'Neuroethics' is the ethics of neuroscience, analogous to the term 'bioethics' which denotes the ethics of biomedical science more generally.
Neuroethics encompasses a wide array of ethical issues emerging from different branches of clinical neuroscience (neurology, psychiatry, psychopharmacology) and basic neuroscience (cognitive neuroscience, affective neuroscience).
These include ethical problems raised by advances in functional neuroimaging, brain implants and brain-machine interfaces and psychopharmacology as well as by our growing understanding of the neural bases of behavior, personality, consciousness, and states of spiritual transcendence.
Neuroethics.upenn.edu is a source of information on neuroethics, provided by Martha Farah of the Center for Cognitive Neuroscience at the University of Pennsylvania.
Friday, March 02, 2007
Thursday, March 01, 2007
Virtual Living - Is this scary, or what???
Here is a followup on a New York Times article by David Pogue on the Second Life phenomenon. I downloaded and tried the game, and soon fled in bored confusion (and fear). Because we can't hack it in real life, we are going to retreat to a virtual world?
From Pogue::
Second Life, as about 2 million people have already discovered, is a virtual world on the Internet. You're represented by a computer-generated character (an avatar) that can walk around, fly, teleport, or exchange typed comments with other people's characters. You can make yourself young and beautiful, equip yourself with fancy clothes, build a dream house by the water, or make the sun set on command. The average member spends four hours a day in Second Life.
One thing that makes Second Life different from other online 3-D games is its economy. People make stuff and sell it to each other: clothes, rockets, cars, new hairstyles. Second Life itself is free, but members nonetheless pay real money-$220 million a year-to buy these imaginary accessories.
From Pogue's interview with Phillip Rosedale, the CEO of Linden Lab, the company behind Second Life:
DP: Is there any worry about the whole isolation thing? First iPod earbuds, and now people substituting virtual interactions for real ones?
PR: Well I'll tell ya, the history of technology has, in the past 50 years, been to increasingly isolate us. We've gone from watching movies in a movie theater, to watching them as a family at home, to watching them alone on our iPod.
But actually I think there's a next wave of technology, of which Second Life is certainly a great example, where we are bringing people back together again into the same place to have these experiences.
The thing about Second Life that is so fascinating and different is not just that it's 3-D. There are always people to share that experience with, or to ask for help. Or to laugh at something with. And that experience is an innately human one that technology has deprived us of. I think many people use Second Llife to have more friends, and more human contact, than they do in the real world.
DP: What's the hard part for the next phase?
PR: Well, we need to grow Second Life as fast as people want it to grow. And right now, that seems to be awfully fast. If you look at the number of people online at one time, that number has doubled in the last 90 days. Right now, the challenge is just scaling up the services, and the computers, and even the policies, and customer support.
Looking farther out, we have to really open it up so that a lot of people can work on it with us. [Linden Lab recently "open-sourced" the code of the Second Life program, in hopes that volunteers worldwide will comb through it for improvements.]
When you look at Second Life today, you may say, "I don't like the graphics." Or, you know, "It's clunky. It runs too slow." But you have to bear in mind that in just a few years, this is gonna look like walking into a movie screen. And that's just gonna be such an amazing thing.
From Pogue::
Second Life, as about 2 million people have already discovered, is a virtual world on the Internet. You're represented by a computer-generated character (an avatar) that can walk around, fly, teleport, or exchange typed comments with other people's characters. You can make yourself young and beautiful, equip yourself with fancy clothes, build a dream house by the water, or make the sun set on command. The average member spends four hours a day in Second Life.
One thing that makes Second Life different from other online 3-D games is its economy. People make stuff and sell it to each other: clothes, rockets, cars, new hairstyles. Second Life itself is free, but members nonetheless pay real money-$220 million a year-to buy these imaginary accessories.
From Pogue's interview with Phillip Rosedale, the CEO of Linden Lab, the company behind Second Life:
DP: Is there any worry about the whole isolation thing? First iPod earbuds, and now people substituting virtual interactions for real ones?
PR: Well I'll tell ya, the history of technology has, in the past 50 years, been to increasingly isolate us. We've gone from watching movies in a movie theater, to watching them as a family at home, to watching them alone on our iPod.
But actually I think there's a next wave of technology, of which Second Life is certainly a great example, where we are bringing people back together again into the same place to have these experiences.
The thing about Second Life that is so fascinating and different is not just that it's 3-D. There are always people to share that experience with, or to ask for help. Or to laugh at something with. And that experience is an innately human one that technology has deprived us of. I think many people use Second Llife to have more friends, and more human contact, than they do in the real world.
DP: What's the hard part for the next phase?
PR: Well, we need to grow Second Life as fast as people want it to grow. And right now, that seems to be awfully fast. If you look at the number of people online at one time, that number has doubled in the last 90 days. Right now, the challenge is just scaling up the services, and the computers, and even the policies, and customer support.
Looking farther out, we have to really open it up so that a lot of people can work on it with us. [Linden Lab recently "open-sourced" the code of the Second Life program, in hopes that volunteers worldwide will comb through it for improvements.]
When you look at Second Life today, you may say, "I don't like the graphics." Or, you know, "It's clunky. It runs too slow." But you have to bear in mind that in just a few years, this is gonna look like walking into a movie screen. And that's just gonna be such an amazing thing.
Wednesday, February 28, 2007
Brain-o-vision - Does Consciousness Cause Behavior?
I want to pass on this stimulating Nature review by Daniel Wegner of "Does Consciousness Cause Behavior?", Pockett, Banks, and Gallagher, Eds. MIT Press, Cambridge, MA, 2006.
Imagine a gadget, call it "brain-o-vision," for brain scanning that doesn't create pictures of brains at all. That's right, no orbs spattered with colorful "activations" that need to be interpreted by neuroanatomists. Instead, with brain-o-vision, what a brain sees is what you get--an image of what that brain is experiencing. If the person who owns the brain is envisioning lunch, up pops a cheeseburger on the screen. If the person is reading a book, the screen shows the words. For that matter, if the brain owner is feeling pain, perhaps brain-o-vision could reach out and swat the viewer with a rolled-up newspaper. Brain-o-vision could give us access to another person's consciousness (1). Figure Credit: Joe Sutliff
Technologies for brain-o-vision are beginning to seem possible. We are learning how brain activations map onto emotions, memories, and mental processes, and it won't be long before we might translate activations into Google searches for images of what the brain is thinking. There is a specific brain area linked with face perception (2), for instance, and even a neuron that fires when it sees Jennifer Aniston (3). So why, in principle, shouldn't we be able to scan a brain and discover when it is looking at her--and eventually even learn what she's wearing? Of course, it may be many years to the beta version. But imagine that everything works out and brain-o-vision goes on sale at Wal-Mart. Could the device solve the problem of whether consciousness causes behavior?
With direct evidence of a person's consciousness, we could do science on the question. We could observe regularities in the relation between consciousness (say, a thought of sipping coffee) and behavior (the actual drink). If the consciousness always preceded the behavior (and never occurred without being followed by the behavior), we could arrive at the inductive inference of causation and, as scientists, be quite happy that we had established a causal connection. In fact, this is the project about which several of the contributors to Does Consciousness Cause Behavior? (Marc Jeannerod, Richard Passingham and Hakwan Lau, Suparna Choudhury and Sarah-Jayne Blakemore) give masterful reports (using measures of consciousness other than brain-o-vision). So what's the problem? Why is the issue so vexing that this book and many others have taken up the question? Certainly, one snag is that we don't yet have brain-o-vision. But that's not the full story. There is a key sidetrack on the way to establishing this causal inference that has left philosophers and scientists in a muddle for years.
