Memory enhancement during your sleep...just wear an electric head strap?

I'm wondering how long it is going to be before we start seeings advertisements for "effortless memory enhancement" devices inspired by the work of Marshall et al reported in Nature. (For example, a tiara that places button electrodes bilaterally over the mastoids and frontolateral cortex and generates a low oscillating current around 0.75 cycles per second during non-REM sleep). Although I'm tempted to cook down their description to make it a bit more palatable, their abstract does do the job:

"There is compelling evidence that sleep contributes to the long-term consolidation of new memories. This function of sleep has been linked to slow per se is unclear, but can easily be investigated by inducing the extracellular oscillating potential fields of interest. Here we show that inducing slow oscillation-like potential fields by transcranial application of oscillating potentials (0.75 Hz) during early nocturnal non-rapid-eye-movement sleep, that is, a period of emerging slow wave sleep, enhances the retention of hippocampus-dependent declarative memories in healthy humans. The slowly oscillating potential stimulation induced an immediate increase in slow wave sleep, endogenous cortical slow oscillations and slow spindle activity in the frontal cortex. Brain stimulation with oscillations at 5 Hz—another frequency band that normally predominates during rapid-eye-movement sleep—decreased slow oscillations and left declarative memory unchanged. Our findings indicate that endogenous slow potential oscillations have a causal role in the sleep-associated consolidation of memory, and that this role is enhanced by field effects in cortical extracellular space."

Is there a biology of intelligence?

Because I once had an article in Behavioral and Brain Science, I receive email on final drafts of forthcoming articles for review. The purpose of this post is to point you to an interesting review and synthesis by R.E. Jung and R.J. Haier that will appear in a future issue. Its title is "The Parieto-Frontal Integration Theory (P-FIT) of Intelligence: Converging Neuroimaging Evidence." (Note added in Sept, 2007: the reference is Behavioral and Brain Sciences (2007) 30, 135-187)

The article reviews 37 modern neuroimaging studies, including functional (i.e. functional Magnetic Resonance Imaging, Positron Emission Tomography) and structural (i.e. Magnetic Resonance Spectroscopy, Diffusion Tensor Imaging,Voxel Based Morphometry)paradigms. They converge on a striking consensus suggesting that variations in a distributed network predict individual differences found on intelligence and reasoning tasks. They describe this network as the Parieto-Frontal Integration Theory: P-FIT. (How is a network a theory? Oh well, not to worry).

The P-FIT includes, by Brodmann Areas (BAs): dorsolateral prefrontal cortex (BAs 6, 9, 10, 45, 46, 47), the inferior (BAs 39/40) and superior parietal (BA 7) lobe, the anterior cingulate (BA 32), and regions within the temporal (BAs 21, 37) and occipital lobes (BAs 18 & 19). White matter regions (i.e., arcuate fasciculus) are also implicated.

The P-FIT is examined in light of findings from both human lesion studies, including missile wounds, frontal lobotomy/leukotomy, temporal lobectomy, and lesions resulting in damage to the language network (e.g., aphasia), as well as from imaging research identifying brain regions under significant genetic control. Overall, they conclude that modern neuroimaging techniques are beginning to articulate a biology of intelligence. They propose that the P-FIT provides a parsimonious account for many of the empirical observations to-date relating individual differences in intelligence test scores to variations in brain structure and function. They hope the model provides a framework for testing new hypotheses in future experimental designs.

Here is a graphic of the brain areas (copyright Cambridge University Press).


Legend: Brain regions by Brodmann Area (BA) associated with better performance on measures of intelligence and reasoning. Numbers represent BAs; solid blue circles = predominant left hemisphere associations; shadow blue circle = predominant left medial associations; shadow red circles = predominant bilateral associations; yellow arrow = arcuate fasciculus.

Gender and sexual orientation regulate the effect of invisible images.

