Resting brain default mode activity under genetic control

From Glahn et al:

The default-mode network, a coherent resting-state brain network, is thought to characterize basal neural activity. Aberrant default-mode connectivity has been reported in a host of neurological and psychiatric illnesses and in persons at genetic risk for such illnesses. Whereas the neurophysiologic mechanisms that regulate default-mode connectivity are unclear, there is growing evidence that genetic factors play a role. In this report, we estimate the importance of genetic effects on the default-mode network by examining covariation patterns in functional connectivity among 333 individuals from 29 randomly selected extended pedigrees. Heritability for default-mode functional connectivity was 0.424 ± 0.17 (P = 0.0046). Although neuroanatomic variation in this network was also heritable, the genetic factors that influence default-mode functional connectivity and gray-matter density seem to be distinct, suggesting that unique genes influence the structure and function of the network. In contrast, significant genetic correlations between regions within the network provide evidence that the same genetic factors contribute to variation in functional connectivity throughout the default mode. Specifically, the left parahippocampal region was genetically correlated with all other network regions. In addition, the posterior cingulate/precuneus region, medial prefrontal cortex, and right cerebellum seem to form a subnetwork. Default-mode functional connectivity is influenced by genetic factors that cannot be attributed to anatomic variation or a single region within the network. By establishing the heritability of default-mode functional connectivity, this experiment provides the obligatory evidence required before these measures can be considered as endophenotypes for psychiatric or neurological illnesses or to identify genes influencing intrinsic brain function.

Fig. 1 (A) Group-ICA map of the default-mode network derived from resting state scans of 333 individuals from large extended pedigrees. (B) Significant genetic correlations for functional connectivity between heritable regions in the default-mode network. The left parahippocampal gyrus (green) was genetically correlated with the posterior cingulate/precuneus (yellow), medial prefrontal (blue), right cerebellar (red), and right temporal-parietal (pink) regions. In addition, the posterior cingulate/precuneus, medial prefrontal, and right cerebellar regions form a circuit influenced by the same genetic factors. (C) Significant environmental correlations between these same regions.

The pattern of significant environmental correlations differed dramatically from those of the genetic correlations (Fig. 1C). Environmental correlations typically result from unmeasured aspects of the environment or correlated measurement errors. The right temporal–parietal region was significantly correlated with the posterior cingulate/precuneus and medial prefrontal cortex. Neither of these regions showed significant genetic correlations. In addition, the right cerebellum and medial prefrontal cortex had a significant environmental correlation.

Distinguish Democrats and Republicans from their faces.

Here is a quirky item... it turns out that we can guess the political affiliation of someone, more accurately than by chance, by looking at their photograph. Faces perceived to be more powerful are more likely to be perceived as Republicans. Faces perceived as warmer are more likely to also be perceived as Democrats!

The secret life of chaos.

The BBC has produced a beautiful program on Chaos theory. The mathematics of chaos can explain how and why the universe creates exquisite order and pattern, transforming simplicity into complexity. A YouTube version can be viewed here, the BBC web version plays only in the UK. The clip below is the first installment in the six part series.

Thinking of God moves attention

Here is an interesting tidbit:

The concepts of God and Devil are well known across many cultures and religions, and often involve spatial metaphors, but it is not well known if our mental representations of these concepts affect visual cognition. To examine if exposure to divine concepts produces shifts of attention, participants completed a target detection task in which they were first presented with God- and Devil-related words. We found faster RTs when targets appeared at compatible locations with the concepts of God (up/right locations) or Devil (down/left locations), and also found that these results do not vary by participants’ religiosity. These results indicate that metaphors associated with the divine have strong spatial components that can produce shifts of attention, and add to the growing evidence for an extremely robust connection between internal spatial representations and where attention is allocated in the external environment.

Speech perception requires motor system activation.

Yuen et al. find that specific articulatory commands are activated automatically and involuntarily during speech perception, and suggest, in a broader framework, that perception of action entails activation of the motor system. Their behavioral evidence backs up functional MRI studies that have demonstrated that the brain regions involved in the perception of speech overlap with those involved in the production of speech. They reasoned that if articulatory information is activated in speech perception, then this information should interfere with articulation in a scenario in which participants are asked to produce a target syllable while listening to a different auditory distractor. Their approach was to investigate how an auditory distractor impacts upon the actual articulation of a different target. The thought was that if articulatory information is activated in speech perception, then that information might interfere with speech production by introducing particular distortions of the target syllable that reflect the articulatory properties of the distractor. Here is their abstract:

Emerging neurophysiologic evidence indicates that motor systems are activated during the perception of speech, but whether this activity reflects basic processes underlying speech perception remains a matter of considerable debate. Our contribution to this debate is to report direct behavioral evidence that specific articulatory commands are activated automatically and involuntarily during speech perception. We used electropalatography to measure whether motor information activated from spoken distractors would yield specific distortions on the articulation of printed target syllables. Participants produced target syllables beginning with /k/ or /s/ while listening to the same syllables or to incongruent rhyming syllables beginning with /t/. Tongue–palate contact for target productions was measured during the articulatory closure of /k/ and during the frication of /s/. Results revealed “traces” of the incongruent distractors on target productions, with the incongruent /t/-initial distractors inducing greater alveolar contact in the articulation of /k/ and /s/ than the congruent distractors. Two further experiments established that (i) the nature of this interference effect is dependent specifically on the articulatory properties of the spoken distractors; and (ii) this interference effect is unique to spoken distractors and does not arise when distractors are presented in printed form. Results are discussed in terms of a broader emerging framework concerning the relationship between perception and action, whereby the perception of action entails activation of the motor system.

Rats can learn a cooperation game.

Yet another supposed barrier between human and animal smarts has fallen,  the assumption that only humans have the cognitive capabilities to play the famous 'Prisoner's Dilemma' game, i.e. to engage in reciprocity, which requires numerical discrimination, memory, and control of temporal discounting. Viana et al.:

We use an iterated PD game to test rats (Rattus norvegicus) for the presence of such cognitive abilities by manipulating the strategy of the opponent, Tit-for-Tat and Pseudo-Random, or the relative size of the temptation to defect. We found that rats shape their behaviour according to the opponent's strategy and the relative outcome resulting from cooperative or defective moves. Finally, we show that the behaviour of rats is contingent upon their motivational state (hungry versus sated).

Watching our brain decide when it has enough information

Once we think we have sufficient data for a decision, our brains constrain the accumulation of addition information. de Lange et al. actually view this process using magnetoencephalography (MEG, which records the weak magnetic signals generated by brain activity):

In the last decade, great progress has been made in characterizing the accumulation of neural information during simple unitary perceptual decisions. However, much less is known about how sequentially presented evidence is integrated over time for successful decision making. The aim of this study was to study the mechanisms of sequential decision making in humans. In a magnetoencephalography (MEG) study, we presented healthy volunteers with sequences of centrally presented arrows. Sequence length varied between one and five arrows, and the accumulated directions of the arrows informed the subject about which hand to use for a button press at the end of the sequence (e.g., LRLRR should result in a right-hand press). Mathematical modeling suggested that nonlinear accumulation was the rational strategy for performing this task in the presence of no or little noise, whereas quasilinear accumulation was optimal in the presence of substantial noise. MEG recordings showed a correlate of evidence integration over parietal and central cortex that was inversely related to the amount of accumulated evidence (i.e., when more evidence was accumulated, neural activity for new stimuli was attenuated). This modulation of activity likely reflects a top–down influence on sensory processing, effectively constraining the influence of sensory information on the decision variable over time. The results indicate that, when making decisions on the basis of sequential information, the human nervous system integrates evidence in a nonlinear manner, using the amount of previously accumulated information to constrain the accumulation of additional evidence.

One thing that doesn't deteriorate as we age!