The problem is that we each have our own personal brain-o-vision shimmering and blaring in our heads all day long. We have our own consciousness, and we find its images mesmerizing. The picture that our minds produce shows what looks exactly like a causal relationship: I thought of drinking the coffee and then I did it. This apparent relationship anchors our intuition about the conscious causation of behavior so deeply that it is difficult to understand that this causal inference is something that ought to be a scientific matter, not an intuitive one. We can't turn off the inner television and try to figure out what really happened. Each of the volume's contributors struggles to find some rapprochement between the personal experience of conscious causation and the possibility that consciousness might not cause behavior--leaving the experience an illusion.
An occasional undercurrent in the volume is the idea that exceptions to the standard inner experience of conscious causation should be discarded as uninformative. For example, Libet's classic finding (4) that brain activation precedes the reported conscious experience of willing action is often cited as evidence that consciousness is not the initial cause of behavior, and that it instead occurs in a chain of events initiated by brain events. Several contributors examine this finding in creative ways--but, curiously, others belittle the finding as a laboratory-bound oddity. The dismissal of exceptional cases extends to some chapters that question the value of examining any unusual lapses of conscious causation--such as those in hypnosis, facilitated communication, schizophrenia, or psychogenic movement disorders or in automatisms such as dowsing and table-turning. These anomalous cases sometimes reveal that the experience of conscious causation can diverge from the actual causal circumstances surrounding behavior. We need to understand such cases to establish when it is that consciousness thinks it is causing behavior. Exploring a phenomenon by studying its boundaries is a standard operating procedure of science, and it is curious that some students of mind would wish such informative exceptions swept under the rug.
Research into conscious causation is complicated by the fact that the scientists and philosophers studying the problem are people. Our own personal brain-o-vision leads us to idealize apparent conscious causation and disparage exceptions. We may not be able to turn off our own consciousness and consider the question dispassionately, but it probably would help.
References and Notes
1. Thanks to D. Dennett for this idea.
2. N. Kanwisher, J. McDermott, M. M. Chun, J. Neurosci. 17, 4302 (1997).
3. R. Q. Quiroga, L. Reddy, G. Kreiman, C. Koch, I. Fried, Nature 435, 1102 (2005).
4. B. Libet, Behav. Brain Sci. 8, 529 (1985).
Imagine a gadget, call it "brain-o-vision," for brain scanning that doesn't create pictures of brains at all. That's right, no orbs spattered with colorful "activations" that need to be interpreted by neuroanatomists. Instead, with brain-o-vision, what a brain sees is what you get--an image of what that brain is experiencing. If the person who owns the brain is envisioning lunch, up pops a cheeseburger on the screen. If the person is reading a book, the screen shows the words. For that matter, if the brain owner is feeling pain, perhaps brain-o-vision could reach out and swat the viewer with a rolled-up newspaper. Brain-o-vision could give us access to another person's consciousness (1). Figure Credit: Joe Sutliff
Technologies for brain-o-vision are beginning to seem possible. We are learning how brain activations map onto emotions, memories, and mental processes, and it won't be long before we might translate activations into Google searches for images of what the brain is thinking. There is a specific brain area linked with face perception (2), for instance, and even a neuron that fires when it sees Jennifer Aniston (3). So why, in principle, shouldn't we be able to scan a brain and discover when it is looking at her--and eventually even learn what she's wearing? Of course, it may be many years to the beta version. But imagine that everything works out and brain-o-vision goes on sale at Wal-Mart. Could the device solve the problem of whether consciousness causes behavior?
With direct evidence of a person's consciousness, we could do science on the question. We could observe regularities in the relation between consciousness (say, a thought of sipping coffee) and behavior (the actual drink). If the consciousness always preceded the behavior (and never occurred without being followed by the behavior), we could arrive at the inductive inference of causation and, as scientists, be quite happy that we had established a causal connection. In fact, this is the project about which several of the contributors to Does Consciousness Cause Behavior? (Marc Jeannerod, Richard Passingham and Hakwan Lau, Suparna Choudhury and Sarah-Jayne Blakemore) give masterful reports (using measures of consciousness other than brain-o-vision). So what's the problem? Why is the issue so vexing that this book and many others have taken up the question? Certainly, one snag is that we don't yet have brain-o-vision. But that's not the full story. There is a key sidetrack on the way to establishing this causal inference that has left philosophers and scientists in a muddle for years.
The problem is that we each have our own personal brain-o-vision shimmering and blaring in our heads all day long. We have our own consciousness, and we find its images mesmerizing. The picture that our minds produce shows what looks exactly like a causal relationship: I thought of drinking the coffee and then I did it. This apparent relationship anchors our intuition about the conscious causation of behavior so deeply that it is difficult to understand that this causal inference is something that ought to be a scientific matter, not an intuitive one. We can't turn off the inner television and try to figure out what really happened. Each of the volume's contributors struggles to find some rapprochement between the personal experience of conscious causation and the possibility that consciousness might not cause behavior--leaving the experience an illusion.
An occasional undercurrent in the volume is the idea that exceptions to the standard inner experience of conscious causation should be discarded as uninformative. For example, Libet's classic finding (4) that brain activation precedes the reported conscious experience of willing action is often cited as evidence that consciousness is not the initial cause of behavior, and that it instead occurs in a chain of events initiated by brain events. Several contributors examine this finding in creative ways--but, curiously, others belittle the finding as a laboratory-bound oddity. The dismissal of exceptional cases extends to some chapters that question the value of examining any unusual lapses of conscious causation--such as those in hypnosis, facilitated communication, schizophrenia, or psychogenic movement disorders or in automatisms such as dowsing and table-turning. These anomalous cases sometimes reveal that the experience of conscious causation can diverge from the actual causal circumstances surrounding behavior. We need to understand such cases to establish when it is that consciousness thinks it is causing behavior. Exploring a phenomenon by studying its boundaries is a standard operating procedure of science, and it is curious that some students of mind would wish such informative exceptions swept under the rug.
Research into conscious causation is complicated by the fact that the scientists and philosophers studying the problem are people. Our own personal brain-o-vision leads us to idealize apparent conscious causation and disparage exceptions. We may not be able to turn off our own consciousness and consider the question dispassionately, but it probably would help.
References and Notes
1. Thanks to D. Dennett for this idea.
2. N. Kanwisher, J. McDermott, M. M. Chun, J. Neurosci. 17, 4302 (1997).
3. R. Q. Quiroga, L. Reddy, G. Kreiman, C. Koch, I. Fried, Nature 435, 1102 (2005).
4. B. Libet, Behav. Brain Sci. 8, 529 (1985).
Breakdown can be a positive development.
Michael Wolff, columnist for Vanity Fair, offers this paragraph on the joys of failing enterprises:
"The good news where I come from, as a prisoner here in the American media business, is all about entropy. The massive and ridiculous systems that we've built to control and market expression and culture, with their dissipations of so many people's energy, are deteriorating and coming apart. Everyday the media—a much more vexing monolith than religion and God—takes another transforming step from consolidation and uniformity toward uncertainty and chaos. This is not just because new technologies are revolutionizing production and distribution—though that's no small part of this creative destruction—but as much because of the inevitable disorder and randomness of closed systems. What's optimistic is that so many strategists and consultants and bureaucrats and moguls have not been able to maintain control and have been shown to be as clueless as everybody else (this is true, come to think of it, not just at Time Warner and Viacom, but at the Pentagon). Breakdown can be a positive development."