As we are contantly bombarded with vast amounts of information, selective attention mechanisms help us quickly attend to what is important while ignoring what is irrelevant. It makes ecological and evolutionary sense if important events can influence our spatial attention even before we become aware of the event. Recent studies have shown that subliminal presentation of emotional stimuli can modulate activity of the amygdala. Jiang et al ask whether activation of the emotional system directs observers' attention to the stimulus in the absence of awareness.

They show that information that has not entered our consciousness, such as interocularly suppressed (invisible) erotic pictures, can direct the distribution of spatial attention. They further show that invisible erotic information can either attract or repel observers' spatial attention depending on their gender and sexual orientation. While unaware of the suppressed pictures, heterosexual males' attention was attracted to invisible female nudes, heterosexual females' attention was attracted to invisible male nudes, gay males behaved similarly to heterosexual females, and gay/bisexual females performed in-between heterosexual males and females.

Here is their description of how information is presented so that it does not enter consciousness. "In the interocular suppression paradigm, a pair of high-contrast dynamic noise patches are presented to both sides of a fixation point in one eye, and a test picture and its scrambled control are presented to the fellow eye in spatial locations corresponding to the noise patches. Because of strong interocular suppression, the intact meaningful image and its scrambled control remain invisible for the period they are presented. If the suppressed images exert a location-specific effect on the attentional system, these images could potentially act as attentional cues that would influence the distribution of spatial attention and thus performance on a subsequent detection task."

(click on image to enlarge it)
Figure: Schematic representation of the experimental paradigm for the invisible condition. For the visible condition, the noise patches were replaced with the same pair of intact and scrambled pictures presented to the other eye. In each trial, observers pressed one of two buttons to indicate the perceived orientation (CW or CCW) of a Gabor patch (the circle with lines in the right frame) briefly presented on either side of fixation. In the invisible condition, as shown, if observers detected any difference between the two sides of the fixation, they pressed another button to abort that trial.

Heterosexual male observers were more accurate at the orientation discrimination task when the Gabor targets followed the site of the invisible nude female pictures (attentional benefit) and were less accurate when the Gabor patches were at the site of invisible nude male pictures (attentional cost). Thus, heterosexual male observers' attention was attracted to nude female images and was repelled from nude male images, even though the images were not consciously perceived by the observers. Similarly, heterosexual female participants showed an attentional benefit (attraction) to invisible nude male pictures (positive attentional effect, although they did not show a significant attentional effect to invisible nude female pictures. Gay males had a similar pattern to female participants in that invisible female nude pictures did not attract their attention while male erotic images enhanced performance. Gay/bisexual females fell in-between the heterosexual male group and the heterosexual female group.

Mind over Matter: how depression causes bone loss through nerve activation.

The chronic activation of the arousal part of our autonomic nervous system (the sympathetic nervous system) that can occur during stress has been shown to cause an array of degenerative effects. Yirmiya et al, using a mouse model system, now link this system to the low bone mass and increased incidence of osteoporotic fractures associated with major depression. They show that mice subjected to chronic mild stress (CMS) show behavioral depression and impaired bone mass and structure. Antidepressant therapy, which prevents the behavioral responses to CMS, completely inhibits the decrease in bone formation and markedly attenuates the CMS-induced bone loss. The depression-triggered bone loss is associated with a substantial increase in bone norepinephrine levels and can be blocked by the beta-adrenergic antagonist propranolol, suggesting that the sympathetic nervous system mediates the skeletal effects of stress-induced depression. These results demonstrate an interaction among behavioral responses, the brain, and the skeleton, which leads to impaired bone structure. This suggests that depression is a potential major risk factor for osteoporosis in the aging population.

Imaging the brain during "speaking in tongues"

The charismatic practice of speaking with the full conviction that God is talking through you has ancient roots in many religious traditions, notably the Old and New Testaments. Its technical term is glossolalia. It is experienced as a normal and expected behavior in religious prayer groups in which the individual appears to be speaking in an incomprehensible language.

