's some sort of uh uh, you know, there's a lack of unity there. Or it's like you're you're staring through the stereo view and then you look at the card and you see that it's two images side by side

to create the united whole. Like it's it's a glimpse at the duality that that is making the at least, you know, the sort of the illusion, the experience of the whole possible. Um. But but but then it's it's we we shouldn't fall under the we shouldn't then fall into the trap of thinking that it is dual by nature. It's like taking the US is up and saying, oh, the world is really red, the world is really blue. Well, no, no,

that the world is the thing that comes together. Yeah, And and the glasses are designed to give you this three D image the same way that the brain is designed by evolution to have compensating processes, to have one way of doing something or another way of doing something depending on the situational need. And so, of course I indicated that the authors tend to think this third answer is probably the correct one about the compensating mechanism taking

over in real life scenarios. Uh And as evidence, they cite the fact that in the experiment, split brain patients would sometimes spontaneously blurred out a rationalization of an answer that ignored intentions, almost as if after giving the answer out loud that ignored intentions, they realized something was wrong with it. So here's one example. A split brain patient named JW hurt a scenario where a waitress thought that serving sesame seeds to a customer would give him a

terrible allergic reaction. She thought he was allergic to sesame seeds. She tried, she served him sesame seeds, but it turns out he wasn't actually allergic. She was wrong about that, and the seeds didn't hurt him, even though she thought they would. J W said the waitress had done nothing wrong. Then he paused for a few moments, then spontaneously blurted out, sesame seeds are tiny little things. They don't hurt nobody,

you know. It's it's almost as if he was searching for a post talk rationalization of an answer he'd already given, but which began to seem wrong to him as it sank in, you know, given a few more seconds to think about it, and the patient j W alone, they reported spontaneously blurted out rationalizations like this in five of the twenty four scenarios, so like more than a fifth, and again, I just think back to the fact, you know,

post talk rationalization is a huge part of life. We talked about this in the last episode with the the writer and the elephant, right, like, how often do we do things that honestly we don't understand why we did them, but we just come up with a story, and we even believe that story ourselves as an explanation for why we did it. But you can see clear evidence that

that is not the reason. Right, Yeah, you end up telling yourself, well I wanted that product, or perhaps oh well you might even you know, you might even end up telling you so the st of the story about how you were tricked into buying it. But but there is some sort of rationalization about the about the movements of the beast beneath you. Alright, on that note, we're going to take another break, but we'll be right back.

Than all right, we're back, Okay, I think we should take a look at another study about moral judgment and the division of the brain hemispheres. So this is one from Royal Society Open Science from called moral judgment by the disconnected left and right cerebral hemispheres, a split brain investigation, and this is by Steckler, Hamlin, Miller, King and Kingstone. Uh. And when you get king and Kingstone together, you never

know what's gonna happen. So to recap from the last study, we know that lots of parts of the brain are used in making moral judgments, including you know, regions and networks in the left hemisphere such as the the left medial prefrontal cortex, the left temporal parietal junction, and the

left singulate. But in order to make moral decisions based on people's intentions, when you're imagining what other people mean to do and what they know, we seem to require use of an area in or around the area mentioned in the last study, the right tempo parietal junction or rTPJ. And it seems that without it you can't properly imagine other people's intentions and beliefs to make a quick moral judgment.

So here's a question. Then the right hemisphere seems necessary in making a quick moral judgment in the normal way based on people's intent, But is it sufficient Could the right hemisphere alone make a judgment? So the authors try to find out with the help of a split brain patient. They write, quote, here we use non linguistic morality plays with split brain patient j W to examine the moral

judgments of the disconnected right hemisphere. So obviously you've got a problem if you're trying to just talk to the right hemisphere, because the right hemisphere is not going to do super well at understanding a verbal scenario you describe to them. Right it doesn't want to listen to you tell a story. It doesn't want a lot of dialogue. It just wants some sweet, muted YouTube action the silent

film hemisphere. And again not to not to be overly simplistic, because we do know from some research that the right brain does seem to understand some language, it's just not nearly as linguistically sophisticated as the left hemisphere. Um So they use these nonverbal videos of people trying to help someone and succeeding or failing, or trying to thwart someone

and succeeding or failing. So an example might be somebody's trying to get something down off of a high shelf, and then somebody either like bumps into them to try to knock them off the shelf or tries to help them get the thing down or something like that. And then they had j W watch all these videos and point with the finger of a specific hand which is controlled by the opposite hemisphere, to indicate which character was nicer.

So in a series of test sessions like this over the course of a year, they found that JW was able to make pretty normal intent based judgments with his right hemisphere alone pointing with his left hand, but had a lot more trouble making intent based judgments with the left left hemisphere, in some cases seeming to respond almost

at random with the left hemisphere. And yet the left hemisphere is the hemisphere that the talks, so there were more signs of the left hemisphere making up ex post facto justifications when it did not understand what what the person had done. For example, after one video, when asked why he made the choice he did of which character was nicer, JW just offered the rationalization that blonds can't be trusted. When one of the actors in the video

was blonde. So here's one question why the discrepancy with the last study. In the last study, the left hemisphere defaulted more often in making moral judgments based on, remember the objective good or bad outcomes, rather than people's intentions. Why did it seem to make judgments at random this time?