"The good news where I come from, as a prisoner here in the American media business, is all about entropy. The massive and ridiculous systems that we've built to control and market expression and culture, with their dissipations of so many people's energy, are deteriorating and coming apart. Everyday the media—a much more vexing monolith than religion and God—takes another transforming step from consolidation and uniformity toward uncertainty and chaos. This is not just because new technologies are revolutionizing production and distribution—though that's no small part of this creative destruction—but as much because of the inevitable disorder and randomness of closed systems. What's optimistic is that so many strategists and consultants and bureaucrats and moguls have not been able to maintain control and have been shown to be as clueless as everybody else (this is true, come to think of it, not just at Time Warner and Viacom, but at the Pentagon). Breakdown can be a positive development."
Tuesday, February 27, 2007
A new description of our inner lives....
I rarely mention my internal experience and sensations on this blog - first, because I have viewed readers as "wanting the beef," objective stuff on how minds work. Second and more important, because my experience of noting the flow of my brain products as emotion laced chunks of sensing/cognition/action - knowing the names of the neurotransmitters and hormones acting during desire, arousal, calming, or affiliation - strikes me as a process which would feel quite alien to most people. Still, if we are materialists who believe that someday we will understand how the brain-body generates our consciousness and sense of a self, we will be able to think in terms like the following (a quote taken from Larissa MacFarquhar's profile of Paul and Patricia Churchland in the Feb. 12 New Yorker Magazine):
"...he and Pat like to speculate about a day when whole chunks of English, especially the bits that consitute folk psychology, are replaced by scientific words that call a thing by its proper name rather than some outworn metaphor... as people learn to speak differently they will learn to experience differently, and sooner or later even their most private introspections will be affected. Already Paul feels pain differently than he used to: when he cut himself shaving now he fells not "pain" but something more complicated - first the sharp, superficial A-delta-fibre pain, and then a couple of seconds later, the sickening, deeper feeling of C-fibre pain that lingers. The new words, far from being reductive or dry, have enhanced his sensations, he feels, as an oenophile's complex vocabulary enhances the taste of wine."
"Paul and Pat, realizing that the revolutionary neuroscience they dream of is still in its infancy, are nonetheless already preparing themselve for this future, making the appropriate adjustments in their everyday conversation. One afternoon recently, Paul says, he was home making dinner when Pat burst in the door, having come straight from a frustrating faculty meeting. "She said, 'Paul, don't speak to me, my serotonin levels have hit bottom, my brain is awash in glucocortocoids, my blood vessels are full of adrenaline, and if it weren't for my endogenous opiates I'd have driven the car into a tree on the way home. My dopamine levels need lifting. Pour me a Chardonnay, and I'll be down in a minute.' " Paul and Pat have noticed that it is not just they who talk this way - their students now talk of psychopharmacology as comfortably as of food."
"...he and Pat like to speculate about a day when whole chunks of English, especially the bits that consitute folk psychology, are replaced by scientific words that call a thing by its proper name rather than some outworn metaphor... as people learn to speak differently they will learn to experience differently, and sooner or later even their most private introspections will be affected. Already Paul feels pain differently than he used to: when he cut himself shaving now he fells not "pain" but something more complicated - first the sharp, superficial A-delta-fibre pain, and then a couple of seconds later, the sickening, deeper feeling of C-fibre pain that lingers. The new words, far from being reductive or dry, have enhanced his sensations, he feels, as an oenophile's complex vocabulary enhances the taste of wine."
"Paul and Pat, realizing that the revolutionary neuroscience they dream of is still in its infancy, are nonetheless already preparing themselve for this future, making the appropriate adjustments in their everyday conversation. One afternoon recently, Paul says, he was home making dinner when Pat burst in the door, having come straight from a frustrating faculty meeting. "She said, 'Paul, don't speak to me, my serotonin levels have hit bottom, my brain is awash in glucocortocoids, my blood vessels are full of adrenaline, and if it weren't for my endogenous opiates I'd have driven the car into a tree on the way home. My dopamine levels need lifting. Pour me a Chardonnay, and I'll be down in a minute.' " Paul and Pat have noticed that it is not just they who talk this way - their students now talk of psychopharmacology as comfortably as of food."
Neuroscience will change society
Interesting reflections by Marco Iacoboni, one of the discoverers of mirror neurons, which have been mentioned a number of times in this blog:
"...a concept that emerges from recent neuroscience research is that humans are "wired for empathy". We have cells in our brains that make us understand each other in a simple, unmediated, automatic manner. But, if our neurobiology makes us wired for empathy, why is our world so full of atrocities?
The explanation for this apparent paradox is probably as follows. The neurobiological mechanisms that make us wired for empathy work at a pre-reflective, automatic, implicit level. Our societies are built on deliberate, reflective, explicit discourse. The two different levels of implicit and explicit mental processes rarely intersect; indeed there is evidence that they can often dissociate. This is probably why the massive belief systems—from religious to political ones—that operate at the deliberate, reflective level are able to divide us in such a powerful way even though our neurobiology should bring us together.
The good news is that the awareness of neurobiological mechanisms that make us wired for empathy is entering the public discourse.... This awareness won't go away and will seep through the reflective level of our mental processes. Indeed, people seem to have an intuitive understanding of how neural mechanisms for empathy work. It seems that people 'recognize' how their brain works, when they are told about it. People can finally articulate what they already 'knew' at a pre-reflective level. My optimism is that this explicit level of understanding of our empathic nature will at some point dissolve the massive belief systems that dominate our societies and that threaten to destroy us."
"...a concept that emerges from recent neuroscience research is that humans are "wired for empathy". We have cells in our brains that make us understand each other in a simple, unmediated, automatic manner. But, if our neurobiology makes us wired for empathy, why is our world so full of atrocities?
The explanation for this apparent paradox is probably as follows. The neurobiological mechanisms that make us wired for empathy work at a pre-reflective, automatic, implicit level. Our societies are built on deliberate, reflective, explicit discourse. The two different levels of implicit and explicit mental processes rarely intersect; indeed there is evidence that they can often dissociate. This is probably why the massive belief systems—from religious to political ones—that operate at the deliberate, reflective level are able to divide us in such a powerful way even though our neurobiology should bring us together.
The good news is that the awareness of neurobiological mechanisms that make us wired for empathy is entering the public discourse.... This awareness won't go away and will seep through the reflective level of our mental processes. Indeed, people seem to have an intuitive understanding of how neural mechanisms for empathy work. It seems that people 'recognize' how their brain works, when they are told about it. People can finally articulate what they already 'knew' at a pre-reflective level. My optimism is that this explicit level of understanding of our empathic nature will at some point dissolve the massive belief systems that dominate our societies and that threaten to destroy us."
Monday, February 26, 2007
Planning for the future is not uniquely human, Scrub Jays do it!
It is commonly believed that planning for the future is a skill unique to humans. Raby and colleagues now present experiments with western scrub-jays that show that these birds plan for the future by preferentially caching food where it will be needed most.
From the Editor's summary: "There is much debate as to whether animals can travel mentally in time, to plan for the future in anticipation of an expected need. It is difficult to prove that an animal's actions are a result of such time-shifting but work on a bird, the western scrub-jay, seems to have done exactly that. The two protocols, the 'planning for breakfast' and 'breakfast choice' experiments, show that jays can provide for a future need, both by preferentially caching food in a place in which they have learned that they will be hungry the next morning, and by differentially storing a particular food in a place where it will not be available next day. The results suggest that the birds spontaneously plan for tomorrow without reference to their current motivational state."
From the Editor's summary: "There is much debate as to whether animals can travel mentally in time, to plan for the future in anticipation of an expected need. It is difficult to prove that an animal's actions are a result of such time-shifting but work on a bird, the western scrub-jay, seems to have done exactly that. The two protocols, the 'planning for breakfast' and 'breakfast choice' experiments, show that jays can provide for a future need, both by preferentially caching food in a place in which they have learned that they will be hungry the next morning, and by differentially storing a particular food in a place where it will not be available next day. The results suggest that the birds spontaneously plan for tomorrow without reference to their current motivational state."
