Evaluating effects of genes and environment on early reading.

Work from Taylor et al. studying mono- and dizygotic twins in kindergarten through 5th grade suggests, not suprisingly, that that better teachers allow children to fulfill their genetic potential:

Children’s reading achievement is influenced by genetics as well as by family and school environments. The importance of teacher quality as a specific school environmental influence on reading achievement is unknown. We studied first- and second-grade students in Florida from schools representing diverse environments. Comparison of monozygotic and dizygotic twins, differentiating genetic similarities of 100% and 50%, provided an estimate of genetic variance in reading achievement. Teacher quality was measured by how much reading gain the non-twin classmates achieved. The magnitude of genetic variance associated with twins’ oral reading fluency increased as the quality of their teacher increased. In circumstances where the teachers are all excellent, the variability in student reading achievement may appear to be largely due to genetics. However, poor teaching impedes the ability of children to reach their potential.

When do human groups form states?

Spencer suggests that human states evolve (without contact with any preexisting states) when the area controlled by a group becomes larger than a day's round trip from the capital:

A major research problem in anthropology is the origin of the state and its bureaucratic form of governance. Of particular importance for evaluating theories of state origins are cases of primary state formation, whereby a first-generation state evolves without contact with any preexisting states. A general model of this process, the territorial-expansion model, is presented and assessed with archaeological data from six areas where primary states emerged in antiquity: Mesoamerica, Peru, Egypt, Mesopotamia, the Indus Valley, and China. In each case, the evidence shows a close correspondence in time between the first appearance of state institutions and the earliest expansion of the state's political-economic control to regions lying more than a day's round-trip from the capital. Although additional research will add detail and clarity to the empirical record, the results to date are consistent with the territorial-expansion model, which argues that the success of such long-distance expansion not only demanded the bureaucratization of central authority but also helped provide the resources necessary to underwrite this administrative transformation.

Do brain training programs work?

ScienceNow reports an interesting tussle over the effectiveness of brain training programs. BBC producers contacted Adrian Owen at the MRC Cognition and Brain Sciences Unit in Cambridge, U.K., to help design an experiment to test the efficacy of computer brain training exercises and tested them in 11,430 healthy adults who registered on a Web site set up by the BBC. One group trained on a program that emphasized reasoning and problem-solving skills, and another group trained on a program that emphasized different skills, including short-term memory and attention. A third, control group, essentially did busywork, hunting for answers to general knowledge questions on the Internet. All participants were asked to "train" for at least 10 minutes, three times a week for 6 weeks, and all received a battery of cognitive tests before and after this 6-week period....Not surprisingly, people in both training groups got better at the tasks they actually practiced. But that's as far as it went - none of the brain-training tasks transferred to other mental or cognitive abilities beyond what had been specifically practiced.

These conclusion are contested by Klingberg, who has published one of the few studies demonstrating benefits of training can generalize beyond a specific task. He notes subjects were trained only three hours in total.

I'm a bit puzzled over why the work of Jaeggi et al. showing the effects of short term memory training on general intelligence, which I have mentioned previously, was not mentioned.

Old age improves reasoning about social conflicts

Interesting observation from Grossmann et al.:

It is well documented that aging is associated with cognitive declines in many domains. Yet it is a common lay belief that some aspects of thinking improve into old age. Specifically, older people are believed to show better competencies for reasoning about social dilemmas and conflicts. Moreover, the idea of aging-related gains in wisdom is consistent with views of the aging mind in developmental psychology. However, to date research has provided little evidence corroborating this assumption. We addressed this question in two studies, using a representative community sample. We asked participants to read stories about intergroup conflicts and interpersonal conflicts and predict how these conflicts would unfold. We show that relative to young and middle-aged people, older people make more use of higher-order reasoning schemes that emphasize the need for multiple perspectives, allow for compromise, and recognize the limits of knowledge. Our coding scheme was validated by a group of professional counselors and wisdom researchers. Social reasoning improves with age despite a decline in fluid intelligence. The results suggest that it might be advisable to assign older individuals to key social roles involving legal decisions, counseling, and intergroup negotiations. Furthermore, given the abundance of research on negative effects of aging, this study may help to encourage clinicians to emphasize the inherent strengths associated with aging.

Internet enhancing, not diminishing, the public square.

