Tuesday, October 14, 2008

MRI of moral emotions while causing harm.

Kédia et al. perform brain imaging of subjects as they imagine harm in several different contexts of subject and victim:
The statement "An agent harms a victim" depicts a situation that triggers moral emotions. Depending on whether the agent and the victim are the self or someone else, it can lead to four different moral emotions: self-anger ("I harm myself"), guilt ("I harm someone"), other-anger ("someone harms me"), and compassion ("someone harms someone"). In order to investigate the neural correlates of these emotions, we examined brain activation patterns elicited by variations in the agent (self vs. other) and the victim (self vs. other) of a harmful action. Twenty-nine healthy participants underwent functional magnetic resonance imaging while imagining being in situations in which they or someone else harmed themselves or someone else. Results indicated that the three emotional conditions associated with the involvement of other, either as agent or victim (guilt, other-anger, and compassion conditions), all activated structures that have been previously associated with the Theory of Mind (ToM, the attribution of mental states to others), namely, the dorsal medial prefrontal cortex, the precuneus, and the bilateral temporo-parietal junction. Moreover, the two conditions in which both the self and other were concerned by the harmful action (guilt and other-anger conditions) recruited emotional structures (i.e., the bilateral amygdala, anterior cingulate, and basal ganglia). These results suggest that specific moral emotions induce different neural activity depending on the extent to which they involve the self and other.

This year's Ig-Noble prize in cognitive science goes to a slime mold

A clip from Steve Nadis' write up in Nature News of this year's Ig-Noble prizes:
Slime moulds exhibit the kind of "contemplative behaviour" that Hamlet is famous for, muses Toshiyuki Nakagaki of Hokkaido University in Japan. ...The slime mold's puzzle-solving ability — Shakespearean or otherwise — is a discovery that is unlikely to change the world, but it won Nakagaki and his colleagues an Ig Nobel Prize for cognitive science last week at the annual event held at Harvard University in Cambridge, Massachusetts. Their research... showed that slime molds looking for food have "the ability to find the minimum-length solution between two points in a labyrinth".

Subsequently, the team has found that molds can find the shortest path between 30–50 points, which is something even supercomputers cannot yet work out. "We can't even check the mold's solution," notes Nakagaki, "but it looks good."

Monday, October 13, 2008

How context can set our emotional reaction to a smell.

Rolls et al. do a piece of work on how selective attention to affective value can alter how our brains process olfactory stimuli:
How does selective attention to affect influence sensory processing? In a functional magnetic resonance imaging investigation, when subjects were instructed to remember and rate the pleasantness of a jasmin odor, activations were greater in the medial orbitofrontal and pregenual cingulate cortex than when subjects were instructed to remember and rate the intensity of the odor. When the subjects were instructed to remember and rate the intensity, activations were greater in the inferior frontal gyrus. These top–down effects occurred not only during odor delivery but started in a preparation period after the instruction before odor delivery, and continued after termination of the odor in a short-term memory period. Thus, depending on the context in which odors are presented and whether affect is relevant, the brain prepares itself, responds to, and remembers an odor differently. These findings show that when attention is paid to affective value, the brain systems engaged to prepare for, represent, and remember a sensory stimulus are different from those engaged when attention is directed to the physical properties of a stimulus such as its intensity. This differential biasing of brain regions engaged in processing a sensory stimulus depending on whether the cognitive demand is for affect-related versus more sensory-related processing may be an important aspect of cognition and attention. This has many implications for understanding the effects not only of olfactory but also of other sensory stimuli.

Autistic people have the visual acuity of hawks.

Ashwin et al. have come up with a fascinating observation during their testing of 15 men with autism-spectrum disorders using the Freiburg Visual Acuity and Contrast Test. They found them to have, on average, 20:7 vision. This means they can see the same detail on an object 20 meters away that a person with average vision can see at 7 meters. Birds of prey have roughly 20:6 vision. What gives these people with autism hawk-like vision isn't known.

Early Fall on Twin Valley Road

Picture of my front yard taken Saturday at my home in Town of Middleton, Wisconsin.

Friday, October 10, 2008

We seek mates that resemble our opposite-sex parents.

The research highlights section of Nature points to work by Bereczkei and his colleagues at the University of Pécs in Hungary who find new evidence linking partner choices to parental appearance. By measuring 14 facial proportions of 312 adults from 52 families, Bereczkei et al. show significant correlations in appearance between young men and their partner's father and young women and their partner's mother. This supports the theory that children are imprinted with their opposite-sex parent's face. The abstract from Proc. Roy. Soc. B:
Former studies have suggested that imprinting-like processes influence the shaping of human mate preferences. In this study, we provide more direct evidence for assessing facial resemblance between subjects' partner and subjects' parents. Fourteen facial proportions were measured on 312 adults belonging to 52 families, and the correlations between family members were compared with those of pairs randomly selected from the population. Spouses proved to be assortatively mated in the majority of measured facial proportions. Significant correlations have been found between the young men and their partner's father (but not his mother), especially on facial proportions belonging to the central area of the face. Women also showed resemblance to their partner's mother (but not to their father) in the facial characteristics of their lower face. Replicating our previous studies, facial photographs of participants were also matched by independent judges who ascribed higher resemblance between partners, and subjects and their partners' opposite-sex parents, compared with controls. Our results support the sexual imprinting hypothesis which states that children shape a mental template of their opposite-sex parents and search for a partner who resembles that perceptual schema. The fact that only the facial metrics of opposite-sex parents showed resemblance to the partner's face tends to rule out the role of familiarity in shaping mating preferences. Our findings also reject several other rival hypotheses. The adaptive value of imprinting-related human mating is discussed, and a hypothesis is made of why different facial areas are involved in males' and females' search for resemblance.

Light exciting our eyes, an intimate picture.

