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Episode 32: On Consciousness with Bernard Baars
41 Plays4 years ago
Joe and Rolf talk to Dr. Bernard Baars, a leader in the field of consciousness research. Dr. Baars has recently published "On Consciousness", which is a compendium on his work integrating research in psychology and neuroscience on what consciousness is and how it functions. T
Special Guest: Bernard Baars.
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Transcript
Introduction to Bernard Bars and Global Workspace Theory
00:00:09
Speaker
Hello and welcome to Cog Nation. I'm your host, Rolf Nelson. And I'm Joe Hardy.
00:00:15
Speaker
And today we have a very special guest with us, Bernard Bars. So Bernard Bars is one of the most important researchers and writers about the topic of consciousness. And he's played a formative role in the emergence of consciousness as a scientific topic, starting in the 1980s and then in the 1990s. His book, A Cognitive Theory of Consciousness, was one of the most foundational texts in the current research in consciousness.
00:00:41
Speaker
And it outlines his theory called global workspace theory, which is a cognitive theory about how consciousness works. And that's what our main topic will be about today. Recently, he published an updated version of this book along with an enormous amount of evidence and updated thinking, as the idea of global workspace has been an enormously productive endeavor over the last 30 or 40 years.
Defining Consciousness: Historical and Cultural Context
00:01:06
Speaker
And this book is called Unconsciousness, Science and Subjectivity, published by Nautilus Press. Yeah, it's great to have Bernie on the show, and we hope you guys enjoy it. Welcome, Bernie, to the show. We're so pleased to have you here. I'm very happy to be here. Thank you.
00:01:23
Speaker
Great, so why don't we start out with a little bit of a definition of what we're talking about when we're talking about consciousness, because we can mean a whole lot of different things by it, thinking of the history of the philosophy of consciousness, which sort of goes under a lot of different
00:01:40
Speaker
words that maybe refer to the same sort of thing. I'm wondering if you can set the stage a little bit for how you got involved in research in consciousness and sort of thinking about it as something that could be tackled scientifically. Right. That's the crucial question. Consciousness has been talked about, as far as I can tell, by every single culture that I know anything about. And that is partly because
00:02:08
Speaker
People simply talk about, you know, waking somebody up in order to talk to them or asking them about their dream experiences, as the Jarawa people do, who are apparently very ancient remnant culture from perhaps 90,000 years ago.
00:02:29
Speaker
And one of the things these people do very interestingly is that every, I assume every morning, they discuss their dreams. And so they posit a world of their dreams, which is also the world of their ancestors.
00:02:47
Speaker
But that's all very fancy compared to the kind of everyday-ness of, let's say you're talking to a classroom of kids and they're six years old and they're noisy and distractable. And the first thing you do, of course, is to call their attention to whatever it is that you want to teach them. That is one way in which we access consciousness, and it's very commonsensical.
00:03:16
Speaker
the difficulty historically, and this even is true of William James, who's the greatest consciousness summarizer of the 19th century, I believe, and it's widely considered to be that.
Unconscious Processing: Dichotic Listening and Vision
00:03:34
Speaker
And his great book, The Principles of Psychology, is about 90% empirical work on consciousness. And so he talks about pretty much all the things that we know today. But he has a difficulty
00:03:51
Speaker
a very profound difficulty because for James, the mind is nothing but consciousness. And that means basically that he doesn't have any basis for comparison.
00:04:06
Speaker
And I think that by the 1970s or the 1980s, partly influenced by computers and so on, we started to realize that the brain was processing language, for example, unconsciously, as well as consciously. And that became really obvious
00:04:28
Speaker
to people like myself who tried to keep up with that literature because it showed up in a situation called dichotic listening. And the word dichotic means that you get two different messages into your two different ears.
00:04:46
Speaker
And if you force the listener to track only one ear, let's say the left ear, that also meant that the person could not hear what was coming into the right ear. And nevertheless, the evidence showed up that whatever the unconscious stuff was coming into the right ear was still being processed up to quite a high level.
00:05:11
Speaker
And that was a very, very important realization. Originally, we learned it from language and audition studies, and then it became obvious, I believe, in vision in the 1970s. And at that time, vision scientists started to go back to Herman von Helmholtz, who in the 1840s had proposed
00:05:40
Speaker
that vision requires a lot of unconscious processing and it's intelligent, unconscious processing. So these days, for example, we can't even think about eye movements in reading without thinking about a lot of unconscious processing that's involved with directing our eye movements,
00:06:05
Speaker
and in the kind of snapshots that we take of whatever it is that we're reading and the snapshots that we do not take, but which we infer unconsciously, the visual system does that beautifully. And so I think the actual viewpoint that we have all arrived at in the sensory sciences, and you can correct me on this, of course,
00:06:33
Speaker
is that what we experience as conscious vision or conscious hearing or even conscious comprehension of language that is simply surrounded by all kinds of intelligent, unconscious little helpers, if you will. And that realization, I think, then made it possible for us to imagine experiments
00:07:02
Speaker
that were extremely well controlled because we would compare consciousness or the conscious flow of information in one eye, for example, at the same that there was unconscious processing in the other eye, and that is called binocular rivalry. And binocular rivalry has been known for a long time, but it was puzzling to people because they did not have this
00:07:32
Speaker
computer-like concept of unconscious, intelligent information processing that is so enormously important in our current way of thinking about things. And the key thing there was that it suddenly became possible for us to run comparison studies between conscious and unconscious conditions and to imagine that they were similar
00:08:01
Speaker
that the two streams, the conscious one and the unconscious ones were similar in their type of information processing. So it wasn't that the conscious one was intelligent and the unconscious one was dumb or automatic or unable to adapt or anything else like that. They were strikingly similar. And that I think opened the gates.