Kadota and Gomi find that our speed of detecting visual stimuli in our peripheral visual field during reaching movements shows little decay with aging, in contrast to other visual functions.

It is well established that humans can react more quickly to a visual stimulus in the visual field center than to one in the visual periphery and that the reaction to a stimulus in the visual periphery markedly deteriorates with aging. These tendencies are true in conventional discrimination-reaction tasks. Surprisingly, however, we found that they are entirely different when reactions are induced by the same visual stimuli during reaching movements. The reaction time for a stimulus in the visual periphery was significantly faster than in the central vision, and age-related slowing of reactions to the stimulus in the visual periphery were quite small, compared to that observed in the conventional reaction tasks. This inconsistent slowing of reactions in different motor conditions underscores a distinctive visuomotor pathway for online control, which is more robust against age-related deterioration.

Why I am a snowbird...

Scenes from the yard in my Wisconsin home. Beautiful, but chilly. 

A thought to speech machine.

When I was a post-doctoral fellow in the Neurobiology Dept. at Harvard Medical School in 1967-68, I regularly attended tea time discussions in the Hubel and Wiesel laboratory (These guys got a Nobel Prize a few years later for their work on how the visual cortex works). I recall being astounded by their discussions about experiments with microelectrodes implanted in a monkey brain that were finding that the activity of almost any nerve cell reported by an electrode could be trained to fire on demand by operant conditioning (for example, a cell being trained that a certain pattern of its activity could produce a reward stimulus like fruit juice). This memory came back to me when Mindblog reader Tristan emailed me excited about work (which turns out to have been in my queue of potential post topics) that is a logical extension of those experiments over 40 years ago.

This work by Guenther et al. implanted in the motor cortex a long-term cone electrode that records from neurites that grow onto its recording surface. The subject was a 26 year old male suffering from locked-in syndrome due to a brain stem stroke incurred at age 16, leaving the brain areas responsible for consciousness, cognition, and higher-level aspects of movement control intact while eliminating nearly all voluntary movement. They were able to effect some speech restoration by decoding continuous auditory parameters for a real-time speech synthesizer from neuronal activity during attempted speech reported by implanted motor cortex electrode. The paper has interesting figures and a video. Here is a central summary figure:

Black circles and curved arrows represent neurons and axonal projections, respectively, in the neural circuitry for speech motor output. The volunteer's stroke-induced lesion in the efferent motor pathways (red X) disconnects motor plans represented in the cerebral cortex from the speech motoneurons, thus disabling speech output while sparing somatic, auditory, and visual sensation as well as speech motor planning centers in cerebral cortex. Signals collected from an electrode implanted in the subject's speech motor cortex are amplified and sent wirelessly across the scalp as FM radio signals. The signals are then routed to an electrophysiology recording system for further amplification, analog-to-digital conversion, and spike sorting. The sorted spikes are sent to a Neural Decoder which translates them into commands for a Speech Synthesizer. Audio signals from the synthesizer are fed back to the subject in real time. [Abbreviation: PrCG = precentral gyrus.]

Distinguishing a new evolutionary track?

This interesting article considers society as an evolutionary track distinct from culture and genes, noting that social and cultural units relate to different informational categories (roles versus beliefs); they are learned in different ways (experience versus interpretation), and have different accuracy and consistency requirements (necessary versus unnecessary). The authors consider cultural exaptation in footbinding, marriage form, and religious practices in early 20th-century Taiwan. (Exaptation refers to a trait evolving because it serves one particular function, but subsequently having the unintended consequence of serving another.) Their analysis notes changes in religious and grave-site rituals that were an unintended and unintuitive consequence of legally imposed changes in footbinding in southwestern Taiwan early in the century. This provides a demonstration of how associations across distinct social and cultural inheritance tracks - having different evolutionary dynamics - affect behavior. Here is the abstract:

Social theorists have long recognized that changes in social order have cultural consequences but have not been able to provide an individual-level mechanism of such effects. Explanations of human behavior have only just begun to explore the different evolutionary dynamics of social and cultural inheritance. Here we provide ethnographic evidence of how cultural evolution, at the level of individuals, can be influenced by social evolution. Sociocultural epistasis—association of cultural ideas with the hierarchical structure of social roles—influences cultural change in unexpected ways. We document the existence of cultural exaptation, where a custom's origin was not due to acceptance of the later associated ideas. A cultural exaptation can develop in the absence of a cultural idea favoring it, or even in the presence of a cultural idea against it. Such associations indicate a potentially larger role for social evolutionary dynamics in explaining individual human behavior than previously anticipated.

Internet hive mind - the madness of crowds

John Tierney does an interesting review of computer guru Jaron Lanier's new book "You Are Not a Gadget." which is a manifesto against “hive thinking” and “digital Maoism” - by which he means the glorification of open-source software, free information and collective work at the expense of individual creativity. Lanier (slightly edited):

...blames the Web’s tradition of “drive-by anonymity” for fostering vicious pack behavior on blogs, forums and social networks. He acknowledges the examples of generous collaboration, like Wikipedia, but argues that the mantras of “open culture” and “information wants to be free” have produced a destructive new social contract....“The basic idea of this contract,” he writes, “is that authors, journalists, musicians and artists are encouraged to treat the fruits of their intellects and imaginations as fragments to be given without pay to the hive mind. Reciprocity takes the form of self-promotion. Culture is to become precisely nothing but advertising.” ...masses of “digital peasants” are forced to provide free material to a few “lords of the clouds” like Google and YouTube.

Mr. Lanier was once an advocate himself for piracy, arguing that his fellow musicians would make up for the lost revenue in other ways. Sure enough, some musicians have done well selling T-shirts and concert tickets, but it is striking how many of the top-grossing acts began in the predigital era, and how much of today’s music is a mash-up of the old....“It’s as if culture froze just before it became digitally open, and all we can do now is mine the past like salvagers picking over a garbage dump,” Mr. Lanier writes. Or, to use another of his grim metaphors: “Creative people — the new peasants — come to resemble animals converging on shrinking oases of old media in a depleted desert.”...To save those endangered species, Mr. Lanier proposes rethinking the Web’s ideology, revising its software structure and introducing innovations like a universal system of micropayments.

Category errors in politics (the rage of the left) and mind science

Hendrik Hertzberg, in an interesting piece in the Jan. 11 issue of The New Yorker 'Talk of the Town' section, comments on the alienation and disappointment of the liberal left with the health care reform bill in congress.  He cites this as an example of John Ruskin's "Pathetic Fallacy' (Violent feelings producing in us a falseness in all our impressions of external things - as in anthropomorphic treatment of inanimate objects as if they had human feelings, thought, or sensations).  A more recent description would be philosopher Gilbert Ryle's 'Category Error' - ascribing a property to a thing that could not possibly have that property. (We do this with our minds, taking our 'selves' to be 'real,' rather being a illusory model generated by our brain hardware, cf. The I-Illusion). Anyway, from Hertzberg's article:

...It's the false attribution of human feelings, thoughts, or intentions to inanimate objects, or to living entities that cannot possibly have such feelings, thoughts, or intentions...The American government has its human aspects - it is staffed by human beings, mostly - but its atomized, at-odds-with-itself legislative structure (House and Senate, each with its arcane rules, its semi-feudal committee chairs, andits independently elected members, none of whom are accountable or fully responsible for outcomes) make it more like an inanimate object. In our sclerotic lawmaking process, it is not enough that the President, a majority of bothy House of Congress, and a majority of the voters at he last election favor extending health care to all citizens.

The left-wing critics are right about the conspicuous flaws of the pending health-care reform - its lack of even a weak "public option," its too meager subsidies, its windfalls for Big Pharma...etc. But it is nonsense to attribute the less than fully satisfactory result to the alleged perfidy of the President or "the Democrats." The critics' indignation would be better be direction at what an earlier generation malcontents called "the system" - starting, perhaps, with the Senate's filibuster rule, an inanimate object if there ever was one.