In a former life, I spent 30 years running a laboratory that studies how light is changed into a nerve signal in our eyes. Much of our work centered on the visual pigment rhodopsin, which starts an excitation cascade after its excitation by light by binding to the alpha subunit of a G-protein. I am in awe of new technologies that have, since my work, revealed many of the finer details of this process. Thus I can't resist showing this beautiful graphic from a recent review by Schwartz and Hubbell, describing work by Sheerer et al.


a, Rhodopsin, shown here in its inactivated conformation, is a light-sensing receptor found in cell membranes. It consists of a protein (opsin, green) and a ligand (retinal, pink, also shown in its inactivated conformation). When activated by light, rhodopsin binds to part of an adjacent G protein (binding region in red), triggering a cascade of biological responses. The protein plug (blue) is part of the extracellular domain of opsin, and immobilizes the extracellular transmembrane segments of the receptor. b, Scheerer et al. have determined the activated structure of opsin in complex with the receptor-binding peptide fragment of the G protein (the Galpha peptide). The most notable difference when compared with the inactivated receptor is that transmembrane helix 6 (TM-VI) has moved substantially outward (indicated by the red arrow), thereby creating the binding pocket for the G-protein peptide.

Thursday, October 09, 2008

Models to compute and predict our current economic chaos?

Here is an interesting article on the resistance of economic theorists to using modeling approaches that have proven useful in predicting dramatic and sudden transitions. Such models have been successfully applied to predicting heart attacks, epileptic seizures, stock market bubbles, eutrophication of lakes, etc. They are based in part on the observation that variance in an apparent steady state begins to change in predictable ways in advance of large rapid transitions. Modeling the dynamics of a systems of agents by simulating their workings from the bottom up can reveal how instabilities or phase transitions can rise in a system of linked agents by trouble in one of them.

Visualization challenge.

Science Magazine and the National Science Foundation have announced the winners and honorable mentions in the categories of photography, illustration, informational graphics, interactive media, and noninteractive media in this year's International Science & Engineering Visualization Challenge. The first place was this image of diatoms from the Mediterranean off the coast of Italy.

Wednesday, October 08, 2008

Hope that we might be governed by the head rather than the gut?

Instinctual basis of fury at Wall Street

Benedict Carey has a great article in last Tuesday's NYTimes science section on the evolved psychology of retaliation and forgiveness we share with a large number of other social animal species, particularly with reference to the current public anger at the financial community:
The fury is based in instincts that have had a protective and often stabilizing effect on communities throughout human history. Small, integrated groups in particular often contain members who will stand up and — often at significant risk to themselves — punish cheaters, liars and freeloaders...The catch in this highly sensitive system, most researchers agree, is that it most likely evolved to inoculate small groups against invasive rogues, and not to set right the excesses of a vast and wildly diverse community like the American economy. Some experts believe that Japan’s disastrous delay in bailing out its banks in the early 1990s was caused in part by a collective urge to punish corrupt bankers, and they fear a similar outcome today.
Carey describes a variety of investment game experiments that probe, for example, how our retribution behaviors depend on whether we are being observed by others.

Feeling helpless can enhance our magical thinking

Some experiments very relevant to our current economic chaos are reported by Whitson and Galinsky, who show that when we feel out of control, our need to impose order and rationale is strong enough cause us to see patterns where they do not exist, or conspiracies where there are none.
We present six experiments that tested whether lacking control increases illusory pattern perception, which we define as the identification of a coherent and meaningful interrelationship among a set of random or unrelated stimuli. Participants who lacked control were more likely to perceive a variety of illusory patterns, including seeing images in noise, forming illusory correlations in stock market information, perceiving conspiracies, and developing superstitions. Additionally, we demonstrated that increased pattern perception has a motivational basis by measuring the need for structure directly and showing that the causal link between lack of control and illusory pattern perception is reduced by affirming the self. Although these many disparate forms of pattern perception are typically discussed as separate phenomena, the current results suggest that there is a common motive underlying them.

Tuesday, October 07, 2008

A college course blog - The Biology of Mind course at the Univ. of Wisconsin

I began a course called "The Biology of Mind" at the University of Wisconsin Madison in 1993, cross listed between the departments of Zoology, Psychology, Anthropology, and Neuroscience. The links to my personal website in the left column of this blog describe that course, whose lecture notes generated the "Biology of Mind" book. On my retirement in 2001, I was very grateful that John Hawks of the UW Anthropology Dept. took over the course, putting his own particular stamp on its contents. He has tried a number of innovations, such as podcasts of the lectures, and now has set up a blog on which students post their writing and commentary. It makes a fascinating read. Here is John's description of the effort:
I am doing a unique experiment with my course this semester, "Biology of Mind." The course has a history of collaborative peer review on writing assignments, and the students do a lot of writing -- students who earn an "A" in the course will be required to produce 10,000 words of written assignments during the semester. In the past, I have used the university's online course system to administer the assignments, and the students have really benefited from their peers' feedback as well as my own.

This semester, I've decided to take it all public. The students are collaborating as before, except this semester they are doing it on a blog. The blog's name is "Biology of Mind", and it has been up and running for a couple of weeks. Right now there are over 200 posts over there, and the number continues to grow.

The students write weekly reviews of papers in psychology, neuroscience, evolutionary biology, philosophy of mind, and naturally anthropology -- a broad scope. Many of the students have been following new research, others have chosen to delve more deeply into the history of one or more fields. In any event, if you're interested in the brain, you may like this site. I think the students (mostly seniors with some graduate students) are producing some nice work, and the site is open for feedback from the public as well.

Our visual long-term memory has a massive storage capacity for object details

In the Sept 23 issue of PNAS Brady et al. make some striking observations on the capacity of our visual memory stores:
One of the major lessons of memory research has been that human memory is fallible, imprecise, and subject to interference. Thus, although observers can remember thousands of images, it is widely assumed that these memories lack detail. Contrary to this assumption, here we show that long-term memory is capable of storing a massive number of objects with details from the image. Participants viewed pictures of 2,500 objects over the course of 5.5 h. Afterward, they were shown pairs of images and indicated which of the two they had seen. The previously viewed item could be paired with either an object from a novel category, an object of the same basic-level category, or the same object in a different state or pose. Performance in each of these conditions was remarkably high (92%, 88%, and 87%, respectively), suggesting that participants successfully maintained detailed representations of thousands of images. These results have implications for cognitive models, in which capacity limitations impose a primary computational constraint (e.g., models of object recognition), and pose a challenge to neural models of memory storage and retrieval, which must be able to account for such a large and detailed storage capacity.