Future discoveries: illusions of order versus stochastic science.
Nassim Taleb on future discoveries: "...we are victims of the narrative fallacy — even in scientific research ...The pattern-seeking, causality producing machine in us blinds us with illusions of order... I hold that not only discoveries are also largely the result of a random process, but that their randomness is even less tractable than, and not as simple as, biological evolution....this makes me extremely optimistic about the future in several selective research-oriented domains, those in which there is an asymmetry in outcomes favoring the positive over the negative — like evolution. These domains thrive on randomness. The higher the uncertainty in such environments, the rosier the future — since we only select what works and discard the rest.
I am convinced that the future of America is rosier than people claim — I've been hearing about its imminent decline ever since I started reading. Take the following puzzle. Whenever you hear or read a snotty European presenting his stereotypes about Americans, he will often describe them as "uncultured", "unintellectual" and "poor in math" because, unlike his peers, they are not into equation drills and the constructions middlebrows people call "high culture". Yet the person making these statements will be likely to be addicted to his Ipod, wearing t-shirts and blue jeans, and using Microsoft Word to jot down his "cultural" statements on his (Intel) PC, with some Google searches on the Internet here and there interrupting his composition. Well, it so happened that the U.S. is currently far, far more tinkering an environment than that of these nations of museum goers and equation solvers — in spite of the perceived weakness of the educational system - which allows the bottom-up uncertainty-driven trial-and-error system to govern it, whether in technology or in business....it produces "doers", Black Swan hunting, dream-chasing entrepreneurs, or others with a tolerance for risk-taking which attracts aggressive tinkering foreigners. And globalization allowed the U.S. to specialize in the creative aspect of things, the risk-taking production of concepts and ideas... by exporting jobs, separate the less scalable and more linear components and assign them to someone in more mathematical and "cultural" states happy to be paid by the hour and work on other people's ideas.
All the while institutional science is largely driven by causal certainties, or the illusion of the ability to grasp these certainties; stochastic tinkering does not have easy acceptance. Yet we are increasingly learning to practice it without knowing — thanks to overconfident entrepreneurs, naive investors, greedy investment bankers, and aggressive venture capitalists brought together by the free-market system. I am also optimistic that the academy is losing its power and ability to put knowledge in straightjackets and more out-of-the-box knowledge will be generated Wiki-style."
I am convinced that the future of America is rosier than people claim — I've been hearing about its imminent decline ever since I started reading. Take the following puzzle. Whenever you hear or read a snotty European presenting his stereotypes about Americans, he will often describe them as "uncultured", "unintellectual" and "poor in math" because, unlike his peers, they are not into equation drills and the constructions middlebrows people call "high culture". Yet the person making these statements will be likely to be addicted to his Ipod, wearing t-shirts and blue jeans, and using Microsoft Word to jot down his "cultural" statements on his (Intel) PC, with some Google searches on the Internet here and there interrupting his composition. Well, it so happened that the U.S. is currently far, far more tinkering an environment than that of these nations of museum goers and equation solvers — in spite of the perceived weakness of the educational system - which allows the bottom-up uncertainty-driven trial-and-error system to govern it, whether in technology or in business....it produces "doers", Black Swan hunting, dream-chasing entrepreneurs, or others with a tolerance for risk-taking which attracts aggressive tinkering foreigners. And globalization allowed the U.S. to specialize in the creative aspect of things, the risk-taking production of concepts and ideas... by exporting jobs, separate the less scalable and more linear components and assign them to someone in more mathematical and "cultural" states happy to be paid by the hour and work on other people's ideas.
All the while institutional science is largely driven by causal certainties, or the illusion of the ability to grasp these certainties; stochastic tinkering does not have easy acceptance. Yet we are increasingly learning to practice it without knowing — thanks to overconfident entrepreneurs, naive investors, greedy investment bankers, and aggressive venture capitalists brought together by the free-market system. I am also optimistic that the academy is losing its power and ability to put knowledge in straightjackets and more out-of-the-box knowledge will be generated Wiki-style."
Friday, February 23, 2007
Social Networks - the twenty-first century science?
Duncan Watts suggests (Nature 445, 489; 1 February 2007) that "If handled appropriately, data about Internet-based communication and interactivity could revolutionize our understanding of collective human behaviour."
The social sciences "have been much less successful than the physical and life sciences in producing a coherent theoretical framework that can account for their discoveries. This is not because social scientists are less clever than their peers in other fields, but because social phenomena are among the hardest scientific problems to solve."
"For the past 50 years or so, sociologists have thought deeply about the importance of interactions between people, institutions and markets in determining collective social behaviour. They have even built a language — network analysis — to describe these interactions in quantitative terms. But the objects of analysis, such as friendship ties, are hard to observe, especially for large numbers of people over extended periods of time. As a result, network data have historically comprised one-time snapshots, often for quite small groups. And most studies have relied on self-reports from participants, which suffer from cognitive biases, errors of perception and framing ambiguities."
"The striking proliferation over the past decade of Internet-based communication and interactivity, however, is beginning to lift these constraints. For the first time, we can begin to observe the real-time interactions of millions of people at a resolution that is sensitive to effects at the level of the individual. Meanwhile, ever-faster computers permit us to simulate large networks of social interactions. The result has been tremendous interest in social networks: thousands of papers and a growing number of books have been published in less than a decade, leading some to herald the arrival of a 'science of networks'."
Thursday, February 22, 2007
Steven Kosslyn on increasing human intelligence:
I think this brief essay is worth reproducing here:
"I am optimistic that human intelligence can be increased, and can be increased dramatically in the near future. I see three avenues that will lead to this end.
First, the fruits of cognitive neuroscience and related fields have identified a host of distinct neural systems in the human brain. Different combinations of these systems are used in the service of accomplishing different tasks, and each system can be made more efficient by "targeted training." Such training involves having people perform tasks that are designed to exercise very specific abilities, which grow out of distinct neural networks. Just as a body builder can do curls to build up biceps and dips on parallel bars to build up triceps, we can design computer-game-like tasks that exercise specific parts of the brain—mental muscles, if you will. By exercising the right sets of systems, specific types of reasoning not only can be improved but—the holy grail of training studies—such improvement can generalize to new tasks that draw on those systems.
Second, people often grapple with problems in groups, be they formally designated teams or casual huddles around the water cooler. I am optimistic that understanding the nature of such group interactions will increase human intelligence. Just as a mechanical calculator can extend our mental capacities, other people help us extend our intelligence—both in a cognitive sense (as required to solve problems) and in an emotional sense (as required to detect and respond appropriately to emotions, ours and those of others). In this sense, other people can serve as "social prosthetic systems," as extensions of our own brains; a wooden leg can fill in for a missing limb, and others' brains can fill in for our cognitive and emotional limitations. To the extent that researchers come to understand how such social prosthetic systems arise and operate, they will understand how to increase human intelligence.
Third, the line between animate and inanimate information processing is becoming increasingly blurry as research in multiple fields proceeds apace. I expect that engineers will continue to press forward, designing increasingly powerful machines to help us extend our intelligence. For example, some people carry computers with them everywhere they go, and treat Google as an extension of their own knowledge bases. Or, in my case, my PDA extends my organizational ability enormously. We soon will have a wide variety of mechanical helpmates. The distinction between what goes on in the head and what relies on external devices is becoming more subtle and nuanced, and in so doing human intelligence is being extended.