Hertzberg goes on to point out that the senate defeat of John F. Kennedy's health care reform attempts in 1962 was reversed only after his assassination, and establishing Medicare required both Lyndon Johnson's landslide election and his legendary legislative talents.

The health-care bill now being kicked and prodded and bribed toward passage will not "do the job," either - only part of it. Are Barack Obama and the Demoncrats in Congress doing enough? No. But they are doing what's possible. That may be pathetic, but it's no fallacy.

High-Tech Sex... and gestural interactions with electronics

Would RealTouch have saved Elliot Spitzer or Tiger Woods? I doubt it. An article on the Adult Entertainment Expo that follows the Consumer Electronics Show discusses several new approaches to mechanically providing our titillation. I was particularly struck by the RealTouch site, which has a promotional video, as well as the YouTube clip below. I wonder if their library of on demand movies that synch with the device includes any gay porn? Again, I doubt it......By the way, some fascinating new technology for interacting with television and computers using body gestures was noted at the Consumer Electronic Show).

Attention alters appearance

An interesting article by Störmer et al. addresses the neural basis of our phenomenological experience, probing a central question in perception: Does attention alter our subjective experience of the world? The authors found that attention increases the perceived contrast of visual stimuli (sine wave gratings) by boosting early sensory processing in the visual cortex. Here are some slightly edited clips from a review by Carrasco in the same journal:

Voluntary attention refers to the sustained, endogenous directing of attention to a location in the visual field. Involuntary attention is the transient, exogenous capture of attention to a location, brought about by a sudden change in the environment. (Visual attention can be covertly deployed, without eye movements. We use covert attention routinely in everyday situations, when we search for objects, drive a car, cross the street, play sports, or dance, as well as in social situations—for example, when moving the eyes would provide a cue to intentions that we wish to conceal.)... Störmer et al. modified an existing experimental paradigm in two insightful and exciting ways to investigate the effect of attention on appearance with concurrent electrophysiological and behavioral measures. First, to eliminate any possibility of intramodal sensory interactions between the cue and the stimulus, they used a lateralized auditory cue rather than a visual cue. This modification enabled the authors to study the effects of cross-modal attention on appearance. Second, they recorded evoked electrical fields on the scalp—event-related potentials (ERPs)—from visual cortex in response to the cued target as observers judged the relative contrast of visual stimuli presented to the right and left visual fields. ERPs are electrophysiological responses that arise during sensory, cognitive, and motor processing, which provide precise information about the time course of information processing. In this study, they help pinpoint the level of processing at which attention exerts its effect on judgments of contrast appearance. Short-latency evoked responses, P1 (90–150 ms) and N1 (180–240 ms), reflect early sensory processes that can be modulated by selective attention; longer-latency components (250–500 ms) arise from multiple cortical generators and reflect postperceptual processing, including decision-making, working memory encoding, and response selection.

Here is the abstract from the article:

The question of whether attention makes sensory impressions appear more intense has been a matter of debate for over a century. Recent psychophysical studies have reported that attention increases apparent contrast of visual stimuli, but the issue continues to be debated. We obtained converging neurophysiological evidence from human observers as they judged the relative contrast of visual stimuli presented to the left and right visual fields following a lateralized auditory cue. Cross-modal cueing of attention boosted the apparent contrast of the visual target in association with an enlarged neural response in the contralateral visual cortex that began within 100 ms after target onset. The magnitude of the enhanced neural response was positively correlated with perceptual reports of the cued target being higher in contrast. The results suggest that attention increases the perceived contrast of visual stimuli by boosting early sensory processing in the visual cortex.

The Messiah Complex

Yes,  of course I went to see Avatar in 3-D IMAX.  Loved it. (The picture shows Deric using a chemical depressant to recover from the sensory overload, at a dinner with friends afterwards.) I thought David Brook's column on the movie was a treat,  and have to agree with his critical points:

...would it be totally annoying to point out that the whole White Messiah fable, especially as Cameron applies it, is kind of offensive?...It rests on the stereotype that white people are rationalist and technocratic while colonial victims are spiritual and athletic. It rests on the assumption that nonwhites need the White Messiah to lead their crusades. It rests on the assumption that illiteracy is the path to grace. It also creates a sort of two-edged cultural imperialism. Natives can either have their history shaped by cruel imperialists or benevolent ones, but either way, they are going to be supporting actors in our journey to self-admiration...It’s just escapism, obviously, but benevolent romanticism can be just as condescending as the malevolent kind — even when you surround it with pop-up ferns and floating mountains.

Breaking the addiction to connectivity and networking.

This post is a personal note.......As the holidays have drawn to a close and I am overloaded and  behind on almost everything,  I realize yet again that I spend an inordinate amount of time 'just checking' a continuous incoming flux of emails, listserves, google alerts, tweets, SMS messages.  This time spent thinking in multiple small (Twitter is 140 character) chunks is time subtracted from thinking in more depth (or at least in paragraph size chunks!).  The post I did recently on this issue obviously hasn't influenced my behavior.  So, one of my new year's resolutions has been to cancel subscriptions to virtually everything, and check email only twice a day. Removing my google alerts and hitting the 'unsubscribe' link on many incoming emails has reduced my email volume by half. Ignoring Facebook, YouTube, LinkedIn and all their 'friend' requests has made life a bit more manageable (I regret being 'unfriendly,' but it can't be helped). I'm finding that the connectivity of email exchanges related to mindblog.dericbownds.net is almost more than I can handle.  I  haven't really gotten into either Facebook or LinkedIn (interesting experiments, but no thank you), so I've decided to condense down to spending time only on this blog and an occasional 'tweet' as my venues for reaching out to others. Anyone who wishes to chat with me can easily find my email address, and the email exchanges I have had with  mindblog readers have been engaging and worthwhile.   It begins to feel like a shroud is slowly lifting.....    is it possible that I am beginning to smash my mind's  "Twittering Machine"?  (The figure is the classic Paul Klee painting of that title).

Distinguishing conscious from unconscious brain activity.

Schurger et al. nudge a bit further towards finding one holy grail of neuroscience - identifying the neuronal correlates of conscious awareness.

What qualifies a neural representation for a role in subjective experience? Previous evidence suggests that the duration and intensity of the neural response to a sensory stimulus are factors. We introduce another attribute—the reproducibility of a pattern of neural activity across different episodes—that predicts specific and measurable differences between conscious and nonconscious neural representations indepedently of duration and intensity. We found that conscious neural activation patterns are relatively reproducible when compared with nonconscious neural activation patterns corresponding to the same perceptual content. This is not adequately explained by a difference in signal-to-noise ratio.

Clips from their account:

Functional magnetic resonance imaging (fMRI)was used to measure brain activity while subjects performed a simple visual category-discrimination task. The stimuli were simple line drawings of faces and houses (12 of each), rendered in two opposing but isoluminant colors (see the figure and legend). Visibility of the stimuli was manipulated by using dichoptic color masking. Subjects were asked to identify the category of the stimulus (face or house) on each trial, guessing if necessary, and to wager ("high" or "low" for monetary rewards) on the accuracy of each of their perceptual decisions. Wagering was used as a collateral index of subjects’ awareness of the object.

Dichoptic-color masking. This method of manipulating awareness... relies on the phenomenon of dichoptic color fusion. The "same color" mode corresponds to the visible condition, and the "opposite color" mode corresponds to the invisible condition. In order to achieve disappearance of the image in the opposite color mode, the two colors must be approximately isoluminant and the object boundaries slightly blurred. Before the experiment, subjects were trained to maintain steady fixation and were cued to do so during each trial with the appearance of the fixation point (500 ms before stimulus onset). Stimuli were presented stereoscopically in the fMRI scanner by using a cardboard divider and prism lenses

Brain correlates of strategic and experiential emotional intelligence.

