Brain cells and arrangements unique to human cerebral cortex

A New Focus article in the March 2 issue of Science by Michael Balter reviews work on several brain neuronal types and arrangements that are distinctive to humans and great apes.

Spindle neurons (also called Von Economo or VEN neurons after their Austrain discoverer) are provide one example (credit J. Allman):

...these neurons are located in only two parts of the brain: the anterior cingulate cortex, deep in the center of the brain, and the frontoinsular cortex, located inside the frontal lobes. In humans, both of these structures appear to be involved in aspects of social cognition such as trust, empathy, and feelings of guilt and embarrassment. Not only were VENs unique to great apes, but humans had many more VENs than other apes. And the human VENs were markedly larger.

John Allman of Cal Tech suggests that

...the large VENs might relay information rapidly from the anterior cingulate and frontoinsular cortices to other parts of the brain....They are really stripped-down, high-performance kinds of cells...the big VENs might help humans adjust behavior swiftly in response to rapidly changing social situations....

New data on dementia seem to fit that notion.

Last December, a team led by William Seeley at UC San Francisco reported in Annals of Neurology that subjects afflicted with a type of dementia that causes inappropriate and impulsive social behavior had 74% fewer VENs in their anterior cingulate cortex compared to normal controls.

The article goes on to discuss the fact that minicolumns of the, groups of 80 to 100 nerve cells bundled together vertically in the cerebral cortex are much wider in humans than in chimps and monkeys (average of 51 versus 36 micrometers) due to an increase in the space taken up by neuropil (the axons, dendrites, and synapses that make neural connections). That is, there are many more connections.

Astrocyte Cells: (Credit: Oberheim et al. Univ. Rochester)

It also turns out that that levels of the messenger RNA that makes thrombospondins - large proteins released by astrocytes which trigger synapse formation - are six times higher in human cerebral cortex than in chimps or monkeys. The differences were seen in the cerebral cortex but not in the cerebellum and nonbrain tissues. (Astrocytes are support cells that make up nearly half the cells in the human brain, but their functions have remained a mystery.)

Alter a gene - make more fearless mice

Here is a brief clip on material I have mentioned previously...

Odor cues during sleep stimulate memory.

The March 9 issue of Science has an interesting report by Rasch et al. and commentary by Miller on experiments demonstrating that pulses of an odor (rose scent) given during a learning task, improve consolidation of the memory of that task if given also during slow-wave sleep. The abstract:

Sleep facilitates memory consolidation. A widely held model assumes that this is because newly encoded memories undergo covert reactivation during sleep. We cued new memories in humans during sleep by presenting an odor that had been presented as context during prior learning, and so showed that reactivation indeed causes memory consolidation during sleep. Re-exposure to the odor during slow-wave sleep (SWS) improved the retention of hippocampus-dependent declarative memories but not of hippocampus-independent procedural memories. Odor re-exposure was ineffective during rapid eye movement sleep or wakefulness or when the odor had been omitted during prior learning. Concurring with these findings, functional magnetic resonance imaging revealed significant hippocampal activation in response to odor re-exposure during SWS.

Robot Dreams

There is a very interesting exchange in the Letter section of the March 2 issue of Science Magazine. R. Conduit comments on a perspectives article "What do robots dream of?" (17 Nov. 2006, p. 1093) by C. Adami, which provides an interesting interpretation of the Report "Resilient machines through continuous self-modeling" by J. Bongard et al. (17 Nov. 2006, p. 1118).

Bongard et al. designed a robot with an algorithm of its stored sensory data to indirectly infer its physical structure. The robot was able to generate forward motion more adaptively by manipulating its gait to compensate for simulated injuries. Adami equates this algorithm to "dreams" of prior actions and asks whether such modeling could extend to environmental mapping algorithms. If this were possible, then a robot could explore a landscape until it is challenged by an obstacle; overnight, it could replay its actions against its model of the environment and generate (or synthesize) new actions to overcome the obstacle (i.e., "dream up" alternative strategies). It could then return the next day with a new approach to the obstacle......

This work in robotics complements current findings regarding sleep and dreaming in humans. There is now strong evidence in human sleep research showing that performance on motor and visual tasks is strongly dependent on sleep, with improvements consistently greater when sleep occurs between test and retest. This is generally believed to be related to neural recoding processes that are possibly connected to dreaming during sleep). However, when one considers human dreaming, it is not a simple replay of daily scenarios. It has complex, distorted images from a vast variety of times and places in our memory, arranged in a random, bizarre fashion. If we are to model such activity in robots, we would need to have some form of "sleep" algorithm that randomizes memory and combines it in unique arrays. This could be a way to generate unique approaches to scenarios that could be simulated. Otherwise, how else would scenario replay be an improvement over repeated trials in the environment?when one considers human dreaming, it is not a simple replay of daily scenarios. It has complex, distorted images from a vast variety of times and places in our memory, arranged in a random, bizarre fashion. If we are to model such activity in robots, we would need to have some form of "sleep" algorithm that randomizes memory and combines it in unique arrays. This could be a way to generate unique approaches to scenarios that could be simulated. Otherwise, how else would scenario replay be an improvement over repeated trials in the environment?