Newberg et al. at the University of Pennsylvania have now performed brain imaging on five women while they spoke in tongues (Psychiatry Research: Neuroimaging, Volume 148, Issue 1 , 22 November 2006, Pages 67-71) They tracked changes in blood flow in each woman’s brain as she sang a gospel song and again while speaking in tongues.

An interesting difference was observed between these two emotional, devotional activities , described in a review by Carey, was that the "frontal lobes — the thinking, willful part of the brain through which people control what they do — were relatively quiet, as were the language centers. The regions involved in maintaining self-consciousness were active. The women were not in blind trances, and it was unclear which region was driving the behavior."... "a co-author of the study, was also a research subject. She is a born-again Christian who says she considers the ability to speak in tongues a gift. “You’re aware of your surroundings,” she said. “You’re not really out of control. But you have no control over what’s happening. You’re just flowing. You’re in a realm of peace and comfort, and it’s a fantastic feeling.”

"The scans also showed a dip in the activity of the left caudate. .. the caudate is usually active when you have positive affect, pleasure, positive emotions, and is also involved in motor and emotional control...it may be that practitioners, while mindful of their circumstances, nonetheless cede some control over their bodies and emotions."

Putting humans and their climate in perspective

I always find it theraputic to renew my awareness of the fact that humans as we know them occupy only an eyeblink in the timeline of complex life on this planet. If just the period in which complex organisms arose is thought of in terms of a single year, fish would have appeared in January, land animals in March, dinosaurs in June, monkeys in December and humans late on New Year’s Eve.



This graphic from the Nov. 7 Science section of the NYTimes, prepared by Robert Rohde at Berkeley, is so striking that I wanted to pass it on. Carbon dioxide levels have been much higher at various times in the past than they are now. The accompanying article helps frame the debate over carbon dioxide in the atmosphere.

Deric and MindBlog are moving south for the winter...

From Madison, WI to Fort Lauderdale, FL. The pictures below show why… Five years after retiring as a department chair at the Univ. of Wisconsin I still am grateful and a bit incredulous that I can actually do what I want to do when I feel like doing it. I'm not sure how quickly I'll get my broadband connection running again, so apologies ahead of time for any lapse in posting.

From my office in Bock Labs and the Wisconsin summer, to what it looks like now (It was 16 degress Farenheit last week), to the new alternative:

The Brain Making Choices: The Lesser of Two Evils or the Better of Two Goods....

The relevance of this topic to yesterday's election was mentioned in the post just below. Blair et al. have now used functional magnetic resonance imaging to delineate the functional roles of the ventromedial prefrontal cortex (vmPFC) and dorsal anterior cingulate cortices (ACd), which are considered important for reward-based decision making. Response choice often occurs in situations where both options are desirable (e.g., choosing between mousse au chocolat or crème caramel cheesecake from a menu) or, alternatively, in situations where both options are undesirable. Moreover, response choice is easier when the reinforcements associated with the objects are far apart, rather than close together, in value. The authors used functional magnetic resonance imaging to delineate the functional roles of the vmPFC and ACd by investigating these two aspects of decision making: (1) decision form (i.e., choosing between two objects to gain the greater reward or the lesser punishment), and (2) between-object reinforcement distance (i.e., the difference in reinforcements associated with the two objects). Responses within the ACd and vmPFC were both related to decision form but differentially. ACd showed greater responses when deciding between objects to gain the lesser punishment, while vmPFC showed greater responses when deciding between objects to gain the greater reward. Moreover, vmPFC was sensitive to reinforcement expectations associated with both the chosen and the forgone choice. In contrast, responses within ACd, but not vmPFC, related to between-object reinforcement distance, increasing as the distance between the reinforcements of the two objects decreased.


Figure: anterior cingulate and ventromedial prefrontal areas examined in study.

