Why are we fooled by the ventriloquist?

As we watch the movement's of a dummy's mouth while it is sitting in a ventriloguist's lap, we perceive the speech as coming from the dummy's mouth, rather than it's master's voice. Berger and Ehrsson show that this illusory translocation is associated with increased activity the left superior temporal sulcus (L. STS). This is the region that has been shown to be central in determining the spatial coordinates of our experienced self. (It is associated also, for example, with the out of body illusion.)

It is well understood that the brain integrates information that is provided to our different senses to generate a coherent multisensory percept of the world around us, but how does the brain handle concurrent sensory information from our mind and the external world? Recent behavioral experiments have found that mental imagery—the internal representation of sensory stimuli in one's mind—can also lead to integrated multisensory perception; however, the neural mechanisms of this process have not yet been explored. Here, using functional magnetic resonance imaging and an adapted version of a well known multisensory illusion (i.e., the ventriloquist illusion), we investigated the neural basis of mental imagery-induced multisensory perception in humans. We found that simultaneous visual mental imagery and auditory stimulation led to an illusory translocation of auditory stimuli and was associated with increased activity in the left superior temporal sulcus (L. STS), a key site for the integration of real audiovisual stimuli. This imagery-induced ventriloquist illusion was also associated with increased effective connectivity between the L. STS and the auditory cortex. These findings suggest an important role of the temporal association cortex in integrating imagined visual stimuli with real auditory stimuli, and further suggest that connectivity between the STS and auditory cortex plays a modulatory role in spatially localizing auditory stimuli in the presence of imagined visual stimuli.

Our microbial aura - in the house and in the garden

I've always been fascinated by the fact that in "our" bodies most of the cells are not our own, they are microbial symbionts. I pass on here two more takes on this. First, from Lax et al. on microbial interaction between humans and the indoor environment, signature microbes follow us from house to house:

The bacteria that colonize humans and our built environments have the potential to influence our health. Microbial communities associated with seven families and their homes over 6 weeks were assessed, including three families that moved their home. Microbial communities differed substantially among homes, and the home microbiome was largely sourced from humans. The microbiota in each home were identifiable by family. Network analysis identified humans as the primary bacterial vector, and a Bayesian method significantly matched individuals to their dwellings. Draft genomes of potential human pathogens observed on a kitchen counter could be matched to the hands of occupants. After a house move, the microbial community in the new house rapidly converged on the microbial community of the occupants’ former house, suggesting rapid colonization by the family’s microbiota.

And, Anna North points to the beneficial effects of exposure to soil organisms. Some soil bacteria have the same antidepressant effect on mice as serotonin reuptake inhibitors like Prozac. Clips from Lowry et al.'s abstract:

We have found that peripheral immune activation with antigens derived from the nonpathogenic, saprophytic bacterium, Mycobacterium vaccae, activated a specific subset of serotonergic neurons in the interfascicular part of the dorsal raphe nucleus (DRI) of mice...The effects of immune activation were associated with increases in serotonin metabolism within the ventromedial prefrontal cortex, consistent with an effect of immune activation on mesolimbocortical serotonergic systems. The effects of M. vaccae administration on serotonergic systems were temporally associated with reductions in immobility in the forced swim test, consistent with the hypothesis that the stimulation of mesolimbocortical serotonergic systems by peripheral immune activation alters stress-related emotional behavior.

Boredom = Stress.... and misbehavior

From Merrifield and Danckert, a crisp piece of work (using the usual covey of college undergraduate as subjects) demonstrating that boredom increases stress indicators:

Research on the experience and expression of boredom is underdeveloped. The purpose of the present study was to explore the psychophysiological signature of the subjective experience of boredom. Healthy undergraduates (n = 72) viewed previously validated and standardized video clips to induce boredom, sadness, and a neutral affective state, while their heart rate (HR), skin conductance levels (SCL), and cortisol levels were measured. Boredom yielded dynamic psychophysiological responses that differed from the other emotional states. Of particular interest, the physiological signature of boredom relative to sadness was characterized by rising HR, decreased SCL, and increased cortisol levels. This pattern of results suggests that boredom may be associated with both increased arousal and difficulties with sustained attention. These findings may help to resolve divergent conceptualizations of boredom in the extant literature and, ultimately, to enhance our understanding and treatment of clinical syndromes in which self-reported boredom is a prominent symptom.

And, Bruursema et al. note a correlation between boredom and counterproductive work behavior:

In this study, the relationships among boredom proneness, job boredom, and counterproductive work behaviour (CWB) were examined. Boredom proneness consists of several factors, which include external stimulation and internal stimulation. Given the strong relationships between both the external stimulation factor of boredom proneness (BP-ext) and anger as well as the strong relationship between trait anger and CWB, we hypothesized that examining BP-ext would help us to better understand why employees commit CWB. Five types of CWB have previously been described: abuse against others, production deviance, sabotage, withdrawal and theft. To those we added a sixth, horseplay. Using responses received from 211 participants who were recruited by email from throughout North America (112 of them matched with co-workers), we found support for our central premise. Indeed, both BP-ext and job boredom showed significant relationships with various types of CWB. The boredom proneness factor also moderated the relationship between job boredom and some types of CWB, suggesting that a better understanding of boredom is imperative for designing interventions to prevent CWB.