Crucially, each of these three developments amplifies the effects of the others, producing synergies: As "brain exercises" enhance our personal intellectual abilities, we can learn how to make better use of mechanical aids and how to rely more effectively on other people. The confluence of all three types of developments will produce positive feedback loops, where the very act of interacting with others or working with smart devices will help us continue to develop our brains, and as our brains develop we will in turn be able to use increasingly sophisticated devices and rely on people in more complex and powerful ways.
With luck, such developments will produce news sorts of extended social links and highly integrated social networks, and a new kind of "smart society" will emerge. And, who knows, such a society may not only be smarter, but also wiser."
"I am optimistic that human intelligence can be increased, and can be increased dramatically in the near future. I see three avenues that will lead to this end.
First, the fruits of cognitive neuroscience and related fields have identified a host of distinct neural systems in the human brain. Different combinations of these systems are used in the service of accomplishing different tasks, and each system can be made more efficient by "targeted training." Such training involves having people perform tasks that are designed to exercise very specific abilities, which grow out of distinct neural networks. Just as a body builder can do curls to build up biceps and dips on parallel bars to build up triceps, we can design computer-game-like tasks that exercise specific parts of the brain—mental muscles, if you will. By exercising the right sets of systems, specific types of reasoning not only can be improved but—the holy grail of training studies—such improvement can generalize to new tasks that draw on those systems.
Second, people often grapple with problems in groups, be they formally designated teams or casual huddles around the water cooler. I am optimistic that understanding the nature of such group interactions will increase human intelligence. Just as a mechanical calculator can extend our mental capacities, other people help us extend our intelligence—both in a cognitive sense (as required to solve problems) and in an emotional sense (as required to detect and respond appropriately to emotions, ours and those of others). In this sense, other people can serve as "social prosthetic systems," as extensions of our own brains; a wooden leg can fill in for a missing limb, and others' brains can fill in for our cognitive and emotional limitations. To the extent that researchers come to understand how such social prosthetic systems arise and operate, they will understand how to increase human intelligence.
Third, the line between animate and inanimate information processing is becoming increasingly blurry as research in multiple fields proceeds apace. I expect that engineers will continue to press forward, designing increasingly powerful machines to help us extend our intelligence. For example, some people carry computers with them everywhere they go, and treat Google as an extension of their own knowledge bases. Or, in my case, my PDA extends my organizational ability enormously. We soon will have a wide variety of mechanical helpmates. The distinction between what goes on in the head and what relies on external devices is becoming more subtle and nuanced, and in so doing human intelligence is being extended.
Crucially, each of these three developments amplifies the effects of the others, producing synergies: As "brain exercises" enhance our personal intellectual abilities, we can learn how to make better use of mechanical aids and how to rely more effectively on other people. The confluence of all three types of developments will produce positive feedback loops, where the very act of interacting with others or working with smart devices will help us continue to develop our brains, and as our brains develop we will in turn be able to use increasingly sophisticated devices and rely on people in more complex and powerful ways.
With luck, such developments will produce news sorts of extended social links and highly integrated social networks, and a new kind of "smart society" will emerge. And, who knows, such a society may not only be smarter, but also wiser."
Most popular consciousness articles for January
From the monthy report of downloads from the archive maintained by the Association for the Scientific Study of Consciousness (ASSC) the "five most popular papers" are:
1. Seth, A.K. and Izhikevich, E.I. and Reeke, G.N. and Edelman, G.M. (2006)
*Theories and measures of consciousness: An extended framework.* Proceedings
of the National Academy of Sciences USA, 103 (28). pp. 10799-10804. With
1481 downloads from 24 countries. See: http://eprints.assc.caltech.edu/162/
2. Koch, Christof and Tsuchiya, Nao (2006) *(PART 1) The relationship
between attention and consciousness.* In: 10th annual meeting of the
Association for the Scientific Study of Consciousness, June, Oxford. With
1356 downloads from 19 countries. See:
http://eprints.assc.caltech.edu/37/
3. Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel
and Sackur,
Jérôme and Sergent, Claire (2006) *Conscious, preconscious, and subliminal
processing: a testable taxonomy.* Trends in Cognitive Science, 10 (5).
pp. 204-211. With 1185 downloads from 22 countries. See:
http://eprints.assc.caltech.edu/20
4. Windt, Jennifer Michelle and Metzinger, Thomas (2006) *The philosophy of
dreaming and self-consciousness: What happens to the experiential subject
during the dream state?* In: The new science of dreaming. Praeger
Imprint/Greenwood Publishers, Estport, CT. With 1034 downloads from 24
countries. See: http://eprints.assc.caltech.edu/200/
5. Destrebecqz, Arnaud and Peigneux, Philippe (2005) *Methods for studying
unconscious learning.* In: Progress in Brain Research. Elsevier, pp. 69-80.
With 1009 downloads from 20 countries. See:
http://eprints.assc.caltech.edu/170/
Five other publications that were also very popular last month and that have not been mentioned before:
- Carruthers, Peter (2007) *The illusion of conscious will.* In: Synthese,
96. See: http://eprints.assc.caltech.edu/213/
- Robbins, Stephen E (2006) *Bergson and the holographic theory of
mind.* Phenomenology
and the Cognitive Sciences, 5. pp. 365-394. See:
http://eprints.assc.caltech.edu/206/
- Vandenberghe, Muriel and Schmidt, Nicolas and Féry, Patrick and Cleeremans,
Axel (2006) *Can amnesic patients learn without awareness? New evidence
comparing deterministic and probabilistic sequence learning.*
Neuropsychologia, 44. pp. 1629-1641. See:
http://eprints.assc.caltech.edu/124/
- Moore, James W and Haggard, Patrick (2006) *Awareness of action: Inference
and prediction.* Consciousness and Cognition, In press. See:
http://eprints.assc.caltech.edu/199/
- Rosen, Alan and Rosen, David B. (2006) *The Design of a
Sensation-generating Mechanism in the Brain: A first step towards a
quantitative definition of consciousness.* Consciusness and Cognition,
CONCOG-06-00174 (tbd). See:
http://eprints.assc.caltech.edu/195/
1. Seth, A.K. and Izhikevich, E.I. and Reeke, G.N. and Edelman, G.M. (2006)
*Theories and measures of consciousness: An extended framework.* Proceedings
of the National Academy of Sciences USA, 103 (28). pp. 10799-10804. With
1481 downloads from 24 countries. See: http://eprints.assc.caltech.edu/162/
2. Koch, Christof and Tsuchiya, Nao (2006) *(PART 1) The relationship
between attention and consciousness.* In: 10th annual meeting of the
Association for the Scientific Study of Consciousness, June, Oxford. With
1356 downloads from 19 countries. See:
http://eprints.assc.caltech.edu/37/
3. Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel
and Sackur,
Jérôme and Sergent, Claire (2006) *Conscious, preconscious, and subliminal
processing: a testable taxonomy.* Trends in Cognitive Science, 10 (5).
pp. 204-211. With 1185 downloads from 22 countries. See:
http://eprints.assc.caltech.edu/20
4. Windt, Jennifer Michelle and Metzinger, Thomas (2006) *The philosophy of
dreaming and self-consciousness: What happens to the experiential subject
during the dream state?* In: The new science of dreaming. Praeger
Imprint/Greenwood Publishers, Estport, CT. With 1034 downloads from 24
countries. See: http://eprints.assc.caltech.edu/200/
5. Destrebecqz, Arnaud and Peigneux, Philippe (2005) *Methods for studying
unconscious learning.* In: Progress in Brain Research. Elsevier, pp. 69-80.
