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).
Wednesday, February 28, 2007
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.
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."
Tuesday, February 27, 2007
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."
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."
Monday, February 26, 2007
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."
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."
Friday, February 23, 2007
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
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."
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:
3. Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel
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:
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:
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
and the Cognitive Sciences, 5. pp. 365-394. See:
- 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:
- Moore, James W and Haggard, Patrick (2006) *Awareness of action: Inference
and prediction.* Consciousness and Cognition, In press. See:
- 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:
Wednesday, February 21, 2007
"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."
Tuesday, February 20, 2007
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."
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."
Monday, February 19, 2007
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)
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.
Posted by Deric Bownds at 5:53 AM
Friday, February 16, 2007
A cloud formation that some have interpreted as the face of God. (Credit, N.Y.Times)
Left: A grilled cheese sandwich, top, with an image of what some see as the Virgin Mary sold for $28,000 on eBay. Jesus Christ is seen in an oyster shell, a frying pan and a pirogi. (Credit, N.Y.Times).
Why do we see faces everywhere? An interesting article on this topic in this week's Science N.Y. Times. For some years, it has been known that specialized cells in our temporal lobes are strongly attuned to faces. Strokes in this region can cause prosopagnosia, the inability to recognize the faces of familiar people. Perhaps seeing faces where there are none in fact involves the activation of this area by non-face objects containing sufficient features to trigger the face cells.
Pawan Sinha of M.I.T., has developed face recognition software by giving the input of hundreds of faces; it was able to discover relationships that were of great significance to almost all faces, but very few nonfaces.
“These turn out to be very simple relationships, things like the eyes are always darker than the forehead, and the mouth is darker than the cheeks,” Dr. Sinha said. “If you put together about 12 of these relationships, you get a template that you can use to locate a face.”
"....whether the hair-trigger response to faces is innate or learned, it represents a critical evolutionary adaptation, one that dwarfs side effects like seeing Beelzebub in a crumpled tissue...The information faces convey is so rich — not just regarding another person’s identity, but also their mental state, health and other factors,” he said. “It’s extremely beneficial for the brain to become good at the task of face recognition and not to be very strict in its inclusion criteria. The cost of missing a face is higher than the cost of declaring a nonface to be a face.”
Thursday, February 15, 2007
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."
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."
Wednesday, February 14, 2007
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.
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."
Tuesday, February 13, 2007
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."
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.
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."
Monday, February 12, 2007
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).
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.
Friday, February 09, 2007
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."
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.
Thursday, February 08, 2007
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.
Wednesday, February 07, 2007
Studying consciousness is difficult because asking subjects to report their awareness of a stimulus perturbs that awareness. A new paper by Persaud and Cowey shows that asking subjects to wager on whether their response is correct can solve this problem.
From their paper: "The performance of any cognitive task, from recognizing a face to running a business, is an amalgam of many decisions. Some are made consciously and some are not. There is no agreed-upon way of determining which decisions are conscious. Simply asking people might seem a straightforward method, but they may deny awareness if the question asked does not relate to the method they think they used to reach the decision. Numerical confidence ratings have been suggested as an alternative to verbal report but participants may underrate their confidence or withhold conscious knowledge, as they are given no motivation to reveal it. Here we demonstrate that a newly created measure, post-decision wagering, in which people are offered cash rewards for revealing conscious knowledge, can be used to determine which decisions are made without awareness. We asked participants performing three very different tasks—visual discrimination in blindsight, string selection in an artificial grammar task and pack selection in the Iowa gambling task—to place wagers on the outcomes of their decisions. We found above chance performance in the tasks, but the wagers indicated a lack of awareness that the decisions were correct. By making it clear when awareness is absent, this method may help to answer one of the central questions of contemporary neuroscience: how does neural activity give rise to conscious experience?"
A single point of light can be moved about in a biological or non-biological manner. Meary et al. report that 4-day old human neonates look longer at the non-biological motions, suggesting violation of an expectation. This indicates that neonates' motion perception — like adults'—is attuned to biological kinematics.