From Krueger et al. evidence that two central components of emotional intelligence are most strongly associated with different regions of the prefrontal cortex:

Emotional intelligence (EI) refers to a set of competencies that are essential features of human social life. Although the neural substrates of EI are virtually unknown, it is well established that the prefrontal cortex (PFC) plays a crucial role in human social-emotional behavior. We studied a unique sample of combat veterans from the Vietnam Head Injury Study, which is a prospective, long-term follow-up study of veterans with focal penetrating head injuries. We administered the Mayer-Salovey-Caruso Emotional Intelligence Test as a valid standardized psychometric measure of EI behavior to examine two key competencies of EI: (i) Strategic EI as the competency to understand emotional information and to apply it for the management of the self and of others and (ii) Experiential EI as the competency to perceive emotional information and to apply it for the integration into thinking. The results revealed that key competencies underlying EI depend on distinct neural PFC substrates. First, ventromedial PFC damage diminishes Strategic EI, and therefore, hinders the understanding and managing of emotional information. Second, dorsolateral PFC damage diminishes Experiential EI, and therefore, hinders the perception and integration of emotional information. In conclusion, EI should be viewed as complementary to cognitive intelligence and, when considered together, provide a more complete understanding of human intelligence.

Where did the time go?

Benedict Carey offers a nice piece on our sense of time. The article relates a number of interesting experiments on the variety of ways in which our brains expand or contact our sense of time:

...emotional events — a breakup, a promotion, a transformative trip abroad — tend to be perceived as more recent than they actually are, by months or even years...the findings support the philosopher Martin Heidegger’s observation that time “persists merely as a consequence of the events taking place in it.”...the reverse may also be true: if very few events come to mind, then the perception of time does not persist; the brain telescopes the interval that has passed.

Have fun.....NOW!

I've been meaning to pass on this nice article by John Tierney.  Postponed pleasures are much less likely to happen at all....

Anhedonia - frontal lobe correlates

An interesting open access article from Heller et al. that suggest that diminished pleasure from previously rewarding contexts is due to inability to sustain positive affect, not to a reduction in ability to experience pleasure:

Anhedonia, the loss of pleasure or interest in previously rewarding stimuli, is a core feature of major depression. While theorists have argued that anhedonia reflects a reduced capacity to experience pleasure, evidence is mixed as to whether anhedonia is caused by a reduction in hedonic capacity. An alternative explanation is that anhedonia is due to the inability to sustain positive affect across time. Using positive images, we used an emotion regulation task to test whether individuals with depression are unable to sustain activation in neural circuits underlying positive affect and reward. While up-regulating positive affect, depressed individuals failed to sustain nucleus accumbens activity over time compared with controls. This decreased capacity was related to individual differences in self-reported positive affect. Connectivity analyses further implicated the fronto-striatal network in anhedonia. These findings support the hypothesis that anhedonia in depressed patients reflects the inability to sustain engagement of structures involved in positive affect and reward.

We are what our ancestors did or didn't eat.

Ann Gibbons does a nice summary of our human ancestral diet and how it has changed to give us a modern array of diseases. Some slightly edited clips:

By the time hunter-gatherer modern humans swept into Europe about 40,000 years ago, they were adept at hunting large game and had also expanded their palates to dine regularly on small animals and freshwater fish....By studying the ratios of carbon and nitrogen isotopes from collagen in bones, ...the main sources of dietary protein of 27 early Europeans and Neandertals is known; fish eaters, for example, have more nitrogen-15 in their bones than meat eaters...the oldest known modern human in Europe—the 35,000-year-old jawbone from Pestera cu Oase cave in Romania—got much of his protein from fish. By 30,000 years ago, other modern humans got as much as 20% of their protein from fish.

The next big dietary shift came about 10,000 years ago, when humans began to domesticate plants and, later, animals. The move to agriculture introduced staples of the Western diet: cereal grains, sugars, and milk after weaning...The agricultural revolution favored people lucky enough to have gene variants that helped them digest milk, alcohol, and starch...when ethnic groups abandon traditional lifestyles and rapidly adopt Western diets, they often suffer. Researchers have known for more than a decade that the Pima of the southwestern United States have "thrifty phenotypes": sluggish metabolisms that store fat efficiently and boost survival on low-calorie diets. That's probably because their ancestors in Mexico underwent frequent famine. When they eat the calorie-rich Western diet, the Pima develop high rates of obesity, diabetes, and high cholesterol, although their blood pressure stays relatively low...the Evenki reindeer herders and other indigenous peoples of Siberia have very high metabolisms, an adaptation to the cold that allows them to convert fat into energy efficiently. When the Soviet Union collapsed in the 1990s, many Siberians abandoned traditional lifestyles and diets. They too became obese and developed heart disease but in a different way from the Pima: The Evenki retained low levels of cholesterol and diabetes but developed high blood pressure.

Although we are what our ancestors ate, we are also what they didn't eat. In India, for example, more than 66% of the population in some regions experienced famine during British colonialism a century ago. Women who survived tended to have low-birth-weight babies, whose bodies were small and efficient at storing fat. It's as though these babies took cues during fetal and early development about their mothers' lifelong nutritional experience and adjusted their growth and body and organ size accordingly. Human stature often tracks the nutritional status of mothers, and it can take generations for descendants to recover. In India, average height in males dropped at a rate of almost 2 centimeters per century in the decades following colonialism...When these small babies gain weight in childhood, though, it stresses their smaller organs, such as the pancreas and heart, making them more susceptible to obesity, diabetes, and heart disease. This is the case in south India today, where many people have thrifty phenotypes with less muscle and more fat per body size. Yet they are shifting rapidly to a high-fat, high-sugar diet. As a result, India risks becoming the diabetes capital of the world.

Similarity breeds connection

Aral et al. examine the huge dataset available on the spread (contagion) of a new mobile service product (Yahoo! Go) among 27.5 million users of Yahoo.com. The dataset comprehensively captures the diffusion of this mobile service product over a social network for 5 months after its launch date. They note that a key challenge in identifying true contagions in such data is to distinguish peer-to-peer influence, in which a node influences or causes outcomes in its neighbors, from homophily, in which dyadic similarities between nodes create correlated outcome patterns among neighbors that merely mimic viral contagions without direct causal influence.   Here is their abstract:

Node characteristics and behaviors are often correlated with the structure of social networks over time. While evidence of this type of assortative mixing and temporal clustering of behaviors among linked nodes is used to support claims of peer influence and social contagion in networks, homophily may also explain such evidence. Here we develop a dynamic matched sample estimation framework to distinguish influence and homophily effects in dynamic networks, and we apply this framework to a global instant messaging network of 27.4 million users, using data on the day-by-day adoption of a mobile service application and users' longitudinal behavioral, demographic, and geographic data. We find that previous methods overestimate peer influence in product adoption decisions in this network by 300–700%, and that homophily explains >50% of the perceived behavioral contagion. These findings and methods are essential to both our understanding of the mechanisms that drive contagions in networks and our knowledge of how to propagate or combat them in domains as diverse as epidemiology, marketing, development economics, and public health.

God's beliefs as what we want them to be.

Epley et al., in an open access article, find that what we believe about God's views is more egocentric than what we believe about the views of other humans:

People often reason egocentrically about others' beliefs, using their own beliefs as an inductive guide. Correlational, experimental, and neuroimaging evidence suggests that people may be even more egocentric when reasoning about a religious agent's beliefs (e.g., God). In both nationally representative and more local samples, people's own beliefs on important social and ethical issues were consistently correlated more strongly with estimates of God's beliefs than with estimates of other people's beliefs (Studies 1–4). Manipulating people's beliefs similarly influenced estimates of God's beliefs but did not as consistently influence estimates of other people's beliefs (Studies 5 and 6). A final neuroimaging study demonstrated a clear convergence in neural activity when reasoning about one's own beliefs and God's beliefs, but clear divergences when reasoning about another person's beliefs (Study 7). In particular, reasoning about God's beliefs activated areas associated with self-referential thinking more so than did reasoning about another person's beliefs. Believers commonly use inferences about God's beliefs as a moral compass, but that compass appears especially dependent on one's own existing beliefs.

