Tuesday, February 12, 2008

Could a presidential debate on science backfire?

An interesting essay by David Goldston argues that a debate on science by presidential candidates might do more harm than good.

Monday, February 11, 2008

Sharing posts, bookmarking, related content, etc.

My friend Kelly Doering who does internet consulting and website design, has just helped me dink around a bit with the mechanics of MindBlog. You will now notice a single icon after each post that lets you bookmark or share a post using more than 30 of the major services like StumbleUpon, Reddit, Del.icio.us, Reddit, etc. If you haven't already, you should try the sphere:related content link that may appear just below the bookmark icon with a post that interests you. It sometimes does a very nice job of bringing up related material on other websites.

Your brain is shrinking sooner than you thought...

Here is a chilling little item from Pieperhoff et al., who examined MRI images of the brains of 51 healthy male subjects from 18 to 51 years old. They found age-related volume declines in circumscribed brain regions: the sensorimotor system, encompassing the cerebellum, thalamus, somatosensory and motor cortices, and the prefrontal system, encompassing the anterior cingulate as well as the lateral and basomedial frontal cortices. Regions belonging to other functional systems, such as the auditory system or the visual system, did not show such age–volume relationships.

Horizontal sections of the reference brain with statistical maps, showing the t values of age-related volume decline and increase. t values were calculated by a two-sided t test for a linear regression in the voxels of the LVR maps, depending on age.

The incubator of suicide attacks - Fictive Kinship

Anthropologist Scott Atran (Author of "In Gods We Trust") writes an essay laying out his change of mind about why people are willing to die for a cause. He has moved from thinking that individual cognition and personality, influences from broad socio-economic factors, and degree of devotion to religious or political ideology were determinant, to seeing friendship and others aspects of small group dynamics, especially acting together, trumping most everything else.
...people don't kill and die simply for a cause. They do it for friends — campmates, schoolmates, workmates, soccer buddies, body-building buddies, pin-ball buddies — who share a cause. Some die for dreams of jihad — of justice and glory — but nearly all in devotion to a family-like group of friends and mentors, of "fictive kin." (Atran gives a number of explicit examples of such groups)

... it is no accident that nearly all religious and political movements express allegiance through the idiom of the family — Brothers and Sisters, Children of God, Fatherland, Motherland, Homeland, and the like. Nearly all such movements require subordination, or at least assimilation, of any real family (genetic kinship) to the larger imagined community of "Brothers and Sisters." Indeed, the complete subordination of biological loyalty to ideological loyalty for the Ikhwan, the "Brotherhood" of the Prophet, is Islam's original meaning, "Submission."
...Social psychology tends to support the finding that "groupthink" often trumps individual volition and knowledge, whether in our society or any other. But for Americans bred on a constant diet of individualism the group is not where one generally looks for explanation.

Sunday, February 10, 2008

Back in Wisconsin....

I am SO grateful that I am able to be a snowbird, now in Ft. Lauderdale. Here is a picture of my home in Wisconsin, where more snow has fallen this winter than in any year since recordings of snowfall began in the 19th century.

Friday, February 08, 2008

MindBlog's second anniversary

I just realized that today is MindBlog's second anniversary. It is hard for me to believe that there have been 902 postings since Feb. 8, 2006. Back then I had just read an article in the New York Times on the rising blogging fad and thought to myself, "Since I am reading and thinking about all this stuff anyway, I might as well take the small extra effort to clean it up a bit and present it." The extra effort turns out to be not so small. The number of subscribers to the MindBlog feed has risen to over 400, and on a given day there are 300-1,500 views of individual postings. Being a borderline (or maybe not even borderline) obsessive-compulsive, I've become yoked to the lockstep production of at least two blog postings a day. The retired professor isn't feeling all that retired..... Anyway, I am grateful for the kind emails I have received, and I've enjoyed responding to requests for further analysis or information.

Middle Age Misery

Blanceflower and Oswald have done a fascinating study (PDF here) showing that across cultures, from Azerbaijan to Zimbabwe, we are happiest towards the beginning and end of our lives, leaving us most miserable in middle years between 40 and 50. For both men and women in the UK, the probability of depression peaked at around the age of 44. In the US, men were most likely to be unhappiest at 50, while for women the age was 40. The cause of the apparent U-shaped curve is not known. Quoting Oswald (the graphic is from his website):
...one possibility is that individuals learn to adapt to their strengths and weaknesses, and in mid-life quell their infeasible aspirations. Another possibility is that cheerful people live systematically longer...A third possibility is that older people might compare their lives with their peers'. Seeing their friends die could mean people value their remaining years more highly...It looks from the data like something happens deep inside humans. For the average person in the modern world, the dip in mental health and happiness comes on slowly, not suddenly in a single year...Only in their 50s do most people emerge from the low period. But encouragingly, by the time you are 70, if you are still physically fit then on average you are as happy and mentally healthy as a 20-year-old. Perhaps realising that such feelings are completely normal in mid-life might even help individuals survive this phase better.