Improvement of performance by transcranial stimulation depends on existing degree of expertise.

Furuya et al. make the interesting observation that the fine motor hand performance of musically untrained people is improved by transcranial direction current stimulation (tDCS) over the primary motor cortices, but the performance of skilled pianists can be degraded.

The roles of the motor cortex in the acquisition and performance of skilled finger movements have been extensively investigated over decades. Yet it is still not known whether these roles of motor cortex are expertise-dependent. The present study addresses this issue by comparing the effects of noninvasive transcranial direction current stimulation (tDCS) on the fine control of sequential finger movements in highly trained pianists and musically untrained individuals. Thirteen pianists and 13 untrained controls performed timed-sequence finger movements with each of the right and left hands before and after receiving bilateral tDCS over the primary motor cortices. The results demonstrate an improvement of fine motor control in both hands in musically untrained controls, but deterioration in pianists following anodal tDCS over the contralateral cortex and cathodal tDCS over the ipsilateral cortex compared with the sham stimulation. However, this change in motor performance was not evident after stimulating with the opposite montage. These findings support the notion that changes in dexterous finger movements induced by bihemispheric tDCS are expertise-dependent.

Our sleep cycle started 700 million years ago in a worm?

Zimmer points to a nice piece of work by Tosches et al. suggesting that the melatonin rhythm that regulates our sleep may have arisen ~700 million years ago in a marine worm larvae - to regulate swarming up to the surface of the sea at twilight to feed and then sink back to lower depths during light to avoid sunlight and predation. A clip from the Zimmer review:

The new study offers an intriguing idea for how our vertebrate ancestors adapted the melatonin genes as they evolved a complex brain.

Originally, the day-night cycle was run by all-purpose cells that could catch light and make melatonin. But then the work was spread among specialized cells. The eyes now took care of capturing light, for example, while the pineal gland made melatonin.

The new study may also help explain how sleep cuts us off from the world. When we’re awake, signals from our eyes and other senses pass through the thalamus, a gateway in the brain. Melatonin shuts the thalamus down by causing its neurons to produce a regular rhythm of bursts. “They’re busy doing their own thing, so they can’t relay information to the rest of the brain,” Dr. Tosches said.

It may be no coincidence that in worms, melatonin also produces electrical rhythms that jam the normal signals of the day. We may sink into sleep the way our ancestors sank into the depths of the ocean.

Inflammatory signaling is bad for the aging brain.

Baruch et al. do some interesting work suggesting that preventing antiviral-like responses may protect aging brain function. They find that the choroid plexus of older mice produces more RNA for the inflammatory cytokine interferon-I than younger mice. This increase is also seen in human post-mortem brain samples. (The choroid plexus produces cerebrospinal fluid that bathes the brain, is exposed both to blood and cerebrospial fluid, and constitutes the blood–cerebrospinal fluid barrier.) Blocking interferon signaling in the aging mouse brain partially restored cognitive function. Here is their abstract:

Aging-associated cognitive decline is affected by factors produced inside and outside the brain. By using multiorgan genome-wide analysis of aged mice, we found that the choroid plexus, an interface between the brain and the circulation, shows a type I interferon (IFN-I)–dependent gene expression profile that was also found in aged human brains. In aged mice, this response was induced by brain-derived signals, present in the cerebrospinal fluid. Blocking IFN-I signaling within the aged brain partially restored cognitive function and hippocampal neurogenesis and reestablished IFN-II–dependent choroid plexus activity, which is lost in aging. Our data identify a chronic aging-induced IFN-I signature, often associated with antiviral response, at the brain’s choroid plexus and demonstrate its negative influence on brain function, thereby suggesting a target for ameliorating cognitive decline in aging.

Why our childhood takes so long - the metabolic costs of brain development

Kuzawa et al. do a nice job of explaining how the energy requirements of our brain growth slow down our body growth in childhood:

The metabolic costs of brain development are thought to explain the evolution of humans’ exceptionally slow and protracted childhood growth; however, the costs of the human brain during development are unknown. We used existing PET and MRI data to calculate brain glucose use from birth to adulthood. We find that the brain’s metabolic requirements peak in childhood, when it uses glucose at a rate equivalent to 66% of the body’s resting metabolism and 43% of the body’s daily energy requirement, and that brain glucose demand relates inversely to body growth from infancy to puberty. Our findings support the hypothesis that the unusually high costs of human brain development require a compensatory slowing of childhood body growth.

Is it love or lust? Look at eye gaze.

Bolmont et al. ask:

When you are on a date with a person you barely know, how do you evaluate that person’s goals and intentions regarding a long-term relationship with you? Love is not a prerequisite for sexual desire, and sexual desire does not necessarily lead to love. Love and lust can exist by themselves or in combination, and to any degree.

Using the usual collection of heterosexual college students as subjects, the authors tracked eye movements as subjects viewed a series of photographs of persons they had never met before. In a separate session the subjects were asked whether the same photographs elicited feelings (yes or no) of sexual desire or romantic love. The results of a lot of fancy eye tracking analysis?

