Tuesday, February 26, 2013

Michael Gazzaniga on consciousness, top-down causation, responsibility

Some excerpts from this article:

Quoting The Ethical Brain: "Should we abandon the concept of personal responsibility? I don't think so. We need to distinguish among brains, minds, and personhood. People are free and therefore responsible for their actions; brains are not responsible" (pp.88-89).

On his latest book, Who's In Charge: "Michael Gazzaniga reviews the extraordinary discoveries of neuroscience that explain the mind as something embodied in the brain, but also as software to the brain’s hardware, a kind of abstract non-physical information that is nevertheless capable of exerting 'downward causation' on the physical world. We live in a determined universe, he says, and the mind is not free from the causal laws of nature. But he finds the kind of freedom needed for moral responsibility is not some indeterminism inside the brain but in our social interactions.

"How does Gazzaniga defend the philosophically difficult proposition that immaterial ideas in an emergent mind can constrain the physical world? Can he solve the great problem of mind-body dualism? In his Gifford lectures, Gazzaniga proposes something analogous to the controversial Baldwin effect in evolutionary theory, the notion that learned behaviors transmitted culturally can so modify the environment that selection pressures now favor random mutations that have more reproductive success in the now changed environment. This creates a feedback loop called genetic assimilation when the new environment gets reflected in the genes, or niche construction when humans adapt the environment (as opposed to animals, who adapt to the environment). Gazzaniga proposes a similar feedback process in the mind-brain, where top-level mental ideas exert 'downward causation' on the brain, biasing its decisions that are being made from the bottom (the neurons) up....the mind puts constraints on the physical world to further its goals."

And from this interview with Gazzaniga:

Paulson: "And there's another question, perhaps even a deeper philosophical question, which is: what is consciousness?"

Gazzaniga: "I can tell you that it's not unpaged or whatever. That is the sixty-four dollar question and to have the view that it'll never be understood, I think, is a strong claim because, if you just look back sixty years, we had a pretty measly understanding of what a gene is, and in fact, in the last sixty years we produced this phenomenal body of molecular, biological and genetics that is responsible for all our modern medicine and actually, we still don't know what a gene is because it has become so much more complicated to think about. So, we have this situation where just because we can't fully define something, people think, well, it'll never be defined and we shouldn't work on it till we get it defined. I don't agree with that, I think that we have plenty of examples in science where something's not really nailed down in full definition, but yet advances are made on it and understanding is gained, and that the same is going to be true for the problem of consciousness."

Paulson: "You've talked about the mind as an emergent phenomenon....so how does that apply to the brain then?"

Gazzaniga: "Neurons interact in a way to produce a mental state that we all enjoy. That mental state can, and in fact, interacts with the layers that produce it and constrain the layer that produces it, namely the neurons themselves."

Paulson: "I know when people talk about emergence, or the mind as an emergent phenomenon, sometimes the talk about the whole being greater than the sum of the parts. In other words, if you just sort of try to add up, you know, all the different neurons, the neural connections, you're not going to explain something at a higher level of organization."

Gazzaniga: "Right. And, that is an idea that's been widely discussed and talked about, you cannot predict the properties of the layer above you by a full analysis of the elements that produce it, that's generally what is meant by an emergent property. There's examples of that through all of biology, and many areas of science and, you know, analysis of how processes work."

Paulson: "Well, okay, let me follow up on more of the topic of your new book. You've tackled the old question of free will, whether we actually have free will in what would seem to be, in many ways, a deterministic universe. So, how do you break that down, do we have free will?"

Gazzaniga: "I think it's an arcane concept that seems just out of place, given the modern knowledge of what we're discovering about how the brain works. It's not needed, it has no utility to our understanding of things. What the brain is is a great big information processing device that has with it many features, one of which is this interpreter that creates the illusion that we're in charge and acting freely of our own choice, right? I mean, that's just what it does, it does it in all of us and we all experience it, and that's that. But if you actually understand, begin to understand how the brain works, you find that that's just not what's at stake here, and we should move on to thinking about other issues, and for me, the importance of the concept of, that people thought was so important with the concept of free will is the question of personal responsibility. I say that, what I'm arguing is that the place to look for the answer to what responsibility is, is not in the brain, but it's in the social group. One way to kind of come at it is that if you're the only person in the world, the idea of personal responsibility doesn't mean much. You're responsible to others, and so, when we move into the social group, what we're doing is we're now having a relationship with other people and we have rules and laws and what-have-you. And so, that's where we look for responsibility, and people can follow rules in ninety-nine point nine nine nine percent of cases, so we look for responsibility there, we don't look for it in the brain."

Paulson: "I want to come back to this paradox that you have raised in the way you have put it in your book, you say: we are personally responsible agents and are to be held accountable for our actions, even though we live in a determined universe. Because it would seem that if we live in a determined universe, then we're in some way, we're not responsible anymore."

Gazzaniga: "Yeah, and again, so we have, the metaphor I've used is, cars are determined devices and yet, understanding them helps us in no way to understand traffic, when they start to interact. That's a different level of organization and description of an event that 's going on. I would similarly say brains are automatic, but people are free. When brains start to interact, there's a level of relationships, there's a social ether that's created, and that ether can be, you can be held accountable to play by the rules of that new level of organization."

Paulson: "If you could pinpoint one question that you would most liked answered in the study of neuroscience, what would it be? What are the big question, or the big two questions that you are really trying to unpack?"

Gazzaniga: "Alright, so, this brings us right up to the present, right when I was spending the rest of my time thinking about. Traditional neuroscience thinks there's this linear causal chain. A produces B, which produces C, and so forth, right? What I'm suggesting is there is, really, how to think about it is there's this layered system, where it's not that A produces B, A and B are in a relationship with each other, one layer above the other. And so, when you want to think about the processes going on in the middle of it, you have to think of that interaction of A and B, not that A produces B and that's the end of the story. So, it's figuring out how those layers interact, which is a deep deep problem in science, working it all kinds of levels in science, how those layers interact, how those protocols are going to work between the layers, that's the scientific question of the next generation and the one after it, but I think that's where we're going to have to go if we're going to come to a more full understanding of how brain enables mind."

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