00:08:29
Speaker
for experimental psychologists and by now experimental brain people as well, to study two streams of information, the conscious one and the unconscious one. And some of my favorite work was actually done in Paris by a team at the National Center for Research and for Scientific Research in Paris, which is their
00:08:57
Speaker
National Science Foundation, in a sense. And the two scientists who were involved with that, both extremely good, are named Stanislas Dahan and Jean-Pierre Changer, who's also the discoverer, actually, of some of the first neurotransmitter, chemical neurotransmitters. So he's a very distinguished scientist.
00:09:27
Speaker
These very good people have been interested in all this stuff and they have conducted the right kind of systematic research with brain imaging and so on. And it's gotten better and better. And that has been only one of the research lines. There have been medical research lines dealing with coma, for example, because coma has been very mysterious. And today also dealing with sleep and other
00:09:57
Speaker
a whole crop of questions that all implicate consciousness and that all kind of require a conceptual framework with which to think about consciousness.
Scientific Methodology in Consciousness Research
00:10:12
Speaker
So the gathering of the evidence over the last 30 years has really gone hand in hand with our emerging ideas.
00:10:23
Speaker
about consciousness. And the key thing to understand here is that in this kind of science, which is inductive science, it's bottom up science, we don't start with definitions. We start with what are called operational definitions. And basically anything is an operational definition that gives you kind of a solid intuitive handle.
00:10:51
Speaker
on the phenomena that you think might be involved. And there's a lot of guesswork in that early grasp for this idea, but it's absolutely routine in the history of science. So that in the Renaissance, you get Galileo, for example, working on his conception of temperature. And he devised very cleverly
00:11:21
Speaker
a very crude measure of temperature involving little glass balls filled with oil that went up and down in a glass tank that you could see through. And so you could tell if it got warmer, some of the little glass balls filled with oil.
00:11:47
Speaker
drifted up to the top and some of the others drifted down to the bottom because it has to do with the density of the liquid inside of the little glass balls. And Galileo is very brilliant at this process of beginning to get a handle on an empirical phenomenon that at that time was not really defined because definitions come quite late in that process.
00:12:16
Speaker
What he was talking about, of course, was what modern physicists call heat. And heat has to do with the motion of molecules and so on. But that only came in the 19th century. Galileo started three centuries before that. And he had no idea about molecules, right? Or about quantum mechanics or about infrared light. Absolutely no idea about those kinds of things. What he did though,
00:12:44
Speaker
And what made Galileo so important is that he found a way to have a pretty good first approximation that was empirically very solid so that you could build on it empirically over a period of time. And eventually, a few centuries later, Maxwell, I guess, came up with the concept of heat as the central
00:13:14
Speaker
node in thermodynamic theory. But that took centuries. And in the meantime, people were mostly wandering around clutching their heads and trying
Philosophical Perspectives and Critiques
00:13:25
Speaker
to figure out what the hell this temperature thing was. So that's the way inductive science proceeds. And when I got started with this, I had done a fair amount of reading in the way inductive science works.
00:13:42
Speaker
It was very much the way in which psychometric theory was working because you had the same problem. You had these personality features that people had talked about forever in literature and history and so on.
00:14:01
Speaker
But you didn't really know how to capture those personality features. And so the idea came about that what you needed to do is get any paper and pencil tests usually with questions about personality. How do you feel about this? How do you feel about that?
00:14:20
Speaker
And very slowly, people did statistical testing on this kind of thing and found out that there were correlates with certain personality features and low correlates or non correlates with other personality features. And they developed the series of personality tests that we have today, which is very rich and very revealing. And they really do have to do
00:14:48
Speaker
with the way human personality develops over the lifetime from childhood to old age. So that was the same kind of inductive science program that started very modestly, very simply with some very, very basic ideas, and then found a way to experimentally and observationally hone in
00:15:18
Speaker
on the concept that you were trying to understand, and with a lot of luck and a lot of hard work, that turned into a more sophisticated and more refined scientific concept. So that consciousness is something that emerges after 30, 40 years of work, or actually much longer, of course, because we have a prehistory, an enormous prehistory,
00:15:46
Speaker
philosophy about consciousness. And I think that in the last 10 years, maybe, of research in brain science and psychology, what we're looking at is a pretty good grasp of what is happening in the brain, wherever it is happening, and how it relates to the difference
00:16:15
Speaker
between conscious and unconscious streams of information in the brain.
00:16:23
Speaker
Good. OK, so you said lots of interesting things. And so with that set up and sort of thinking about this inductive process of going about trying to conceptualize something, maybe we could jump into your attempt to do this for consciousness, which is creating an operational definition of consciousness
00:16:48
Speaker
I guess you would call global workspace theory an operational, well, I guess that's a question. Yeah, the global workspace theory actually is a theory. That is to say it's a set of hypotheses that are testable and that appear to hang together. So this is not a sophisticated advanced theory. This is an early
00:17:13
Speaker
attempt to organize what is actually a very large body of information that we have by now. And the key to that body of information kind of gelled as early as 1982 for me, because you have to remember, of course, that we had had 200 years of really excellent research already.