Figure: Example test pairs presented during the two-alternative forced-choice task for all three conditions (novel, exemplar, and state). The number of observers reporting the correct item is shown for each of the depicted pairs.

How do you like your coffee?

A cute piece by Katherine Sanderson from the Oct. 1 Nature:

The floating fractal (top, left) is formed 90 seconds after a drop of instant coffee falls into a cup of milk.

Coffee is heavier than milk and the battle between gravity and surface tension plays out at the boundary between the two liquids. The coffee falls vertically through the milk (bottom, left, with water replacing milk for ease of viewing), and the fractal pattern emerges.

The pattern constantly shifts as parts of it are sucked into the milk, producing a fractal structure with the same dimension as a Sierpi´nski carpet — formed when a square is cut into nine identical squares; the central square is removed; and the procedure is repeated with the remaining eight squares and so on infinitely.

Michiko Shimokawa and Shonosuke Ohta, fluid scientists at Kyushu University in Fukuoka City, Japan, say that it is the first time this kind of fractal has been shown experimentally (http://www.arxiv.org/abs/0809.2458), and they managed to recreate the process using a magnetic liquid instead of coffee (far right).

Monday, October 06, 2008

A Grieg Air for Monday morning

Yesterday was a rainy afternoon at my home on Twin Valley Road in Middleton Wisconsin, so I decided to a video recording of a relatively tranquil, lyrical piece by Edvard Grieg that I enjoy playing - the Air from his Holberg Suite.

Political Attitudes Vary with Physiological Traits

Not exactly surprising, but fascinating never the less, from Oxley et al.
Although political views have been thought to arise largely from individuals' experiences, recent research suggests that they may have a biological basis. We present evidence that variations in political attitudes correlate with physiological traits. In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats.

Friday, October 03, 2008

Subliminal Neuroeconomics

It turns out that we can learn to assess risks on the basis of visual hints we are not aware of seeing. In other words, without conscious processing of contextual cues, our brains can learn their reward value and use them to provide a bias on decision making. Functional neuroimaging reveals a correlation of cue values and prediction errors with activity in ventral striatum during conditioning. From the summary in Nature:
Mathias Pessiglione et al. repeatedly showed 20 subjects abstract symbols as they played a gambling game. Each symbol presentation involved one of three choices and was followed by a 'masking image' in a series that flickered so fast that the subjects could not consciously perceive the symbol shapes. The subjects were told that the symbols were associated with winning or losing, and then allowed to gamble.

The subjects won more than they lost, indicating that their brains recognized the unperceived symbols and learned to associate them with reward or punishment. Functional neuroimaging showed that the mechanism involves the ventral striatum (see figure), a brain area associated with assessing reward value.

Is the bisphenol (BPA) in plastic products making us dumb?

Estrogens are known to increase the number of excitatory synapses in our hippocampus and enhance both cognitive performance and spatial memory. This is why there is such interest in the possible disruptive effects of estrogenic compounds in the environment, particularly bisphenol A (BPA) that is present in some plastics. Leranth et al. now demonstrate in monkeys that a daily dose of BPA considered within the safe range for humans (50 μg/kg) completely blocks the estradiol-induced increase in axospinous synapses in three distinct fields of the hippocampus. This would be expected to have profound effects on the highly plastic excitatory (glutamatergic) circuits in both our hippocampus and prefrontal cortex. Here is their chilling abstract:
Exposure measurements from several countries indicate that humans are routinely exposed to low levels of bisphenol A (BPA), a synthetic xenoestrogen widely used in the production of polycarbonate plastics. There is considerable debate about whether this exposure represents an environmental risk, based on reports that BPA interferes with the development of many organs and that it may alter cognitive functions and mood. Consistent with these reports, we have previously demonstrated that BPA antagonizes spine synapse formation induced by estrogens and testosterone in limbic brain areas of gonadectomized female and male rats. An important limitation of these studies, however, is that they were based on rodent animal models, which may not be representative of the effects of human BPA exposure. To address this issue, we examined the influence of continuous BPA administration, at a daily dose equal to the current U.S. Environmental Protection Agency's reference safe daily limit, on estradiol-induced spine synapse formation in the hippocampus and prefrontal cortex of a nonhuman primate model. Our data indicate that even at this relatively low exposure level, BPA completely abolishes the synaptogenic response to estradiol. Because remodeling of spine synapses may play a critical role in cognition and mood, the ability of BPA to interfere with spine synapse formation has profound implications. This study is the first to demonstrate an adverse effect of BPA on the brain in a nonhuman primate model and further amplifies concerns about the widespread use of BPA in medical equipment, and in food preparation and storage.

Thursday, October 02, 2008

Take a bird-nap, not a cat nap.

A complete group of sleep characteristics (rapid-eye-movement sleep and slow-wave sleep as well as transition stages and quick spikes) has been found outside of mammals, in zebra finches, a surprising finding because birds lack a neocortex, the part of the mammalian brain thought necessary for such patterns. Low et al. suggest that ancestral characteristics of sleep evolved under selective pressures common to songbirds and mammals. This would fit with Tononi's suggestion that sleep is required for synaptic homeostasis and regenerations (a form of sleep is also observed in fruitflies). Here is their abstract:
A suite of complex electroencephalographic patterns of sleep occurs in mammals. In sleeping zebra finches, we observed slow wave sleep (SWS), rapid eye movement (REM) sleep, an intermediate sleep (IS) stage commonly occurring in, but not limited to, transitions between other stages, and high amplitude transients reminiscent of K-complexes. SWS density decreased whereas REM density increased throughout the night, with late-night characterized by substantially more REM than SWS, and relatively long bouts of REM. Birds share many features of sleep in common with mammals, but this collective suite of characteristics had not been known in any one species outside of mammals. We hypothesize that shared, ancestral characteristics of sleep in amniotes evolved under selective pressures common to songbirds and mammals, resulting in convergent characteristics of sleep.