Tuesday, February 06, 2007
A review by Montague and Chiu and article by Tankersley et al. describe studies showing that watching a computer perform an altruistic act, earning monitary points for charity (in contrast with human subjects playing the game themselves), activates the posterior superior temporal sulcus (pSTS). This brain region is important for considering the goals and intentions of other beings and specifically for understanding the behavior of social agents as they relate to the goals of a social interaction. An important point differentiates this work from other studies: the computer is an agent only in that the human player has been instructed that it is generating a purposeful act (earning money for a cause). Without these instructions, the human participant is simply viewing a series of flashing symbols, and the experiment might as well assess questions about visual perception. The pSTS may thus be implicated in generic computations about agency, regardless of whether a social interaction is involved.
Figure: Increased right pSTC activation to action perception compared with action performance.
Yesterday's post on fish brains switching their sexuality reminds me of another bit of work on fish that I have been meaning to mention:
Transitive inference involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, Transitive inference has since been reported in nonhuman primates, rats, and birds.
In many social species (whether they are teleost fish or mammals) a behavioral hierarchy establishes itself which regulates who gets first access to food and mates. A reason that transitive behavior would evolve is that it saves a lot of energy if you don't have to go into head on competition with every other male you meet to determine who is on top. If you can see competitions between other males and learn who wins over who, you learn who is safer to hang out with. This rationale should be true for both territorial and non-territorial species that maintain social hierarchies, so you might not be surprised to find it wherever such hierarchies are established.
Experiments in Fernald's lab at Stanford now show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units.
What this says about fish brains is that they can perform a transitive analysis, just as they can do many other quite amazing feats of analysis. It does not say anything about the kind of experienced awareness or consciousness they have. It could a process as automatic and rote as the operant conditioning which trains them to avoid stimuli in the past have resulted in dangerous or unpleasant experiences.
Monday, February 05, 2007
OK, so it is actually a fish doing it. But, Remage-Healey and Bass suggest that their findings may help explain the widespread distribution of rapidly induced intrasexual behavioral phenotypes among vertebrates in general. They observe that the male acoustic sexual behavior of the teleost type I male midshipman can be rapidly (~ 5 min) induced in type II males (that normally show female like behaviors) by the action of the androgen 11-ketotestosterone on receptors in the brain's vocal pattern generator. (11-ketotestosterone is the dominant circulating androgen in type I males, and testosterone is the dominant androgen in type II males and females). This suggests that steroid-dependent expression of "maleness" and "femaleness" may now include rapid steroid actions on the neurophysiological patterning of behavior, uncoupled from gonadal phenotype.
Friday, February 02, 2007
I just came across a complete web version of this book by R. Dale Guthrie which I enjoyed reading in the 1970s. Its perspective on the mixes of behavior and anatomy that comprise our social organs continues to be an original one.
Thursday, February 01, 2007
Check out this site that invites you to sign up for experiments on face and voice preferences.
Corcoran and Quirk have blocked nerve signals (using the sodium channel blocker tetradotoxin) in the prelimbic subregion of the medial prefrontal cortex (PL) of rats during fear learning and expression. Inactivation of PL reduced freezing to both a tone and a context that had been previously paired with footshock (learned fear) but had no effect on freezing to a cat (innate fear). Inactivation of PL before conditioning, however, did not prevent the formation of auditory or contextual fear memories. Thus, activity in PL is critical for the expression, but not the acquisition, of learned fears. They suggest that PL integrates information from auditory and contextual inputs and regulates expression of fear memories via projections to the basal nucleus of the amygdala.
Tom et al show that activity in the ventral striatum and ventromedial prefrontal cortex appears to correlate with judgments of potential loses versus gains in monetary choices. Activity in brain structures thought to mediate negative emotions in decision-making (such as the amygdala or anterior insula) does not change.