...subjects were more likely to fixate on the face when making decisions about romantic love than when making decisions about sexual desire, and the same subjects were more likely to look at the body when making decisions about sexual desire than when making decisions about romantic love

Duh........anyway, here is their abstract, which inexplicably doesn't include the above bottom line:

"Reading other people’s eyes is a valuable skill during interpersonal interaction. Although a number of studies have investigated visual patterns in relation to the perceiver’s interest, intentions, and goals, little is known about eye gaze when it comes to differentiating intentions to love from intentions to lust (sexual desire). To address this question, we conducted two experiments: one testing whether the visual pattern related to the perception of love differs from that related to lust and one testing whether the visual pattern related to the expression of love differs from that related to lust. Our results show that a person’s eye gaze shifts as a function of his or her goal (love vs. lust) when looking at a visual stimulus. Such identification of distinct visual patterns for love and lust could have theoretical and clinical importance in couples therapy when these two phenomena are difficult to disentangle from one another on the basis of patients’ self-reports."

Having 'no self' as self transcendence, or spirituality.

I've finally read another item in my queue of potential posts, an interview by Gary Gutting of Sam Harris, whose most recent book is titled "Waking Up: A Guide to Spirituality Without Religion. " I recommend the article to philosophically inclined MindBlog readers. Harris takes deities and religion to be nonsense, but argues that spirituality (probably the foundation of many religions) is a noble pursuit. The following clip is Harris on contrasting the claims about mind and cosmos made by science and religion:

There is a big difference between making claims about the mind and making claims about the cosmos. Every religion (including Buddhism) uses first-person experience to do both of these things, but the latter pretensions to knowledge are almost always unwarranted. There is nothing that you can experience in the darkness of your closed eyes that will help you understand the Big Bang or the connection between consciousness and the physical world. Look within, and you will find no evidence that you even have a brain, much less gain any insight into how it works.

However, one can discover specific truths about the nature of consciousness through a practice like meditation. Religious people are always entitled to claim that certain experiences are possible — feelings of bliss or selfless love, for instance. But Christians, Hindus and atheists have experienced the same states of consciousness. So what do these experiences prove? They certainly don’t support claims about the unique divinity of Christ or about the existence of the monkey god Hanuman. Nor do they demonstrate the divine origin of certain books. These reports only suggest that certain rare and wonderful experiences are possible. But this is all we need to take “spirituality” (the unavoidable term for this project of self-transcendence) seriously. To understand what is actually going on — in the mind and in the world — we need to talk about these experiences in the context of science.

In the interview Harris gives one of the nicest and most simple expositions of how our sense of self can be an illusion that I have seen. It is a response to Gutting's question:

You deny the existence of the self, understood as “an inner subject thinking our thoughts and experiencing our experiences.” You say, further, that the experience of meditation (as practiced, for example, in Buddhism) shows that there is no self. But you also admit that we all “feel like an internal self at almost every waking moment.” Why should a relatively rare — and deliberately cultivated — experience of no-self trump this almost constant feeling of a self?

Harris:

Because what does not survive scrutiny cannot be real. Perhaps you can see the same effect in this perceptual illusion:

It certainly looks like there is a white square in the center of this figure, but when we study the image, it becomes clear that there are only four partial circles. The square has been imposed by our visual system, whose edge detectors have been fooled. Can we know that the black shapes are more real than the white one? Yes, because the square doesn’t survive our efforts to locate it — its edges literally disappear. A little investigation and we see that its form has been merely implied.

What could we say to a skeptic who insisted that the white square is just as real as the three-quarter circles and that its disappearance is nothing more than, as you say, “a relatively rare — and deliberately cultivated — experience”? All we could do is urge him to look more closely.

The same is true about the conventional sense of self — the feeling of being a subject inside your head, a locus of consciousness behind your eyes, a thinker in addition to the flow of thoughts. This form of subjectivity does not survive scrutiny. If you really look for what you are calling “I,” this feeling will disappear. In fact, it is easier to experience consciousness without the feeling of self than it is to banish the white square in the above image.

An update of dericbownds.net

I wanted to mention some recent changes to my main website, dericbownds.net, which first started during my transition from a career of laboratory research on vision to a second phase of studies of the human mind in the early 1990's. It is the parent from which Deric's MindBlog sprung in 2006. In recent years I have not been very attentive to the site, and just haphazardly added to it the web versions of lectures I have prepared and given in various venues. I've now obtained the latest version of the web editing program Adobe Dreamweaver (the one I originally used now being dysfunctional), and done a bit of a cleanup, simplifying the home page to just list a few of the more recent lectures ( Upstairs/Downstairs in our Brain  What’s running our show?  -  Making our Brains Younger  -   Are you holding your breath? - Structures of arousal and calm   -   and Making Minds - Evolving and Constructing the "I"), as well as noting two earlier lectures that have been popular ("The I Illusion" and "The Beast Within"). A link is provided to a complete list of my mind lectures, writings, and podcasts. I also realized that a social history of my vision research laboratory at the University of Wisconsin done for a laboratory reunion in 2012 (using the Prezi lecture and web presentation tool) was not very user-friendly, and so attempted to make it easier to click through.