The faith instinct

Schulevitz reviews Nicholas Wade's new book "The Faith Instinct - How it evolved and how it endures."

According to Wade, a New York Times science writer, religions are machines for manufacturing social solidarity. They bind us into groups. Long ago, codes requiring altruistic behavior, and the gods who enforced them, helped human society expand from families to bands of people who were not necessarily related. We didn’t become religious creatures because we became social; we became social creatures because we became religious. Or, to put it in Darwinian terms, being willing to live and die for their coreligionists gave our ancestors an advantage in the struggle for resources.

...Rituals take time; sacrifices take money or its equivalent. Individuals willing to lavish time and money on a particular group signal their commitment to it, and a high level of commitment makes each coreligionist less loath to ignore short-term self-interest and to act for the benefit of the whole. What are gods for? They’re the enforcers. Supernatural beings scare away cheaters and freeloaders and cow everyone into loyal, unselfish, dutiful and, when appropriate, warlike behavior.

...our innate piety has adapted to our changing needs. Hunter-gatherers were egalitarian and, shamans aside, had direct access to the divine. But when humans began to farm and to settle in cities and states, religion became hierarchical. Priests emerged, turning unwritten rules and chummy gods into opaque instruments of surveillance and power. Church bureaucracies created crucial social institutions but also suppressed the more ecstatic aspects of worship, especially music, dance and trance. Wade advances the delightfully explosive thesis that the periodic rise of exuberant mystery cults represent human nature rebelling against the institutionalization of worship: “A propensity to follow the ecstatic behaviors of dance and trance was built into people’s minds and provided consistently fertile ground for revolts against established religion,”

A gentle start to the new year...some Debussy

I offer the mellow romantic energy of this Debussy piece "Valse Romantique" to start the new year. I continue to be amazed at how many people listen to and comment on some of these piano pieces I have posted on YouTube.

Reward regions in the adolescent brain.

Van Leijenhorst et al examine brain activations associated with anticipation, receipt, and omission of reward in several different age groups:

The relation between brain development across adolescence and adolescent risky behavior has attracted increasing interest in recent years. It has been proposed that adolescents are hypersensitive to reward because of an imbalance in the developmental pattern followed by the striatum and prefrontal cortex. To date, it is unclear if adolescents engage in risky behavior because they overestimate potential rewards or respond more to received rewards and whether these effects occur in the absence of decisions. In this study, we used a functional magnetic resonance imaging paradigm that allowed us to dissociate effects of the anticipation, receipt, and omission of reward in 10- to 12-year-old, 14- to 15-year-old, and 18- to 23-year-old participants. We show that in anticipation of uncertain outcomes, the anterior insula is more active in adolescents compared with young adults and that the ventral striatum shows a reward-related peak in middle adolescence, whereas young adults show orbitofrontal cortex activation to omitted reward. These regions show distinct developmental trajectories. This study supports the hypothesis that adolescents are hypersensitive to reward and adds to the current literature in demonstrating that neural activation differs in adolescents even for small rewards in the absence of choice. These findings may have important implications for understanding adolescent risk-taking behavior.

Unconscious strategic recruitment of resources measured with pupil diameter.

Recent research suggests that reward cues, in the absence of awareness, can enhance people's investment of physical resources (for an example, see this previous post). Bijleveld et al. make the interesting observation that pupil dilation can reveal strategic recruitment of resources when subliminal reward cues are presented. They make use of the fact that our pupils dilate with sympathetic activity and constrict with parasympathetic activity so that their size can be an unobtrusive measure of the resources invested in a task. Their rationale:

If subliminal reward cues input into the strategic processes involved in resource recruitment, the effects of rewards on pupil dilation should occur when the task is demanding (here, recall of five digits), but not when the task is undemanding (recall of three digits), as undemanding tasks can be completed routinely and do not require many resources. It is important to note that this interactive effect of reward and demand on recruitment of resources is expected to occur regardless of whether the reward is processed consciously or nonconsciously.

Their results:

Pupil-dilation data indicated that valuable (compared with nonvaluable) rewards led to recruitment of more resources, but only when obtaining the reward required considerable mental effort. This pattern was identical for supraliminal and subliminal reward cues. This indicates that awareness of a reward is not a necessary condition for strategic resource recruitment to take place. These findings are in line with recent research suggesting that the unconscious has flexible and adaptive capabilities (Hassin, Uleman, & Bargh, 2005; Wilson, 2002). More generally, whereas analyses of costs (required effort) and benefits (value of rewards) are usually thought to require consciousness, our findings suggest that such strategic processes can occur outside of awareness—and these processes show in the eyes.

Inhibited behavior and our right frontal cortex.

Another interesting piece of work from Richie Davidson and colleagues at the University of Wisconsin.  Continuing their general catalog of correlations of left versus right frontal lobe activation with outgoing versus protective behaviors they find  that individuals with greater tonic (resting) activity in right-posterior dorsolateral prefrontal cortex rate themselves as more behaviorally inhibited. (The authors point out some limitation of the study: It is done with only female subjects and self reports of inhibition, so this clearly needs to be expanded. Their conclusions rest on a model, not a direct measurement, of the cerebral sources underlying the EEG, and the study did not address the degree to which individual differences in behavioral inhibition reflect altered functional connectivity between right-posterior DLPFC and other structures thought to underlie the behavioral inhibition system - e.g., amygdala, PAG, or ACC). Here is their abstract followed by a graphic from the article:

Individuals show marked variation in their responses to threat. Such individual differences in behavioral inhibition play a profound role in mental and physical well-being. Behavioral inhibition is thought to reflect variation in the sensitivity of a distributed neural system responsible for generating anxiety and organizing defensive responses to threat and punishment. Although progress has been made in identifying the key constituents of this behavioral inhibition system in humans, the involvement of dorsolateral prefrontal cortex (DLPFC) remains unclear. Here, we acquired self-reported Behavioral Inhibition System Sensitivity scores and high-resolution electroencephalography from a large sample (n= 51). Using the enhanced spatial resolution afforded by source modeling techniques, we show that individuals with greater tonic (resting) activity in right-posterior DLPFC rate themselves as more behaviorally inhibited. This observation provides novel support for recent conceptualizations of behavioral inhibition and clues to the mechanisms that might underlie variation in threat-induced negative affect.

Figure - Relations between individual differences in behavioral inhibition and tonic activity in right-posterior dorsolateral prefrontal cortex (DLPFC). The images in (a) depict the results of the electroencephalography source modeling analyses. The cluster lies at the intersection of the precentral and inferior frontal sulci, encompassing the right-posterior midfrontal and inferior-frontal gyri and including the inferior frontal junction (cluster-corrected p= .02). The crosshair shows the location in right-posterior DLPFC of the peak correlation in the sagittal (green outline), coronal (cyan outline), and axial (yellow outline) planes. The magnitude of voxel-wise correlations is depicted using a red-yellow scale; lighter shades of yellow indicate stronger correlations. "L" and "R" indicate the left and right hemispheres, respectively. The scatter plot (b) depicts the peak correlation between scores on the Behavioral Inhibition System (BIS) scale and standardized activity in right-posterior DLPFC (area 9/46v), r(48) =−.37, uncorrected p= .003. Standardized activity is in units of z-transformed cortical current density, log10(A/m2). Lines depict the regression line and 95% confidence envelope.