00:17:40
Speaker
It was not very reputable at that time, but we had extraordinary research in sensory psychophysics, for example, starting around 1800. And sensory psychophysics is what we use today for all of our
00:17:58
Speaker
edutainment electronics, right? So if you're listening to audio phones or looking at a screen of some kind, that's all engineered by reference to that 200 years of work in sensory psychophysics.
00:18:17
Speaker
Now, from your perspective, too, I mean, a lot's going on in philosophy at this time, really starting with Descartes, I guess. Do you find a lot of the philosophy surrounding consciousness from this time onward to be helpful in conceiving it? Or do you find it to be a block in some ways? Because it talks about very different things. Yes, exactly right. What happened
00:18:47
Speaker
I started as an undergrad being interested in philosophy actually and then very early on I realized that Anglo-American philosophy had essentially painted itself into a corner
00:19:03
Speaker
that it could not get out from. That was what was called the language approach to philosophy, which basically said that all of science was outside of academic philosophy of the Anglo-American kind. And so from that point onward, philosophers essentially became, I'm going to say this, even though it's critical of people that I like and respect, philosophy essentially became a very defensive
00:19:33
Speaker
defensive in that it had to play a second role to empirical research? Well, that's very much true, yes. You have to remember that philosophy was never separate.
00:19:48
Speaker
from natural science until about 1900. Because if you read William James' great book, The Principles, something like, I'm guessing 80, 90% of that book is purely empirical. It covers a huge amount of research that was done in the 19th century. Psychophysics was part of it. Wilhelm Wundt was a very great experimentalist and done a lot of work
00:20:18
Speaker
selective attention, for example, and on the integration interval of sensory information, which is usually less than 100 milliseconds. And this was very clever because the technology, of course, was very simple at that time. And also, there are people who who understood a great deal and had read very widely philosophy
00:20:49
Speaker
The philosophy of mind, I should say, really starts with Aristotle, and Aristotle was an empiricist, he was a naturalist, and he described the conscious mind, which was all he knew and didn't know about the unconscious. There's a lot of unconscious stuff going on, of course, but Aristotle knew
00:21:12
Speaker
and explored in a very intelligent way. He was a great, great scientist. And in the fourth century BC, he wrote a book that is now translated quite differently from the way it used to be translated. The current translation, as I understand it, the bio-psychology of the conscious mind. And that's a recent translation. That book came to be known as On the Soul,
00:21:40
Speaker
in English translation, but of course the word soul kept on changing and by the 19th century it was already a discredited notion because it fell victim to the war between
00:21:53
Speaker
science and religion of the 19th century. So the word soul became utterly misleading and people tried to deal with it by using the Latin or maybe using the Greek, but that didn't help very much because those were also ambiguous words. What Aristotle was talking about is a very plain and straightforward naturalist
00:22:20
Speaker
He was talking about the mind as he could study it, and of course, collect all kinds of other opinions on it, introspectively, so that the five senses, for example, were part of Aristotle's way of thinking about the mind.
00:22:42
Speaker
It's nothing particularly wrong with that. They are very, very important senses, vision, hearing, olfaction, taste, touch. But of course, we now think of those senses as much more complex because we understand much more about the physiology of those senses. And we also have an inner sense that we know about, which is the
00:23:10
Speaker
It's not quite clear how to call this, but this is the sense that would include feelings of knowledge, for example.
Evolution of Consciousness as a Scientific Field
00:23:19
Speaker
And today it is associated with a piece of cortex called the insular cortex, especially the anterior half of the insular cortex. And like other aspects of cortex, this one has a left half or right half that are intimately connected to each other.
00:23:41
Speaker
So we actually have a very good grasp empirically right now on these inner senses that have to do with love and despair and fear and all these things that we refer to the inner body, even though their sources are much more complex. So we actually have some wonderful work right now on the
00:24:09
Speaker
what we could call the gut sense, the gut feeling sense or something like that, because we know something about the anatomy and the physiology of that structure. But of course it's all over human poetry and songs. And in fact, I would guess half the songs, half the popular songs that you can hear on the radio are about, you know,
00:24:36
Speaker
You hurt my feelings because I loved you, but you didn't love me, something along those lines. And that's very much part of the common experience of humanity. Anyway, so there were, Aristotle thought there were five senses and they were all external senses, very, very important. And then of course, by the 19th century, if you skip way far ahead,
00:25:03
Speaker
you get all kinds of empirical work being done on the sensory systems that were fairly easy for people to experiment with. So yeah, so in the 19th century, so start of empirical psychology. So you mentioned a couple different researchers that are pursuing this. So Wonta is pursuing it and Helmholtz is pursuing it, starting out the project of psychophysics relating the mental to
00:25:33
Speaker
Exactly, yes. An objective description. So if philosophy and psychology are mostly convergent during, you know, up until the 20th century, as you mentioned, I wonder, have you found philosophy, other philosophy, recently to be helpful or useful?
00:25:55
Speaker
And also, I guess I'm getting at these distinctions how consciousness is talked about in a different way. So Thomas Nagel or Chalmers who think of consciousness as possibly ineffable or something that can't be described, maybe sharpens that divide that Descartes started out with.