For a kid to learn - positive strokes work way better than negative.

An interesting study by van Duijvenvoorde et al. compares the utility of positive versus negative strokes during learning in three age groups (8–9, 11–13, and 18–25 year of age). Cognitive control areas are engaged best by positive feedback in the youngest group, and by negative feedback in the oldest. Here is their abstract:
How children learn from positive and negative performance feedback lies at the foundation of successful learning and is therefore of great importance for educational practice. In this study, we used functional magnetic resonance imaging (fMRI) to examine the neural developmental changes related to feedback-based learning when performing a rule search and application task. Behavioral results from three age groups (8–9, 11–13, and 18–25 years of age) demonstrated that, compared with adults, 8- to 9-year-old children performed disproportionally more inaccurately after receiving negative feedback relative to positive feedback. Additionally, imaging data pointed toward a qualitative difference in how children and adults use performance feedback. That is, dorsolateral prefrontal cortex and superior parietal cortex were more active after negative feedback for adults, but after positive feedback for children (8–9 years of age). For 11- to 13-year-olds, these regions did not show differential feedback sensitivity, suggesting that the transition occurs around this age. Pre-supplementary motor area/anterior cingulate cortex, in contrast, was more active after negative feedback in both 11- to 13-year-olds and adults, but not 8- to 9-year-olds. Together, the current data show that cognitive control areas are differentially engaged during feedback-based learning across development. Adults engage these regions after signals of response adjustment (i.e., negative feedback). Young children engage these regions after signals of response continuation (i.e., positive feedback). The neural activation patterns found in 11- to 13-year-olds indicate a transition around this age toward an increased influence of negative feedback on performance adjustment. This is the first developmental fMRI study to compare qualitative changes in brain activation during feedback learning across distinct stages of development.

Wednesday, October 01, 2008

Brain correlates of the muting of our emotions as we age.

My boyfriend in the early 19980’s was a pharmacy graduate student whose t-shirt read “Drugs are my life.” If I were to wear such a t-shirt now it would read “Hormones and neurotransmitters are my life.” I increasingly feel that all this verbal stuff we do - chattering in person or in the electronic ether, writing blogs, etc. - is a superficial veneer, noise on top of what is really running the show, which is the waxing and waning of hormones and neurotransmitters directed by an “it”, a martian inside us utterly running its own show. These compounds regulate our assertiveness versus passivity , our trust versus mistrust, our anxiety versus calm, our pleasure during antipication and reward. (They function, respectively, in neural systems that use testosterone, oxytocin, adrenaline, and dopamine.). The swings in these systems become less dramatic as we 'mellow' with aging.

Dreher et al. have published an interesting bit of work that deals specifically with the muting of the intensity of the pleasures we feel during anticipation and reward, in their article on “Age-related changes in midbrain dopaminergic regulation of the human reward system.” Their data show what is going on as we experience less excitement at opening a present when we are 60 than when we are 10 years old. There are changes in the brain's production of dopamine, which plays a central role in our reward system, as well as in which parts of the brain respond to it, and by how much they respond. (a recent brief article on dopamine and the reward system of the brain is here.) Here is their abstract, followed by a figure from the paper.
The dopamine system, which plays a crucial role in reward processing, is particularly vulnerable to aging. Significant losses over a normal lifespan have been reported for dopamine receptors and transporters, but very little is known about the neurofunctional consequences of this age-related dopaminergic decline. In animals, a substantial body of data indicates that dopamine activity in the midbrain is tightly associated with reward processing. In humans, although indirect evidence from pharmacological and clinical studies also supports such an association, there has been no direct demonstration of a link between midbrain dopamine and reward-related neural response. Moreover, there are no in vivo data for alterations in this relationship in older humans. Here, by using 6-[18F]FluoroDOPA (FDOPA) positron emission tomography (PET) and event-related 3T functional magnetic resonance imaging (fMRI) in the same subjects, we directly demonstrate a link between midbrain dopamine synthesis and reward-related prefrontal activity in humans, show that healthy aging induces functional alterations in the reward system, and identify an age-related change in the direction of the relationship (from a positive to a negative correlation) between midbrain dopamine synthesis and prefrontal activity. These results indicate an age-dependent dopaminergic tuning mechanism for cortical reward processing and provide system-level information about alteration of a key neural circuit in healthy aging. Taken together, our findings provide an important characterization of the interactions between midbrain dopamine function and the reward system in healthy young humans and older subjects, and identify the changes in this regulatory circuit that accompany aging.


Legend (click on figure to enlarge). Statistical t maps of the within-groups effects in the different phases of the reward paradigm. (A) (Left) Main effect of anticipating reward in young subjects during the delay period, showing activation in the left intraparietal cortex, ventral striatum, caudate nucleus, and anterior cingulate cortex. (Right) Main effect of anticipating reward in older subjects during the delay period, showing activation in the left intraparietal cortex only. The glass brain and the coronal slice indicate that no ventral striatum activity was observed in older subjects. (B) (Left) Main effect of reward receipt in young subjects at the time of the rewarded outcome showing activation in a large bilateral prefronto-parietal network. (Right) Main effect of reward receipt in older subjects at the time of the rewarded outcome showing bilateral prefronto-parietal activation.

Is Art the future of Science?

I want to point out a lovely essay by Johan Lehrer that explores how esthetic and artistic explorations have influenced paradigm shifting insights in physics, psychology and neuroscience - metaphorical leaps that have broken the iron grip of models that have reached their dead end.

Tuesday, September 30, 2008

Can you see me?

Check out this interesting piece from John Tierney on modern camouflage that is based on knowledge of how a deer's eye perceives the world.