The power of music

North and Hargreaves introduce a special issue of The Psychologist which looks at musical ability; how and why people let music into their lives, and the impact of musical proficiency. They focus on the power of music to do harm (Rock music and self-injurious behavior), its effects on animal welfare, and its ability to influence pain stress and immunity. Some clips regarding the latter:

The most convincing evidence comes from Standley’s (1995) meta-analysis of 55 studies concerning the effect of music on 129 medically related variables. Podiatric pain, paediatric respiration, pulse, blood pressure and use of analgesia (in dental patients), pain, medication in paediatric surgery patients and EMG all showed effect sizes over 2, and the mean effect size over all 129 variables was .88, meaning that the impact of music was almost one standard deviation greater than without music.

The largest single body of literature concerns the impact of music on chronic pain, pain experienced during and after treatment, and pain experienced specifically by cancer patients and those undergoing palliative care. Research suggests that music can mediate pain in these cases by distracting the patient’s attention from it and/or by increasing their perceived control over the pain (since if patients believe that they have access to music as a means of pain control, then this belief itself decreases the aversiveness of pain). Similar research on stress has yielded the not entirely unsurprising conclusion that it may be reduced by music; but also that the amount of stress reduction varies according to age, the stressor, the listener’s musical preference, and their prior level of musical experience. More interestingly still, this reduction in stress manifests itself through physical measures, such as reduced levels of cortisol, and this has a very provocative further implication. Lower levels of stress are associated with greater immunity to illness of course, and several studies have indicated effects of music listening on physical measures of immune system strength, such as salivary immunoglobulin A. Although the mechanism by which this occurs is not well understood, the implication is clear: music contributes directly to physical health.

Changes in our brain connectivities as a funcion of age and sex

From Gong et al. one of those studies I take personally (i.e. describing my aging male brain):

Neuroanatomical differences attributable to aging and gender have been well documented, and these differences may be associated with differences in behaviors and cognitive performance. However, little is known about the dynamic organization of anatomical connectivity within the cerebral cortex, which may underlie population differences in brain function. In this study, we investigated age and sex effects on the anatomical connectivity patterns of 95 normal subjects ranging in age from 19 to 85 years. Using the connectivity probability derived from diffusion magnetic resonance imaging tractography, we characterized the cerebral cortex as a weighted network of connected regions. This approach captures the underlying organization of anatomical connectivity for each subject at a regional level. Advanced graph theoretical analysis revealed that the resulting cortical networks exhibited "small-world" character (i.e., efficient information transfer both at local and global scale). In particular, the precuneus and posterior cingulate gyrus were consistently observed as centrally connected regions, independent of age and sex. Additional analysis revealed a reduction in overall cortical connectivity with age. There were also changes in the underlying network organization that resulted in decreased local efficiency, and also a shift of regional efficiency from the parietal and occipital to frontal and temporal neocortex in older brains. In addition, women showed greater overall cortical connectivity and the underlying organization of their cortical networks was more efficient, both locally and globally. There were also distributed regional differences in efficiency between sexes. Our results provide new insights into the substrates that underlie behavioral and cognitive differences in aging and sex.

Figure- The spatial distribution of cortical regions showing significant age effect (p less than 0.05, corrected) on the integrated regional efficiency. The color represents t statistic of the age effect that was calculated from the general linear model. Each identified region was marked out. Notably, negative age effect was mainly distributed in the parietal and occipital cortex, whereas the positive age effect was localized only in the frontal and temporal cortex.

Subtle transmission of race bias by televised nonverbal behavior

It is well known that whites who appear nonprejudiced on self-report measures tend to display negative nonverbal behaviors as a function of unconscious, automatically activated racial bias. Weisbuch et al. illustrate how racial prejudice can be covertly spread and reinforced by noting uncover racial bias in actors' nonverbal displays despite the highly scripted nature of prime-time television shows, which generally minimizes expressions of racial bias. They obtain their findings with samples of white college undergraduates, who are more favorable toward outgroups (individuals whom the white students consider outside their group) and more inclined to conceal negative responses toward outgroups than the "average" white American. Here is their abstract:

Compared with more explicit racial slurs and statements, biased facial expressions and body language may resist conscious identification and thus produce a hidden social influence. In four studies, we show that race biases can be subtly transmitted via televised nonverbal behavior. Characters on 11 popular television shows exhibited more negative nonverbal behavior toward black than toward status-matched white characters. Critically, exposure to prowhite (versus problack) nonverbal bias increased viewers’ bias even though patterns of nonverbal behavior could not be consciously reported. These findings suggest that hidden patterns of televised nonverbal behavior influence bias among viewers.

Culture modulate eye movement responses to visual novelty

Goh et al. find a robust cultural bias in visual processing even when external stimuli draw attention in an opposite manner to the cultural bias.:

When viewing complex scenes, East Asians attend more to contexts whereas Westerners attend more to objects, reflecting cultural differences in holistic and analytic visual processing styles respectively. This eye-tracking study investigated more specific mechanisms and the robustness of these cultural biases in visual processing when salient changes in the objects and backgrounds occur in complex pictures.

Chinese Singaporean (East Asian) and Caucasian US (Western) participants passively viewed pictures containing selectively changing objects and background scenes that strongly captured participants' attention in a data-driven manner. We found that although participants from both groups responded to object changes in the pictures, there was still evidence for cultural divergence in eye-movements. The number of object fixations in the US participants was more affected by object change than in the Singapore participants. Additionally, despite the picture manipulations, US participants consistently maintained longer durations for both object and background fixations, with eye-movements that generally remained within the focal objects. In contrast, Singapore participants had shorter fixation durations with eye-movements that alternated more between objects and backgrounds.

Indirect reward and punishment - their payoff

Ule et al. examine indirect reciprocity, which in widespread in human culture - rewarding those we know have been kind to others or punishing those we know have been unkind to others. They devise a game to show that cooperation is enhanced best by a system in which both indirect rewards and indirect punishment can occur. Here is their experimental setup, followed by their abstract:

Our experimental design builds on the so-called "indirect helping game". In total, 140 participants are repeatedly (100 rounds), anonymously, and randomly matched into donor-recipient pairs. Because roles are determined randomly, participants will typically be the donor in approximately half of the rounds. In the indirect helping game, only donors make decisions. In any round, each donor first observes the recipient’s recent behavior in the role of donor and then decides whether to "help" the recipient or to "pass." Helping is costly for the donor and beneficial for the recipient, with the benefits exceeding the costs. In earlier experiments, indirect punishment was not available as an option, a restriction that is arguably not a realistic feature of human interactions. In our experiment, the donor can choose to "hurt" the recipient instead of passing or helping. Hurting is costly for the donor, but we vary its impact on the receiver. We conducted two treatments that differ only in this impact, which allows us to isolate the effect of indirect punishment on the payoff performance of different types of behavior. In our main treatment [harmful punishment (HP)], a hurt recipient loses 250 units of our experimental money, "francs." In the control treatment [symbolic punishment (SP)], a hurt recipient loses or earns no francs. We say that punishment is harmful in HP but only symbolic in SP. In both treatments, the donor loses 50 francs for hurting or 200 francs for helping, and the recipient earns 250 francs when he or she receives help. Passing does not affect either player’s payoff. In both treatments the recipient observes the donor’s action. Treatment SP is a control for HP, because it identifies differences in behavior between environments where indirect punishment has material consequences for the recipient and where it does not, while holding all other parameters constant across treatments.

the final conclusions, from the abstract:

We find that if unkind strangers cannot be punished, defection earns most. If they can be punished, however, then indirect rewarding earns most. Indirect punishment plays this important role, even if it gives a low payoff and is rarely implemented.

Describing our inner experience...

