Analytic thinking promotes religious disbelief.

From Gervais and Norenzayan's introduction to their paper:

According to dual-process theories of human thinking, there are two distinct but interacting systems for information processing. One (System 1) relies upon frugal heuristics yielding intuitive responses, while the other (System 2) relies upon deliberative analytic processing. Although both systems can at times run in parallel, System 2 often overrides the input of system 1 when analytic tendencies are activated and cognitive resources are available. Dual-process theories have been successfully applied to diverse domains and phenomena across a wide range of fields

If religious belief emerges through a converging set of intuitive processes, and analytic processing can inhibit or override intuitive processing, then analytic thinking may undermine intuitive support for religious belief. Thus, a dual-process account predicts that analytic thinking may be one source of religious disbelief. Recent evidence is consistent with this hypothesis.

We adopted three complementary strategies to test for robustness and generality. First, study 1 tested whether individual differences in the tendency to engage analytic thinking are associated with reduced religious belief. Second, studies 2 to 5 established causation by testing whether various experimental manipulations of analytic processing, induced subtly and implicitly, encourage religious disbelief. These manipulations of analytic processing included visual priming, implicit priming, and cognitive disfluency. Third, across studies, we assessed religious belief using diverse measures that focused primarily on belief in and commitment to religiously endorsed supernatural agents. Samples consisted of participants from diverse cultural and religious backgrounds

From their abstract:

...Combined, these studies indicate that analytic processing is one factor (presumably among several) that promotes religious disbelief. Although these findings do not speak directly to conversations about the inherent rationality, value, or truth of religious beliefs, they illuminate one cognitive factor that may influence such discussions.

We don't project our visceral states onto dissimilar others.

Interesting observations from O’Brien and Ellsworth on limits to the empathy of our embodied cognition:

What people feel shapes their perceptions of others. We have examined the assimilative influence of visceral states on social judgment. Replicating prior research, we found in a first experiment that participants who were outside during winter overestimated the extent to which other people were bothered by cold, and in a second study found that participants who ate salty snacks without water thought other people were overly bothered by thirst. However, in both studies, this effect evaporated when participants believed that the other people under consideration held political views opposing their own. Participants who judged these dissimilar others were unaffected by their own strong visceral-drive states, a finding that highlights the power of dissimilarity in social judgment. Dissimilarity may thus represent a boundary condition for embodied cognition and inhibit an empathic understanding of shared out-group pain. Our findings reveal the need for a better understanding of how people’s internal experiences influence their perceptions of the feelings and experiences of those who may hold values different from their own.

Facial theory of politics

I wanted to pass on this piece by Leonard Mlodinow to continue the thread started in previous posts (also, click on 'faces' in the blog categories in the left column).  He points to work suggesting that voters, regardless of issues and ideology, unconsciously favor the candidate that seems to radiate competence and most 'looks the part.'

Better brains through exercise

Reynolds points to some fascinating work by Justin Rhodes that upends previous assumptions about the importance of a rich environment leading to increased brain power (in mice). Apparently physical exercise alone is the sine qua non. Rhodes:

...gathered four groups of mice and set them into four distinct living arrangements. One group lived in a world of sensual and gustatory plenty, dining on nuts, fruits and cheeses, their food occasionally dusted with cinnamon, all of it washed down with variously flavored waters. Their “beds” were colorful plastic igloos occupying one corner of the cage. Neon-hued balls, plastic tunnels, nibble-able blocks, mirrors and seesaws filled other parts of the cage. Group 2 had access to all of these pleasures, plus they had small disc-shaped running wheels in their cages. A third group’s cages held no embellishments, and they received standard, dull kibble. And the fourth group’s homes contained the running wheels but no other toys or treats. All the animals completed a series of cognitive tests at the start of the study and were injected with a substance that allows scientists to track changes in their brain structures. Then they ran, played or, if their environment was unenriched, lolled about in their cages for several months. Afterward, Rhodes’s team put the mice through the same cognitive tests and examined brain tissues. It turned out that the toys and tastes, no matter how stimulating, had not improved the animals’ brains...Animals that didn’t run, no matter how enriched their world was otherwise, did not improve their brainpower in complex, lasting ways...