With 1009 downloads from 20 countries. See:
http://eprints.assc.caltech.edu/170/
Five other publications that were also very popular last month and that have not been mentioned before:
- Carruthers, Peter (2007) *The illusion of conscious will.* In: Synthese,
96. See: http://eprints.assc.caltech.edu/213/
- Robbins, Stephen E (2006) *Bergson and the holographic theory of
mind.* Phenomenology
and the Cognitive Sciences, 5. pp. 365-394. See:
http://eprints.assc.caltech.edu/206/
- Vandenberghe, Muriel and Schmidt, Nicolas and Féry, Patrick and Cleeremans,
Axel (2006) *Can amnesic patients learn without awareness? New evidence
comparing deterministic and probabilistic sequence learning.*
Neuropsychologia, 44. pp. 1629-1641. See:
http://eprints.assc.caltech.edu/124/
- Moore, James W and Haggard, Patrick (2006) *Awareness of action: Inference
and prediction.* Consciousness and Cognition, In press. See:
http://eprints.assc.caltech.edu/199/
- Rosen, Alan and Rosen, David B. (2006) *The Design of a
Sensation-generating Mechanism in the Brain: A first step towards a
quantitative definition of consciousness.* Consciusness and Cognition,
CONCOG-06-00174 (tbd). See:
http://eprints.assc.caltech.edu/195/
Wednesday, February 21, 2007
Are ideas like food and sex?
"Does human creativity stem from a process that turns arbitrary ideas into goals like food and sex?"
..asks Andy Clark, in his review (Nature 445, 711-712, 15 February 2007) of "Why Choose This Book? How We Make Decisions," by Read Montague (Dutton: 2006):
"The most obvious rewards are the basic biological achievements of life maintenance (such as the ingestion of a tasty and nourishing morsel) and reproduction (or rather its precursor, sexual intercourse). Montague is motivated, however, by a strong desire to unravel the mechanistic underpinnings of what he describes as a uniquely human 'superpower': the capacity to make choices that seem to value biologically arbitrary objects, achievements and actions. Examples of such biologically arbitrary goal states mentioned in the text include solving Fermat's last theorem and committing group suicide in the belief that a spaceship hidden in a comet's tail will then take you to 'the next level'. What makes all this possible, in Montague's model, is the capacity of ideas themselves to act as reward signals, hijacking the prediction-error systems implemented by dopamine neurons in the brain. When this happens, the dopamine outputs start to act as error signals that encourage the rest of the brain to learn and to make decisions in ways that increase the chances of acquiring some biologically arbitrary reward."
"Given the potentially biologically catastrophic consequences of such re-tooling of mere thoughts as rewards, Montague suggests that powerful filtering processes control what gets into the reward slot. But such processes can be fooled — in ways that the book describes in compelling and often sinister detail — by damage, by drug abuse, and perhaps even by some forms of advertising and branding (brands are just cues that predict rewards). Montague's proposal is that biologically arbitrary goals can somehow plug into a kind of 'special status reward socket', and thus become a basic, primary reward, like food or sex. He does not claim that these ideas become associated, either directly or indirectly, with food or sex; rather, they plug directly into the 'socket' normally occupied only by the most basic high-status rewards. If we humans have indeed learnt such a powerful trick, it is no surprise that it fuels so much that is both good (creative and expansive) and ill (pathological and restrictive) in our species. Montague begins by laying out this possibility, then follows it deep into the fascinating territories of creative thought, addiction, obsessive–compulsive disorder, Parkinson's disease, and then on to the psychosocial realms of trust and regret."
"The book spans several seldom-bridged worlds, from neuroscience to psychiatry, economics and social psychology, and does so with wit, precision and elegance. It succeeds in many of its goals. Above all, it left me feeling I had actually learnt something about myself: a thinking, feeling, choosing, yet painfully vulnerable chemically modulated learning machine."
..asks Andy Clark, in his review (Nature 445, 711-712, 15 February 2007) of "Why Choose This Book? How We Make Decisions," by Read Montague (Dutton: 2006):
"The most obvious rewards are the basic biological achievements of life maintenance (such as the ingestion of a tasty and nourishing morsel) and reproduction (or rather its precursor, sexual intercourse). Montague is motivated, however, by a strong desire to unravel the mechanistic underpinnings of what he describes as a uniquely human 'superpower': the capacity to make choices that seem to value biologically arbitrary objects, achievements and actions. Examples of such biologically arbitrary goal states mentioned in the text include solving Fermat's last theorem and committing group suicide in the belief that a spaceship hidden in a comet's tail will then take you to 'the next level'. What makes all this possible, in Montague's model, is the capacity of ideas themselves to act as reward signals, hijacking the prediction-error systems implemented by dopamine neurons in the brain. When this happens, the dopamine outputs start to act as error signals that encourage the rest of the brain to learn and to make decisions in ways that increase the chances of acquiring some biologically arbitrary reward."
"Given the potentially biologically catastrophic consequences of such re-tooling of mere thoughts as rewards, Montague suggests that powerful filtering processes control what gets into the reward slot. But such processes can be fooled — in ways that the book describes in compelling and often sinister detail — by damage, by drug abuse, and perhaps even by some forms of advertising and branding (brands are just cues that predict rewards). Montague's proposal is that biologically arbitrary goals can somehow plug into a kind of 'special status reward socket', and thus become a basic, primary reward, like food or sex. He does not claim that these ideas become associated, either directly or indirectly, with food or sex; rather, they plug directly into the 'socket' normally occupied only by the most basic high-status rewards. If we humans have indeed learnt such a powerful trick, it is no surprise that it fuels so much that is both good (creative and expansive) and ill (pathological and restrictive) in our species. Montague begins by laying out this possibility, then follows it deep into the fascinating territories of creative thought, addiction, obsessive–compulsive disorder, Parkinson's disease, and then on to the psychosocial realms of trust and regret."
"The book spans several seldom-bridged worlds, from neuroscience to psychiatry, economics and social psychology, and does so with wit, precision and elegance. It succeeds in many of its goals. Above all, it left me feeling I had actually learnt something about myself: a thinking, feeling, choosing, yet painfully vulnerable chemically modulated learning machine."
Tuesday, February 20, 2007
Collective minds - Higher order computation?
From the Editor's summary and Couzin's essay in Nature on this topic:"Watching a giant flock of birds swoop across the sky as one, or a school of fish darting this way and that, it's impossible for our minds to conceive of a process that unites so many individuals so seamlessly."
"We now know that such synchronized group behaviour is mediated through sensory modalities such as vision, sound, pressure and odour detection. Individuals tend to maintain a personal space by avoiding those too close to themselves; group cohesion results from a longer-range attraction to others; and animals often align their direction of travel with that of nearby neighbours. These responses can account for many of the group structures we see in nature, including insect swarms and the dramatic vortex-like mills formed by some species of fish and bat. By adjusting their motion in response to that of near neighbours, individuals in groups both generate, and are influenced by, their social context — there is no centralized controller."
"For individuals within groups, survival can depend critically on how local behavioural rules scale to collective properties. Pertinent information, such as the location of resources or predators, may often be detected by only a relatively small proportion of group members due to limitations in individual sensory capabilities, often further restricted by crowding. Close behavioural coupling among near neighbours, however, allows a localized change in direction to be amplified, creating a rapidly growing and propagating wave of turning across the group. This positive feedback results from the ability of individuals to influence and be influenced by others, and allows them to experience an 'effective range' of perception much larger than their actual sensory range."
"We are beginning to comprehend more fully how individuals in groups can gain access to higher-order collective computational capabilities such as the simultaneous acquisition and processing of information from widely distributed sources. Group members may come to a consensus not only about where to travel but also about what local rules to use. Thus, like the brain, groups may adapt to compute 'the right thing' in different contexts, matching their collective information-strategy with the statistical properties of their environment."