The World in the Brain

Here are a few excerpts from a brief essay by Steve Kosslyn in the Edge.org series "What have you changed your mind about?
There is a really elegant solution to the problem that the genes can't know in advance how far apart the eyes will be. To cope with this problem, the genes overpopulate the brain, giving us options for different environments (where the distance between eyes and length of the arms are part of the brain's "environment," in this sense), and then the environment selects which connections are appropriate, and the useless connections are pruned away. In other words, the genes take advantage of the environment to configure the brain.

This overpopulate-and-select mechanism is not limited to stereovision. In general, the environment sets up the brain (above and beyond any role it may have had in the evolution of the species), configuring it to work well in the world a person inhabits. And by environment I'm including everything outside the brain — including the social environment. For example, it's well known that children can learn multiple languages without an accent and with good grammar, if they are exposed to the language before puberty. But after puberty, it's very difficult to learn a second language so well.

This perspective leads me to wonder whether we can assume that the brains of people living in different cultures process information in precisely the same ways. Yes, people the world over have much in common (we are members of the same species, after all), but even small changes in the wiring may lead us to use the common machinery in different ways. If so, then people from different cultures may have unique perspectives on common problems, and be poised to make unique contributions toward solving such problems... to understand how any specific brain functions, we need to understand how that person was raised, and currently functions, in the surrounding culture.
A similar, more brief, response to the edge.org question was offered by Jeffrey Epstein, A science Philanthropist:
The question presupposes a well defined "you", and an implied ability that is under "your" control to change your "mind". The "you" I now believe is distributed amongst others (family friends , in hierarchal structures,) i.e. suicide bombers, believe their sacrifice is for the other parts of their "you". The question carries with it an intention that I believe is out of one's control. My mind changed as a result of its interaction with its environment. Why? because it is a part of it.

Thursday, February 07, 2008

Nicholas Humphrey on consciousness...

I have always admired Nicholas Humphrey's perspectives on sensing and consciousness, and referenced his ideas on evolution of the nervous system in my Biology of Mind book. He has now written a nice essay in Seed Magazine, and I strongly recommend that you read it. He argues against the idea:
...that consciousness must be helping us do something that we can do only by virtue of being conscious, in the way that, say, a bird can fly only because it has wings, or you can understand this sentence only because you know English.
Rather,
...I want to suggest the role of phenomenal consciousness may not be like this at all. Its role may not be to enable us to do something we could not do otherwise, but rather to encourage us to do something we would not do otherwise: to make us take an interest in things that otherwise would not interest us, or to mind things we otherwise would not mind, or to set ourselves goals we otherwise would not set.

I will not hold back from telling you my own main conclusion from a lifetime's interest in what consciousness does. I may shock you by what may seem the naivety of my conclusion (I've shocked myself): I think the plain and simple fact is that consciousness—on various levels—makes life more worth living.

We like being phenomenally conscious. We like the world in which we're phenomenally conscious. We like ourselves for being phenomenally conscious. And the resulting joie de vivre, the enchantment with the world we live in, and the enhanced sense of our own metaphysical importance have, in the course of evolutionary history, turned our lives around.

Added note 11/16/08: I just found a later published version of this article. PDF here.

Evolutionary psychology on steroids...

Here are Steven Pinker's comments on recent data showing that the human genome has undergone strong recent selection, rendering invalid evolutionary psychology's initial assumption that human evolution halted 10,000 - 50,000 years ago.
New results from the labs of Jonathan Pritchard, Robert Moyzis, Pardis Sabeti, and others have suggested that thousands of genes, perhaps as much as ten percent of the human genome, have been under strong recent selection, and the selection may even have accelerated during the past several thousand years. The numbers are comparable to those for maize, which has been artificially selected beyond recognition during the past few millennia.

If these results hold up, and apply to psychologically relevant brain function (as opposed to disease resistance, skin color, and digestion, which we already know have evolved in recent millennia), then the field of evolutionary psychology might have to reconsider the simplifying assumption that biological evolution was pretty much over and done with 10-000 — 50,000 years ago.