Both human and animal studies have shown that exercise increases levels of brain-derived neurotropic factor, or B.D.N.F., that stimulates growth of the hippocampus as well as some other brain areas, and also improves performance on cognitive tests.

We're talking mice, not humans, and studies on human children and adults continue to suggest that mental exercises like the n-back test to enhance working memory that I've mentioned in several posts can increase fluid intelligence in a long term, but still reversible, way (use it or loose it.)

Walking on air.

I thought I would pass on this nifty video. Calming, but at the same time sobering to see how people are down there.

Physical exertion can impair recall and recognition.

Some interesting observations from Hope et al.:

Understanding memory performance under different operational conditions is critical in many occupational settings. To examine the effect of physical exertion on memory for a witnessed event, we placed two groups of law-enforcement officers in a live, occupationally relevant scenario. One group had previously completed a high-intensity physical-assault exercise, and the other had not. Participants who completed the assault exercise showed impaired recall and recognition performance compared with the control group. Specifically, they provided significantly less accurate information concerning critical and incidental target individuals encountered during the scenario, recalled less briefing information, and provided fewer briefing updates than control participants did. Exertion was also associated with reduced accuracy in identifying the critical target from a lineup. These results support arousal-based competition accounts proposing differential allocation of resources under physiological arousal. These novel findings relating to eyewitness memory performance have important implications for victims, ordinary citizens who become witnesses, and witnesses in policing, military, and related operational contexts.

Increases in stress and amygdala volume reversed by mindfulness meditation.

Davidson and McEwen offer a nice review of stress induced changes in the amygdala and hippocampus, and also describe experiments showing that mindfulness meditation can decrease both stress behavior and amygdala size. Here is their abstract, followed by two figures from the paper:

Experiential factors shape the neural circuits underlying social and emotional behavior from the prenatal period to the end of life. These factors include both incidental influences, such as early adversity, and intentional influences that can be produced in humans through specific interventions designed to promote prosocial behavior and well-being. Here we review important extant evidence in animal models and humans. Although the precise mechanisms of plasticity are still not fully understood, moderate to severe stress appears to increase the growth of several sectors of the amygdala, whereas the effects in the hippocampus and prefrontal cortex tend to be opposite. Structural and functional changes in the brain have been observed with cognitive therapy and certain forms of meditation and lead to the suggestion that well-being and other prosocial characteristics might be enhanced through training.

Figure - Chronic stress causes neurons to shrink or grow, but not necessarily to die. Representation of the chronic stress effects detected in animal models on growth or retraction of dendrites in the basolateral amygdala and orbitofrontal cortex (growth) and in the CA3 hippocampus, dentate gyrus and medial prefrontal cortex (shrinkage). These effects are largely reversible in young adult animals, although aging appears to compromise resilience and medial prefrontal cortex recovery.

Figure - Change in gray matter volume in the right basolateral amygdala from pre to post 8 weeks of mindfulness based stress reduction was associated with decreases in perceived stress over this same time period (see Hölzel et al.). Individuals undergoing MBSR who showed the largest decreases in perceived stress also showed the largest decreases in basolateral amygdala gray matter volume.

Both mental and physical effort rise from deep sub-cortical structures.

Schmidt et al. show that a common motivational system within the basala ganglia underlies performance of both mental and physical efforts.

Mental and physical efforts, such as paying attention and lifting weights, have been shown to involve different brain systems. These cognitive and motor systems, respectively, include cortical networks (prefronto-parietal and precentral regions) as well as subregions of the dorsal basal ganglia (caudate and putamen). Both systems appeared sensitive to incentive motivation: their activity increases when we work for higher rewards. Another brain system, including the ventral prefrontal cortex and the ventral basal ganglia, has been implicated in encoding expected rewards. How this motivational system drives the cognitive and motor systems remains poorly understood. More specifically, it is unclear whether cognitive and motor systems can be driven by a common motivational center or if they are driven by distinct, dedicated motivational modules. To address this issue, we used functional MRI to scan healthy participants while performing a task in which incentive motivation, cognitive, and motor demands were varied independently. We reasoned that a common motivational node should (1) represent the reward expected from effort exertion, (2) correlate with the performance attained, and (3) switch effective connectivity between cognitive and motor regions depending on task demand.