Hoffman writes an article describing the work of Russell T. Hurlburt, who tries to record the mental life of individuals by fitting them with a beeper that randomly prompts them to record whatever is in their awareness several times a day. The resulting mental freeze-frames are remarkably diverse. His research indicates:

...that there are a lot of people who don’t ever naturally form images, and then there are other people who form very florid, high-fidelity, Technicolor, moving images,...Some people have inner lives dominated by speech, body sensations or emotions, and yet others by “unsymbolized thinking” that can take the form of wordless questions.

Their is the point that:

...after-the-fact interviews should be treated with caution: one cannot assume the subjects will be honest, or that they are not twisting their answers to conform with their own biases, or telling the experimenter what they think he wants to hear, or simply filling in details they forgot.

Stephen Kosslyn, a professor of psychology at Harvard notes:

The experience sampling work is a reasonable first step, but only that; the claims need to be followed up and backed up by objective studies.

It may be that turning introspection into a science is as impractical as “trying to turn up the gas quickly enough to see how the darkness looks,” as William James wrote in 1890.

Diminutive digits discern delicate details.

Peters et al. show that tactile perception improves with decreasing finger size, and that this correlation fully explains the better perception of women, who on average have smaller fingers than men.

We have observed that passive tactile spatial acuity, the ability to resolve the spatial structure of surfaces pressed upon the skin, differs subtly but consistently between the sexes, with women able to perceive finer surface detail than men. Eschewing complex central explanations, we hypothesized that this sex difference in somatosensory perception might result from simple physical differences between the fingers of women and men. To investigate, we tested 50 women and 50 men on a tactile grating orientation task and measured the surface area of the participants' index fingertips. In subsets of participants, we additionally measured finger skin compliance and optically imaged the fingerprint microstructure to count sweat pores. We show here that tactile perception improves with decreasing finger size, and that this correlation fully explains the better perception of women, who on average have smaller fingers than men. Indeed, when sex and finger size are both considered in statistical analyses, only finger size predicts tactile acuity. Thus, a man and a woman with fingers of equal size will, on average, enjoy equal tactile acuity. We further show that sweat pores, and presumably the Merkel receptors beneath them, are packed more densely in smaller fingers.

From the Bach Collegium Munchen....

The emotional resonance of this magnificent high church music pierces right through my materialistic rationalist armor. The setting of this performance reminds me of my week in Munich this summer, and visits to several of its Baroque churches.

How our brains keep multiple things in mind.

Siegel et al. have made a fundamental advance in revealing how the brain manages to keep multiple things in mind in our working (short term) memory system. A review by Vogel and Fukada in the same issue of PNAS gives a nice description of the context and nature of the experiments:

...brain oscillations are thought to provide a vehicle for coordinating and sharing information within a given cortical region as well as a means of communicating signals between different brain areas. Oscillations can occur across a number of different frequency bands, ranging from very slow cycles (4–7 Hz, theta band) to very fast cycles (25–100 Hz, gamma band). In the context of working memory, oscillations in the gamma band have been proposed to play a fundamental role in linking up the various attributes of the memoranda (e.g., position, shape, color, etc.) across numerous individual neurons into a unified working memory representation. However, if working memories are all represented in the same gamma oscillation, how do we manage to keep from blurring all of the active memories together? One solution that has been proposed in a number of computational models has been to keep the memories separated by positioning each one in a different phase within the oscillation. That is, individual memories can be kept segregated, so long as they are “out of phase” with one another in the oscillation.

...the study by Siegel et al. appears to provide the first demonstration of such a phase-coding scheme in the brain for working memory. To do this, they recorded the local field potential over the prefrontal cortex while monkeys performed a sequential short-term memory task. In this task, monkeys are shown two pictures, one at a time, that they had to remember. After a short delay, memory was tested by presenting three pictures simultaneously; two of which were the pictures they had seen earlier in the trial, and one was a novel picture. To perform correctly, the monkey responded by initially looking at the first picture in the original sequence, then looking at the second picture, but not the novel picture. This task requires them to actively remember both of the pictures from the sequence and the order of presentation. By examining the gamma oscillation over prefrontal cortex during the blank delay period while these memories were being maintained in mind, Siegel et al. found that the two remembered objects were represented in distinct phase orientations of the oscillation depending on the order of presentation. That is, the first object of the sequence was preferentially coded in one phase orientation, and the second object was always in a separate phase orientation. Thus, they found direct evidence that the brain kept these two active memories separated by keeping them out of phase.

From Siegal et al's abstract:

We recorded neuronal activity from the prefrontal cortices of monkeys remembering two visual objects over a brief interval. We found that during this memory interval prefrontal population activity was rhythmically synchronized at frequencies around 32 and 3 Hz and that spikes carried the most information about the memorized objects at specific phases. Further, according to their order of presentation, optimal encoding of the first presented object was significantly earlier in the 32 Hz cycle than that for the second object. Our results suggest that oscillatory neuronal synchronization mediates a phase-dependent coding of memorized objects in the prefrontal cortex. Encoding at distinct phases may play a role for disambiguating information about multiple objects in short-term memory.

One more light show...

Amazing Grace Techno - Computer Controlled Christmas Lights from Richard Holdman on Vimeo.

The "protocol society"

In a recent Op-Ed piece Brooks makes some points about the new economy:

In the 19th and 20th centuries we made stuff: corn and steel and trucks. Now, we make protocols: sets of instructions. A software program is a protocol for organizing information. A new drug is a protocol for organizing chemicals. Wal-Mart produces protocols for moving and marketing consumer goods. Even when you are buying a car, you are mostly paying for the knowledge embedded in its design, not the metal and glass...Physical stuff is subject to the laws of scarcity: you can use up your timber. But it’s hard to use up a good idea. Prices for material goods tend toward equilibrium, depending on supply and demand. Equilibrium doesn’t really apply to the market for new ideas.

A protocol economy tends toward inequality because some societies and subcultures have norms, attitudes and customs that increase the velocity of new recipes while other subcultures retard it. Some nations are blessed with self-reliant families, social trust and fairly enforced regulations, while others are cursed by distrust, corruption and fatalistic attitudes about the future. It is very hard to transfer the protocols of one culture onto those of another...When the economy was about stuff, economics resembled physics. When it’s about ideas, economics comes to resemble psychology.

For the season...

Can't let the holiday pass without a light show:

'Tis the season to be generous'...but watch the testosterone

A nice nugget from Zak et al:

How do human beings decide when to be selfish or selfless? In this study, we gave testosterone to 25 men to establish its impact on prosocial behaviors in a double-blind within-subjects design. We also confirmed participants' testosterone levels before and after treatment through blood draws. Using the Ultimatum Game from behavioral economics, we find that men with artificially raised T, compared to themselves on placebo, were 27% less generous towards strangers with money they controlled. This effect scales with a man's level of total-, free-, and dihydro-testosterone (DHT). Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially.

More on the psychology of Liberals and Conservatives

Michael Shermer does an interesting column on this topic in the December Scientific American. It focuses mainly on the work of Jonathan Haidt, who explains liberal and conservative stereotypes in terms of his Moral Foundations Theory...

Haidt proposes that the foundations of our sense of right and wrong rest within “ ve innate and universally available psychological systems” that might be summarized as follows:
1. Harm/care: Evolved mammalian attachment systems mean we can feel the pain of others, giving rise to the virtues of kindness, gentleness and nurturance.
2. Fairness/reciprocity: Evolved reciprocal altruism generates a sense of justice.
3. Ingroup/loyalty: Evolved in-group tribalism leads to patriotism.
4. Authority/respect: Evolved hierarchical social structures translate to respect for authority and tradition.
5. Purity/sanctity: Evolved emotion of disgust related to disease and contamination underlies our sense of bodily purity.