00:26:21
Speaker
I wonder if you find some of these things helpful. I mean, say, you know, Nagel's what it's like to be a bat or, you know, any of these sort of recent arguments about consciousness that are mainly thought experiments, but don't necessarily take a lot of the details into consideration. Yes, you're exactly right. I think it's pretty horrible, actually. And I find it to be repetitive and
00:26:49
Speaker
and not very informative, but there are exceptions to that. There is a battle going on within philosophy that has to do with what philosophy is going to be about. And that is a new battle, which is the odd thing about the word philosophy at this point, means at least two different things. One of them is what Anglo-American philosophers
00:27:19
Speaker
redefined it as after 1900, as you were saying. And the other one is what real philosophers have done since Aristotle and long before, which is essentially developed the basis of what we call empirical science, because empirical science is nothing but
00:27:42
Speaker
ancient philosophy, if you will. And at some point in physics, for example, as physicists who were called natural philosophers, by the way, because Isaac Newton, for example, was a natural philosopher in the same sense that Charles Darwin was a naturalist. I don't think he necessarily had to look into it.
00:28:08
Speaker
He necessarily saw a great war between himself and Aristotle, for example, who essentially began this coherent study of biology in the Western history of ideas so that we still use the labeling of species. We still use that, which goes back to Aristotle's notion of a classification. How do you classify
00:28:37
Speaker
animals. How do you classify mammals? Mammals are animals that give birth to live young. And that was a very nice way to talk about that. And what we call the Linnaean labeling of species really is an application of Aristotle's law from 24 centuries ago. So there's a lot of continuities there. And Poirot Descartes
00:29:08
Speaker
poor guy. I think he's gotten totally misinterpreted, but I would have to talk to somebody who understands a lot more about him than I do. But we have to remember that it was Descartes who worked out the optics of the mammalian eye. So he went to his... He does get a bad rap, it's true.
00:29:34
Speaker
Yes, it's a terrible thing. And of course, he was genius in mathematics.
00:29:39
Speaker
He was a theologian, which at that time was a terribly important thing. And I have no idea why he is sort of smeared these days with this mind-body separation because I don't think, as far as I can tell, as an amateur,
Role of Consciousness in Cognitive Processing
00:29:59
Speaker
as far as I can tell, I don't think he was really that much into mind-body separation.
00:30:05
Speaker
Yeah, my understanding was that, you know, from my philosophy courses back in college was that he was sort of carving that out as a way to create some space to do the work that he wanted to do rather than something that he necessarily was super invested in to your point.
00:30:22
Speaker
It's interesting, yes. And again, this would be worth finding a historian particularly who studies that kind of stuff with real care. Because I shared a feeling actually that the cards got in the bad rap.
00:30:42
Speaker
So I mean, thinking back to the, you know, the more empirical side of things, as you know, we're, it kind of brings us together this conversation, the cognitive science, neuroscience of consciousness.
00:30:56
Speaker
What is the processing that's happening unconsciously? What is the processing that's happening consciously? And what's the distinction there? And I guess when I was looking at your work, just reviewing your book just recently, it occurred to me like the question of,
00:31:15
Speaker
Given that there is so much processing happening unconsciously that you're not aware of, and it is intelligent, it's useful, it's helpful for the organism, and it's a lot of the processing that we're doing is that kind of intelligent, as you say, unconscious processing. What then is the purpose of conscious processing? Why would you have it?
00:31:39
Speaker
Right, exactly. And that is the question that once you do the right experiments, right, meaning binocular rivalry or this very beautiful work that's been done for decades now by the French lab and by a number of other labs, I should say, should really give credit to a lot of people many more than I have time for.
00:32:06
Speaker
But a lot of people have jumped on this bandwagon by doing what I call contrastive analysis experiments. And the basic idea is very simple, of course. You're contrasting something that is conscious in the sense that your subject can report it and do stimulus matching and all those other tasks that human beings can do with a sensory, conscious sensory perception.
00:32:36
Speaker
And then you feed in the identical stimulus into the identical foveal part of the retina. And what you find out is that it is not conscious, but it is being processed.
00:32:52
Speaker
So, if you follow the research line that's been pursued by the French group at the Saint-Gernacionate Recherche du Cieltefique by D'Han and Saint-Germain, what you find out basically is that the conscious stream, or the too big conscious stream, if you will,
00:33:20
Speaker
explodes in size, it starts to resonate very nicely the way cortical activities can easily resonate with each other because resonance is the operating code, if you will, of cortex. And then the unconscious stream is also being processed high up in the visual hierarchy
00:33:45
Speaker
But by the time you get to object perception or gestalt perception, it starts to wither away. And that's what you are hoping to find out, of course, by setting up these experiments.
00:34:03
Speaker
And the particular article that I like particularly from that group is first authored by a man named Gayar. And Gayar did very, very sophisticated studies of those two streams of input processing in the visual cortex using
00:34:28
Speaker
very direct electrodes on the cortex, basically. So you don't have to worry about EEG or anything else like that because you've got your electrodes almost on the source of the major amount of electromagnetic radiation coming from the head. If you do scalp EEG,
00:34:55
Speaker
you get all kinds of difficult evidence, but scalp AG turns out to be only, turns out to have filtered out, I should say, 99.9% of the signal of the voltage at the cortex. And so you're much better off if you can somehow get human patients, and this requires a lot of ethical consideration, of course,
00:35:22
Speaker
But you can find human patients who need surgical operations while they are awake and able to respond to direct stimulation on cortex. And so that was done by Galyar and people working with him.
00:35:42
Speaker
But it goes back to Wilder Penfield, if you remember. Penfield and Roberts published a book about this, but it actually started when Penfield received the support from the Canadian government and his colleagues at the Montreal Neurological Institute, and that started as early as 1934.