The ventral striatum fulfilled all three criteria and therefore qualified as a common motivational node capable of driving both cognitive and motor regions of the dorsal striatum. Thus, we suggest that the interaction between a common motivational system and the different task-specific systems underpinning behavioral performance might occur within the basal ganglia.

Liljeholm and O'Doherty also offer context and perspective on this work.

Young blood enhances repair of old brains.

In a Neuroscience perspective in Science Redmond and Chan summarize work of Ruckh et al. showing that factors present in the blood of younger mice (introduced by joining the circulatory systems of a young and old mouse) enhance repair of the myelin sheath around neuronal axons in the older mice. Here is a graphic from the summary:

Legend - The circulatory system of an “old” mouse (gray) with a demyelinated lesion was surgically joined with that of a healthy “young” mouse (white. The old mouse exhibited enhanced remyelination relative to the control, an old-old mouse pair. Remyelination depended on the recruitment of circulatory factors from the young mouse, including macrophages. Resident “old” oligodendroglia retain remyelination potential even as they age, but macrophage-mediated clearance of inhibitory myelin debris from the lesion may become impaired.

John Cleese on creativity

For the second time, I've come across some engaging comments by the British actor John Cleese, and I though I would pass them on. Cleese's model for creativity centers on the interplay of two modes of operating – open, where we take a wide-angle, abstract view of the problem and allow the mind to ponder possible solutions, and closed, where we zoom in on implementing a specific solution with narrow precision.  In the 10 minute video, he stresses the role of the unconscious. 

-Space ("You can't become playful, and therefore creative, if you're under your usual pressures.")

-Time ("It's not enough to create space; you have to create your space for a specific period of time.")


-Time ("Giving your mind as long as possible to come up with something original," and learning to tolerate the discomfort of pondering time and indecision.)

-Confidence ("Nothing will stop you being creative so effectively as the fear of making a mistake.")
 -Humor ("The main evolutionary significance of humor is that it gets us from the closed mode to the open mode quicker than anything else.")

Further points:

Creativity is not a talent. It is a way of operating.

We need to be in the open mode when pondering a problem – but! – once we come up with a solution, we must then switch to the closed mode to implement it. Because once we've made a decision, we are efficient only if we go through with it decisively, undistracted by doubts about its correctness.

To be at our most efficient, we need to be able to switch backwards and forward between the two modes. But – here's the problem – we too often get stuck in the closed mode. Under the pressures which are all too familiar to us, we tend to maintain tunnel vision at times when we really need to step back and contemplate the wider view. This is particularly true, for example, of politicians. The main complaint about them from their nonpolitical colleagues is that they've become so addicted to the adrenaline that they get from reacting to events on an hour-by-hour basis that they almost completely lose the desire or the ability to ponder problems in the open mode. Cleese concludes with a beautiful articulation of the premise and promise of his recipe for creativity:

This is the extraordinary thing about creativity: If just you keep your mind resting against the subject in a friendly but persistent way, sooner or later you will get a reward from your unconscious.

Swarm Intelligence - The Simpleton Ant and the Intelligent Ants

Another posting from my scan of responses to the edge.org annual question "What is your favorite deep elegant or beautiful explanation?" In his essay, Robert Sapolsky does a curious stroll through several candidate beautiful stories he considered (the double helix, the work of Hubel and Wiesel on how the visual brain extracts features, how the GI tract moves stuff along…) and comes to rest on this selection:

...emergence and complexity, as represented by "swarm intelligence."

Observe a single ant, and it doesn't make much sense, walking in one direction, suddenly careening in another for no obvious reason, doubling back on itself. Thoroughly unpredictable.

The same happens with two ants, a handful of ants. But a colony of ants makes fantastic sense. Specialized jobs, efficient means of exploiting new food sources, complex underground nests with temperature regulated within a few degrees. And critically, there's no blueprint or central source of command—each individual ants has algorithms for their behaviors. But this is not wisdom of the crowd, where a bunch of reasonably informed individuals outperform a single expert. The ants aren't reasonably informed about the big picture. Instead, the behavior algorithms of each ant consist of a few simple rules for interacting with the local environment and local ants. And out of this emerges a highly efficient colony.