After a further comment letter from C. Adami, Lipson, Zykov and Bongard (the original authors) comment:

The analogy between machine and human cognition may suggest that reported bizarre, random dreams may not be entirely random. The robot we described did not just replay its experiences to build consistent internal self-models and then "dream up" an action based on those models. Instead, it synthesized new brief actions that deliberately caused its competing internal models to disagree in their predictions, thus challenging them to falsify less plausible theories and, as a result, improving its overall knowledge of self. It is possible that the mangled experiences that people report as bizarre dreams correspond to this unconscious search for actions able to clarify their self-perceptions. Many of the intermediate candidate models and actions developed by the robot (as seen in Movie S1 in our Supporting Online Material) were indeed very contorted, but were optimized nonetheless to elucidate uncertainties. Edelman (1), Calvin (2), and others have suggested the existence of competitive processes in the brain. Perhaps the fact that human dreams appear mangled and brief is exactly because they are--as in the robot--"optimized" to challenge and improve these competing internal models?

Indeed, analogies between machines learning from past experiences and human dreaming are potentially very fruitful and may be applicable in both directions. Although robots and their onboard algorithms are clearly simpler and may bear little or no direct relation to humans and their minds, it may be much easier to test hypotheses about humans in robots. Conversely, ideas from human cognition research may help direct robotic research beyond merely serving as inspiration. Specifically, it is likely that as robots become more complex and their internal models are formed indirectly rather than being explicitly engineered and represented, indirect probing techniques developed for studying humans may become essential for analyzing machines too.

Ultimately, monopolies fail...

An essay by Barry Smith argues that attempts to dictate our tastes, our preference, our culture, our media, our political policies, or moral choices are bound in the end to fail because of the basic nature of our human cognition.

...Restless creatures that we are, we seek out variety and difference, opportunities to extend the scope of our thinking and to exercise discrimination and taste. This may make us hard to satisfy, but, ultimately, it is this lack of satisfaction that leads to progress and spells the end of hegemonies in ideology, religion, or science...I am optimistic that people who are fed a constant diet of the same ideas, the same foods, the same TV programmes, the same religious or political dogmas will eventually come to consider other possibilities...The lesson is already being learned in the corporate world where monopolies try to cope with this by diversifying their range of services. Their chance of survival will depend on how cynically or sincerely they respond to this restless aspect of the human mind.

Human cognition depends on change and movement in order to function. Evolution has built us this way. Try staring at a blank wall for several seconds without blinking and you will find the image eventually bleaching until you can see nothing. The eye’s visual workings respond to movement and change. So too do the other parts of our cognitive systems. Feed them the same inputs successively and they cease to produce very much worth having as output. Like the shark in water, we need to keep moving or, cognitively, we die.

...there is a paradox in our nature and our restless search for change. For unless we countenance change for change’s sake, or the relativist doctrine that anything goes (—and I don’t) how do we preserve the very best of our thinking, select better quality experiences, and maintain our purposes, directions and values? How do we avoid losing sight of older wisdom while rushing towards something new? It is here, perhaps, that our need for variation and discrimination serves us best. For the quick and gimmicky, the superficially appealing but weakest objects of our thinking or targets of desire will also be the least substantial and have an essential blandness that can tire us quickly. Besides, the more experience we have, the larger the background against which to compare and judge the worth or quality of what is newly encountered, and to decide if it will be ultimately rewarding. Certainly, people can be fickle or stubborn, but they are seldom fickle or stubborn for long. They will seek out better, according to what they are presently capable of responding to, and they will be dissatisfied by something not worthy of the attention they are capable of. For this reason attempts to dictate their tastes, cultural goods, ideologies or ideas are bound in the end to fail, and about that, and despite of many dark forces around us, I am optimistic.

Losing a night's sleep makes you less able to form new memories.

Yoo et al. report that :

..a single night of sleep deprivation produces a significant deficit in hippocampal activity during episodic memory encoding, resulting in worse subsequent retention. Furthermore, these hippocampal impairments instantiate a different pattern of functional connectivity in basic alertness networks of the brainstem and thalamus. We also find that unique prefrontal regions predict the success of encoding for sleep-deprived individuals relative to those who have slept normally. These results demonstrate that an absence of prior sleep substantially compromises the neural and behavioral capacity for committing new experiences to memory. It therefore appears that sleep before learning is critical in preparing the human brain for next-day memory formation—a worrying finding considering society's increasing erosion of sleep time.