"...today there is a rapidly expanding and vibrant community of biologists, engineers, mathematicians and physicists for whom flocking serves as inspiration. Such group behaviour holds clues about the evolution of sociality, and also for the development of novel technological solutions, from autonomous swarms of exploratory robots to flocks of communicating software agents that help each other to navigate through complex and unpredictable data environments."
Human Nature Redux
David Broder writes an Op-Ed piece with this title in the 2/18/07 Sunday NY Times, noting how public consciousness has shifted away from a belief in the essential goodness of human nature. "As Steven Pinker has put it, Hobbes was more right than Rousseau.....human beings are not as pliable as the social engineers imagined. Human beings operate according to preset epigenetic rules, which dispose people to act in certain ways. We strive for dominance and undermine radical egalitarian dreams. We’re tribal and divide the world into in-groups and out-groups...This darker if more realistic view of human nature has led to a rediscovery of different moral codes and different political assumptions. Most people today share what Thomas Sowell calls the Constrained Vision, what Pinker calls the Tragic Vision and what E. O. Wilson calls Existential Conservatism. This is based on the idea that there is a universal human nature; that it has nasty, competitive elements; that we don’t understand much about it; and that the conventions and institutions that have evolved to keep us from slitting each other’s throats are valuable and are altered at great peril."
" Today, parents don’t seek to liberate their children; they supervise, coach and instruct every element of their lives. Today, there really is no antinomian counterculture — even the artists and rock stars are bourgeois strivers. Today, communes and utopian schemes are out of favor. People are mostly skeptical of social engineering efforts and jaundiced about revolutionaries who promise to herald a new dawn. Iraq has revealed what human beings do without a strong order-imposing state....This is a big pivot in intellectual history. The thinkers most associated with the Tragic Vision are Isaiah Berlin, Adam Smith, Edmund Burke, Alexander Hamilton, James Madison, Friedrich Hayek and Hobbes. Many of them are conservative...And here’s another perversity of human nature. Many conservatives resist the theory of evolution even though it confirms many of conservatism’s deepest truths."
" Today, parents don’t seek to liberate their children; they supervise, coach and instruct every element of their lives. Today, there really is no antinomian counterculture — even the artists and rock stars are bourgeois strivers. Today, communes and utopian schemes are out of favor. People are mostly skeptical of social engineering efforts and jaundiced about revolutionaries who promise to herald a new dawn. Iraq has revealed what human beings do without a strong order-imposing state....This is a big pivot in intellectual history. The thinkers most associated with the Tragic Vision are Isaiah Berlin, Adam Smith, Edmund Burke, Alexander Hamilton, James Madison, Friedrich Hayek and Hobbes. Many of them are conservative...And here’s another perversity of human nature. Many conservatives resist the theory of evolution even though it confirms many of conservatism’s deepest truths."
Monday, February 19, 2007
Blogalogues (and mud wrestling) on religion...
Here is the latest in the civilized exchange (a dialogue is now a blogaloue) between Sam Harris and Andrew Sullivan . The whole series can be seen here on BeliefNet. I continue to find Harris' comments clear and stimulating, and Sullivan's tortuous evasions increasingly mind-numbing.
And here is a parallel battle on the internet, with two very different groups arguing over the existence of God. Check out blasphemychallenge.com and challengeblasphemy.com. Or, if you wish to be up on the latest on Jesus Christ coming soon check out RaptureAlert.com.
Finally, if your appetite for wacko irrationality is not sated by these links you can follow Oprah's advice and learn "The Secret," (self-help book and DVD by Rhoda Byrne) based on the "Law of Attraction" a re-hash of Norman Vincent Peale's 1952 "Power of Positive Thinking" in new-age pseudo-scientific form. If we all think positivitely the larger field of energy which surrounds us will sum this to cure all the world's ills!
(Some of the above is pulled from several sources in the 2/17/2006 New York Times)
And here is a parallel battle on the internet, with two very different groups arguing over the existence of God. Check out blasphemychallenge.com and challengeblasphemy.com. Or, if you wish to be up on the latest on Jesus Christ coming soon check out RaptureAlert.com.
Finally, if your appetite for wacko irrationality is not sated by these links you can follow Oprah's advice and learn "The Secret," (self-help book and DVD by Rhoda Byrne) based on the "Law of Attraction" a re-hash of Norman Vincent Peale's 1952 "Power of Positive Thinking" in new-age pseudo-scientific form. If we all think positivitely the larger field of energy which surrounds us will sum this to cure all the world's ills!
(Some of the above is pulled from several sources in the 2/17/2006 New York Times)
Blocking the death of retinal cells after retina detachment
I did research on visual receptor cells for 38 years, so this recent item really struck me as important:
Nakazawa et al. started by noting that increased expression of monocyte chemoattractant protein 1 (MCP-1) has been reported in vitreous humor samples of patients with RD (retinal detachment) and diabetic retinopathy as well as in the brain tissues of patients with neurodegenerative diseases, including Alzheimer's disease and multiple sclerosis. They moved on to do experiments showing that that MCP-1 plays a critical role in mediating photoreceptor apoptosis (cell death) in an experimental (mouse) model of RD. RD led to increased MCP-1 expression in the Müller glia and increased CD11b+ macrophage/microglia in the detached retina. An MCP-1 blocking antibody greatly reduced macrophage/microglia infiltration and RD-induced photoreceptor apoptosis. Confirming these results, MCP-1 gene-deficient mice showed significantly reduced macrophage/microglia infiltration after RD and very little photoreceptor apoptosis.
The work shows that MCP-1 expression and subsequent macrophage/microglia infiltration and activation are critical for RD-induced photoreceptor apoptosis. This pathway may be an important therapeutic target for preventing photoreceptor apoptosis in RD and other CNS diseases that share a common etiology.
Photomicrograph showing the close physical relationship between the photoreceptor cells of the retina and the retinal pigment epithelium (RPE). There is constant metabolic exchange between the two cell systems.
Diagram of a cross-section of the eye with retinal detachment (open arrow) and retina hole (solid arrow). Fluid exchange between the subretinal space and vitreous cavity through the hole compromises metabolic exchange between the retina and retinal pigment epithelium.
Nakazawa et al. started by noting that increased expression of monocyte chemoattractant protein 1 (MCP-1) has been reported in vitreous humor samples of patients with RD (retinal detachment) and diabetic retinopathy as well as in the brain tissues of patients with neurodegenerative diseases, including Alzheimer's disease and multiple sclerosis. They moved on to do experiments showing that that MCP-1 plays a critical role in mediating photoreceptor apoptosis (cell death) in an experimental (mouse) model of RD. RD led to increased MCP-1 expression in the Müller glia and increased CD11b+ macrophage/microglia in the detached retina. An MCP-1 blocking antibody greatly reduced macrophage/microglia infiltration and RD-induced photoreceptor apoptosis. Confirming these results, MCP-1 gene-deficient mice showed significantly reduced macrophage/microglia infiltration after RD and very little photoreceptor apoptosis.
The work shows that MCP-1 expression and subsequent macrophage/microglia infiltration and activation are critical for RD-induced photoreceptor apoptosis. This pathway may be an important therapeutic target for preventing photoreceptor apoptosis in RD and other CNS diseases that share a common etiology.
Photomicrograph showing the close physical relationship between the photoreceptor cells of the retina and the retinal pigment epithelium (RPE). There is constant metabolic exchange between the two cell systems.
Diagram of a cross-section of the eye with retinal detachment (open arrow) and retina hole (solid arrow). Fluid exchange between the subretinal space and vitreous cavity through the hole compromises metabolic exchange between the retina and retinal pigment epithelium.