The psychology of framing in this election - are we deciding whom to accept or whom to reject?

Barry Schartz (a psychology professor at Swarthmore, and author of “The Paradox of Choice: Why More Is Less.”) has a nice OpEd piece in today's NYTimes which I want to pass on because it is relevant to today's election...

ANOTHER national election season has come to an end — the sorriest, sleaziest, most disheartening and embarrassing in memory. The best one can hope for is a candidate who is a complete cipher. How has American electoral politics come to this?

I think we can gain insight from a study published by the psychologist Eldar Shafir 13 years ago. Suppose you are confronted with the following problem:

You’re serving as a juror in a custody case in which each parent is demanding sole custody of an only child. The facts of the case are complicated by ambiguous economic, social and emotional considerations, and you decide to base your decision entirely on the following few observations:

Parent A
• average income
• reasonable rapport with child
• relatively stable social life
• average working hours
• average health

Parent B
• above-average income
• close relationship with child
• extremely active social life
• lots of work-related travel
• minor health problems

To which parent would you award sole custody of the child?

Parent A is average in every way, without compelling positive or negative features. Parent B has a mix of strong positive (very close to the child) and strong negative (lots of travel) features. Asked to make this choice, the majority of respondents — 64 percent — choose Parent B.

What makes this study really interesting is what happens when another group of respondents is given the same character sketches, but asked a slightly different question: “To which parent would you deny custody of the child?” Here again, a majority, 55 percent, choose Parent B.

How can it be that a majority both accept and reject the same parent?

Professor Shafir’s explanation is that when people are asked whom to accept, they look for positive features in the parents — reasons to accept one over the other — and Parent B has them. In contrast, when people are asked whom to reject, they look for negative features — and again, Parent B has them. No matter which question you ask, Parent B stands out.

What does this tell us about modern electoral politics? When you go into the voting booth, you’re trying to decide whom to accept or whom to reject. Are you judging who the good candidate is or who the less bad candidate is?

The effort by each side to coat the opposition in slime has made many of us cynical, giving us the sense that our task is to reject the worst, not select the best. Nobody’s any good, we think, but some are worse than others. Let’s keep those candidates out of office. Our job becomes one of denying, not awarding, office.

What that means is that if you want to win an election, you need to find candidates like Parent A, who give us no reason to say no, rather than Parent B, who present a complex set of features, some attractive and some problematic.

If somehow the cynicism lifted, and we saw ourselves charged with the task of deciding who to say yes to, we’d have more candidates like Parent B. Just one negative feature would not be enough to disqualify someone, in our minds. There would be little to gain by capturing and broadcasting “macaca moments,” or subtly invoking old Southern fears of black men cavorting with white women. Candidates would be able to take positions and speak their minds. This might lead to the arrival of candidates who actually have positions and minds. We might even be willing to risk generating a little enthusiasm at the prospect of being led by them.

But unless something is done to quell “gotcha” journalism and relentlessly negative campaigning — and as long as we continue to enter the voting booth looking for reasons to say no — the ciphers will be the winners.

The evolution of morals - a nudge of clarity

Relevant to my recent post, This letter to the editor in the science section of the NYTimes from my Univ. of Wisconsin colleague Larry Shapiro, in the Philosophy Department:

To the Editor:

As a professional philosopher, I found myself with no worries about whether Marc Hauser’s theory would put my colleagues in ethics out of business. There’s a tremendous difference between the two questions: 1) Why do human beings make the judgments of right and wrong that they do?; and 2) Are these judgments correct?

Perhaps an evolutionary story can suffice to answer the first question, but I can’t imagine how it might answer the second.

Larry Shapiro
Madison, Wis.

Where your brain sizes up your competition...