And if so, the result could be evolutionary psychology on steroids. Humans might have evolutionary adaptations not just to the conditions that prevailed for hundreds of thousands of years, but also to some of the conditions that have prevailed only for millennia or even centuries. Currently, evolutionary psychology assumes that any adaptation to post-agricultural ways of life are 100% cultural.

Though I suspect some revisions will be called for, I doubt they will be radical, for two reasons. One is that many aspects of the human (and ape) environments have been constant for a much longer time than the period in which selection has recently been claimed to operate. Examples include dangerous animals and insects, toxins and pathogens in spoiled food and other animal products, dependent children, sexual dimorphism, risks of cuckoldry and desertion, parent-offspring conflict, risk of cheaters in cooperation, fitness variation among potential mates, causal laws governing solid bodies, presence of conspecifics with minds, and many others. Recent adaptations would have to be an icing on this cake -- quantitative variations within complex emotional and cognitive systems.

The other is the empirical fact that human races and ethnic groups are psychologically highly similar, if not identical. People everywhere use language, get jealous, are selective in choosing mates, find their children cute, are afraid of heights and the dark, experience anger and disgust, learn names for local species, and so on. If you adopt children from a technologically undeveloped part of the world, they will fit in to modern society just fine. To the extent that this is true, there can't have been a whole lot of uneven psychological evolution postdating the split among the races 50-100,000 years ago (though there could have been parallel evolution in all the branches).

Wednesday, February 06, 2008

Staying a Step Ahead of Aging

Being a person who exercises daily at moderate levels, the New York Times article with the title of this post was not a welcome read. It argues that blowing yourself away every few days is a better deal - i.e., that exercising intensely is more important than exercising often. I've always been suspicious of the 'no pain, no gain' school of exercise, thinking that while it might work for younger folks, it might not be taking enough account of potential long term inflammatory responses in people over 50.

Accurate visual movement without visual perception in normal subjects

An interesting article by Christensen et al. demonstrates blindsight in normal subjects:
Clinical cases of blindsight have shown that visually guided movements can be accomplished without conscious visual perception. Here, we show that blindsight can be induced in healthy subjects by using transcranial magnetic stimulation over the visual cortex. Transcranial magnetic stimulation blocked the conscious perception of a visual stimulus, but subjects still corrected an ongoing reaching movement in response to the stimulus. The data show that correction of reaching movements does not require conscious perception of a visual target stimulus, even in healthy people.
Here is part of their analysis:
It has been suggested that an important mechanism for the ability to perform fast corrections of goal-directed movement is an efference copy (i.e. a parallel signal indicating the expected sensory consequence of a motor command)... The argument is that the initial motor reaction time, when the subject reaches toward the first target, requires that the visual signal is processed via the visual cortex to motor regions of the brain. The advantage of an efference copy is that already at a very early point in the movement process any deviation in the performed movement from the intended movement can be adjusted. Hence, lower reaction time during the correction can be accomplished compared with the initial motor reaction time.

Furthermore, our results suggest that the mechanism responsible for fast visually guided corrective movements lies outside visual cortex and that the visual signals used for correction of movements bypass visual cortex. There may be subcortical routes for visually guided reaching that bypass the cortical regions affected by TMS.

Tuesday, February 05, 2008

Our left hemisphere is superior at perceiving global topology.

Most theories on how we extract visual information from our environment start with the sensible hierarchy of detecting features first and then integrating them to build objects. Li Chen and colleagues have also argued for the importance of extracting global topological properties as primitives in object perception, and they now have reported the intriguing discovery that the human visual system's sensitivity to topological properties is superior in the left hemisphere, at least for right-handers. Here is a graphic showing the basic conclusion of their work, from the commentary by He:
Figure - Schematic depiction of the left hemisphere's superiority in topological discrimination. A pair of shapes was briefly presented in either the right or the left visual field, projecting initially to the left or right hemispheres (LH or RH), respectively. Observers were asked to respond to whether the two shapes were the same or different. Although the triangle may appear more different from the disk than the ring does, human observers are more sensitive to the difference between the disk and the ring, which are topologically different, but are less sensitive to the difference between the triangle and the disk, which are topologically equivalent. Now, the authors show that the ability to discriminate topological differences is more superior in the left hemisphere than in the right hemisphere, as indicated by the bar plots showing the percent correct discrimination

Poetry in your genome?