Sad News....

A friend has emailed me that his beloved iMac was laid to rest today in Chicago Heights..it was an open-pallet service.

Why stronger sniffing catches weak odors...

Grosmaitre et al. report in Nature Neuroscience that up to half of mammalian olfactory sensory neurons respond to mechanical stimulation through air-pressure changes, as well as to specific smells. The responses seem to share the same cellular pathway, with increased air pressure raising the firing rate of neurons that have been weakly stimulated by odorants. This mechanism may help to synchronize the firing of neurons in the olfactory bulb with breathing.

Why do we believe - Darwin’s God

Credit: New York Times

The New York Times Sunday Magazine of 3/4/07 contains an interesting article by Robin Marantz Henig on why:

...there seems an inherent human drive to believe in something transcendent, unfathomable and otherworldly, something beyond the reach or understanding of science...The debate over why belief evolved is between byproduct theorists and adaptationists.

Byproduct Theorists:

Darwinians who study physical evolution distinguish between traits that are themselves adaptive, like having blood cells that can transport oxygen, and traits that are byproducts of adaptations, like the redness of blood. There is no survival advantage to blood’s being red instead of turquoise; it is just a byproduct of the trait that is adaptive, having blood that contains hemoglobin.

Something similar explains aspects of brain evolution, too, say the byproduct theorists...Hardships of early human life favored the evolution of certain cognitive tools, among them the ability to infer the presence of organisms that might do harm, to come up with causal narratives for natural events and to recognize that other people have minds of their own with their own beliefs, desires and intentions. Psychologists call these tools, respectively, agent detection, causal reasoning and theory of mind (or folk psychology). [See Atran, “In Gods We Trust: The Evolutionary Landscape of Religion,” 2002.]

Folkpsychology, as Atran and his colleagues see it, is essential to getting along in the contemporary world, just as it has been since prehistoric times. It allows us to anticipate the actions of others and to lead others to believe what we want them to believe; it is at the heart of everything from marriage to office politics to poker...The process begins with positing the existence of minds, our own and others’, that we cannot see or feel. This leaves us open, almost instinctively, to belief in the separation of the body (the visible) and the mind (the invisible). If you can posit minds in other people that you cannot verify empirically, suggests Paul Bloom, a psychologist and the author of “Descartes’ Baby,” published in 2004, it is a short step to positing minds that do not have to be anchored to a body. And from there, he said, it is another short step to positing an immaterial soul and a transcendent God.

The bottom line, according to byproduct theorists, is that children are born with a tendency to believe in omniscience, invisible minds, immaterial souls — and then they grow up in cultures that fill their minds, hard-wired for belief, with specifics. It is a little like language acquisition, Paul Bloom says, with the essential difference that language is a biological adaptation and religion, in his view, is not. We are born with an innate facility for language but the specific language we learn depends on the environment in which we are raised. In much the same way, he says, we are born with an innate tendency for belief, but the specifics of what we grow up believing — whether there is one God or many, whether the soul goes to heaven or occupies another animal after death — are culturally shaped...

The Adaptationists:

Trying to explain the adaptiveness of religion means looking for how it might have helped early humans survive and reproduce. As some adaptationists see it, this could have worked on two levels, individual and group. Religion made people feel better, less tormented by thoughts about death, more focused on the future, more willing to take care of themselves. As William James put it, religion filled people with “a new zest which adds itself like a gift to life . . . an assurance of safety and a temper of peace and, in relation to others, a preponderance of loving affections.”

Such sentiments, some adaptationists say, made the faithful better at finding and storing food, for instance, and helped them attract better mates because of their reputations for morality, obedience and sober living. The advantage might have worked at the group level too, with religious groups outlasting others because they were more cohesive, more likely to contain individuals willing to make sacrifices for the group and more adept at sharing resources and preparing for warfare.

One of the most vocal adaptationists is David Sloan Wilson, an occasional thorn in the side of both Scott Atran and Richard Dawkins. Wilson, an evolutionary biologist at the State University of New York at Binghamton, focuses much of his argument at the group level. “Organisms are a product of natural selection,” he wrote in “Darwin’s Cathedral: Evolution, Religion, and the Nature of Society,” which came out in 2002...Through countless generations of variation and selection, [organisms] acquire properties that enable them to survive and reproduce in their environments. My purpose is to see if human groups in general, and religious groups in particular, qualify as organismic in this sense.”