Some interesting points from David Brooks, noting a study by Gentzkow and Shapiro which counters the prevailing assumption that the internet has created a collection of information cocoons which people occupy to confirm their existing prejudices:

...they tracked how people of different political views move around the Web...The study measures the people who visit sites, not the content inside...a person who visited only Fox News would have more overlap with conservatives than 99 percent of Internet news users. A person who only went to The Times’s site would have more liberal overlap than 95 percent of users....the core finding is that most Internet users do not stay within their communities. Most people spend a lot of time on a few giant sites with politically integrated audiences, like Yahoo News.

But even when they leave these integrated sites, they often go into areas where most visitors are not like themselves. People who spend a lot of time on Glenn Beck’s Web site are more likely to visit The New York Times’s Web site than average Internet users. People who spend time on the most liberal sites are more likely to go to foxnews.com than average Internet users. Even white supremacists and neo-Nazis travel far and wide across the Web....Gentzkow and Shapiro found that the Internet is actually more ideologically integrated than old-fashioned forms of face-to-face association — like meeting people at work, at church or through community groups. You’re more likely to overlap with political opponents online than in your own neighborhood.

...Looking at a site says nothing about how you process it or the character of attention you bring to it. It could be people spend a lot of time at their home sites and then go off on forays looking for things to hate. But it probably does mean they are not insecure and they are not sheltered....If this study is correct, the Internet will not produce a cocooned public square, but a free-wheeling multilayered Mad Max public square. The study also suggests that if there is increased polarization (and there is), it’s probably not the Internet that’s causing it.

How pain impairs cognition

Ji et al. use an animal model of arthritis pain to show that pain-related cognitive deficits result from amygdala-driven impairment of medial prefrontal cortical (mPFC) function.

Oxytocin enhances social learning as well as empathy.

From Hurlemann et al.:

Oxytocin (OT) is becoming increasingly established as a prosocial neuropeptide in humans with therapeutic potential in treatment of social, cognitive, and mood disorders. However, the potential of OT as a general facilitator of human learning and empathy is unclear. The current double-blind experiments on healthy adult male volunteers investigated first whether treatment with intranasal OT enhanced learning performance on a feedback-guided item–category association task where either social (smiling and angry faces) or nonsocial (green and red lights) reinforcers were used, and second whether it increased either cognitive or emotional empathy measured by the Multifaceted Empathy Test. Further experiments investigated whether OT-sensitive behavioral components required a normal functional amygdala. Results in control groups showed that learning performance was improved when social rather than nonsocial reinforcement was used. Intranasal OT potentiated this social reinforcement advantage and greatly increased emotional, but not cognitive, empathy in response to both positive and negative valence stimuli. Interestingly, after OT treatment, emotional empathy responses in men were raised to levels similar to those found in untreated women. Two patients with selective bilateral damage to the amygdala (monozygotic twins with congenital Urbach–Wiethe disease) were impaired on both OT-sensitive aspects of these learning and empathy tasks, but performed normally on nonsocially reinforced learning and cognitive empathy. Overall these findings provide the first demonstration that OT can facilitate amygdala-dependent, socially reinforced learning and emotional empathy in men.

The brain's default mode, our ego, and Freud

Carhart-Harris and Friston offer an open access article exploring the notion that Freudian constructs may have neurobiological substrates.

Specifically, we propose that Freud’s descriptions of the primary and secondary processes are consistent with self-organized activity in hierarchical cortical systems and that his descriptions of the ego are consistent with the functions of the default-mode and its reciprocal exchanges with subordinate brain systems. This neurobiological account rests on a view of the brain as a hierarchical inference or Helmholtz machine. In this view, large-scale intrinsic networks occupy supraordinate levels of hierarchical brain systems that try to optimize their representation of the sensorium. This optimization has been formulated as minimizing a free-energy; a process that is formally similar to the treatment of energy in Freudian formulations. We substantiate this synthesis by showing that Freud’s descriptions of the primary process are consistent with the phenomenology and neurophysiology of rapid eye movement sleep, the early and acute psychotic state, the aura of temporal lobe epilepsy and hallucinogenic drug states.

The best illusion of the year contest

The top ten candidates for the 2010 best Illusion of the Year context have been chosen. The site show the illusions from previous years' competitions.

Doing two things at once splits the brain.

...and we are not very good at managing more than two things at once. Here is the fascinating abstract from Charron and Koechlin:

The anterior prefrontal cortex (APC) confers on humans the ability to simultaneously pursue several goals. How does the brain’s motivational system, including the medial frontal cortex (MFC), drive the pursuit of concurrent goals? Using brain imaging, we observed that the left and right MFC, which jointly drive single-task performance according to expected rewards, divide under dual-task conditions: While the left MFC encodes the rewards driving one task, the right MFC concurrently encodes those driving the other task. The same dichotomy was observed in the lateral frontal cortex, whereas the APC combined the rewards driving both tasks. The two frontal lobes thus divide for representing simultaneously two concurrent goals coordinated by the APC. The human frontal function seems limited to driving the pursuit of two concurrent goals simultaneously.