Thursday, February 15, 2007
A clash of two cultures - biology and physics
In an essay with this title in Nature, Evelyn Fox Keller notes that physicists come from a tradition of looking for all-encompassing laws, and asks whether this the best approach to use when probing complex biological systems.
"How appropriate is it to look for all-encompassing laws to describe the properties of biological systems? By its very nature, life is both contingent and particular, each organism the product of eons of tinkering, of building on what had accumulated over the course of a particular evolutionary trajectory. Of course, the laws of physics and chemistry are crucial. But, beyond such laws, biological generalizations (with the possible exception of natural selection) may need to be provisional because of evolution, and because of the historical contingencies on which both the emergence of life and its elaboration depended.
Perhaps it is time to face the issues head on, and ask just when it is useful to simplify, to generalize, to search for unifying principles, and when it is not. There is also a question of appropriate analytical tools. Biologists clearly recognize their need for new tools; ought physical scientists entering systems biology consider that they too might need different methods of analysis — tools better suited to the importance of specificity in biological processes? Finally, to what extent will physicists' focus on biology demand a shift in epistemological goals, even the abandonment of their traditional holy grail of universal 'laws'? These are hard questions, but they may be crucial to the forging of productive research strategies in systems biology. Even though we cannot expect to find any laws governing the search for generalities in biology, some rough, pragmatic guidelines could be very useful indeed."
"How appropriate is it to look for all-encompassing laws to describe the properties of biological systems? By its very nature, life is both contingent and particular, each organism the product of eons of tinkering, of building on what had accumulated over the course of a particular evolutionary trajectory. Of course, the laws of physics and chemistry are crucial. But, beyond such laws, biological generalizations (with the possible exception of natural selection) may need to be provisional because of evolution, and because of the historical contingencies on which both the emergence of life and its elaboration depended.
Perhaps it is time to face the issues head on, and ask just when it is useful to simplify, to generalize, to search for unifying principles, and when it is not. There is also a question of appropriate analytical tools. Biologists clearly recognize their need for new tools; ought physical scientists entering systems biology consider that they too might need different methods of analysis — tools better suited to the importance of specificity in biological processes? Finally, to what extent will physicists' focus on biology demand a shift in epistemological goals, even the abandonment of their traditional holy grail of universal 'laws'? These are hard questions, but they may be crucial to the forging of productive research strategies in systems biology. Even though we cannot expect to find any laws governing the search for generalities in biology, some rough, pragmatic guidelines could be very useful indeed."
Warmth and competence
Fiske et al. suggest that these are universal dimensions of social cognition, in their review article in Trends in Cognitive Sciences:
"Like all perception, social perception reflects evolutionary pressures. In encounters with conspecifics, social animals must determine, immediately, whether the ‘other’ is friend or foe (i.e. intends good or ill) and, then, whether the ‘other’ has the ability to enact those intentions. New data confirm these two universal dimensions of social cognition: warmth and competence. Promoting survival, these dimensions provide fundamental social structural answers about competition and status. People perceived as warm and competent elicit uniformly positive emotions and behavior, whereas those perceived as lacking warmth and competence elicit uniform negativity. People classified as high on one dimension and low on the other elicit predictable, ambivalent affective and behavioral reactions. These universal dimensions explain both interpersonal and intergroup social cognition."
"Like all perception, social perception reflects evolutionary pressures. In encounters with conspecifics, social animals must determine, immediately, whether the ‘other’ is friend or foe (i.e. intends good or ill) and, then, whether the ‘other’ has the ability to enact those intentions. New data confirm these two universal dimensions of social cognition: warmth and competence. Promoting survival, these dimensions provide fundamental social structural answers about competition and status. People perceived as warm and competent elicit uniformly positive emotions and behavior, whereas those perceived as lacking warmth and competence elicit uniform negativity. People classified as high on one dimension and low on the other elicit predictable, ambivalent affective and behavioral reactions. These universal dimensions explain both interpersonal and intergroup social cognition."
Wednesday, February 14, 2007
Distinct brain codings of reward value and risk attitude.
When deciding between different options, individuals are guided by the expected (mean) value of the different outcomes and by the associated degrees of uncertainty. Tobler et al. have used used functional magnetic resonance imaging to identify brain activations coding the key decision parameters of expected value (magnitude and probability) separately from uncertainty (statistical variance) of monetary rewards. Participants discriminated behaviorally between stimuli associated with different expected values and uncertainty. Stimuli associated with higher expected values elicited monotonically increasing activations in distinct regions of the striatum, irrespective of different combinations of magnitude and probability.
Figure: Coding of magnitude, probability and expected value in lateral prefrontal cortex. Common and distinct increases in activation to stimuli associated with increasing reward magnitude, probability and expected value as indicated by different colors.
Stimuli associated with higher uncertainty (variance) elicited increasing activations in the lateral orbitofrontal cortex. Uncertainty-related activations covaried with individual risk aversion in lateral orbitofrontal regions and risk-seeking in more medial areas.
Figure: Differential coding of reward uncertainty but not expected value in lateral orbitofrontal cortex.
Furthermore, activations in expected value-coding regions in prefrontal cortex covaried differentially with uncertainty depending on risk attitudes of individual participants, suggesting that separate prefrontal regions are involved in risk aversion and seeking. These data demonstrate the distinct coding in key reward structures of the two basic and crucial decision parameters, expected value, and uncertainty.
Figure: Coding of magnitude, probability and expected value in lateral prefrontal cortex. Common and distinct increases in activation to stimuli associated with increasing reward magnitude, probability and expected value as indicated by different colors.
Stimuli associated with higher uncertainty (variance) elicited increasing activations in the lateral orbitofrontal cortex. Uncertainty-related activations covaried with individual risk aversion in lateral orbitofrontal regions and risk-seeking in more medial areas.
Figure: Differential coding of reward uncertainty but not expected value in lateral orbitofrontal cortex.
Furthermore, activations in expected value-coding regions in prefrontal cortex covaried differentially with uncertainty depending on risk attitudes of individual participants, suggesting that separate prefrontal regions are involved in risk aversion and seeking. These data demonstrate the distinct coding in key reward structures of the two basic and crucial decision parameters, expected value, and uncertainty.
Malthus was wrong...
Geoffrey Carr notes: "...the demographic shift that all populations (so far) have undergone as they have enriched themselves. For the negative exponent is starting to show up, and its cause is not lack of space or resources, nor yet is it conflict or disease (even AIDS, malaria and tuberculosis make only a small difference in global terms). Instead, it is the thing that the doomsters feared most after population growth — economic growth."
"Perhaps the answer lies in the old idea of r and K selection. Indeed, the terms r and K come from variables in two-term logistic equation that describes real population dynamics. K-selected species, people may remember from their college ecology classes, have few offspring but nurture them lovingly. Those that are r-selected have lots, but display a Devil-take-the-hindmost attitude to their issue's survival. The crucial point is that K-selected species live in safe, predictable environments, while r-selected ones live in unsafe, unpredictable ones. If the individuals of a species were able to shift opportunistically between r and K strategies in response to shifts in the environment, then something like the demographic transition in response to wealth might be the result."
"Perhaps the answer lies in the old idea of r and K selection. Indeed, the terms r and K come from variables in two-term logistic equation that describes real population dynamics. K-selected species, people may remember from their college ecology classes, have few offspring but nurture them lovingly. Those that are r-selected have lots, but display a Devil-take-the-hindmost attitude to their issue's survival. The crucial point is that K-selected species live in safe, predictable environments, while r-selected ones live in unsafe, unpredictable ones. If the individuals of a species were able to shift opportunistically between r and K strategies in response to shifts in the environment, then something like the demographic transition in response to wealth might be the result."
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