So the authors say, maybe in the previous study it's because subjects were explicitly asked to judge whether a behavior was morally acceptable or not, and in this study instead, the subject was just asked who's nicer, Maybe to the left hemisphere, you know, separated and on its own devices. Maybe it doesn't use any kind of moral reasoning to judge who is nicer, but uses some other kind of rubric.

Maybe nicer means something non moral to it. Then again, there's also the possibility, well, you know, we're again limited to small sample sizes, in this case very small of just one patient. So it's possible that maybe JW is

just unusual. That's always a thing to consider with this kind of study, and it's what you know, unfortunately, what what this sort of research is by nature limited to one of the things that I think is interesting and looking at this research, we we've looked at today with the different kinds of moral reasoning in the different hemispheres, is that we see again the role of something that we talked about in in part one of this series back in the first episode, about the role of what's

thought of as the interpreter, or at least in Michael Gazzaniga's theory, that the interpreter in the left hemisphere. So the idea is, of course, that your brain constantly makes up stories to explain why you just did what you did. But split brain research indicates that we have no guarantee that the stories we give to explain our own behaviors

have any explanatory power at all. A lot of times it seems more like they are just confabulated post talk rationalizations, that you just came up with something to explain something you did when you really have no idea why you did what you did. The brain just pulled it out of its own button. If the brain had a butt. In the previous experiments, this had to do with stuff

like why did you draw this picture you know? Or why did you pick this object out of a drawer with your left hand when you couldn't name that object in speech, or anything like that, and people would make up excuses. Now you you see a similar kind of thing perhaps going on with making moral judgments. And I think that there is some research that this is indicative not just of something about split brain patients, but of something larger about this phenomenon of interpretation in the left

hemisphere and of the human condition itself. Yeah, like we've we've touched on in this episode Sode, in the previous episode, and in any other episodes before. It's like there's always a story that is told, right, We're constantly telling a story about ourselves, and that story involves rationalizations, rationalizations for our actions and uh and interpretations of who we are and why we're doing everything we do exactly. And it

happens in multiple level. It happens to explain why you have why you took certain actions that you can't actually explain.

It happens to explain why your mood changes. Because Aniga writes about this that there are these cases where you can have somebody who's has a mood shift triggered, like for example, you get you have split brain patients where you show some positive or negative mood, triggering stimulus to the right hemisphere, and then the speaking part of the brain expresses being upset, but then we'll be unable to express why, and we'll just make up a story about why, like, well,

because you did this thing that made me upset. And crucially, I think it seems to be the case that when we make up stories like this, they're not just you know, they're not just outward facing. It's not just pr for the brain, it's inward facing. We are convincing our cell that this made up story is correct. Yeah, it helps create like the internal reality that we cling to. Yeah, exactly. And so it's it's interesting, I think, to notice that

this appears to be linked to the brain's capacity for language. That, at least, according to Kazaniga's theory here, if he's correct, the part of the brain that makes up explanations for why something happened is also highly associated with the part of the brain that is able to talk about things.

And that very well might not be an accident. It seems possible there's a link between the networks of the brain that have the most to do with generating conscious experience and the networks of the brain that are able to put things into words. And that's fascinating alright. So under under Gazaniga's ideas here, the consciousness generating capacity is

located primarily in the left hemisphere. And what happens when you have a split brain patient is you essentially cut off the conscious part of the brain's access to half of what the brain is doing, right, Yeah, though that half of the brain is still over there doing stuff. Yeah. With with each example that we we we pull out here, each each study, it is still very difficult to really grasp. You know. It's it's again this kind of you can't

see the forest for the tree situation. It's hard to imagine the consciousness we're experiencing, uh, in a in a system that's been divided, you know. Well, yeah, that's one thing that that's so interesting here. I think one way you could misunderstand what the split brain cases show is that if you cut the brain in half, you generate two conscious, independent people. And that appears to not be

the case. People still get the man with two brains, like with Steve Martin, right, you get one conscious experience. The person generally does not report feeling any different, as we talked about last time, Their behavior and stuff is generally about the same as it was before, except you have the ability to show under certain conditions, there's this whole half of the brain over there doing things that

you cannot be conscious of or put into words. So it can still sense, it can still control the body is just apparently not integrating or synthesizing into whatever creates your conscious experience, which I mean in a way that is that that is sort of like having the other fellow in there, in the words of Robert Louis Stevenson. Now to bring up another literary example. We've talked about

Peter Watt's book Blindside on the program before. I'm sure you remember the character Siri Keaton, who loses his brains left hemisphere to infection, and and and and and as a result of that, entire hemisphere is largely or entirely replaced with like a cybernetic implant. Yes, and this creates a lot of the strange psychology of the narrator in that book. Yes, yes, I can help and think of that.