00:36:10
Speaker
And Penfield basically talked to his patients while they were only locally anesthetized in the section, part of the skull that had been removed and you had to put that in a sort of a
00:36:29
Speaker
Flap so that the blood supply would be maintained to all the tissue because otherwise you don't have blood supply of course and the tissue dies and they did a very very competent job as early as nineteen thirty four.
00:36:46
Speaker
and then found out with a little bit of voltage applied to cortex itself, there were actual conscious experiences that the patients who were awake and not in pain, that the patients could report. And the main discovery of that time that we still
00:37:12
Speaker
think about in those terms, of course, is the sensory homunculus. The homunculus is a word for little man or little human being, which refers to the map, the cortical map of the external body.
00:37:35
Speaker
And basically what happens is that if you stimulate the hand area of the sensory homunculus, people tell you, I feel something on my hand. And in other situations, they'll tell you other things that correspond extremely well to these areas of cortex that were, for the first time in history, being mapped.
00:38:01
Speaker
And there's no question that they were conscious of the sensory events. There's a lot more to be said about that because this was a research program that developed from the late 20s to the 1950s. And there were as many as 1,200
00:38:24
Speaker
epileptic adult subjects who were studied in those operations. And they were the people, of course, who were in terrible trouble because of seizures. And that provided an ethical ground for engaging in these rather risky operations. I don't think they actually lost any people due to operative failures, technical failures.
00:38:53
Speaker
But the people themselves, of course, were at risk of death because of these horrible seizures that ruined their lives. And that made it ethically, medically acceptable to work on these human beings, 1,200 of them. And their individual medical records are still protected today because the ethical
00:39:21
Speaker
criteria of the time made it necessary to protect their privacy. The only one we know from that series, or from a closely related series, actually not the same surgical team, but very much a part of that time,
00:39:41
Speaker
is the patient called HM, whose real name was Henri Molaison. They were Henri Molaison. I think you could pronounce it. In Canada, you have two languages, of course.
00:39:56
Speaker
And Henri-Moulisot, known as HM, was studied, as you know, of course, for decades, going from one laboratory to another laboratory to see what it was like to be in his head.
00:40:15
Speaker
And basically, HM received an extremely radical surgery that excised the hippocampi on both sides of his brain. And this was a revelatory patient
00:40:35
Speaker
And H.M. basically was unable to, he was conscious, he was in a sensory way, and he had the capacity to comprehend, I believe, but he was unable to take his consciousness and store it in a way that he could use later on. So H.M. is a kind of a radical discovery
00:41:01
Speaker
in psychology and brain science. He was not replicated, I believe, not in humans in animal studies, yes, because it was such a
00:41:16
Speaker
such a desperate kind of surgery. And there was a lot of medical debate about whether that radical surgery should even have been done, because after all, he lost his ability to learn from his conscious experiences.
00:41:31
Speaker
So he was not a success story on strict medical grounds. For science, though, I think, and you can tell me if you agree or not, I think that HM was really a breakthrough patient. Oh, absolutely. Yeah, yeah.
00:41:49
Speaker
Yeah, and as we're thinking about, you know, the question of the role of consciousness in, you know, human cognitive processing. You know, HM is an interesting example, because in some sense, he can report on the things that he just heard, he can process that information, apparently, but cannot remember that information later. Right. So memories is one way that you can explore consciousness,
00:42:19
Speaker
Yeah, consciously too. And he had that dissociation between implicit memory formation and explicit memory formation. So he could improve on tasks, but he couldn't, he didn't have that declarative sense of remembering that it was him doing it. Right. And that's extremely important. There's so much depth in the discoveries of that time, and so much that
00:42:45
Speaker
You kind of need to think through a lot because it's not so obvious what that means. Anyway, I think the quick answer in terms of the difference between conscious and unconscious input processing comes from the
00:43:02
Speaker
the Paris group, which actually represents a number of other groups, but I'm just going to mention them to focus on one excellent research group that's been going for 20 years or longer. And so they have really worked out these tricky procedures. And essentially what they have ended up with is a 100 millisecond presentation of a visual
00:43:31
Speaker
object or event, and you can actually take in 100 milliseconds because, for example, if you look at a flash, a flash that you get these days from a cell phone camera, that flash is extremely fast.
Future of Consciousness Studies and AI
00:43:51
Speaker
It's on the order of milliseconds, but it lasts for a much longer time.
00:43:58
Speaker
And that means that we have more time to report it and think about it and look at the changes in the conscious percept. So they did this much more carefully and with much better defined stimuli for the 100 milliseconds of presentation. And then followed it by 100 milliseconds of the identical visual input into the retina.
00:44:28
Speaker
But in a way that was masked in what's called backward masking. And because we can now see what's happening in the brain during the conscious and the unconscious input, identical input,
00:44:47
Speaker
In the conscious case, you get what the researchers call an ignition, which I called a broadcast way back when. But I like the word ignition, actually, because it is closer to the reality. Broadcasting is a kind of a media metaphor. And it turns out that it is actually quite meaningful, I think, to talk in terms of an intra-psychic
00:45:17
Speaker
media where you have a sort of a society on the inside, which is a very, very popular idea that poets and playwrights have come up with it for a long time. And the internal society of processes has similarities to the external society in which we live. And one of the
00:45:44
Speaker
ways in which our society is controlled, of course, is by way of media. And they may be social media. They may be private telephone calls from one to one person. But there is a genuine role for what I call the global broadcast, because I got that idea from Alan Newell and his work on very, very good work in artificial intelligence.