Dawkins once called Wilson’s defense of group selection “sheer, wanton, head-in-bag perversity.” Atran, too, has been dismissive of this approach, calling it “mind blind” for essentially ignoring the role of the brain’s mental machinery. The adaptationists “cannot in principle distinguish Marxism from monotheism, ideology from religious belief,” Atran wrote. “They cannot explain why people can be more steadfast in their commitment to admittedly counterfactual and counterintuitive beliefs — that Mary is both a mother and a virgin, and God is sentient but bodiless — than to the most politically, economically or scientifically persuasive account of the way things are or should be.”

So,

What can be made of atheists, then? If the evolutionary view of religion is true, they have to work hard at being atheists, to resist slipping into intrinsic habits of mind that make it easier to believe than not to believe. Atran says he faces an emotional and intellectual struggle to live without God in a nonatheist world, and he suspects that is where his little superstitions come from, his passing thought about crossing his fingers during turbulence or knocking on wood just in case. It is like an atavistic theism erupting when his guard is down. The comforts and consolations of belief are alluring even to him, he says, and probably will become more so as he gets closer to the end of his life. He fights it because he is a scientist and holds the values of rationalism higher than the values of spiritualism.

This internal push and pull between the spiritual and the rational reflects what used to be called the “God of the gaps” view of religion. The presumption was that as science was able to answer more questions about the natural world, God would be invoked to answer fewer, and religion would eventually recede. Research about the evolution of religion suggests otherwise. No matter how much science can explain, it seems, the real gap that God fills is an emptiness that our big-brained mental architecture interprets as a yearning for the supernatural. The drive to satisfy that yearning, according to both adaptationists and byproduct theorists, might be an inevitable and eternal part of what Atran calls the tragedy of human cognition.

A membrane protein controlling social memory and maternal care in mice.

Oxytocin is gaining increasing recognition as a master regulator of affiliative behaviors in mice as well as humans. Duo Jin et al. now show that genetically knocking out CD38, a transmembrane glycoprotein required for oxytocin secretion by axon terminals in the hypothalamus, causes defective maternal nurturing and social behavior in male and female mice. Replacement of oxytocin by subcutaneous injection or lentiviral-vector-mediated delivery of human CD38 in the hypothalamus rescues social memory and maternal care.

Yet another molecule the genetic engineers might one day dink with to make us more kind and gentle people??

Getting past "mind bugs"

From Mahzarin Banaji, Psychology Department at Harvard:

I am bullish about the mind's ability to unravel the beliefs contained within it—including beliefs about its own nature...the ability of humans everywhere to go against the grain of their own beliefs that are familiar, that feel natural and right, and that appear to be fundamentally true...

We've done this sort of unraveling many times before, whether it is about the relationship of the sun to the earth, or the relationship of other species to us. We've put aside what seemed natural, what felt right, and what came easily in favor of the opposite. I am optimistic that we are now ready to do the same with questions about the nature of our own minds. From the work of pioneers such as Herb Simon, Amos Tversky, and Danny Kahneman we know that the beliefs about our own minds that come naturally, feel right, and are easy to accept aren't necessarily true. That the bounds on rationality keep us from making decisions that are in our own interest, in the interest of those we love, in the long-term interest of our societies, even the planet, even perhaps the universe, with which we will surely have greater opportunity to interact in this century.

Here are some examples of what seems natural, feels right, and is easy to believe in—even though it isn't rational or true.

We irrationally anchor: ask people to generate their social security number and then the number of doctors in their city and the correlation between the two numbers will be significantly positive, when in fact it ought to be zero—there's no relation between the two variables. That's because we can't put the first one aside as we generate the second.

We irrationally endow: give somebody a cheap mug, and once it's "my mug" through ownership (and nothing else) it becomes, in our minds, a somewhat less cheap mug. Endowed with higher value, we are likely to demand a higher price for it than it is worth or is in our interest to demand.

We irrationally see patterns where non exist: Try to persuade a basketball player, fan, or statistician that there isn't anything to the idea of streak shooting; that chance is lumpy and that that's all there is to Michael Jordan's "hot hand".

...such "mind bugs" extend to the beliefs and preferences we have about ourselves, members of our own social groups, and those who sit farther away on a scale of social distance....We don't intend to discriminate or treat unfairly, but we do....The ability to think about one's own long range interest, to self-regulate and delay gratification, to consider the well-being of the collective, especially to view the collective as unbounded by religion, language, or nationality requires a mental leap that isn't natural or easy. And yet each new generation seems to be able to do it more successfully than the previous one...old beliefs come unraveled because such unraveling is in our self-interest...we unravel existing beliefs and preferences because we wish them to be in line with our intentions and aspirations and recognize that they are not. I see evidence of this everywhere—small acts to be the person one wishes to be rather than the person one is—and it is the constant attempt at this alignment that gives me optimism.