A few Self-Help Nostrums.

I thought I would pass on a few random self-help pieces from the NY Times that caught my eye and have accumulated in my queue of potential posts. (I call these items "nostrums" because having insight or knowledge is an ‘unproven cure,’ - its application to our real life behaviors frequently doesn't happen.)

Feel starved for physical contact,touching?, hugs?, affection? There's an App for that! It's called Cuddlr, described by Anna Altman, that allows individuals to find others nearby who wish to cuddle in a PG-rated, non-sexual way.

Feel like you've caught the general mood of despondency, passivity, and despondency that has seemed to go with an unravelling of the international and domestic order? David Brooks argues that we should get a grip, snap out of it, noting that the scope of the problems we face are way below historic averages. He suggests possible remedies to the current international domestic and international leadership crises.

Wondering why your favorite pleasures loose their glow as you repeat them?  Anna North writes on how performing the pleasures of life in a habitual way....Duh!.... causes them to habituate, loose their force and intensity.  It's how nerve cells work.... If you really want to enjoy something, don't repeat it in a routine way.

Fish as brain food - it’s not just the omega-3

An interesting study from Raji et al., examines data from 260 cognitively normal people with an average age of 78, and finds baked or broiled fish (but not fried fish) consumption correlates with volumes of brain grey matter areas responsible for memory and cognition, the areas where amyloid plaques associated with Alzheimer's disease first appear. The correlation persists after controlling for co-variates such as age, eduction, physical activity, body mass index, race, sex, etc. From their summary:

Data were analyzed from 260 cognitively normal individuals from the Cardiovascular Health Study with information on fish consumption from the National Cancer Institute Food Frequency Questionnaire and brain magnetic resonance imaging (MRI). The relationship between fish consumption data collected in 1989–1990 and brain structural MRI obtained in 1998–1999 was assessed using voxel-based morphometry in multiple regression analyses in 2012. Covariates were age, gender, race, education, white matter lesions, MRI-identified infarcts, waist–hip ratio, and physical activity as assessed by the number of city blocks walked in 1 week. Volumetric changes were further modeled with omega-3 fatty acid estimates to better understand the mechanistic link between fish consumption, brain health, and Alzheimer disease.

Weekly consumption of baked or broiled fish was positively associated with gray matter volumes in the hippocampus, precuneus, posterior cingulate, and orbital frontal cortex even after adjusting for covariates. These results did not change when including omega-3 fatty acid estimates in the analysis....Dietary consumption of baked or broiled fish is related to larger gray matter volumes independent of omega-3 fatty acid content. These findings suggest that a confluence of lifestyle factors influence brain health, adding to the growing body of evidence that prevention strategies for late-life brain health need to begin decades earlier.

Status and the brain.

I want to pass on this summary by Utevsky and Platt of the article by Noonan et al. (both are PLOS open source) on brain neural circuits that covary with an individual's place in the social hierarchy:

Social hierarchy is a fact of life for many animals. Navigating social hierarchy requires understanding one's own status relative to others and behaving accordingly, while achieving higher status may call upon cunning and strategic thinking. The neural mechanisms mediating social status have become increasingly well understood in invertebrates and model organisms like fish and mice but until recently have remained more opaque in humans and other primates. In a new study in this issue, Noonan and colleagues explore the neural correlates of social rank in macaques. Using both structural and functional brain imaging, they found neural changes associated with individual monkeys' social status, including alterations in the amygdala, hypothalamus, and brainstem—areas previously implicated in dominance-related behavior in other vertebrates. A separate but related network in the temporal and prefrontal cortex appears to mediate more cognitive aspects of strategic social behavior. These findings begin to delineate the neural circuits that enable us to navigate our own social worlds. A major remaining challenge is identifying how these networks contribute functionally to our social lives, which may open new avenues for developing innovative treatments for social disorders.

The good order - creativity needs routine

I really liked David Brooks' recent OpEd piece in the NYTimes. It is one of many published comments praising Obama's recent speech at the United Nations on the world order, putting it in the context of the general conditions required for building and maintaining the kind of order required for creativity at individual, political, and global levels. The piece starts by noting the disciplined routines of creative writers (which makes me feel much better about my fuddy-duddy rigid morning schedule of thinking and writing from exactly 8:30 till 11:30 a.m. every weekday.) Some clips:

..Maya Angelou..would go off to a hotel room she kept — a small modest room...She would arrive at the room at 7 a.m. and write until 12:30 p.m. or 2 o’clock....John Cheever would get up...ride the elevator in his apartment building down to a storage room in the basement.. and write until noon...Anthony Trollope would arrive at his writing table at 5:30 each morning... He would write 250 words every 15 minutes for two and a half hours every day... “I cannot imagine life without work as really comfortable,” Sigmund Freud wrote... W.H. Auden...checked his watch constantly, making sure each task filled no more than its allotted moment. “A modern stoic,” he argued, “knows that the surest way to discipline passion is to discipline time..”