Ant colonies excel at generating trails that connect locations in the shortest possible way, accomplished with simple rules about when to lay down a pheromone trail and what to do when encountering someone else's trail—approximations of optimal solutions to the Traveling Salesman problem. This has useful applications. In "ant-based routing," simulations using virtual ants with similar rules can generate optimal ways of connecting the nodes in a network, something of great interest to telecommunications companies. It applies to the developing brain, which must wire up vast numbers of neurons with vaster numbers of connections without constructing millions of miles of connecting axons. And migrating fetal neurons generate an efficient solution with a different version of ant-based routine.

A wonderful example is how local rules about attraction and repulsion (i.e., positive and negative charges) allow simple molecules in an organic soup to occasionally form more complex ones. Life may have originated this way without the requirement of bolts of lightening to catalyze the formation of complex molecules

. And why is self-organization so beautiful to my atheistic self? Because if complex, adaptive systems don't require a blue print, they don't require a blue print maker. If they don't require lightening bolts, they don't require Someone hurtling lightening bolts. 

Two different ways of making choices in two brain areas.

Kolling et al. note brain correlates of two different ways of making decisions. They use fMRI of humans to examine neural correlates of foraging, which involves a choice of whether or not to engage with options as they are encountered (which is different from the sort of binary choice between currently available options studied by behavioral economics.) Here is their abstract:

Behavioral economic studies involving limited numbers of choices have provided key insights into neural decision-making mechanisms. By contrast, animals’ foraging choices arise in the context of sequences of encounters with prey or food. On each encounter, the animal chooses whether to engage or, if the environment is sufficiently rich, to search elsewhere. The cost of foraging is also critical. We demonstrate that humans can alternate between two modes of choice, comparative decision-making and foraging, depending on distinct neural mechanisms in ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) using distinct reference frames; in ACC, choice variables are represented in invariant reference to foraging or searching for alternatives. Whereas vmPFC encodes values of specific well-defined options, ACC encodes the average value of the foraging environment and cost of foraging.

More on why exercise is so good for us...

Many studies show that egular physical activity confers enormous fitness benefits. Exercise training enhances muscular endurance and strength, expends calories, and combats the development of common diseases such as obesity and type 2 diabetes. The effects of exercise are systemic and seemingly cannot be explained solely by the expenditure of calories in muscle.  Daniel Kelly writes a perspective on recent work showing how a new protein messenger named irisin (after Iris, the Greek messenger goddess) is released during muscle activity and triggers remodeling and energy expenditure in distant subcutaneous fat tissue deposits. Here is a summary figure of the muscle cell (myocyte) - fat cell (adipocyte) connection. 

Figure: The proposed irisin messenger system is depicted for humans [but was characterized in mice]. Exercise and energy expenditure induces the transcriptional regulator PGC-1α in the skeletal myocyte, which in turn drives the production of the membrane protein FNDC5. The circulating factor irisin, cleaved from FNDC5, activates thermogenic programs in white adipose tissue (“browning”), including mitochondrial biogenesis and the expression of uncoupling protein 1 (UCP1), leading to mitochondrial heat production and energy expenditure.

Seeing the whole reduces access to its parts.

The content of our conscious experience is automatically dictated by higher level stages of visual processing, which are associated with the representation of more abstract and meaningful interpretations. Poljac et. al. show that the ability to form a more abstract representation of a given visual input (in terms of a particular object) does not simply mean that the details of this stimulus are not immediately or automatically accessible to conscious perception, but that these details become fundamentally less accessible. The whole decreases access to the parts.

The experiments used computer generated walking dot figures of humans, both upright (easy to form the gestalt as human walking), and upside-down (more difficult to form the gestalt), as well as random stationary or moving dots. The rates of changes in dot colors were not perceived as well in the upright walking figures which generated the clearest gestalts.

They suggest that the rapid extraction of a perceptual Gestalt, and the inaccessibility of the parts that make up that Gestalt, may in fact reflect two sides of the same coin whereby human vision provides only the most useful level of abstraction to conscious awareness. This whole point is explained very beautifully in Metzinger's book, "The Ego Tunnel." (I did a series of five daily posts on this post, starting on 6/30/09)

Clothes can invade our body and brain...