Some bird friends

From my condo porch:

Why are primate brains smarter than rodent brains of the same size?

Herculano-Houzel et al. ask whether a difference the cellular composition of rodent and primate brains might underlie the better cognitive abilities of primates. They show that that in primates:

...brain size increases approximately isometrically as a function of cell numbers, such that an 11x larger brain is built with 10x more neurons and {approx}12x more nonneuronal cells of relatively constant average size. This isometric function is in contrast to rodent brains, which increase faster in size than in numbers of neurons. As a consequence of the linear cellular scaling rules, primate brains have a larger number of neurons than rodent brains of similar size, presumably endowing them with greater computational power and cognitive abilities.

If the same rules relating numbers of neurons to brain size in rodents also applied to primates, a brain comparable to ours, with {approx}100 billion neurons, would weigh >45 kg and belong to a body of 109 tons, about the mass of the heaviest living mammal, the blue whale. This simple calculation indicates quite dramatically that cellular scaling rules differ between rodents and primates, not surprising given the different cognitive abilities of rodents and primates of similar brain size (e.g., between agoutis and owl monkeys or between capybaras and macaque monkeys).

Understanding the brain - an inductive leap?

This clip from a brief essay by Steve Grand, A.I. researcher:

"...it seems to me that almost everything we think we understand about the brain is wrong. We know an enormous amount about it now and just about none of it makes the slightest bit of sense. That's a good sign, I think. It shows us we've been looking at the wrong page of the map.

Let me try to illustrate this with a thought experiment: Suppose I give you a very complex system to study – not a brain but something equally perplexing. You discover quite quickly that one part of the system is composed of an array of elements, of three types. These elements emit signals that vary rapidly in intensity, so you name these the alpha, beta and gamma elements, and set out eagerly to study them. Placing a sensor onto examples of each type you find that their actual signal patterns are distressingly random and unpredictable, but with effort you discover that there are statistical regularities in their behaviour: beta and gamma elements are slightly more active than alpha elements; when betas are active, gammas in the same region tend to be suppressed; if one element changes in activity, its neighbours tend to change soon after; gammas at the top of the array are more active than those at the bottom, and so on. Eventually you amass an awful lot of information about these elements, but still none of it makes sense. You're baffled.

So allow me to reveal that the system you've been studying is a television set, and the alpha, beta and gamma elements are the red, green and blue phosphor dots on the screen. Does the evidence start to fit together now? Skies are blue and tend to be at the top, while fields are green and tend to be at the bottom; objects tend to move coherently across the picture. If you know what the entire TV image represents at any one moment, you'll be able to make valid predictions about which elements are likely to light up next. By looking at the entire array of dots at once, in the context of a good system-level theory of what's actually happening, all those seemingly random signals suddenly make sense. "Aha!"

The single-electrode recordings of the equivalent elements in the brain have largely been replaced by system-wide recordings made by fMRI now, but at the moment we still don't know what any of it means because we have the wrong model in our heads. We need an "aha" moment akin to learning that the phosphor dots above belong to a TV set, upon which images of natural scenes are being projected. Once we know what the fundamental operating principles are, everything will start to make sense very quickly. Painstaking deduction won't reveal this to us; I think it will be the result of a lucky hunch. But the circumstances are in place for that inductive leap to happen soon, and I find that tremendously exciting."

Fascinating Rhythm

This is the title of a review in Nature Magazine by Mayank Mehta of "Rhythms of the Brain" ( György Buzsáki, Oxford University Press: 2006. 464 pp. £42, $69.95)


Brain waves are chaotic during an epileptic attack, as this electroencephalogram shows. (Credit, Nature Magazine).

Some clips from the review:

...neurons not only respond to stimuli, but often do so in a rhythmic fashion. The strength of neural rhythms can predict a subject's performance on a task. Even when we sleep, neurons in most parts of the brain are active in a highly rhythmic fashion. By contrast, epileptic fits and Parkinson's disease are accompanied by an abnormal increase in certain brain rhythms...Buzsáki describes a wide range of brain rhythms, ranging from very slow rhythms of the order of 1 cycle per second up to several hundred cycles per second. The frequency of rhythms changes as a function of development, ageing and disease. The frequency of oscillations often changes dramatically within a few seconds, as a function of the animal's behaviour...Buzsáki then moves on to describe possible functions of brain rhythms, such as resonance, synchronization of neural circuits, and improvement of signal-to-noise ratio by stochastic resonance...Buzsáki's book describes the amazing influence of oscillations on information encoding in the hippocampus and how this may be critical for learning facts and events. It ends with a discussion of some of the toughest problems in the field, such as what consciousness is, and how to irrefutably demonstrate the role of oscillations in brain function.