Male promiscuity versus monogamy in humans nudged by same genes as in Prarie Voles

A series of elegant experiments done on meadow voles versus prairie voles (promiscuous versus monogamous males) show that the different behaviors correlate with genetic variation in the gene for a vasopressin receptor (V1aR). Nonmonogamous meadow voles become more monogamous when V1aR density is increased in relevant brain areas by using viral vector gene transfer. As you might suspect, a similar genetic variation has now been shown by Walum et al.(open access) to correlate with pair-bonding behavior in human males. (I would be most curious to know whether I have the repeat polymorphism that would correlate with my wandering ways!) Here is their abstract:
Pair-bonding has been suggested to be a critical factor in the evolutionary development of the social brain. The brain neuropeptide arginine vasopressin (AVP) exerts an important influence on pair-bonding behavior in voles. There is a strong association between a polymorphic repeat sequence in the 5′ flanking region of the gene (avpr1a) encoding one of the AVP receptor subtypes (V1aR), and proneness for monogamous behavior in males of this species. It is not yet known whether similar mechanisms are important also for human pair-bonding. Here, we report an association between one of the human AVPR1A repeat polymorphisms (RS3) and traits reflecting pair-bonding behavior in men, including partner bonding, perceived marital problems, and marital status, and show that the RS3 genotype of the males also affects marital quality as perceived by their spouses. These results suggest an association between a single gene and pair-bonding behavior in humans, and indicate that the well characterized influence of AVP on pair-bonding in voles may be of relevance also for humans.

Monday, September 29, 2008

The sucker to saint effect.

Here is an interesting tidbit in Psychological Science from Jordan and Monin. They suggest we protect our own self image by feeling morally superior when we otherwise might feel foolish.
When people's rationality and agency are implicitly called into question by the more expedient behavior of others, they sometimes respond by feeling morally superior; this is referred to as the sucker-to-saint effect. In Experiment 1, participants who completed a tedious task and then saw a confederate quit the same task elevated their own morality over that of the confederate, whereas participants who simply completed the task or simply saw the confederate quit did not. In Experiment 2, this effect was eliminated by having participants contemplate a valued personal quality before encountering the rebellious confederate, a result suggesting a role for self-threat in producing moralization. These studies demonstrate that moral judgments can be more deeply embedded in judges' immediate social contexts—and driven more by motivations to maintain self-image—than is typically appreciated in contemporary moral-psychology research. Rather than uphold abstract principles of justice, moral judgment may sometimes just help people feel a little less foolish.

Brain processing of action language influenced by sports experience.

There is abundant evidence that if we train and enhance our skill at a particular kind of action (piano playing, serving a tennis ball, etc.) areas of the premotor and motor cortex involved in the skill increase their relative area. Beilock et al. now provide evidence, in an open access article, that specialized (sports) motor experience enhances action-related language understanding by recruitment of left dorsal lateral premotor cortex, a region normally devoted to higher-level action selection and implementation—even when there is no intention to perform a real action. Thus, the language system is sufficiently plastic and dynamic to encompass expertise-related neural recruitment outside core language networks.

Friday, September 26, 2008

A memory activates the same brain cells as the original experience.

A fascinating observation from Gelbard-Sagiv et al., who studied patients with pharmacologically intractable epilepsy with implanted depth electrodes to localize the focus of seizure onset. Benedict Carey discusses the work. Here is the original abstract:
The emergence of memory, a trace of things past, into human consciousness is one of the greatest mysteries of the human mind. Whereas the neuronal basis of recognition memory can be probed experimentally in human and nonhuman primates, the study of free recall requires that the mind declare the occurrence of a recalled memory (an event intrinsic to the organism and invisible to an observer). Here, we report the activity of single neurons in the human hippocampus and surrounding areas when subjects first view television episodes consisting of audiovisual sequences and again later when they freely recall these episodes. A subset of these neurons exhibited selective firing, which often persisted throughout and following specific episodes for as long as 12 seconds. Verbal reports of memories of these specific episodes at the time of free recall were preceded by selective reactivation of the same hippocampal and entorhinal cortex neurons. We suggest that this reactivation is an internally generated neuronal correlate of the subjective experience of spontaneous emergence of human recollection.

The teenage brain.

Harvard Magazine has an interesting brief article describing work on the teenage brain being done at Harvard Medical School.

Thursday, September 25, 2008

Online brain and cognitive science courses

Every week or so I get an email from a reader asking "how do I find out more about......" or "what is a good book on...." Apart from specific information that I can pass on, I should mention here what I suggest to them (in addition to a google search using proper search terms): The MIT open course ware, for example in Brain and Cognitive science, is amazing. There are a total of 1800 offerings in all college areas.

A taste test for depression?

From a report by Cahoon on the July Physiological Society Meetings in Cambridge, UK.
Melichar and Donaldson gave healthy volunteers a tiny dab of faint flavor on the tongue and asked if they could taste it. The sample was so diluted that they couldn't. The researchers then gave the volunteers pills that boosted brain levels of one of two neurotransmitters, serotonin or noradrenaline. To boost serotonin, for example, patients took a Prozac-like drug known as a selective serotonin-reuptake inhibitor. When volunteers got a serotonin jump, they were suddenly able to taste the feeble flavor if it was bitter or sweet. With noradrenaline boosted, the volunteers were able to taste the dab if it was bitter or sour. Donaldson and Melichar suspected that depressed people had blunted taste buds--the illness is often tied to a lack of either neurotransmitter--and that the right antidepressant would allow depressed people to experience the true vibrancy of flavors.
Experiments are being planned to determine the validity of a taste test for depression:
If those results validate the flavor test, it could become the equivalent of the cholesterol test that persuades someone to take action against heart disease. "The patient has no objective marker" that tells them they're depressed, says Melichar. As a result, he notes, a lot of people end up not taking their medication.

Moreover, given that the researchers have found that serotonin is linked to sweet and noradrenaline is linked to sour, the taste test could be a useful way to determine which drug to use, a big plus because antidepressants can take several weeks or more to have an effect. And with this disease, time is of the essence--if treated within 3 months of becoming depressed, a person has a very good chance of getting better.