Over the years Haidt and his University of Virginia colleague Jesse Graham have surveyed the moral opinions of more than 110,000 people from dozens of countries and have found this consistent difference: self-reported liberals are high on 1 and 2 (harm/ care and fairness/reciprocity) but are low on 3, 4 and 5 (ingroup/loyalty, authority/respect and purity/sanctity), whereas selfreported conservatives are roughly equal on all five dimensions, although they place slightly less emphasis on 1 and 2 than liberals do. (Take the survey yourself.)

Clever octopus, using tools.

No sooner do I get back from a restaurant in which I had a marvelous octopus ceviche, than I come across this video. 

The origins of tidyness.

Turns out that ~800,000 year old Neanderthal dwellings excavated in Israel show signs of separate "activity areas" such as hearths, stone-tool knapping areas, food preparation areas, sleeping areas, etc. (added note: this morning's NYTimes has an article on the work)

Editor's choice at the Journal of Behavioral and Brain Science

Back in the dark ages I had an article in a special issue of Behavioral and Brain Science (in an issue devoted to publishing the papers given at a meeting on vision - "Controversies in Neuroscience III: Signal Transduction in the Retina and Brain"). They put me on the mailing list of reviewers, which is how I can occasionally pass on interesting papers that are appearing in the journal.   A recent email offered a list of articles what the editors found most interesting.  I've enjoyed reading several of them.   Here is that list, with links:

Consciousness, accessibility, and the mesh between psychology and neuroscience -  Ned Block

The myth of language universals: Language diversity and its importance for cognitive science -  Nicholas Evans and Stephen C. Levinson

Understanding and sharing intentions: The origins of cultural cognition (a PDF download) - Michael Tomasello, Malinda Carpenter, Josep Call, Tanya Behne, and Henrike Moll

Consciousness without a cerebral cortex: A challenge for neuroscience and medicine Bjorn Merker

Resolving the paradox of common, harmful, heritable mental disorders: Which evolutionary genetic models work best?  - Matthew C. Keller and Geoffrey Miller

Précis of the book: "Principles of Brain Evolution" - Georg F. Striedter

Cruelty's rewards: The gratification of perpetrators and spectators  - Victor Nell

How to lie more skillfully

Just apply transcranial direct current stimulation (tDCS) to your anterior prefrontal cortex (aPFC). From Karim et al:

Recent neuroimaging studies have indicated a predominant role of the anterior prefrontal cortex (aPFC) in deception and moral cognition, yet the functional contribution of the aPFC to deceptive behavior remains unknown. We hypothesized that modulating the excitability of the aPFC by transcranial direct current stimulation (tDCS) could reveal its functional contribution in generating deceitful responses. Forty-four healthy volunteers participated in a thief role-play in which they were supposed to steal money and then to attend an interrogation with the Guilty Knowledge Test. During the interrogation, participants received cathodal, anodal, or sham tDCS. Remarkably, inhibition of the aPFC by cathodal tDCS did not lead to an impairment of deceptive behavior but rather to a significant improvement. This effect manifested in faster reaction times in telling lies, but not in telling the truth, a decrease in sympathetic skin-conductance response and feelings of guilt while deceiving the interrogator and a significantly higher lying quotient reflecting skillful lying. Increasing the excitability of the aPFC by anodal tDCS did not affect deceptive behavior, confirming the specificity of the stimulation polarity. These findings give causal support to recent correlative data obtained by functional magnetic resonance imaging studies indicating a pivotal role of the aPFC in deception.

Neuromarketing nonsense

A blog reader pointed out to me this nice popular press debunking, by Sally Satel (interestingly, a resident scholar at the American Enterprise Institute), of the headset marketed by EmSense to gauge consumer reactions to advertising and products. The company website is notably lacking in documentation of any studies supporting their claims.  Here are clips from Satel's piece:

Neuromarketers are becoming the next generation of Mad Men. They are working for companies like Google, Frito-Lay and Disney. But instead of directly asking consumers whether they like a product, neuromarketers are asking their brains....Using electroencephalography (EEG)--a technology typically used by neurologists to diagnose seizures--marketers measure brain wave activity in response to advertisements and products. Electrodes placed on the subject's scalp collect the data. The consumer herself doesn't say a thing.

And that's the point. In the new world of neuromarketing, it is the more immediate, unedited emotional brain-level reaction to a product or ad that presumably indicates what the consumer really wants, even if she doesn't really know it. The rational and deliberate responses elicited in focus groups are considered unreliable....No wonder EmSense, a San Francisco-based market research company, succeeded in raising $9 million in capital last month....EmSense tests products with a band-like EEG device called the Emband that goes across the consumer's forehead. As she shops, the four sensors contained in the Emband collect data that, according to the company Web site, "open a window into the mind of the consumer."

Brain activation detected through the band's sensors is believed to signal the consumer's emotional engagement with a product. Engagement, in turn, is essential to sustaining interest and in enhancing memorability, important for developing brand loyalty. Yet the practical dimensions of neuromarketing are far from well-established.

First, how well does EEG detect emotion? It can gauge alertness, yes, but the more subtle kinds of mental states that relate to purchasing decisions--such as attraction, disgust, nostalgia or aspirational fantasy--are not accessible via brain wave analysis....Second, the notion of a discrete "buy button in the brain," as marketers call the holy grail of marketing, is deeply naive. Response to the shape, smell and color of a product is the culmination of complex processes that engage many areas of the brain...there is nothing close to a direct path between brain activation and actual consumer behavior.

Third, and most important, we still don't know whether any measure of neural activity predicts actual market performance or sales better than existing methods. Right now the data that are trumpeted by neuromarketers as revelatory have not been published in peer-reviewed journals. Nor has testing occurred under real-world circumstances in which consumers juggle their pocketbooks, the foreseeable reaction from spouse (you bought what?!?), other purchases they have recently made and even their mood at the time they go shopping.

Companies don't sell to brains; they sell to people. And human actions are determined by an array of motives and impulses that come into play once the subject removes the EEG apparatus from her head....Until the EEG marketing paradigm can prove itself to independent scientists, consumer actions will always speak louder than brain activation. Nonetheless, the allure of neuromarketing is obvious: Traditional focus groups seem too fuzzy and subjective; brain technology is objective, measurable and scientific...Having raised an impressive $9 million, the least one can safely say about EmSense is that it surely knows how to market itself. But whether EmSense, or other neuromarketers for that matter, can deliver on their high-tech promises remains to be seen.

Transiently blocking our concern for our good reputation

A fascinating open access piece by Knoch et al shows that brief disruption of our right lateral prefrontal cortex with low-frequency repetitive transcranial magnetic stimulation diminishes our ability to build a favorable reputation (by increasing our tendency to defect in a game of trust), even though ability to recognize both the fairness standards necessary for acquiring a good reputation and its future benefits are intact. This may help explain why reputation formation remains less prominent in most other species with less developed prefrontal cortices.

Reputation formation pervades human social life. In fact, many people go to great lengths to acquire a good reputation, even though building a good reputation is costly in many cases. Little is known about the neural underpinnings of this important social mechanism, however. In the present study, we show that disruption of the right, but not the left, lateral prefrontal cortex (PFC) with low-frequency repetitive transcranial magnetic stimulation (rTMS) diminishes subjects' ability to build a favorable reputation. This effect occurs even though subjects' ability to behave altruistically in the absence of reputation incentives remains intact, and even though they are still able to recognize both the fairness standards necessary for acquiring and the future benefits of a good reputation. Thus, subjects with a disrupted right lateral PFC no longer seem to be able to resist the temptation to defect, even though they know that this has detrimental effects on their future reputation. This suggests an important dissociation between the knowledge about one's own best interests and the ability to act accordingly in social contexts. These results link findings on the neural underpinnings of self-control and temptation with the study of human social behavior, and they may help explain why reputation formation remains less prominent in most other species with less developed prefrontal cortices.