Goodman reports on a study led by Caroline Zink, a postdoctoral fellow at the National Institute of Mental Health, that found that several brain regions showed increased activity when people were evaluating their standings in a social hierarchy. Zink recruited 24 healthy volunteers — 12 men and 12 women — and had them play a game of skill while their brain activity was imaged using fMRI. Participants were told they would simultaneously be playing two other people: an inferior “one star” player and a superior “three star” player. These other players were invented, however, and their actions carried out by a computer. To convince the participants that the other players where real, the research team constructed elaborate ruses — postponing the start of the game for 15 minutes because another player was running late, for example, or leaving the room under the pretense of helping a player get set up. The volunteers were asked to press a button as soon as they were given a signal. If they responded quickly enough, they won a dollar. Though the researchers emphasized that the participants were not competing against the other players, they also made sure that the volunteers saw the scores of the one-star players and three-star players.

The results were clear and strong...When the volunteers won more money than the three-star players, raising their status in the game, the brain scanner showed increased activity in three brain regions: the anterior cingulate, an area that has been shown to monitor conflict and resolve discrepancies; the medial prefrontal cortex, which processes thoughts about other people; and the precuneus, a region that some speculate is involved in the brain’s ability to think about itself.

In contrast, when the one-star players won more money during the game than the volunteers, lowering their status, activity increased in the ventral striatum and the insular cortex, or insula. This area appears to be responsible for the somatic representation of emotional states, such as disgust. The ventral striatum is a deep brain structure linked in primates to motivation and reward, and may be part of the neural circuitry that keeps track of progress through learning.

No effect of DHEA or Testosterone in Elderly

Nicholas Bakalar reviews a study reported in the New England Journal of Medicine involving 87 men, average age 79, and 57 women, average age 68. The men were divided into three groups who received daily doses of 5 milligrams of testosterone, 75 milligrams of DHEA or a placebo. The women were divided into two groups that received either DHEA or a placebo.

Are we born with a moral grammar?

By now I've probably read at least 5 mixed (mainly positive) reviews of Mark Hauser's new book "Moral Minds," and the commentary on the book by Nicholas Wade in the 10/31/06 New York Times stirs me to mention it in a post.

Hauser suggests that we have a universal and innate capacity for developing moral rules analogous to our capacity to develop language in the presence of other humans. A more reserved review in an earlier New York Times Book Review Magazine by Richard Rorty raises some concerns: "The exuberant triumphalism of the prologue to “Moral Minds” leads the reader to expect that Hauser will lay out criteria for distinguishing parochial moral codes from universal principles, and will offer at least a tentative list of those principles. These expectations are not fulfilled......the reader is left guessing about how he proposes to distinguish morality not just from etiquette, but also from prudential calculation, mindless conformity to peer pressure and various other things. This makes it hard to figure out what exactly his moral module is supposed to do. It also makes it difficult to envisage experiments that would help us decide between his hypothesis and the view that all we need to internalize a moral code is general-purpose learning-from-experience circuitry — the same circuitry that lets us internalize, say, the rules of baseball."

A review by Bloom and Jarudi in Nature makes some further points: "Certain deep parallels between language and morality make Hauser's proposal worth taking seriously. ....In other regards, however, language seems very different from morality. For one thing, linguistic knowledge is distinct from emotion. You might be disgusted or outraged by what somebody says, but the principles that make sense of sentences are themselves entirely cold-blooded. Your eyes do not well with tears as you unconsciously determine the structural geometry of a verb phrase. By contrast — and Hauser wrestles with this throughout Moral Minds — even those who accept that some moral capacity is innate often see it as inextricably linked to emotion. Perhaps the universal core of morality is a set of emotional responses — disgust, shame, sympathy, guilt and so on — that are triggered by certain situations. This hypothesis is supported by clear demonstrations that, at least in some circumstances, emotion precedes intuition. ...A different concern is that languages are combinatorial symbolic systems. An English speaker, for example, knows perhaps hundreds of thousands of words, and also knows principles of syntax that dictate how these words combine with one another to form sentences. There are other combinatorial systems in human cognition, such as number and music, but it's not clear that morality is one of them. Even if it is distinct from emotion, moral knowledge might be better characterized as a small list of evolved rules, perhaps simple (such as a default prohibition against intentional harm), perhaps complex (such as some version of the doctrine of double effect), but still very different in character from linguistic knowledge."