Wednesday, September 24, 2008

Training young brains to behave

Benedict Carey offers an informative article on brain development in children, and the growth of self control as the prefrontal cortex matures. The article has an excellent interactive graphic that permits you to move a slider and see brain changes during development.

Social exclusion causes unconscious mimicry

Lakin et al. make some interesting observations on our reactions to being socially excluded by others, we are likely to unconsciously start mimicking their behaviors:
Research across various disciplines has demonstrated that social exclusion has devastating psychological, emotional, and behavioral consequences. Excluded individuals are therefore motivated to affiliate with others, even though they may not have the resources, cognitive or otherwise, to do so. The current research explored whether nonconscious mimicry of other individuals—a low-cost, low-risk, automatic behavior—might help excluded individuals address threatened belongingness needs. Our first experiment demonstrated that excluded people mimic a subsequent interaction partner more than included people do. A second experiment showed that individuals excluded by an in-group selectively (and nonconsciously) mimic a confederate who is an in-group member more than a confederate who is an out-group member. The relationship between exclusion and mimicry suggests that there are automatic behaviors people can use to recover from the experience of being excluded. In addition, this research demonstrates that nonconscious mimicry is selective and sensitive to context.

Tuesday, September 23, 2008

Chill out aids

A few links for calming your mental chatter during these tumultuous financial times:
Worriers Annonymous
Sacred Geometry

Gender gaps widen

A New York Times article by John Tierney describes the work of Schmitt and others:
When men and women take personality tests, some of the old Mars-Venus stereotypes keep reappearing. On average, women are more cooperative, nurturing, cautious and emotionally responsive. Men tend to be more competitive, assertive, reckless and emotionally flat. Clear differences appear in early childhood and never disappear.

What’s not clear is the origin of these differences. Evolutionary psychologists contend that these are innate traits inherited from ancient hunters and gatherers. Another school of psychologists asserts that both sexes’ personalities have been shaped by traditional social roles, and that personality differences will shrink as women spend less time nurturing children and more time in jobs outside the home.

To test these hypotheses, a series of research teams have repeatedly analyzed personality tests taken by men and women in more than 60 countries around the world. For evolutionary psychologists, the bad news is that the size of the gender gap in personality varies among cultures. For social-role psychologists, the bad news is that the variation is going in the wrong direction. It looks as if personality differences between men and women are smaller in traditional cultures like India’s or Zimbabwe’s than in the Netherlands or the United States. A husband and a stay-at-home wife in a patriarchal Botswanan clan seem to be more alike than a working couple in Denmark or France. The more Venus and Mars have equal rights and similar jobs, the more their personalities seem to diverge.

...new data from 40,000 men and women on six continents...suggests that as wealthy modern societies level external barriers between women and men, some ancient internal differences are being revived...biggest changes recorded by the researchers involve the personalities of men, not women. Men in traditional agricultural societies and poorer countries seem more cautious and anxious, less assertive and less competitive than men in the most progressive and rich countries of Europe and North America.

“Humanity’s jaunt into monotheism, agriculturally based economies and the monopolization of power and resources by a few men was ‘unnatural’ in many ways,” Dr. Schmitt says, alluding to evidence that hunter-gatherers were relatively egalitarian. “In some ways modern progressive cultures are returning us psychologically to our hunter-gatherer roots,” he argues. “That means high sociopolitical gender equality over all, but with men and women expressing predisposed interests in different domains. Removing the stresses of traditional agricultural societies could allow men’s, and to a lesser extent women’s, more ‘natural’ personality traits to emerge.”

Monday, September 22, 2008

Cherokee story for a Monday morning...

While I was doing some idle web cruising using StumbleUpon this item came up, which I thought was a good way to frame one basic cognitive therapy technique:
One evening an old Cherokee told his grandson about a battle that goes on inside people.

He said, "My son, the battle is between two wolves inside us all.

One is Evil. It is anger, envy, jealousy, sorrow, regret, greed, arrogance, self-pity, guilt, resentment, inferiority, lies, false pride, superiority, and ego.

The other is Good. It is joy, peace, love, hope, serenity, humility, kindness, benevolence, empathy, generosity, truth, compassion and faith."

The grandson thought about it for a minute and then asked his grandfather: "Which wolf wins?"

The old Cherokee simply replied, "The one you feed."

Neural correlates of Zen meditation

The complete title of the article by Pagoni et al. is “Thinking about Not-Thinking”: Neural Correlates of Conceptual Processing during Zen Meditation. Here is their abstract:
Recent neuroimaging studies have identified a set of brain regions that are metabolically active during wakeful rest and consistently deactivate in a variety the performance of demanding tasks. This “default network” has been functionally linked to the stream of thoughts occurring automatically in the absence of goal-directed activity and which constitutes an aspect of mental behavior specifically addressed by many meditative practices. Zen meditation, in particular, is traditionally associated with a mental state of full awareness but reduced conceptual content, to be attained via a disciplined regulation of attention and bodily posture. Using fMRI and a simplified meditative condition interspersed with a lexical decision task, we investigated the neural correlates of conceptual processing during meditation in regular Zen practitioners and matched control subjects. While behavioral performance did not differ between groups, Zen practitioners displayed a reduced duration of the neural response linked to conceptual processing in regions of the default network, suggesting that meditative training may foster the ability to control the automatic cascade of semantic associations triggered by a stimulus and, by extension, to voluntarily regulate the flow of spontaneous mentation.

Friday, September 19, 2008

Bad mothering, good fathering..

Two interesting pieces of work on the chemistry underlying parental care of children:

Lerch-Haner et al. find in mice that serotonergic function is required for the nurturing and survival of offspring. Mothers with a specific disruption in serotonin neuron development built poor-quality nests and did not keep their offspring huddled together, leaving the litter exposed to the cold. Their litters died within a few days of birth despite adequate nursing. When these mothers' young were fostered by normal mothers immediately after birth, their odds of living rose to normal.

Prudom et al. find in Marmosets (a bi-parental primate) that fathers exposed to isolated scents of their infant displayed a significant drop in serum testosterone levels within 20 min after exposure, enhancing their positive infant care.