Now that we are able to synthesize complete genomes for organisms, we can also write what we want in its individual genes. Andrew Pollack describes several such literary efforts:
You were expecting poetry, perhaps? The secret messages hidden in J. Craig Venter’s synthetic bacterial genome have now been revealed. They are Dr. Venter’s name, and that of his research institute and co-workers....Dr. Venter announced last week in the journal Science that his team had become the first to synthesize the complete DNA of a bacterium. He revealed that the genome had five “watermarks,” sequences of genetic code that would spell words using the letters for the amino acids that would be produced by the DNA...Wired Science reported Monday that it had ferreted out the messages, with help from government scientists. One watermark said “VenterInstitvte,” using the unusual spelling because there is no amino acid represented by the letter “u.”...The other messages were CraigVenter, HamSmith, GlassandClyde and CindiandClyde for his co-authors Hamilton O. Smith, Clyde A. Hutchison III, John I. Glass and Cynthia Andrews-Pfannkoch. A Venter spokeswoman confirmed them...In 2003, scientists from Icon Genetics, a German biotechnology company, engineered the plant Arabidopsis thaliana to contain a line from Virgil’s “Georgics,” with the meaning “Neither can every soil bear every fruit.”

Monday, February 04, 2008

Stronger or weaker brain synapses after sleep?

Why do we spend a third of our lives asleep? The answers suggested so far are varied and controversial. It is well documented that improvement in learning and memory accompanies a night of sleep. One idea is that most new information is discarded during sleep, as diurnal animals are bombarded by stimuli during the day, most of which we want to (or need to) forget. Synapses need to recover. If this is the dominant reason why we sleep, then decreased numbers of synapses or synapse weakening should be a prominent neuronal feature of sleep. Fountain points to an article by Tonini and colleagues (Nature Neuroscience 11, pp. 200 - 208, 2008) that provides evidence for this option. Tononi suggests that after sleep "“we get a leaner brain — there’s a gain in terms of energy, space and supplies, and you are ready to learn anew.” Here is their abstract:
Plastic changes occurring during wakefulness aid in the acquisition and consolidation of memories. For some memories, further consolidation requires sleep, but whether plastic processes during wakefulness and sleep differ is unclear. We show that, in rat cortex and hippocampus, GluR1-containing AMPA receptor (AMPAR) levels are high during wakefulness and low during sleep, and changes in the phosphorylation states of AMPARs, CamKII and GSK3beta are consistent with synaptic potentiation during wakefulness and depression during sleep. Furthermore, slope and amplitude of cortical evoked responses increase after wakefulness, decrease after sleep and correlate with changes in slow-wave activity, a marker of sleep pressure. Changes in molecular and electrophysiological indicators of synaptic strength are largely independent of the time of day. Finally, cortical long-term potentiation can be easily induced after sleep, but not after wakefulness. Thus, wakefulness appears to be associated with net synaptic potentiation, whereas sleep may favor global synaptic depression, thereby preserving an overall balance of synaptic strength.

The algorithms of love...

John Tierney writes an interesting article on internet match finding services in the Jan 29 New York Times.
Online matchmaking has become a boom industry as rival scientists test their algorithms for finding love...The leading yenta is eHarmony, which pioneered the don’t-try-this-yourself approach eight years ago by refusing to let its online customers browse for their own dates. It requires them to answer a 258-question personality test and then picks potential partners...Another company, Perfectmatch.com, is using an algorithm designed by Pepper Schwartz, a sociologist at the University of Washington at Seattle. Match.com, which became the largest online dating service by letting people find their own partners, set up a new matchmaking service, Chemistry.com, using an algorithm created by Helen E. Fisher, an anthropologist at Rutgers who has studied the neural chemistry of people in love.

As the matchmakers compete for customers — and denigrate each other’s methodology — the battle has intrigued academic researchers who study the mating game. On the one hand, they are skeptical, because the algorithms and the results have not been published for peer review. But they also realize that these online companies give scientists a remarkable opportunity to gather enormous amounts of data and test their theories in the field. EHarmony says more than 19 million people have filled out its questionnaire...In the battle of the matchmakers, Chemistry.com has been running commercials faulting eHarmony for refusing to match gay couples (eHarmony says it can’t because its algorithm is based on data from heterosexuals), and eHarmony asked the Better Business Bureau to stop Chemistry.com from claiming its algorithm had been scientifically validated. The bureau concurred that there was not enough evidence, and Chemistry.com agreed to stop advertising that Dr. Fisher’s method was based on “the latest science of attraction.”