Jaron Lanier on transforming communication...

Some clips from his essay:

One extravagant idea is that the nature of communication itself might transform in the future as much as it did when language appeared.

Suppose you're enjoying an advanced future implementation of Virtual Reality and you can cause spontaneously designed things to appear and act and interact with the ease of sentences pouring forth during an ordinary conversation today.

Whether this is accomplished by measuring what your body does from the outside or by interacting via interior states of your brain is nothing more than an instrumentation question. Either way, we already have some clues about how the human organism might be able to improvise the content of a Virtual World.

That aspect of the brain which is optimized to control the many degrees of freedom of body motion is also well suited to controlling the many degrees of freedom of a superlative programming and design environment of the future.

Imagine a means of expression that is a cross between the three great new art forms of the 20th century: jazz improvisation, computer programming, and cinema. Suppose you could improvise anything that could be seen in a movie with the speed and facility of a jazz improviser.

A finite game is like a single game of baseball, with an end. An infinite game is like the overall phenomenon of baseball, which has no end. It is always a frontier.

So many utopian ideas are about Finite Games: End disease, solve global warming, get people to be more rational, reduce violence, and so on. As wonderful as all those achievements would (will!) be, there is something missing from them. Finite Game optimism suggests a circumscribed utopia, without frontier or mystery. The result isn't sufficiently inspiring for me- and apparently it doesn't quite grab the imaginations of a lot of other people who are endlessly fascinated by dubious religious and political utopias. The problem is heightened at the moment because there's a trope floating around in the sciences, probably unfounded, that we have already seen the outline of all the science we'll ever know, and we're just in the process of filling in the details.

The most valuable optimisms are Infinite Games, and imagining that new innovations as profound as language will come about in the future of human interaction is an example of one.

Would you like to be an experimental subject?

Check out the Visual Cognition Online Laboratory.

Why I am in Fort Lauderdale...

The house back in Madison Wisconsin:

From my porch...

A friend of mine has suggested that I might increase the ratio of visual images to text in this blog, as well as lighten up its tone by throwing in more random bits from my local environment. As a nudge in that direction, here is a gentleman (or lady?) who cruised down the Middle River past the porch of my Fort Lauderdale condo the other day.

Attentional deficit overcome by fearful body language stimulus

Tamietto et al report in J. Cog. Neurosci. the interesting observation that patients having right parietal lobe damage which makes them inattentive to their left visual field notice fearful body language stimuli in that left visual field much more readily than neutral or happy body language. This demonstrates that despite pathological inattention and parietal damage, emotion and action-related information in fearful body language may be extracted automatically, biasing attentional selection and visual awareness. Apparently a neural network in intact fronto-limbic and visual areas still mediates reorienting of attention and preparation for action upon perceiving fear in others.

A neuroethics website

'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.

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.

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).

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."

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."

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."

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."

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."

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'."

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."

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/

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."

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."

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)

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.

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."

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."

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.

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."

The end of ISMs

Marc D. Hauser:

"Racism, Sexism, Species-ism, Age-ism, Elitism, Fundamentalism, Atheism. These –isms, and others, have fueled hatred, inspired war, justified torture, divided countries, prevented education, increased disparities in wealth, and destroyed civilizations...there is a single underlying cause: a brain that evolved an unconscious capacity to seek differences between self and other, and once identified, seek to demote the other in the service of selfish gains... The good news is that science is uncovering some of the details of this destructive capacity, and may hold the key to an applied solution. My optimism: if we play our cards correctly, we may see the day when our instinctive prejudice toward the other will dissolve, gaining greater respect for differences, expanding our moral circle."

Among the items Hauser suggests in a possible playbook:

"Recognize the universality of our moral intuitions...Remove the doctrinal rules and our intuitive moral psychology propels us to decide what is morally right or wrong based on general principles concerning the welfare of others and our own virtues. If the Protestant and Catholic Irish can see past their religious beliefs, empathize with the other, recognize their shared underlying humanity and settle into peaceful co-existence, why not other warring factions?"

"Be vigilant of disgust...Although disgust was born out of an adaptive response to potential disease vectors, things that are normally inside but are now outside such as vomit, blood, and feces, it is a mischievous emotion, sneaking into other problems, alighting, wreaking havoc on group structure, and then spreading. Throughout the history of warfare, every warring group has tagged their enemy with qualities that are reminiscent of disease, filth, and parasites."