When we were talking about this, also, I was reminded of a character in the book Consider Felibus by Ian M. Banks, who who has tweaked his brain so that you can engage in uni hemispheric sleep. We didn't even get into that in in this episode. But of course this is something that for instance, dolphins can do. Uh, it can't just go to sleep, so they'll put one side of their brain, one hemisphere of the brain to sleep at

a time. And so and then that particular book, it was he was probably leaning a little bit into sort of the left brain right brain myth a bit, but he was discussing how if one side of the human brain is sleeping and then only one side is awake,

you are going to have a different expression of that individual. Now, if the Gazonica model of consciousness is correct, Uh, that wouldn't make me wonder that if a human were capable of uni hemispheric sleep, would the human be conscious while the right brain is sleeping and not conscious while the left brain is sleeping, and yet while the left brain is sleeping, still awake, just not conscious. Well, I guess you'd ultimately and then you'd have to work out exactly

how this would work in a human scenario. But you as long as one side would be awake to alert the other side when full brain alertness was required, you know that would that would be the main prerequisite. I just thought to look this up. I wish I thought before we came in here, whether there are any lateralization properties of sleepwalking. Oh, that would be good too. Well, we we need to come back and discuss sleepwalking in in depth, because I'm sure there's a whole episode just

right there. We've done some episodes on what paras omnia in the past, like sort of covering various weird sleep phenomena. But yeah, that would be a fun one to come back to, for sure. You know. Speaking of Peter Watts, I remember he's written about this idea of if thoughts were inserted into your brain from the outside, would you even perceive them as alien or would you just perceive

them as self? Because Gazzaniga's left brain interpreter model might be totally wrong, of course, but let's just assume for a minute that it is correct. Things happen unconsciously in modules all throughout the brain, and then regions in the left hemisphere have the job of synthesizing all that activity and generating a story that explains to you why your brain just did something. And this interpreter function is somehow crucial to what we think of as the human experience

of consciousness. Consciousness is sort of is this story we tell about why we're doing things and who we are now. Normally, if something enters your left visual field, goes to the right hemisphere, gets processed there, and then travels to the interpreter and the left hemisphere through the corpus closum. That doesn't feel like you're getting that thought or information or experience from somewhere else. It's all just self. It all

just gets interpreted and it's you. So if we were to start using some kind of brain to brain interface or a computer to brain interface where it were possible to transmit thoughts into the brain from outside, and who knows if that's really possible, of course, but just assume would we be able to tell the externally inserted thoughts the sort of incoming brain mail from activity arising in networks and modules natively throughout the brain itself, or would

it just all go to the interpreter the same way. So you could send an alien thought into somebody's head and have them immediately rationalize it as part of the interpret itself the same way they would if it came from some network in the right hemisphere, would they just think, yep, this is just me thinking I feel like we're borderline there with certain individuals in their use of smartphones. Oh yeah, where imagine you and I'm listeners out there, you've had

a similar experience. We would be in a conversation with someone and they'll without a phone to remember something. But but but often like not in a way where it's like, oh yeah, I forget that, let me research it, More like, let me access this part of my memory. Yes, I know exactly what you mean, and I, um, I don't know. I mean I wonder what the processes by which the

interpreter function. Again, just assuming this model of the interpreter and the conscious experience is correct, mean this, you know, this might be mistaken. But if this is correct, what is the rubric it uses to decide what gets integrated as self? And what what does it decide is alien? That's a great question. We'll have to come back to that in the future. Maybe there is none. Maybe it's

also maybe there's no future. Oh there's maybe there's no self. Yes, well, you know it also brings up the question, you know, are we limited our Is our identity limited by the things that we have at our disposal in our mind? Do you count the things that we we have to depend upon, that we have externalized, you know, And I feel like that is part of the modern human experience, has been part of the human experience for a while.

I mean, if an author writes, say, thirty books, um, and that author cannot repeat them from memory, they are not a part of his his or her mind. Uh, then you know, how do you weigh that into the equation of self? Yeah? Exactly. And what if you didn't write them? What if these are just books that you have incorporated into your thinking about things? Are those now a part of your brain? If you know that, you could consult them in order to figure out what you

think about something, but you can't do it without consulting them. Yeah, what if it's a book that you've written and you've forgotten. I believe Stephen King has a couple of examples of that right wherever he doesn't remember writing a particular novel. I think one example was Coujo. He said they didn't

remember writing it because he was on drugs. Yeah, so it's Kujo a part of Stephen King likewise, I mean, there we all have, prehaps the books, films, etcetera, some sort of external influence that has been important at one point in our life, and then is discarded later and then sometimes pick back up again. Oh, there's an extremely

strong social component here. Lots of people figure out what they think about something by checking to see what somebody else thinks about it, whether that's a person you know known to them, or some public figure that they you know, derive opinions from. Yeah, and you know what, I'm gonna go ahead and take a stand. That's not behavior I encourage do not do not trust another person as much as you trust your own, right hemisphere, don't just directly

incorporate their their information as as self. I can agree with that. Yes, all right, well there you have it. We're gonna go ahead and cap off these two episodes Part one, Part two, Hemisphere, left hemisphere right if you will, Uh, if you want to check out other episodes of Stuff to Blow your Mind, you know where to go. Head on over to stuff to Blow your Mind dot com. That's the mothership. That's where we'll find all the episodes of the show. And don't forget about Invention at invention

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