00:46:13
Speaker
and speech perception. He came out with that in 1976, I believe. And his book on that is very important because he essentially proposed the same thing. But Newell was still, I think, unable to talk about consciousness, which is an oddity because it was a kind of taboo that was imposed upon psychological science.
00:46:44
Speaker
by the school of behaviorism very much supported by the logical positivist philosophers in England who also criticized the idea of mind and the idea of consciousness quite viciously so that people frankly didn't want to touch the subject. But of course not touching consciousness
00:47:12
Speaker
is a kind of violation of all the other philosophical traditions that we know. And I want to reemphasize that what we call philosophy traditionally is also a very empirical enterprise. There was really no division between speculative thinking and analyzing words and what they really mean, all that stuff.
00:47:34
Speaker
and actual experiments so that in the Indian tradition, for example, you have philosophers who are constantly thinking about their practices. The term, I think, I have to be corrected on this also, the Sanskrit term for this, I think, is that there is no philosophy without practice, which is quite different.
00:48:00
Speaker
from the way Anglo-American philosophy turned out after 1900. But I think that for the long term of philosophical thought, which is essentially identical to the history of ideas in the West and in Asia, for the long, long term, people did all kinds of empirical stuff.
00:48:22
Speaker
because nobody told them not to. And so what we get with Descartes as one example, of course, is this fabulous experimental work that he did
00:48:37
Speaker
in excising an eyeball from a sheep's head, apparently. He used oxen and sheep at various times. And that's important because they had big eyeballs, of course. And then he would scrape off the back, which only leaves what is called the sclera, which is this tough white tissue, which functions essentially as a projection screen. So then if you point at the lens,
00:49:07
Speaker
of the eyeball at a brightly lit object at noon when there's nice bright sunshine in Paris. What you see is the object that you're pointing to projected onto the sclera but upside down. And that, of course, was a mind-boggling discovery
00:49:31
Speaker
for that generation because they did not have the idea that you could process information independently from the way it would have looked onto the back of the eyeball. But nevertheless, what Descartes ended up with was exactly what empiricists always end up with, I think, which is a bunch of puzzles which he couldn't really understand.
00:49:57
Speaker
But he had the wit and the honesty, I think, to say that. And for example, he couldn't figure out why the exposed cortex seemed to consist of two halves, when in fact he knew perfectly well, and this was already known to Aristotle, of course, that our perception of the world is coherent and integrated
00:50:24
Speaker
and it's internally consistent so that we see the world as if there are coherent objects like the people we see or the cards we see or anything else for that matter. And we know, of course, by now that this is a creation of cortex. It's not that the input in our sensory systems comes in in a coherent way. Sometimes it does. Most of the time it doesn't.
00:50:53
Speaker
But if you think of being a rabbit, for example, trying to skirt you across a field, most of the things that you see are grass or these huge leaves and bushes and so on. And the part that you can actually see clearly, you may just see with one eye. And then somehow you have to fill in the rest because you have to make your way through that field.
00:51:20
Speaker
before the dogs get you, the cats get you, or the owls get you. So rodents, rabbits, and so on always have to be scurrying. And that means they get very little exposure to really good information. But then I think what they do very often is they go to
00:51:41
Speaker
They find an underground tunnel. They relax from all the fright of having to scurry across the field. And then I believe they have to replay what they think they saw. If they thought they saw a snake,
00:51:57
Speaker
they have to analyze that information. They have to start sampling the smells and the tastes of that moment and the movements of what they thought was a snake. And humans, of course, we now know, have a specialized snake circuit in our brains that resides in the two amygdala's.
00:52:22
Speaker
And because snakes are so dangerous to human beings, there's plausibly a biological story there that we must by now be able to pass that on genetically.
00:52:35
Speaker
Let me bring up a question about animals. So thinking about animal consciousness again, one of the things that the conception of consciousness that you're describing here has is that it relies on a sufficiently advanced cortex and
00:52:55
Speaker
Right. Your theory relies or the neuronal version of the theory relies on this resonance between the neocortex and the thalamus. I guess one of the tricky questions about this is how do you disentangle ethical considerations of consciousness from a pure scientific description of what's going on consciously because
00:53:19
Speaker
If it takes a mammalian brain in order to perform these operations, it sort of implies that something, and I thought of this as you were talking about a snake, it implies that something without that sort of feedback loop or without that capacity is not conscious.
00:53:38
Speaker
We wouldn't want to think, I mean, we wouldn't, you know, from a value standpoint, I mean, consciousness has a really particular value attached to it. You know, some philosophers would say that, you know, without consciousness, there's nothing because there's no apprehension, there's no, there's no one, there's no one in the universe to understand it.
00:53:58
Speaker
So if we're making a cutoff in consciousness in this way, does that say anything ethically about, say, creatures that don't have this capacity? Or does it say something about the way that cognition could go on in a snake or a creature where you might not have that same sort of dynamic competing for consciousness? Well, you're raising the right questions, obviously.
00:54:27
Speaker
You know, scientists are not particularly comfortable with ethics and we certainly don't have any claim to authority when it comes to ethics because we can claim authority based on evidence, which is not our authority, it's the authority of the evidence.