A figure from the ScienceNow review. When tackling tasks A and B simultaneously, half of the brain handles A (red) while the other handles B (yellow).

Opera singers' brains - and the brain's organization of music knowledge

Numerous studies have shown brain changes that correlate with athletic and musical instrument training. Kleber et al. now extend such work to vocal performance training:

Several studies have shown that motor-skill training over extended time periods results in reorganization of neural networks and changes in brain morphology. Yet, little is known about training-induced adaptive changes in the vocal system, which is largely subserved by intrinsic reflex mechanisms. We investigated highly accomplished opera singers, conservatory level vocal students, and laymen during overt singing of an Italian aria in a neuroimaging experiment. We provide the first evidence that the training of vocal skills is accompanied by increased functional activation of bilateral primary somatosensory cortex representing articulators and larynx. Opera singers showed additional activation in right primary sensorimotor cortex. Further training-related activation comprised the inferior parietal lobe and bilateral dorsolateral prefrontal cortex. At the subcortical level, expert singers showed increased activation in the basal ganglia, the thalamus, and the cerebellum. A regression analysis of functional activation with accumulated singing practice confirmed that vocal skills training correlates with increased activity of a cortical network for enhanced kinesthetic motor control and sensorimotor guidance together with increased involvement of implicit motor memory areas at the subcortical and cerebellar level. Our findings may have ramifications for both voice rehabilitation and deliberate practice of other implicit motor skills that require interoception.

In another article on the brain and music, Omar et al. (open access) compare normal subjects with alzheimer's and dementia patients to find evidence that music knowledge is fractionated, with superordinate musical knowledge relatively more robust than knowledge of particular music. They propose that music constitutes a distinct domain of non-verbal knowledge but shares certain cognitive organizational features with other brain knowledge systems. Within the domain of music knowledge, dissociable cognitive mechanisms process knowledge derived from physical sources and the knowledge of abstract musical entities.

PharmVille

An article by Virginia Heffernan in the NYTimes Sunday Magazine points to the interesting Psych-Babble website hosted by psychiatry professor Robert Hsiung at the University of Chicago.

Hsiung’s F.A.Q. includes a section called, “How should I decide what information to trust?” Compiled entirely from board posts, it’s a masterpiece. Above all, it empowers Web users and psychiatric patients alike to be strong readers, to mediate between dictatorial commercial culture and the radical factionalism and individualism of Web communities. One answer came from a poster called Daveman: “The search for truth reminds me of Hegel. It is neither the ‘thesis’ (the claim by the manufacturer that the medication is some sort of wonder drug) nor the ‘antithesis’ (the claim by someone who blames all their problems on the medication) but rather a ‘synthesis’ (a sober analysis of both positive and negative aspects).” Very sanely put.

The article also points to an online cognitive behavioral therapy site, and the Icarus Project, investigating "the space between brilliance and madness."

Enhanced facial threat detection in elite warriors

Ross et al show that Navy SEALS, compared with a male control group, show more focused neural and performance tuning: greater neural processing resources are directed toward threat stimuli (angry faces), while processing resources are conserved when facing a nonthreatening stimul (fearful or happy faces).

Irrespective of the target emotion, elite warfighters relative to comparison subjects showed relatively greater right-sided insula, but attenuated left-sided insula, activation. Navy SEALs showed selectively greater activation to angry target faces relative to fearful or happy target faces bilaterally in the insula. This was not accounted for by contrasting positive versus negative emotions. Finally, these individuals also showed slower response latencies to fearful and happy target faces than did comparison subjects.

MindBlog's spring home

This picture (click to enlarge) of early spring at my 1860 stone schoolhouse residence in Middleton Wisconsin shows why I recently returned from  winter exile in Fort Lauderdale (which doesn't have seasons). 

Two routes to slowing aging...

Fontana et al. offer a nice article in the April 16 issue of Science Magazine, a review of experiments indicating that caloric restriction and reduced activity of nutrient-sensing pathways may slow aging by similar mechanisms. I am passing on the excellent summary of the article's main points provided by the magazine, as well as the final section of the article on the outlook for the future (well worth a look for resveratrol enthusiasts.  A previous mindblog post on resveratrol side effect has drawn multiple comments):

Nutrient-sensing pathways are central to the aging process
Both dietary restriction -- a reduction of food intake without malnutrition -- and manipulation of nutrient-sensing pathways through mutations or drugs can increase life span and reduce age-related disease in several model organisms. These pathways are conserved during evolution.