..Children need emotional and physical order so they can go off and explore.

..Communities need order to thrive and cooperate since where there is chaos and disorder there is distrust and withdrawal.

..The world needs order, too, a set of assumed norms and routines that all nations adhere to. You can’t have freedom, trust, democracy and self-determination when thugs like Vladimir Putin of Russia are rampaging across borders and monsters like the Islamic State are killing innocents.

..Building and maintaining order — whether artistic, political or global — seems elementary, but it’s surprisingly hard...Preserving world order is even harder. President Obama showed that kind of toughness in his United Nations address this week (you knew I was going to make this leap). It was one of the finest speeches of his presidency.

...the order of global civilization, like the order in a poet’s mind, is something that has to be fought and imposed every day. The best life is a series of daring excursions from a secure and orderly base.

Hearing and imagination shape what we see.

Vetter et al. have done the interesting experiment of blindfolding people and then scanning their brains while they listened to birds singing, traffic noise, or people talking. They were able to identify the category of sounds just by examining the pattern of activity in the primary visual cortex, thus making a nice demonstration of the interconnectedness of the brain's sensory systems.

Highlights

•Early visual cortex receives nonretinal input carrying abstract information 

•Both auditory perception and imagery generate consistent top-down input 

•Information feedback may be mediated by multisensory areas 

•Feedback is robust to attentional, but not visuospatial, manipulation

Summary

Human early visual cortex was traditionally thought to process simple visual features such as orientation, contrast, and spatial frequency via feedforward input from the lateral geniculate nucleus. However, the role of nonretinal influence on early visual cortex is so far insufficiently investigated despite much evidence that feedback connections greatly outnumber feedforward connections. Here, we explored in five fMRI experiments how information originating from audition and imagery affects the brain activity patterns in early visual cortex in the absence of any feedforward visual stimulation. We show that category-specific information from both complex natural sounds and imagery can be read out from early visual cortex activity in blindfolded participants. The coding of nonretinal information in the activity patterns of early visual cortex is common across actual auditory perception and imagery and may be mediated by higher-level multisensory areas. Furthermore, this coding is robust to mild manipulations of attention and working memory but affected by orthogonal, cognitively demanding visuospatial processing. Crucially, the information fed down to early visual cortex is category specific and generalizes to sound exemplars of the same category, providing evidence for abstract information feedback rather than precise pictorial feedback. Our results suggest that early visual cortex receives nonretinal input from other brain areas when it is generated by auditory perception and/or imagery, and this input carries common abstract information. Our findings are compatible with feedback of predictive information to the earliest visual input level, in line with predictive coding models.

The Human Dynamic Clamp

In my distant past when I was doing cellular neurophysiology we used a technique called the "voltage clamp", in which the electrophysiology equipment measuring a nerve signal was linked to a computer that could inject current to alter the signal's behavior in a bi-directional interaction, and thus test models for the ion fluxes underlying the signals. Dumas et al. ask if a similar approach could be applied to study human interactions:

For example, were a human to interact with a model constructed to behave like him- or herself, might this tell us something about human beings and how they work together?....scaling the dynamic clamp paradigm from neurons and neural ensembles to human beings and human brains in a principled fashion is nontrivial. A potential starting point is to ground the design of an HDC (Human Dynamic Clamp) in the empirically based theoretical models of coordination dynamics

From their introduction:

...We will describe the HDC for four classes of behavior. Basically, the HDC models the interactions between a human and a virtual partner (VP) in the language of informationally coupled, nonlinear dynamical systems. The movements of the human enter the equations of motion associated with a specific model. This produces the dynamics of the VP that are displayed on a video screen. To complete the reciprocal coupling between the human and VP, the subject sees the motion of the VP. In a first version, the rhythmic movements of the subject enter the equations of motion of the Haken–Kelso–Bunz (HKB) model, considered one of the most extensively tested quantitative models of human motor behavior. Then, we expand the behavioral repertoire of the VP through the excitator model, which describes both rhythmic and discrete movement generation. In a further elaboration, adaptive behavior is introduced through changing parameter dynamics, illustrated here by modifying the intrinsic frequency of the VP. Finally, to study how a VP may adopt a directed behavior and hence play the role of a “teacher,” we use an adaptation of the empirically verified Schöner–Kelso model of behavioral pattern change.

Here is a section of the article abstract (the article appears to be open source, more detailed procedures and equations can be found there):

...the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject’s own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual “teacher.” We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof.

Finally, the conclusion sounds very cosmic!

The HDC offers a way to bring mind, brain, and machine together through behavior. Under such a framework, we have shown that it is possible to unify and generalize diverse functions and tasks. The approach is principled: Each new version of the HDC carries the mathematics of all previous versions (Table 1). As long as there is a medium for two-way interaction, a deeper understanding of both the model and what the model is purported to be of become possible. Once coupled bidirectionally to an unconstrained, open dynamical system like a human being, HDC’s behavioral repertoire becomes much richer—in a manner akin, perhaps, to the way human behavior develops and gains depth through social interactions. In experiments, the richness of HDC behavior already led to unsolicited verbal reactions by human subjects, e.g., attribution of agency to the VP. Such spontaneous expressions suggest that the HDC may qualify as a Turing test of humanness, even surpassing its original scope. The Turing test implies only that judges are unable to tell if an agent is a human or a machine, and as such says nothing about the genuineness of the path toward that decision. Here, the HDC is a tool to test hypotheses and gain understanding about how humans interact with each other as well as with machines. In the HDC paradigm, exploration of the machine’s behavior may be viewed as an exploration of us as well.