00:54:47
Speaker
But then you run into these ethical problems, and they're really unavoidable. We cannot avoid them. Inherently, that becomes very tough. And I take some wisdom, I think, from the late, very great scientist, Yark Panksap, who investigated
00:55:13
Speaker
and wrote books about affective neuroscience. Yack was the guy who discovered what we should have all known but didn't know, that rat pups and rat moms, when they are lactating, when the rat pup is drinking milk from the mom, that they communicate.
00:55:41
Speaker
And because of the size of their bodies, they communicate in very high pitched ways and really above the human hearing range. So that the human experimenters who worked with rad clubs and rad moms actually did not realize that they were constantly calling to each other in very much the same way that human moms and babies constantly stay in touch.
00:56:11
Speaker
physically in touch by touching and by breastfeeding and by cooling and eye contact and all these ways in which mammals keep in touch with their babies. What Jack basically found was that when he rigged up a little contraption to turn very high frequency sounds into audible frequencies for human beings,
00:56:37
Speaker
that he could hear the rat moms and pups calling to each other. And they have alarm calls. They have, I'm here baby calls that goes squeak orient to the sound. Now it comes closer to the sound squeak like that. And the baby will wander back to the mom if it is going to survive.
00:57:04
Speaker
So all this is very, very, uh, basic mammalian behavior. And Jock, uh, I think did wonderful pioneering work and was very deeply concerned with the question of the, of the way we treat animals. So he spent, I believe something like the last 10 years of his career working on that question. How do we deal with particularly the animals we use for food?
00:57:31
Speaker
So how would you see the relation here? It's hard to ask this question, but how would you, you know, if you're looking at, maybe just personally, if you're looking at different animals, you're thinking about, say, a cow, a dog, a sheep, you know, a goldfish, a worm? Yes, that's exactly the right question.
00:57:53
Speaker
And you may be thinking to yourself, well, we know that we've got these recurrent networks in these mammals, and we know that the brain of a fish looks quite different. There's not this kind of global sharing going on, so that it may be operating in a very different way. How does that inform any ethics that you may have of the treatment? Well, I used to be completely skeptical because I couldn't figure out a way, apparently, to answer those kinds of questions.
00:58:22
Speaker
And then I started to read the comparative biologists on this thing. These comparative people, what they do basically is they study the evolution of species and their relationship to each other. And the conventional viewpoint in brain science, and I'm talking about early brain science, even before
00:58:51
Speaker
Santiago Ramon y Cajal discovered the neuron, because after all, we have anatomy. We have all kinds of interesting sources of information that go back much earlier. And the convention in medicine, because in medicine, of course, this becomes a very practical thing because you, you learn about the body by doing dissections. It goes back as early as Hippocrates in the fourth century BCE.
00:59:20
Speaker
And he basically says, whatever you are conscious of, whatever your emotions are, come from the brain. And so in medicine, I think that was kind of the heuristic, the rule of thumb, that it was probably cortex that did the thing. They studied lots and lots of trauma victims and stroke victims, all that kind of stuff.
00:59:46
Speaker
And they developed some very good intuitions, but very often they couldn't prove it because to prove these things with Cortex, especially, because Cortex is such a flexible organ and so adaptable, it is very difficult to do what I think of as automobile engineering. You know, because when your engine is running rough,
01:00:13
Speaker
What you do is you pull out spark plugs and clean them up and stick them back in and see if it's better. And that is kind of the intuitively easy approach to the way things work. And a lot of the time engineers are right, but biology is different because biology has to build in backups. You don't get a chance to fix your spark plugs.
01:00:44
Speaker
if you get injured and your Homo sapiens, let's say a hundred thousand years ago, and your friends are not going to fix your spark plugs either. So what the brain has done over eons of development is built in all kinds of backups. And Jerry Edelman, who I had the privilege of working with for about a dozen years,
01:01:14
Speaker
talked about this as a very fundamental aspect of all biological systems because he studied it at many different levels. He started off with the immune proteins, the acquired immunity system, which involves proteins that stick into the membranes of the immune cells and bloodstream. And those proteins actually evolved to recognize
01:01:43
Speaker
invading organisms and invading proteins, toxins. And that is a learning process. Ugly enough so that if we're exposed to COVID-19 these days, most of us will never notice it because our acquired immunity system learns to recognize those toxic invaders and learns to protect against it so that by the time
01:02:12
Speaker
our membrane proteins have figured out the crucial shape of maybe that little spike in the protein of the COVID virus. And it picks that up, it learns that, and then it generates hundreds of thousands, maybe millions of copies. And that is the great immune response where you get white cells
01:02:38
Speaker
essentially killing all the copies of the invading virus that it can find. And if that happens early enough in the intubation process of COVID, it's being handled by your body. But then the crisis comes, as you know, later on, and the crisis that kills people in COVID is essentially the explosion of white cells.