YouTube for test tubes...

Something I have been unaware of: A YouTube for scientists called The Journal of Visualized Experiments (JoVE). It is now now being indexed in the popular US National Library of Medicine repositories MEDLINE and PubMed. Many of my experimental successes (more than 15 years ago) were based on extremely subtle manual manipulations of visual receptor cells and their parts. They would have been SO much easier to communicate in this new format.

Thursday, September 18, 2008

Our brains try multiple meanings before a word is finished.

Here are fascinating observations from Revill et al.. Their imaging data provides evidence of activation of relevant perceptual brain regions in response to the semantics (meaning) of a word while lexical competition is in process and before the word is fully recognized:
As a spoken word unfolds over time, it is temporarily consistent with the acoustic forms of multiple words. Previous behavioral research has shown that, in the face of temporary ambiguity about how a word will end, multiple candidate words are briefly activated. Here, we provide neural imaging evidence that lexical candidates only temporarily consistent with the input activate perceptually based semantic representations. An artificial lexicon and novel visual environment were used to target human MT/V5 and an area anterior to it which have been shown to be recruited during the reading of motion words. Participants learned words that referred to novel objects and to motion or color/texture changes that the objects underwent. The lexical items corresponding to the change events were organized into phonologically similar pairs differing only in the final syllable. Upon hearing spoken scene descriptions in a posttraining verification task, participants showed greater activation in the left hemisphere anterior extent of MT/V5 when motion words were heard than when nonmotion words were heard. Importantly, when a nonmotion word was heard, the level of activation in the anterior extent of MT/V5 was modulated by whether there was a phonologically related competitor that was a motion word rather than another nonmotion word. These results provide evidence of activation of a perceptual brain region in response to the semantics of a word while lexical competition is in process and before the word is fully recognized.

Development of sharing in human children.

Unlike chimpanzees, young children develop a particular form of other-regarding behaviour, called inequality aversion, between the ages of three and eight. On average, three- and four- year-olds behave selfishly whereas seven- and eight-year-olds prefer situations that remove inequality - within their group, that is. Here is the abstract from Fehr et al, who carried out studies with 229 Swiss boys and girls between 3 and 8 years of age to note changes in other-regarding behavior with age:
Human social interaction is strongly shaped by other-regarding preferences, that is, a concern for the welfare of others. These preferences are important for a unique aspect of human sociality—large scale cooperation with genetic strangers—but little is known about their developmental roots. Here we show that young children's other-regarding preferences assume a particular form, inequality aversion that develops strongly between the ages of 3 and 8. At age 3–4, the overwhelming majority of children behave selfishly, whereas most children at age 7–8 prefer resource allocations that remove advantageous or disadvantageous inequality. Moreover, inequality aversion is strongly shaped by parochialism, a preference for favoring the members of one's own social group. These results indicate that human egalitarianism and parochialism have deep developmental roots, and the simultaneous emergence of altruistic sharing and parochialism during childhood is intriguing in view of recent evolutionary theories which predict that the same evolutionary process jointly drives both human altruism and parochialism.

Wednesday, September 17, 2008

Symmetrical bodies are the sexiest...an underlying reason

Why do we find someone attractive? The observations of Brown et al. support the idea that we find symmetrical human bodies most attractive, and that this signals underlying genotypic or phenotypic quality. (Across many species and taxa, higher body assymetry is associated with increased morbidity and mortality, decreased fecundity, and other variables linked to natural and sexual selection.) Here is their abstract:
Body size and shape seem to have been sexually selected in a variety of species, including humans, but little is known about what attractive bodies signal about underlying genotypic or phenotypic quality. A widely used indicator of phenotypic quality in evolutionary analyses is degree of symmetry (i.e., fluctuating asymmetry, FA) because it is a marker of developmental stability, which is defined as an organism's ability to develop toward an adaptive end-point despite perturbations during its ontogeny. Here we sought to establish whether attractive bodies signal low FA to observers, and, if so, which aspects of attractive bodies are most predictive of lower FA. We used a 3D optical body scanner to measure FA and to isolate size and shape characteristics in a sample of 77 individuals (40 males and 37 females). From the 3D body scan data, 360° videos were created that separated body shape from other aspects of visual appearance (e.g., skin color and facial features). These videos then were presented to 87 evaluators for attractiveness ratings. We found strong negative correlations between FA and bodily attractiveness in both sexes. Further, sex-typical body size and shape characteristics were rated as attractive and correlated negatively with FA. Finally, geometric morphometric analysis of joint configurations revealed that sex-typical joint configurations were associated with both perceived attractiveness and lower FA for male but not for female bodies. In sum, body size and shape seem to show evidence of sexual selection and indicate important information about the phenotypic quality of individuals.

Stress during pregnancy hard on males

Mueller and Bale offer more information on what stress in female mice during pregnancy can do, particularly to male offspring:
Prenatal stress is associated with an increased vulnerability to neurodevelopmental disorders, including autism and schizophrenia. To determine the critical time window when fetal antecedents may induce a disease predisposition, we examined behavioral responses in offspring exposed to stress during early, mid, and late gestation. We found that male offspring exposed to stress early in gestation displayed maladaptive behavioral stress responsivity, anhedonia, and an increased sensitivity to selective serotonin reuptake inhibitor treatment. Long-term alterations in central corticotropin-releasing factor (CRF) and glucocorticoid receptor (GR) expression, as well as increased hypothalamic–pituitary–adrenal (HPA) axis responsivity, were present in these mice and likely contributed to an elevated stress sensitivity. Changes in CRF and GR gene methylation correlated with altered gene expression, providing important evidence of epigenetic programming during early prenatal stress. In addition, we found the core mechanism underlying male vulnerability may involve sex-specific placenta responsivity... in male placentas but not females. Examination of placental epigenetic machinery revealed basal sex differences, providing further evidence that sex-specific programming begins very early in pregnancy, and may contribute to the timing and vulnerability of the developing fetus to maternal perturbations. Overall, these results indicate that stress experience early in pregnancy may contribute to male neurodevelopmental disorders through impacts on placental function and fetal development.