Countering these reservations, from Wade's article: "Much of the present evidence for the moral grammar is indirect. Some of it comes from psychological tests of children, showing that they have an innate sense of fairness that starts to unfold at age 4. Some comes from ingenious dilemmas devised to show a subconscious moral judgment generator at work. These are known by the moral philosophers who developed them as “trolley problems." ...Suppose you are standing by a railroad track. Ahead, in a deep cutting from which no escape is possible, five people are walking on the track. You hear a train approaching. Beside you is a lever with which you can switch the train to a sidetrack. One person is walking on the sidetrack. Is it O.K. to pull the lever and save the five people, though one will die?...Most people say it is....Assume now you are on a bridge overlooking the track. Ahead, five people on the track are at risk. You can save them by throwing down a heavy object into the path of the approaching train. One is available beside you, in the form of a fat man. Is it O.K. to push him to save the five? Most people say no, although lives saved and lost are the same as in the first problem." (Note: Brain imagining experiments show the second scenario activates emotional areas of the brain that counter the more frontal rational areas engaged by the first scenario.).. "Why does the moral grammar generate such different judgments in apparently similar situations? It makes a distinction, Dr. Hauser writes, between a foreseen harm (the train killing the person on the track) and an intended harm (throwing the person in front of the train), despite the fact that the consequences are the same in either case. It also rates killing an animal as more acceptable than killing a person... Many people cannot articulate the foreseen/intended distinction, Dr. Hauser says, a sign that it is being made at inaccessible levels of the mind. This inability challenges the general belief that moral behavior is learned. For if people cannot articulate the foreseen/intended distinction, how can they teach it?"

This last point seems weak, all kinds of teaching occurs without articulation. Even given that some moral judgements can be more rapid than conscious thought, or are carried out by unconscious background processes, how do we design experiments to distinguish whether they are innate or learned? We need a paradigm as powerful that provided by the Nicaraguan school for deaf children, where the children invented among themselves a unique sign language following Chomsky's rules for a universal grammar. Would a group of children isolated from outside moral influence develop universal moral codes (an experiement that can't be done) or would we have the scenario of Golding's "The Lord of the Flies?"

Tony Auth and Tom Tooles on the resveratrol story

Self recognition - humans, apes, dolphins...and now elephants

Plotnik, de Waal, and Reiss report in PNAS that mirror self recognition (MSR), considered an indicator of self awareness, can be observed in Asian elephants. Slightly edited from their abstract: "MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. The authors exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus "mark test" for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.


Above video (click the rectangle to play) was taken from the Elmo lipstick camera embedded in the mirror on Happy's first day of marking. Happy repetitively touches the mark or the area immediately around the mark with her trunk while in full view of the mirror. She never touches the sham-mark during this session.

Followup: take resveratrol and continue to pig out...

In my 10/31/06 post on caloric restriction I elected not to get into the resveratrol story, but followup articles in the NY Times and Nature now force me to do that (....added note: after writing this post I see the resveratrol story on the NBC Evening News with Brian Williams!) Experiments showing that resveratrol extends lifespan in lower animals have been extended now to mice. Several Biotec companies are testing improved versions of the compound.

Here's the abstract from the Nature article:

Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces changes associated with longer lifespan, including increased insulin sensitivity, reduced insulin-like growth factor-1 (IGF-I) levels, increased AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor- coactivator 1 (PGC-1) activity, increased mitochondrial number, and improved motor function. Parametric analysis of gene set enrichment revealed that resveratrol opposed the effects of the high-calorie diet in 144 out of 153 significantly altered pathways. These data show that improving general health in mammals using small molecules is an attainable goal, and point to new approaches for treating obesity-related disorders and diseases of ageing.