Rules of implicit evaluation by race, religion, and age.

Axt and collaborators look at a very large sample (N > 200,000) of people of varying race, religion, and age and find, that after ranking their own race, religion, or age most favorably, people rank remaining categories in the same hierarchy, suggesting that rules of social evaluation are pervasively embedded in culture and mind. The subjects in the study were American citizens who submitted data to Harvard's Project Implicit. Their abstract:

The social world is stratified. Social hierarchies are known but often disavowed as anachronisms or unjust. Nonetheless, hierarchies may persist in social memory. In three studies (total N > 200,000), we found evidence of social hierarchies in implicit evaluation by race, religion, and age. Participants implicitly evaluated their own racial group most positively and the remaining racial groups in accordance with the following hierarchy: Whites > Asians > Blacks > Hispanics. Similarly, participants implicitly evaluated their own religion most positively and the remaining religions in accordance with the following hierarchy: Christianity > Judaism > Hinduism or Buddhism > Islam. In a final study, participants of all ages implicitly evaluated age groups following this rule: children > young adults > middle-age adults > older adults. These results suggest that the rules of social evaluation are pervasively embedded in culture and mind.

The authors comment on the noteworthy finding that Black people generally received more positive implicit evaluations than Hispanic people.

Past research has indicated that Blacks occupy the lowest rung of the racial status hierarchy. Recent work suggests that Hispanics may in fact occupy a position of lower status in the United States. For example, Hispanic men and women have lower weekly earnings than their White, Asian, and Black counterparts (U.S. Department of Labor, 2013). Our Study now reveals that Hispanics are evaluated less positively on average than Blacks, at least implicitly.

Morality in real life versus the lab.

The majority of studies on morality have used artificial controlled laboratory settings where study participants respond to presented moral issues (such as the famous speeding trolley dilemma: Should you sacrifice one person to save five?). Hoffman et al. have now gone into the real world homeostasis of morality, by calling volunteer study participants on their cell phones at random times to note moral acts that they committed or were the target of, that they witnessed directly, or that they heard about. This allowed them to analyze daily dynamics in a way not possible in the laboratory studies. Their findings confirmed several laboratory studies on moral contagion (receiving a good deed makes it more likely for us to give one), moral licensing (doing good entitles a bit of doing bad), political differences in moral values and concerns, and overoptimistically predicting one's own future moral behavior but accurately predicting the not-so-moral future behavior of others. They found little difference in daily moral behavior between religious and nonreligious people.

The science of morality has drawn heavily on well-controlled but artificial laboratory settings. To study everyday morality, we repeatedly assessed moral or immoral acts and experiences in a large (N = 1252) sample using ecological momentary assessment. Moral experiences were surprisingly frequent and manifold. Liberals and conservatives emphasized somewhat different moral dimensions. Religious and nonreligious participants did not differ in the likelihood or quality of committed moral and immoral acts. Being the target of moral or immoral deeds had the strongest impact on happiness, whereas committing moral or immoral deeds had the strongest impact on sense of purpose. Analyses of daily dynamics revealed evidence for both moral contagion and moral licensing. In sum, morality science may benefit from a closer look at the antecedents, dynamics, and consequences of everyday moral experience.

Neuroanatomy predicts individual risk attitudes.

Gilaie-Dotan et al. show that the volume of a region in the right posterior parietal cortex is relatively larger in individuals with higher risk tolerance (i.e. those more likely to choose a risky option). This region had previously been linked to uncertainty of reward, decision making, and the subjective value of uncertain rewards in both monkey and human brains.

Over the course of the last decade a multitude of studies have investigated the relationship between neural activations and individual human decision-making. Here we asked whether the anatomical features of individual human brains could be used to predict the fundamental preferences of human choosers. To that end, we quantified the risk attitudes of human decision-makers using standard economic tools and quantified the gray matter cortical volume in all brain areas using standard neurobiological tools. Our whole-brain analysis revealed that the gray matter volume of a region in the right posterior parietal cortex was significantly predictive of individual risk attitudes. Participants with higher gray matter volume in this region exhibited less risk aversion. To test the robustness of this finding we examined a second group of participants and used econometric tools to test the ex ante hypothesis that gray matter volume in this area predicts individual risk attitudes. Our finding was confirmed in this second group. Our results, while being silent about causal relationships, identify what might be considered the first stable biomarker for financial risk-attitude. If these results, gathered in a population of midlife northeast American adults, hold in the general population, they will provide constraints on the possible neural mechanisms underlying risk attitudes. The results will also provide a simple measurement of risk attitudes that could be easily extracted from abundance of existing medical brain scans, and could potentially provide a characteristic distribution of these attitudes for policy makers.