Single-celled yeast provides a simple model system for studying aging
The life span of yeast can be increased substantially through both dietary restriction and mutation or drugs. Reduced activity in two major nutrient-sensing pathways is involved.

C. elegans worms are a simple multicellular model system for aging
Life-span increases in C. elegans are similar to those in yeast. As in yeast, aging in C. elegans is delayed by the activation of pathways normally turned on by starvation/food restriction.

Flies provide a more complex model system that allows e.g. sex differences to be studied
The damage response pathways in some unicellular eukaryotes, such as yeast, differ from those in mammals. Their telomeres are tailored to respond to these differences. The way in which telomeres solve the end protection problem thus differs widely between eukaryotes.

Studies of rodents may yield leads for human clinical trials
Both dietary restriction and manipulation of nutrient-sensing pathways through mutation or drugs can reduce the occurrence of age-related diseases and extend life span in rodents. However, dietary restriction in rodents can also have negative effects. Differences in metabolism, life span, and susceptibility to diseases must be taken into account when extrapolating these results to humans.

Limited data exist on life-span extension in primates
Naturally occurring mutations in humans or monkeys help to understand the role of nutrient-sensing pathways in aging. Experimental studies are complicated by the long life spans of primates. The protective effects of dietary restriction against cancer, cardiovascular disease, and diabetes in primates must be weighed against potentially negative long term effects.

A key question is how we can extend the life span without unwanted side effects
The identification of a common set of genes in yeast, worms, flies, and mice that can extend the healthy life span will accelerate progress toward human clinical trials testing drugs that activate these conserved anti-aging pathways. Further mammalian studies are needed to understand whether dietary restriction and the pharmacological modulation of anti-aging pathways can extend life span and reduce pathologies.

Outlook
Extreme dietary restriction can lead to several detrimental health effects such as amenorrhea, infertility, sarcopenia, osteoporosis, and immune deficiencies. Thus, it will be important to examine these negative side-effects in dietary-restricted subjects that are not malnourished. Indeed, experimental studies are required to evaluate the optimal calorie intake and macro- and micronutrient composition needed for healthy aging in humans, on the basis of age, sex, genotype, and energy expenditure.

Although adjustment of dietary intake and composition may be realistic and beneficial, the severe dietary restriction that induces major health benefits is not a desirable option for most people. Drugs that target nutrient-sensing pathways to obtain the health benefits of dietary restriction are realistic, but the effects of chronic administration require study. For instance, rapamycin, the TOR (target of rapamycin) inhibitor that extends mouse life span, is an immunosuppressant and may not produce an overall health benefit in humans living in an environment with pathogens. However, genetic deletion of the GH receptor or of the downstream S6 kinase in mice extends life span and induces a broad-spectrum improvement in health. More testing of potential disadvantages is required and many open questions remain, but these seem promising drug targets and are hopefully the first of many.

More detail on money and happiness

Yet another study, this one by Boyce et al. (open access), confirming that money doesn't buy happiness, people gain "utility" from occupying a higher ranked position within an income distribution rather than from either absolute income or their position relative to a reference wage:

Does money buy happiness, or does happiness come indirectly from the higher rank in society that money brings? We tested a rank-income hypothesis, according to which people gain utility from the ranked position of their income within a comparison group. The rank hypothesis contrasts with traditional reference-income hypotheses, which suggest that utility from income depends on comparison to a social reference-group norm. We found that the ranked position of an individual’s income predicts general life satisfaction, whereas absolute income and reference income have no effect. Furthermore, individuals weight upward comparisons more heavily than downward comparisons. According to the rank hypothesis, income and utility are not directly linked: Increasing an individual’s income will increase his or her utility only if ranked position also increases and will necessarily reduce the utility of others who will lose rank.

Like humans - Leaders, Followers and Schmoozers among animals

Natalie Angier does an interesting article describing work showing that the array of personality types noted within human groups, mostly likely largely due to genetic variation, is seen also in many animal populations (stylistic diversity is seen in chimpanzees, monkeys, barnacle geese, farm minks, blue tits and great tits, bighorn sheep, dumpling squid, pumpkinseed sunfish, zebra finches, spotted hyenas, even spiders and water striders, to name a few). A particular robust parallel is noted with variation in the traits of neophobia (fear of novelty) versus the willingness to explore one’s surroundings (The trait distinctive to birds leading a flock is apparently boldness). Field experiments with birds have now answered the critique that observing these distinct traits in different individuals might be due to the captive environment of laboratory behavioral studies. Researchers have identified:

...hotheads and tiptoers, schmoozers and loners, divas, dullards and fearless explorers.. animals, like us, often cling to the same personality for the bulk of their lives...highly sensitive, arty-type humans have a lot in common with squealing pigs and twitchy mice, and that to call a hypersensitive person thin-skinned or touchy might hold a grain of physical truth.