How emotions modulate memory through the amygdala

Transmission of sensory information through the rhinal cortices is essential for hippocampus-dependent learning. In Nature Neuroscience Quirk & Vidal-Gonzalez provide a nice summary of work by Paz. et. al. showing that amygdala activity elicited by an unexpected reward facilitates communication from perirhinal to entorhinal cortex, providing a physiological mechanism for emotional modulation of memory.


Figure: The amygdala enhances transfer of sensory information.
Sensory input flows from the neocortex to the hippocampus via the rhinal cortices (descending arrows). The hippocampus in turn assists in consolidating and storing this information through projections back to neocortex (ascending arrows). (a) During spontaneous activity, with low amygdala firing rates (blue traces on left), transfer of information from perirhinal cortex (Prh) to entorhinal cortex (Ent) is minimal (thin red arrows). (b) Following reward, the amygdala increases its firing rate and synchrony. This enables the transfer of sensory information through the rhinal cortices into the hippocampus (large red arrow).

Eat less, live longer, now shown for monkeys as well as mice and worms

Mason writes an interesting review in the New York Times 10/31/06 science section focusing on experiments at the University of Wisconsin Primate research center which have closely monitored rhesus monkeys on restricted and normal-calorie diets. Fifty animals survive from the original group of 76, the differences are just now becoming apparent in the older animals. Here are some edited clips from that article:

In a laboratory at the Wisconsin National Primate Research Center, Matthias, the monkey on the right, is learning about time’s caprice the hard way. At 28, getting on for a rhesus monkey, Matthias is losing his hair, lugging a paunch and getting a face full of wrinkles. Yet in the cage next to his, gleefully hooting at strangers, one of Matthias’s lab mates, Rudy, is the picture of monkey vitality, although he is slightly older. Thin and feisty, Rudy stops grooming his smooth coat just long enough to pirouette toward a proffered piece of fruit.

Those on normal diets, like Matthias, are beginning to show signs of advancing age similar to those seen in humans. Three of them, for instance, have developed diabetes, and a fourth has died of the disease. Five have died of cancer.

But Rudy and his colleagues on low-calorie meal plans are faring better. None have diabetes, and only three have died of cancer. It is too early to know if they will outlive their lab mates, but the dieters here and at the other labs also have lower blood pressure and lower blood levels of certain dangerous fats, glucose and insulin.

The suggestion from studies on mice and nematode worms is that animals stressted by caloric restriction activate numerous biochemical pathways that repair cell damage and suppress inflammatory reactions. In mice, calorie restriction doesn’t just extend life span, it also mitigates many diseases of aging: cancer, cardiovascular disease, neurodegenerative disease.

Researchers at Washington University in St. Louis have been tracking the health of small groups of calorie-restricted dieters. Earlier this year, they reported that the dieters had better-functioning hearts and fewer signs of inflammation, which is a precursor to clogged arteries, than similar subjects on regular diets.

In previous studies, people in calorie-restricted groups were shown to have lower levels of LDL, the so-called bad cholesterol, and triglycerides. They also showed higher levels of HDL, the so-called good cholesterol, virtually no arterial blockage, and remarkably low blood pressandure.

Some doubt that calorie restriction can ever work effectively in humans,and that it will make people miserable in the process of attempting it. A mathematical model published last year predicted that the maximum life span gain from calorie restriction for humans would be just 7 percent. A more likely figure, the authors said, was 2 percent.

Relationship between genetic variations in serotonin transporter, brain activity, and depression.