Synchrony between observers' brains during action observation.

Nummenmaa et al. (free access article, check out the nice graphics) have examined how we can understand what another person might be thinking or feeling just by observing their actions:

A frontoparietal action–observation network (AON) has been proposed to support understanding others' actions and goals. We show that the AON “ticks together” in human subjects who are sharing a third person's feelings. During functional magnetic resonance imaging, 20 volunteers watched movies depicting boxing matches passively or while simulating a prespecified boxer's feelings. Instantaneous intersubject phase synchronization (ISPS) was computed to derive multisubject voxelwise similarity of hemodynamic activity and inter-area functional connectivity. During passive viewing, subjects' brain activity was synchronized in sensory projection and posterior temporal cortices. Simulation induced widespread increase of ISPS in the AON (premotor, posterior parietal, and superior temporal cortices), primary and secondary somatosensory cortices, and the dorsal attention circuits (frontal eye fields, intraparietal sulcus). Moreover, interconnectivity of these regions strengthened during simulation. We propose that sharing a third person's feelings synchronizes the observer's own brain mechanisms supporting sensations and motor planning, thereby likely promoting mutual understanding.

Female hurricanes are deadlier than male hurricanes

The fact that I am driving away from Madison Wisconsin tomorrow, to my cold weather nest in Fort Lauderdale Florida, made me recall this interesting bit on hurricanes, which are still a possibility for a month or two after my arrival in Florida.

Meteorologists and geoscientists have called for greater consideration of social science factors that predict responses to natural hazards. We answer this call by highlighting the influence of an unexplored social factor, gender-based expectations, on the human toll of hurricanes that are assigned gendered names. Feminine-named hurricanes (vs. masculine-named hurricanes) cause significantly more deaths, apparently because they lead to lower perceived risk and consequently less preparedness. Using names such as Eloise or Charlie for referencing hurricanes has been thought by meteorologists to enhance the clarity and recall of storm information. We show that this practice also taps into well-developed and widely held gender stereotypes, with potentially deadly consequences. Implications are discussed for understanding and shaping human responses to natural hazard warnings.

Music shapes how we think - whether we see the forrest or the trees.

Hansen and Melzner do a fascinating piece on how musical cues that vary in distance and abstractness versus proximity and concreteness influence us. Think of the difference between the first two notes of “Maria” in West Side Story - a dissonant interval, the tritone - versus the first two notes of Twinkle, Twinkle, Little Star” - a consonant interval, the perfect fifth. They find the former makes us more likely to perceive the global aspects of a visual pattern, the latter enhances perception of its discrete elements (i.e. the forrest versus the trees).

Highlights

• Auditory cues related to distance and abstractness trigger abstract construal.
• Auditory cues related to proximity and concreteness trigger concrete construal.
• Distance/abstractness cues in sounds instigate the formation of broader categories.
• Distance/abstractness cues increase preference for global visual patterns.
• Also, these cues increase the weight placed on aggregate vs. single information.

Abstract

Psychological distance and abstractness primes have been shown to increase one's level of construal. We tested the idea that auditory cues which are related to distance and abstractness (vs. proximity and concreteness) trigger abstract (vs. concrete) construal. Participants listened to musical sounds that varied in reverberation, novelty of harmonic modulation, and metrical segmentation. In line with the hypothesis, distance/abstractness cues in the sounds instigated the formation of broader categories, increased the preference for global as compared to local aspects of visual patterns, and caused participants to put more weight on aggregated than on individualized product evaluations. The relative influence of distance/abstractness cues in sounds, as well as broader implications of the findings for basic research and applied settings, is discussed.

And here is their exposition of construal level theory:

Construal level theory proposes that psychological distance from objects (i.e., temporal, spatial, social, or probabilistic) enhances the tendency to build more high-level construals, whereas proximity enhances the tendency to build more low-level construals of objects. High-level construals are less diverse and include fewer details and less contextual information than low-level construals. High-level construals are abstract mental representations that extract the essential, core aspects of objects. Moving from a concrete representation of an object to a more abstract representation involves retaining central features and omitting features that may vary without significantly changing the meaning of the represented information.

Low-level, concrete construals, in contrast, consist of rich and specific details. They emphasize subordinate (vs. superordinate) features of an object, focusing on local (vs. global) perceptual elements, and processing information in a detailed-oriented (vs. holistic) manner.

Parasites practicing mind control.

Zimmer points to a further installment in the fascinating story of Toxoplasma gondii parasites, who can infect any mammal or bird, but can reproduce only inside of a cat whose feces then contain cysts that infect new hosts. Infected rats and mice become unafraid of feline odor, and thus become easier prey. It turns out the parasites use a very elegant technique to alter their host's behavior: they use an enzyme to remove inhibiting methyl groups from the arginine vasopressin gene, and the resulting increase in arginine vasopressin makes rats become more fearless. The abstract:

Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odors. This behavioral change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odor. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation, and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus – Toxoplasma gondii association.

Associative memory enhanced by brain stimulation.