Adam and Galinsky offer an interesting variant of studies on embodied cognition, a topic that MindBlog has frequently visited (35 postings, see left column) - showing that clothing can invade our body and brain, putting us into a different psychological state. After citing numerous studies of how clothes we wear have power over others, they do a discrete experiment to demonstrate a power of clothing over ourselves, specifically the power and accuracy of our attention:

We introduce the term “enclothed cognition” to describe the systematic influence that clothes have on the wearer's psychological processes. We offer a potentially unifying framework to integrate past findings and capture the diverse impact that clothes can have on the wearer by proposing that enclothed cognition involves the co-occurrence of two independent factors—the symbolic meaning of the clothes and the physical experience of wearing them. As a first test of our enclothed cognition perspective, the current research explored the effects of wearing a lab coat. A pretest found that a lab coat is generally associated with attentiveness and carefulness. We therefore predicted that wearing a lab coat would increase performance on attention-related tasks. In Experiment 1, physically wearing a lab coat increased selective attention compared to not wearing a lab coat. In Experiments 2 and 3, wearing a lab coat described as a doctor's coat increased sustained attention compared to wearing a lab coat described as a painter's coat, and compared to simply seeing or even identifying with a lab coat described as a doctor's coat. Thus, the current research suggests a basic principle of enclothed cognition—it depends on both the symbolic meaning and the physical experience of wearing the clothes.

When two heads are worse than one - the cost of collaboration

An interesting bit in Psychological Science from Minson and Mueller, who demonstrate that joint decision making exacerbates rejection of outside information and lowers accuracy of the effort:

Prior investigators have asserted that certain group characteristics cause group members to disregard outside information and that this behavior leads to diminished performance. We demonstrate that the very process of making a judgment collaboratively rather than individually also contributes to such myopic underweighting of external viewpoints. Dyad members exposed to numerical judgments made by peers gave significantly less weight to those judgments than did individuals working alone. This difference in willingness to use peer input was mediated by the greater confidence that the dyad members reported in the accuracy of their own estimates. Furthermore, dyads were no better at judging the relative accuracy of their own estimates and the advisor’s estimates than individuals were. Our analyses demonstrate that, relative to individuals, dyads suffered an accuracy cost. Specifically, if dyad members had given as much weight to peer input as individuals working alone did, then their revised estimates would have been significantly more accurate.

Why Curry, Wine And Coffee Cure Most Ails

A nice brief essay from Murali Doriaswamy:

What makes an explanation beautiful? Many elegant explanations in science are those that have been vetted fully but there are just as many beautiful wildly popular explanations where the beauty is just skin deep. I want to give two examples from the field of brain health.

When preliminary mice studies showed that an ingredient in dietary curry spice may have anti-Alzheimer effects, I suspect every vindaloo lover thought that was a beautiful explanation for why India had a low rate of Alzheimer's. But does India really have a low Alzheimer's rate after adjusting for life span and genetic differences? No one really knows..Likewise when an observational study in the 1990s reported wine drinkers in Bordeaux had lower rates of Alzheimer's, there was a collective "I knew it" from oenophiles...The latest observational findings now link coffee drinking with lower risk for Alzheimer's, much to the delight of the millions of caffeine addicts.

In reality, neither coffee nor wine nor curry spice have been proven in controlled trials to have any benefits against Alzheimer's. Regardless, the cognitive resonance these "remedies" find with the reader far exceeds the available evidence. One can find similar examples in virtually every field of medicine and science.

I would like to suggest two conditions that might render an explanation unusually beautiful: 1) a ring of truth, 2) confirmation biases. We all favor explanations and test them in a manner that confirms our own beliefs (confirmation bias). A small amount of factual data can be magnified into a beautiful fully proven explanation in one's mind if the right circumstance exist—thus, beauty is in the eye of the beholder. This may occur less often in one's own specialized fields, but we are all vulnerable in fields in which we are less expert in.

Given how often leading scientific explanations are proven wrong in subsequent years, one would do well to bear in mind Santayana's quote that "almost every wise saying has an opposite one, no less wise, to balance it". As for me, I love my curry, coffee and wine but am not yet counting on them to stop Alzheimer's.