Tuesday, September 16, 2008

More on digitial intimacy - MindBlog followers and demographics

No sooner have I done yesterday's posting on the 'ambient intimacy' generated by services like Facebook and Twitter than I find on logging in to my Blogger.com dashboard (menu) page a new icon indicating a feature I have been unaware of, 'followers' of the blog. I added the 'gadget' to the left column of this blog (I'll try anything once), and on reading a bit further discover that it appears to deal only with followers who have blogger accounts. They can choose to have the fact that they are following the blog be either private or have their name listed in the box.

I try not to pay attention to the myriad ways one can monitor a blog's traffic, but when the Scientific American people asked me to join their 'Partner's Network' (see the icon in the left column) they asked me to sign on to the quantcast.com analysis site. If you go to quantcast.com and simply enter mindblog.dericbownds.net in the box, you immediately get a detailed demongraphic analysis of this blog's readers: sex, age, income, and how many addicts, regulars, and passers-by there are.

Our aging brains - impaired suppression of distracting information

This work from Gazzaley et al. strikes WAY to close to home for me, as a description of my own aging (66 year old) brain, and why I get frustrated with the n-back memory exercise. Their abstract:
In this study, electroencephalography (EEG) was used to examine the relationship between two leading hypotheses of cognitive aging, the inhibitory deficit and the processing speed hypothesis. We show that older adults exhibit a selective deficit in suppressing task-irrelevant information during visual working memory encoding, but only in the early stages of visual processing. Thus, the employment of suppressive mechanisms are not abolished with aging but rather delayed in time, revealing a decline in processing speed that is selective for the inhibition of irrelevant information. EEG spectral analysis of signals from frontal regions suggests that this results from excessive attention to distracting information early in the time course of viewing irrelevant stimuli. Subdividing the older population based on working memory performance revealed that impaired suppression of distracting information early in the visual processing stream is associated with poorer memory of task-relevant information. Thus, these data reconcile two cognitive aging hypotheses by revealing that an interaction of deficits in inhibition and processing speed contributes to age-related cognitive impairment.

Monday, September 15, 2008

Digital Intimacy

Several years ago I set up a facebook account, looked up the pages of the students who were taking my seminar course, and at the end of the term told them about my experiment. They were mortified to find the professor had seen their self revelations about their sexual and boozing habits - as anyone on the web could have done. Now my daughter and her friends are broadcasting their latest moods and movements via the FaceBook feed, twitter, etc. This sort of freaks me out, the last thing I want is to surrender the last vestiges of my privacy to the greater web community. But, as Clive Thompson points out in his New York Times Magazine article, this new kind of ambient intimacy makes possible a kind of awareness of others not possible before .
Social scientists have a name for this sort of incessant online contact. They call it “ambient awareness.” It is, they say, very much like being physically near someone and picking up on his mood through the little things he does — body language, sighs, stray comments — out of the corner of your eye. Facebook is no longer alone in offering this sort of interaction online. In the last year, there has been a boom in tools for “microblogging”: posting frequent tiny updates on what you’re doing. ... One of the most popular new tools is Twitter, a Web site and messaging service that allows its two-million-plus users to broadcast to their friends haiku-length updates — limited to 140 characters, as brief as a mobile-phone text message — on what they’re doing. There are other services for reporting where you’re traveling (Dopplr) or for quickly tossing online a stream of the pictures, videos or Web sites you’re looking at (Tumblr). And there are even tools that give your location. When the new iPhone, with built-in tracking, was introduced in July, one million people began using Loopt, a piece of software that automatically tells all your friends exactly where you are.

This is the paradox of ambient awareness. Each little update — each individual bit of social information — is insignificant on its own, even supremely mundane. But taken together, over time, the little snippets coalesce into a surprisingly sophisticated portrait of your friends’ and family members’ lives, like thousands of dots making a pointillist painting. This was never before possible, because in the real world, no friend would bother to call you up and detail the sandwiches she was eating. The ambient information becomes like “a type of E.S.P.,” as Haley described it to me, an invisible dimension floating over everyday life.

You could also regard the growing popularity of online awareness as a reaction to social isolation, the modern American disconnectedness that Robert Putnam explored in his book “Bowling Alone.” The mobile workforce requires people to travel more frequently for work, leaving friends and family behind, and members of the growing army of the self-employed often spend their days in solitude. Ambient intimacy becomes a way to “feel less alone,” as more than one Facebook and Twitter user told me.

What will happen in the next ten years?

Nature magazine asked this question of ten prominent researchers and business people. A common theme emerges: the integration of the worlds of matter and information, whether it be by the blurring of boundaries between online and real environments, touchy-feely feedback from a phone or chromosomes tucked away on databases.

Friday, September 12, 2008

Brooks on how the Republicans just don't get it....

I thought I would pass on this link to David Brook's op-ed piece in today's New York Times, on how Republican party dogma is completely clueless on basic facts about our social brains that have been clearly proven by psychologists, social scientists, cognitive neuroscientists, etc.

Watching practice change the brain cortex.

Our brain cortex is changed by different kinds of learning. These include factual knowledge that is recalled by a purposeful effort and requires the involvement of the explicit memory system (This system is involved in tasks such as spatial navigation and intensive studying). Changes also result from training implicit memory, which refers to intrinsic knowledge about how to perform an action and includes language learning, juggling, mirror reading, and musical training. Duerden and Laverdure-Dupont do a meta-analysis of six morphometric studies that have demonstrated both short- and long-term use-dependent changes caused by these different types of learning. Although structural changes are commonly found in brain regions known to be functionally involved in the particular skill under study, a meta-analytic review of these studies revealed that additional changes often occurred in associative regions including parietal and temporal cortices. studies examining explicit learning showed an overlap of increased gray matter density in the hippocampal gyrus.


Figure - Meta-analysis of voxel-based morphometric studies reporting increased gray matter density after learning in the cortex and cerebellum.