Dr. Fisher now says the ruling against her last year made sense because her algorithm at that time was still a work in progress as she correlated sociological and psychological measures, as well as indicators linked to chemical systems in the brain. But now, she said, she has the evidence from Chemistry.com users to validate the method, and she plans to publish it along with the details of the algorithm...“I believe in transparency,” she said, taking a dig at eHarmony. “I want to share my data so that I will get peer review.”
On reading that Chemistry.com didn't discriminate against gay match making, I naturally decided to give it a spin and went through their series of questions (including one on the relative lengths of one's index and ringer finger). It included psychological profile questions and some interesting tests of susceptibility to visual illusions. Alas, the list of prospective mates for a 65 yr. old retired professor was rather lean, and I ended my experiment by withdrawing my chemistry.com profile after one day.

Sunday, February 03, 2008

Super Bowl preliminaries....the anthropoligist from Mars

The description in the header of this blog includes the phrase "and random curious stuff." Well....this post qualifies. I show you one of the videos used Sunday to warm patrons up for the super bowl orgy at my happy hour bar. "Macho Man", the Village People. Watching this did make me feel like Oliver Sacks' anthropologist from Mars.

Friday, February 01, 2008

Will cognition-enhancing drugs become as acceptable as coffee?

In my backlog of blog-postings-to-do is one on an article in the Dec. 27 issue of Nature on the use of cognition-enhancing drugs not only to treat cognitive disabilities, but also to enhance performance in those without medical issues (Nature 450, 1157–1159; 2007). Two drugs commonly used to reduced extraneous activity and focus attention are methylphenidate (Ritalin) and atomoxetine; both increase brain levels of the neurotransmitter noradrenaline. Sahakia and Morein-Zamir pose a series of questions whose answers become increasingly less obvious, and invite responses in an online forum:
-Should adults with severe memory and concentration problems from neuropsychiatric disorders be given cognitive-enhancing drugs?
-If drugs can be shown to have mild side effects, should they be prescribed more widely for other psychiatric disorders?
-Do the same arguments apply for young children and adolescents with neuropsychiatric disorders, such as those with ADHD?
-Would you boost your own brain power?
-How would you react if you knew your colleagues — or your students — were taking cognitive enhancers?
-How should society react?
I have now received a message from the Nature people, sent to a number of bloggers in the brain and behavior area, suggesting that readers check out some responses to this article and also participate in a survey.

Faith and Healing

Jerome Groopman reviews Anne Harrington's new book "The Cure Within - A History of Mind-Body Medicine" in the NY Times Book review of Jan. 27. Harrington is professor and chair of the History of Science department at Harvard. Here is the final section of that review:
Harrington offers close observations of the interactions between the Harvard cardiologist Herbert Benson (and later the neuroscientist Richard Davidson of the University of Wisconsin) and the Dalai Lama and his Tibetan monks. She admits longing for scientific support for what is, in essence, an “Orientalist” conception, that the “Other” holds wisdom and therapeutic treasures beyond those imaginable to us in the West. Some of Harrington’s wish is fulfilled in the biology of the placebo response. Recent studies show that belief, even in inert treatments, can have profound benefits in relieving pain, likely via release of endorphins and other mediators in the brain. But despite several decades of concerted research in the field of psychoneuroimmunology, to my scrutiny no robust effects of meditation or other relaxation techniques that could combat illnesses like cancer or AIDS have been identified.

Harrington concludes with the questions that her students at Harvard regularly ask: Which mind-body narratives are “true”? Are all the stories we tell ourselves about illness equally valuable? Harrington has already answered these queries in part in the voice of the woman with breast cancer in the Stanford study. Yet, she has still been “haunted” over the years by unusual events, like the case of a man whose tumors seemed to melt “like snowballs on a hot stove” in response to a “worthlesss” cancer treatment that he nonetheless believed in. The physicist Freeman Dyson once noted that, to a scientist, an event like the spontaneous remission of a tumor is viewed as occurring at the asymptote of probability, one in several million, but through the eyes of a believer it becomes not mathematics but a miracle. Harrington shows us that, whatever science reveals about the cause and course of disease, we will continue to tell ourselves stories, and try to use our own metaphors to find meaning in randomness.

The fruits of promiscuity...more dancing and food

From the research highlights section of the Jan. 24 issue of Nature, summarizing work by Matilla et al:
A honeybee colony led by a promiscuous queen does better than one led by a faithful queen: the colony forages more, stores more food and grows faster. Heather Mattila and her colleagues at Cornell University in Ithaca, New York, think this happens because genetically diverse colonies dance more....Honeybees 'waggle dance' to tell each other where to fly to find food. Mattila's team compared colonies in which the queen always bred with the same male to colonies ruled by a queen that had been inseminated by 15 drones. On average, worker bees from the latter category performed 36% more dances daily, kept waggling for 62% longer and communicated about food discoveries farther from the nest than did workers from single-father colonies.