Self control without a self...

The fact that humans are better at self control (delayed gratification) than animals is often attributed to their having a sense of self that animal lack. Simple body chemistry also appears to play a role. Miller et al. point to a regulator of self control that is common to humans and dogs: blood glucose. Here is their abstract:

Self-control constitutes a fundamental aspect of human nature. Yet there is reason to believe that human and nonhuman self-control processes rely on the same biological mechanism—the availability of glucose in the bloodstream. Two experiments tested this hypothesis by examining the effect of available blood glucose on the ability of dogs to exert self-control. Experiment 1 showed that dogs that were required to exert self-control on an initial task persisted for a shorter time on a subsequent unsolvable task than did dogs that were not previously required to exert self-control. Experiment 2 demonstrated that providing dogs with a boost of glucose eliminated the negative effects of prior exertion of self-control on persistence; this finding parallels a similar effect in humans. These findings provide the first evidence that self-control relies on the same limited energy resource among humans and nonhumans. Our results have broad implications for the study of self-control processes in human and nonhuman species.

Lessening moral judgements by a magenetic zap to the brain.

MRI measurements have shown that the the right temporoparietal junction (RTPJ) - an area just above the right ear - receives more blood than usual when we think or read about the beliefs and intentions of other people, particularly if we use the information to judge people negatively. Young et al. show that this area is actually involved in making negative moral judgements, because when it is inactivated by trans cranial magnetic stimulation (TMS), subjects judge an attempted versus an accidental homicide less severely. The abstract:

When we judge an action as morally right or wrong, we rely on our capacity to infer the actor's mental states (e.g., beliefs, intentions). Here, we test the hypothesis that the right temporoparietal junction (RTPJ), an area involved in mental state reasoning, is necessary for making moral judgments. In two experiments, we used transcranial magnetic stimulation (TMS) to disrupt neural activity in the RTPJ transiently before moral judgment...and during moral judgment... In both experiments, TMS to the RTPJ led participants to rely less on the actor's mental states. A particularly striking effect occurred for attempted harms (e.g., actors who intended but failed to do harm): Relative to TMS to a control site, TMS to the RTPJ caused participants to judge attempted harms as less morally forbidden and more morally permissible. Thus, interfering with activity in the RTPJ disrupts the capacity to use mental states in moral judgment, especially in the case of attempted harms.

We separate identity and emotion of a stimulus in under 100 msec.

Liu and Ioannides record the small rapid magnetic signals caused by brain activity (using magnetoencephalography, or MEG) to study whether face affect recognition depends on where the face stimulus (happy, fearful, neutral) appears in the visual field. Emotional appraisal (amygdalar activity) occurs more rapidly than final cognitive appraisal in the pre-frontal cortex - (We jump away from a moving S-shaped figure in our peripheral vision before we have determined whether it is actually a snake). Here is their abstract:

It is now apparent that the visual system reacts to stimuli very fast, with many brain areas activated within 100 ms. It is, however, unclear how much detail is extracted about stimulus properties in the early stages of visual processing. Here, using magnetoencephalography we show that the visual system separates different facial expressions of emotion well within 100 ms after image onset, and that this separation is processed differently depending on where in the visual field the stimulus is presented. Seven right-handed males participated in a face affect recognition experiment in which they viewed happy, fearful and neutral faces. Blocks of images were shown either at the center or in one of the four quadrants of the visual field. For centrally presented faces, the emotions were separated fast, first in the right superior temporal sulcus (STS; 35–48 ms), followed by the right amygdala (57–64 ms) and medial pre-frontal cortex (83–96 ms). For faces presented in the periphery, the emotions were separated first in the ipsilateral amygdala and contralateral STS. We conclude that amygdala and STS likely play a different role in early visual processing, recruiting distinct neural networks for action: the amygdala alerts sub-cortical centers for appropriate autonomic system response for fight or flight decisions, while the STS facilitates more cognitive appraisal of situations and links appropriate cortical sites together. It is then likely that different problems may arise when either network fails to initiate or function properly.