The effect of life stress on depression is moderated by a repeat length variation in the transcriptional control region of the serotonin transporter gene, which renders carriers of the short variant vulnerable for depression. Canli et al. have investigated the underlying neural mechanisms of these epigenetic processes in individuals with no history of psychopathology by using multimodal magnetic resonance-based imaging, genotyping, and self-reported life stress and rumination. Based on functional MRI and perfusion data, They found support for a model in which life stress interacts with the effect of serotonin transporter genotype on amygdala and hippocampal resting activation, two regions involved in depression and stress. Life stress also differentially affected, as a function of serotonin transporter genotype, functional connectivity of the amygdala and hippocampus with a wide network of other regions, as well as gray matter structural features, and affected individuals' level of rumination. They suggest that these interactions may constitute a neural mechanism for vulnerability toward, or protection against, depression.

How Google can nudge the keywords of political debate

There's a great piece "Own your own words" in the Oct. 30 Sunday New York Times Book Review Magazine written by Steven Johnson... on how Google is shifting the landscape of how word meanings are controlled in the political and social landscape. (The same Google I'm swearing at as I write this post, because its Blogger.com is making changes that that have blocked my ability to do posts for the last two days). Commenting and abstracting from Johnson:

Think of the battles that have erupted around terms like “liberal,” “torture,” “pro-life” or “intelligent design.” Now we are more likely to type these key words into Google and instantly get an entire field guide to their present usage: in op-ed columns, advertising blurbs, blog posts, MySpace pages, diaries, scholarly publications, wherever. Does “liberal,” for instance, evoke a big-government, tax-and-spend worldview that never met a bureaucrat it didn’t like? Or is it a tradition of egalitarian open-mindedness? Is “intelligent design” a legitimate scientific discipline, or a Trojan horse for anti-science religious values?

It is precisely this kind of real-world usage that Google lets you see in a single click, which creates a fascinating opportunity for anyone with a vested interest in shaping the popular meaning of words. Johnson suggests a simply strategy for increasing the prominence of your views. Because Google considers links to be a kind of vote endorsing the content of a given page, if you created a specific page, for example, called “affirmative action” — where your various articles and thoughts were collected — and encouraged others to link to that page, you could very quickly “own” affirmative action in Google. Johnson tries this approach with a proper name, by making the title of one of his blog posts the name of the British cultural critic "Raymond Williams." He deliberately titled the page “Raymond Williams” to persuade Google to rank the page highly for people searching using the key words “Raymond Williams.” After it went online, a few other bloggers linked to the page. Within two weeks, if you searched Google using the key word “Raymond Williams,” his little riff showed up as the No. 6 result, behind a Wikipedia entry, a museum bio and a few scholarly papers.

What’s powerful about this strategy is not the sheer number of readers, but the kind of readers he is attracting. By writing a little blog post and seeding it in such a way that it attracts Google searches, he attracts thousands of people who by definition are interested in the question of what Raymond Williams means. By positioning his work so that it will align itself with Google’s vast “database of intentions” — to borrow the memorable phrase coined by the technology writer John Battelle — He gets his meaning in front of the very people who are actively seeking it out.

This strategy happens to be old news to the bottom-feeders of the digital world: the spam artists who have long hacked the Google database to ensure that their sites rank highly when people search for “sex” and “blackjack” and “cheap Canadian meds.” But just because the spammers got there first doesn’t mean that Google-centric positioning cheapens the work of intellectuals. Johnson suggests that it’s inevitable that intellectuals who are interested in speaking to a wider audience will orient their work around Google’s rising influence. That doesn’t mean scholarly publications are irrelevant in this new world: the physicists don’t stop talking to one another simply because most people have a watered down version ofrelativity in their heads. It just means that for the mainstream understanding of complex issues, Google (and Wikipedia, whose entries often rank near the top of Google searches) are quickly becoming central authorities. So the question is whether intellectuals are going to mope about this shift — or whether they’ll see it as an opportunity to shape popular opinion.And if they make that shift, they’ll take their cues from the spammers and charlatans, the drug pushers and the pornographers. They’ll realize that it’s not just the marketplace of ideas they should be worried about. It’s also the database.