How curriculum reform can decrease learning.

In the Editor's choice section of Science Magazine, McCartney reviews an interesting article in the Physics Education Journal:

Since 1975, the same Prior Knowledge Test (PKT) has been given to incoming students studying physics at the University of Bristol, UK. Designed to identify areas of math and physics that might need extra attention in the curriculum, PKT scores remained constant through 1991, decreased dramatically between 1992 and 2000, and stabilized after 2001, suggesting a clear change in the ability of students in the tested subjects. Barham argues that the decrease in scores was caused by modularization of the secondary education curriculum, which resulted in students learning the material required for each module examination and failing to retain it afterward. This highlights the dangers of a “learn and forget” approach to physics and math, and the author suggests that university faculty adapt their teaching methods to allow for the changes in preparedness of incoming students, particularly in math, where large parts of multistage calculations should not be skipped over. Furthermore, he argues for encouraging the understanding that physics and math are coherent disciplines, wherein material taught at all levels must be retained for a complete understanding of the subject.

Our brain structure changes after two hours of learning.

Sagi and colleagues have provided the first evidence that rapid structural plasticity can be detected in humans after just 2 hr of playing a video game. To assess brain structure they used diffusion magnetic resonance imaging, a technique sensitive to the self-diffusion of water molecules that depends on tissue architecture (how freely water diffuses depends on the space between the objects such as neurons, glia, and blood vessels, that it is moving through). They showd that only two hours of learning can cause a mean diffusivity reduction in the human hippocampus. In a similar supporting study on rats, the authors were able to show that changes in brain derived neurotropic growth (BDNF) factor correlated with the structural change measured by MRI. I'm passing on the abstract, and for those of you who like data, one of the figures from their paper.

The timescale of structural remodeling that accompanies functional neuroplasticity is largely unknown. Although structural remodeling of human brain tissue is known to occur following long-term (weeks) acquisition of a new skill, little is known as to what happens structurally when the brain needs to adopt new sequences of procedural rules or memorize a cascade of events within minutes or hours. Using diffusion tensor imaging (DTI), an MRI-based framework, we examined subjects before and after a spatial learning and memory task. Microstructural changes (as reflected by DTI measures) of limbic system structures (hippocampus and parahippocampus) were significant after only 2 hr of training. This observation was also found in a supporting rat study. We conclude that cellular rearrangement of neural tissue can be detected by DTI, and that this modality may allow neuroplasticity to be localized over short timescales.

Figure (Click on figure to enlarge it) - Structural Remodeling of Brain Tissue, Measured by DTI as Changes in MD after 2 hr of Training on a Spatial Learning and Memory TaskThe following statistical analyses were employed: paired t tests between the MD maps before and after the task in the learning group (A and F); planned comparisons analysis of the learning versus control groups with respect to scan time with predicated effect in the learning group only (B and G); and linear effect between groups (C and H) as well as a group by time interaction following ANOVA (D and I). The effects were found in the left hippocampus (A–D) and right parahippocampus (F–I). The parametric maps in these images were generated at a significance level of p less than 0.005 (uncorrected). The enlarged subset in those images indicates the significant voxels following correction for multiple comparisons (p less than 0.05, corrected). In the enlarged subset the corrected p value color scale is between 0.005 and 0.05. L indicates the left side of the brain. (E) and (J) show the MD values in the clusters in the subset of (A) and (F) (mean ± SEM). (K) shows the correlation analysis between subjects' improvement rates (see Figure 1) and decrease in MD in the right parahippocampus (of the cluster in F).

The happiest countries? I'm confused.

Having just done a post on March 2 on an article in the Economist reporting most happiness in poor and middle income countries (most Europeans less happy than rest of world), now appears a "World Happiness Report" (PDF here, Summary by lead author Helliwell here) prepared for a United Nations conference on happiness, that rates developed Northern European countries as having highest happiness. Compare the graphic below with the one in the March 2 post.  Helliwell: "the richest countries are a lot happier than the poorest."  The Economist: "the highest levels of self-reported happiness is not in rich countries."  I guess the way you ask the questions is rather crucial, and also sample size,  but at the moment I'm not patient enough to figure out what is going on.  Maybe a helpful reader will resolve all in a comment on this post.