01:03:07
Speaker
that involve an overreaction of the immune system. So this goes back to Jerry Edelman, who discovered this principle, got a Nobel Prize for it in the 1970s. And it started him thinking in a very biological way because his heuristic in finding the membrane proteins
01:03:35
Speaker
that pick up these novel toxins, his heuristic was really Darwinian thinking. So that he thought that the immune system or at least the learned immune system was a kind of Darwinian selection with variation. Let me see, selection with reproduction and variation. And then re-selection because now you're selecting the successful
01:04:04
Speaker
next generation proteins or cells or animals for that matter. So he thought that the same basic principles occurred at many levels of biology and that has been a very, very important heuristic and it's now part of neural net technology. So Jerry really
01:04:34
Speaker
persuaded me that that was a very important point of view. The cortex does exactly that. That was Jerry's point of view, which he also wrote in a nice book around 2000 with Giulio Tonani, a universe of consciousness. Cortex turns out to be selectionist in
01:05:02
Speaker
very similar ways to which the learned immune system is selectionist and Darwinian evolution is selectionist. And that was a profound insight, I think. And now we get to the question that people came out anatomically over history in quite a different way because Hippocrates already knew
01:05:32
Speaker
about the cortex because it's the first thing you see when you take the cranium off. Hippocrates got to see a lot of trauma victims. The school of Hippocrates actually figured out that there is a cross linking of the motor cortex. So then if you stimulate the right hand, the motor cortex of the right hemisphere, the left arm for the left hand,
01:05:59
Speaker
can move, and that was the realization that was actually made in the fourth century BC, purely empirically, by people who were doing very, very intelligent clinical medicine. And so the idea that cortex is the organ of mind is a very ancient idea because it is true to considerable extent.
01:06:28
Speaker
But then, of course, the really hard evidence didn't really show up in my mind. It didn't really show up until Penfield started to stimulate the brains of these epileptic patients in 1934. And then he got 1200 poor adult epileptics. These poor people who were going to die from seizure disease and their lives were intolerable anyway, even if they were not going to die directly from them.
01:06:58
Speaker
And so they allowed themselves to be operated on in these careful and ethical but very experimental ways. And that's essentially the basis with the reservation, of course, that nobody's ever gotten to see the records from those 1,200 patients. But in a sense, that's what are on the branch right now. It's irrelevant.
01:07:25
Speaker
because other people, epileptologists of all kinds, have started to do these surgeries. It's become a sort of a routine thing. And you can now just go to PubMed or some other biomedical archive and look up direct cortical recording, for example, which is mostly done with these kinds of human surgeries.
01:07:51
Speaker
And then of course, a great many surgeries in macaque monkeys, maybe some chimps, but also other mammals, because it turns out that mammals say this, but it's true that mammals are conscious because mammals have neocortex. And that started more than 1200 million years ago, which I thought was rather shocking, actually.
01:08:19
Speaker
until I started to talk with people in Jerry's orbit. And everybody kind of believed it, but very few people were willing to publish about it. Because it's such a radical claim, it might upset people, it would upset people, certainly. And of course, you get, you know, we're all ethical sinners, basically, because we eat those creatures, right?
01:08:49
Speaker
We eat rabbits, we eat cows, we eat horses, we eat all kinds of conscious creatures. Let me circle back around to, so earlier you were talking about differences between an engineered thing and a product of evolution. So difficulty in trying to understand exactly, you know, what functional role something might have or, you know, because of the
01:09:17
Speaker
sort of long accumulation of different traits. And, you know, just being mindful of our time here, too. Well, one of the things that we think about on this show is the ways in which anybody can be responsible for leading to... Right.
01:09:36
Speaker
negative or unanticipated consequences of their work. So the thing that we sort of jokingly talk about a little bit is how does your work eventually lead to the to the robo apocalypse or the end of the world as it's taken over by AI. And I think of, you know, of your research and your work as, you know, in the worst case scenario, I suppose you could think of
01:10:02
Speaker
as blueprints for how to create a conscious computer. Yes. Thank you for raising that.
01:10:11
Speaker
We don't want to make you responsible for the apocalypse eventually. But I'm just curious as to your thought, and I guess this goes to the direction of conscious computers too, how your cognitive theories have interacted with artificial intelligence ideas of consciousness. Right. And it's one of those things where you think you're working on a scientific problem and maybe you make a little progress.
01:10:40
Speaker
And suddenly the world goes crazy and starts to, you know, starts to fantasize. And maybe it starts to do some pretty horrible things based on what you thought was ethical and reasonably modest work. I find that rather shocking. And of course, a lot of it is so speculative that it's hardly worth talking about.
01:11:09
Speaker
But I do worry, for example, that we now have a new behaviorism, because now it turns out that anything that can act like a human being must be conscious, and that's absurd, obviously. Is there something particular you're referring to with that? Yeah, I hate to say it, because my good friend Stan Franklin,
01:11:34
Speaker
started that, he's an AI, he's really mathematician at heart, who started to do artificial intelligence and has really expanded on global workspace theory to make it more of a complete cognitive architecture, which is important, because it's not just conscious, there's a whole bunch of other apparatus that you need, but Stan
01:12:05
Speaker
confuses assimilation with the reality. And I find that troubling. I talked to him about it. He keeps on going back to his view that global workspace
01:12:20
Speaker
theory is equivalent to consciousness, whereas I'm much more of a trained skeptic and experimental science and so on. And I will not simply jump to that kind of conclusion. I think it's way, way out of our
01:12:37
Speaker
orbit right now. And what we see is people talking about conscious computing, when what we actually know, apparently about consciousness is actually fairly modest. It's not zero. But it's certainly not something that we're ready to, you know, stick into silicon and, and pretend is actually an experiencing human being. It's not
01:13:06
Speaker
Well, I think that might be a good place to end things. Are there any last things that you'd like to get in or Joe, are there any questions that you had that you'd like to ask? I just wanted to say, Bernie, to thank you and wanted to, again, mention the new book that is out. On Consciousness. All right, On Consciousness. On Consciousness. Yeah, so go out and hit the book. And yeah, thank you very much for being on the show.
01:13:34
Speaker
I really appreciate you guys, by the way, for many reasons. One of them is that we are thinking in similar directions, including the ethics but also the science.