Smell of male sweat raises cortisol levels in women.

The use of chemosignals in other mammals has been well documented, especially in rats. Wyart et al. have now found that if women simply smell pure androstadienone (4,16-androstadien-3-one), which is present in the sweat of men, they maintain higher levels of the stress hormone cortisol.

Distortions of world view

Chris Anderson notes how "Certain types of news — for example dramatic disasters and terrorist actions — are massively over-reported, others — such as scientific progress and meaningful statistical surveys of the state of the world — massively under-reported." This derives from: "a deep human psychological response. We're wired to react more strongly to dramatic stories than to abstract facts. There are obvious historical and Darwinian reasons why this should be so. The news that an invader has just set fire to a hut in your village demands immediate response. The genes for equanimity in such circumstances got burned up long ago...Although our village is now global, we still instinctively react the same way. Spectacle, death and gore."

"Percentage of males estimated to have died in violence in hunter gatherer societies? Approximately 30%. Percentage of males who died in violence in the 20th century complete with two world wars and a couple of nukes? Approximately 1%. ...a carefully researched Human Security Report concluded that the numbers of armed conflicts in the world had fallen 40% in little over a decade." (Steven Pinker's essay in the "What are you optimistic about" series also notes the decline of force over the centuries and hopes that it is a real phenomenon, the product of systematic forces that will continue to operate, and that we can identify those forces and perhaps concentrate and bottle them.)

"In fact, most meta-level reporting of trends show a world that is getting better. We live longer, in cleaner environments, are healthier, and have access to goods and experiences that kings of old could never have dreamed of. If that doesn't make us happier, we really have no one to blame except ourselves. Oh, and the media lackeys who continue to feed us the litany of woes that we subconsciously crave."

Evaporation of the Mystique of Religion

Dennett suggests that as young people are exposed to the worldwide spread of information technology, they quietly walk away from the faith of their parents and grandparents. (Side note: I thought I would show you, as an example of shifting fundamental attitudes, a figure from this Andrew Sullilvan post on the increase in the percentage of people who consider homosexuality acceptable, by year and by age group).

A brain correlate of subjective well-being.

Carlen et al. in Richard Davidson's laboratory at Wisconsin have used functional magnetic resonance imaging to examine: "whether individual differences in amygdala activation in response to negative relative to neutral information are related to differences in the speed with which such information is evaluated, the extent to which such differences are associated with medial prefrontal cortex function, and their relationship with measures of trait anxiety and psychological well-being (PWB)...faster judgments of negative relative to neutral information were associated with increased left and right amygdala activation. In the prefrontal cortex, faster judgment time was associated with relative decreased activation in a cluster in the ventral anterior cingulate cortex (ACC, Brodman Area 24). Furthermore, people who were slower to evaluate negative versus neutral information reported higher PWB. Importantly, higher PWB was strongly associated with increased activation in the ventral ACC for negative relative to neutral information.


Figure: Activity in the Ventral Anterior Cingulate predicts judgement time.


Figure: Activity in the ventral ACC in response to negative versus neutral images is positively associated with total PWB.

These findings suggest that people high in PWB effectively recruit the ventral ACC when confronted with potentially aversive stimuli, manifest reduced activity in subcortical regions such as the amygdala, and appraise such information as less salient as reflected in slower evaluative speed.

The Insula is having its ten minutes of fame...

Those interested in how the brain's parts work to put it all together find their focus shifting as recordings and data begin to appear for previously neglected or inaccessible areas. There have been periods of focus, for example, on the hippocampus (learning and memory) and amygdala (fear and other emotions). Now the insula, on the interior of the cortex, is being found central to our feeling experience. (If you enter insula in the search box to the left of this posting you will find it the subject of several previous posts, one here.) Blakeslee draws together an interesting summary in this week's science section of the New York Times.

Here are some clips from that article:

"... the insula “lights up” in brain scans when people crave drugs, feel pain, anticipate pain, empathize with others, listen to jokes, see disgust on someone’s face, are shunned in a social settings, listen to music, decide not to buy an item, see someone cheat and decide to punish them, and determine degrees of preference while eating chocolate. Damage to the insula can lead to apathy, loss of libido and an inability to tell fresh food from rotten."

credit: New York Times

"The insula itself is a sort of receiving zone that reads the physiological state of the entire body and then generates subjective feelings that can bring about actions, like eating, that keep the body in a state of internal balance. Information from the insula is relayed to other brain structures that appear to be involved in decision making, especially the anterior cingulate and prefrontal cortices...The insula was long ignored for two reasons, researchers said. First, because it is folded and tucked deep within the brain, scientists could not probe it with shallow electrodes. It took the invention of brain imaging techniques, such as functional magnetic resonance imaging, or fMRI, to watch it in action."

" ...the insula receives information from receptors in the skin and internal organs. Such receptors are nerve cells that specialize in different senses. Thus there are receptors that detect heat, cold, itch, pain, taste, hunger, thirst, muscle ache, visceral sensations and so-called air hunger, the need to breathe. The sense of touch and the sense of the body’s position in space are routed to different brain regions."

"All mammals have insulas that read their body condition... Information about the status of the body’s tissues and organs is carried from the receptors along distinct spinal pathways, into the brain stem and up to the posterior insula in the higher brain or cortex...Humans, and to a lesser degree the great apes, have evolved two innovations to their insulas that take this system of reading body states to a new level...One involves circuitry, the other a brand new type of brain cell...In humans, information about the body’s state takes a slightly different route inside the brain, picking up even more signals from the gut, the heart, the lungs and other internal organs. Then the human brain takes an extra step, Dr. Craig said. The information on bodily sensations is further routed to the front part of the insula, especially on the right side, which has undergone a huge expansion in humans and apes...The second major modification to the insula is a type of cell found in only humans, great apes, whales and possibly elephants... Humans have by far the greatest number of these cells, which are called VENs, short for Von Economo neurons, named for the scientist who first described them in 1925. VENs are large cigar-shaped cells tapered at each end, and they are found exclusively in the frontal insula and anterior cingulate cortex...Exactly what VENs are doing within this critical circuit is not yet known...but they are in the catbird seat for turning feelings and emotions into actions and intentions."

What kinds of things have minds?

Grey et al report that in a Web-based survey, people conclude that anything that has feelings (such as hunger or pride) and the ability to act (such as communicating or showing self-restraint) possesses a mind.

What are you optimistic about? Why?

After "What is your dangerous idea?" being the question on edge.org for 2005, "What are you optimistic about? Why?" was the question for 2006, and HERE are the responses from prominent thinkers.

MindBlog's 1st Anniversary - Dangerous Ideas

Here is the Feb. 8 2006 post ("Dangerous Ideas") with which I started this blog, no less relevant now than a year ago.

Edge.org is a website sponsored by the "Reality Club" (i.e. John Brockman, literary agent/impressario/socialite). Brockman has assembled a stable of scientists and other thinkers that he defines as a "third culture" that takes the place of traditional intellectuals in redefining who and what we are.... Each year a question is formulated for all to write on... In 2004 it was "What do you believe is true even though you cannot prove it?" The question for 2005 was "What is your dangerous idea?"

The responses organize themselves into several areas. Here are selected thumbnail summaries most directly relevant to human minds. I've not included cosmology and physics. Go to edge.org to read the essays

I. Nature of the human self or mind (by the way see my "I-Illusion" essay on my website):

Paulos - The self is a conceptual chimera
Shirky - Free will is going away
Nisbett - We are ignorant of our thinking processes
Horgan - We have no souls
Bloom - There are no souls, mind has a material basis.
Provine - This is all there is.
Anderson - Brains cannot become minds without bodies
Metzinger - Is being intellectually honest about the issue of free will compatible with preserving one's mental health?
Clark - Much of our behavior is determined by non-conscious, automatic uptake of cues and information
Turkle - Simulation will replace authenticity as computer simulation becomes fully naturalized.
Dawkins - A faulty person is no different from a faulty car. There is a mechanism determining behavior that needs to be fixed. The idea of responsibility is nonsense.
Smith - What we know may not change us. We will continue to conceive ourselves as centres of experience, self-knowing and free willing agents.

II. Natural explanations of culture

Sperber - Culture is natural.
Taylor - The human brain is a cultural artifact.
Hauser- There is a universal grammar of mental life.
Pinker - People differ genetically in their average talents and temperaments.
Goodwin - Similar coordinating patterns underlie biological and cultural evolution.
Venter - Revealing the genetic basis of personality and behavior will create societal conflicts.


III. Fundamental changes in political, economic, social order

O'donnell - The state will disappear.
Ridley - Government is the problem not the solution.
Shermer - Where goods cross frontiers armies won't.
Harari -Democracy is on its way out.
Csikszentmihalyi- The free market myth is destroying culture.
Goleman - The internet undermines the quality of human interaction.
Harris - Science must destroy religion.
Porco - Confrontation between science and religion might end when role played by science in lives of people is the same played by religion today.
Bering - Science will never silence God
Fisher - Drugs such as antidepressants jeopardize feelings of attachment and love
Iacoboni - Media Violence Induces Imitative Violence - the Problem with Mirrors
Morton - Our planet is not in peril, just humans are.