Wang et al. do a proof that the hippocampus facilitates associative memory formation in humans by interacting with distributed brain regions. Here is a description of their approach (sufficiently sophisticated that one will probably not be seeing DIY self help kits on the internet anytime soon!):

We ...developed methods to modulate cortical-hippocampal brain networks in healthy adults (n = 16 subjects) in order to test their role in associative memory. We focused modulatory stimulation on the lateral parietal cortex component of a well-characterized cortical-hippocampal network on the basis of hypothesized interactions between hippocampus and lateral parietal cortex in memory as well as robust functional connectivity between these regions, which is likely mediated by lateral parietal projections to retrosplenial and parahippocampal cortex. We defined a target within the left hippocampus for each subject and used resting-state fMRI to identify a subject-specific left lateral parietal location that demonstrated high functional connectivity with the hippocampal target. Noninvasive high-frequency repetitive transcranial magnetic stimulation (rTMS) was delivered to the parietal location for 5 consecutive days on the basis of evidence that rTMS can induce changes in connectivity within stimulated networks and that such effects can increase over multiple-day stimulation sessions.

Here is their abstract:

The influential notion that the hippocampus supports associative memory by interacting with functionally distinct and distributed brain regions has not been directly tested in humans. We therefore used targeted noninvasive electromagnetic stimulation to modulate human cortical-hippocampal networks and tested effects of this manipulation on memory. Multiple-session stimulation increased functional connectivity among distributed cortical-hippocampal network regions and concomitantly improved associative memory performance. These alterations involved localized long-term plasticity because increases were highly selective to the targeted brain regions, and enhancements of connectivity and associative memory persisted for ~24 hours after stimulation. Targeted cortical-hippocampal networks can thus be enhanced noninvasively, demonstrating their role in associative memory.

Norm enforcement is biased from its emergence.

Interesting work from Jordan et al. on the appearance of in-group bias in punishing selfish behaviors in insiders versus outsiders:

When enforcing norms for cooperative behavior, human adults sometimes exhibit in-group bias. For example, third-party observers punish selfish behaviors committed by out-group members more harshly than similar behaviors committed by in-group members. Although evidence suggests that children begin to systematically punish selfish behavior around the age of 6 y, the development of in-group bias in their punishment remains unknown. Do children start off enforcing fairness norms impartially, or is norm enforcement biased from its emergence? How does bias change over development? Here, we created novel social groups in the laboratory and gave 6- and 8-year-olds the opportunity to engage in costly third-party punishment of selfish sharing behavior. We found that by age 6, punishment was already biased: Selfish resource allocations received more punishment when they were proposed by out-group members and when they disadvantaged in-group members. We also found that although costly punishment increased between ages 6 and 8, bias in punishment partially decreased. Although 8-y-olds also punished selfish out-group members more harshly, they were equally likely to punish on behalf of disadvantaged in-group and out-group members, perhaps reflecting efforts to enforce norms impartially. Taken together, our results suggest that norm enforcement is biased from its emergence, but that this bias can be partially overcome through developmental change.

Early music training improves neural encoding of speech in children and arrests auditory decline in older adults.

Fascinating work from Kraus et al.:

Musicians are often reported to have enhanced neurophysiological functions, especially in the auditory system. Musical training is thought to improve nervous system function by focusing attention on meaningful acoustic cues, and these improvements in auditory processing cascade to language and cognitive skills. Correlational studies have reported musician enhancements in a variety of populations across the life span. In light of these reports, educators are considering the potential for co-curricular music programs to provide auditory-cognitive enrichment to children during critical developmental years. To date, however, no studies have evaluated biological changes following participation in existing, successful music education programs. We used a randomized control design to investigate whether community music participation induces a tangible change in auditory processing. The community music training was a longstanding and successful program that provides free music instruction to children from underserved backgrounds who stand at high risk for learning and social problems. Children who completed 2 years of music training had a stronger neurophysiological distinction of stop consonants, a neural mechanism linked to reading and language skills. One year of training was insufficient to elicit changes in nervous system function; beyond 1 year, however, greater amounts of instrumental music training were associated with larger gains in neural processing. We therefore provide the first direct evidence that community music programs enhance the neural processing of speech in at-risk children, suggesting that active and repeated engagement with sound changes neural function.

This same group has also documented how older adults benefit from early music training:

Aging results in pervasive declines in nervous system function. In the auditory system, these declines include neural timing delays in response to fast-changing speech elements; this causes older adults to experience difficulty understanding speech, especially in challenging listening environments. These age-related declines are not inevitable, however: older adults with a lifetime of music training do not exhibit neural timing delays. Yet many people play an instrument for a few years without making a lifelong commitment. Here, we examined neural timing in a group of human older adults who had nominal amounts of music training early in life, but who had not played an instrument for decades. We found that a moderate amount (4–14 years) of music training early in life is associated with faster neural timing in response to speech later in life, long after training stopped (>40 years). We suggest that early music training sets the stage for subsequent interactions with sound. These experiences may interact over time to sustain sharpened neural processing in central auditory nuclei well into older age.

Study on relationship between genomics and well being receives a critical trashing.

I recently did a post passing on (as usual, uncritically) what looked like a neat correlation between genomics and human well-being. Brown et al. now issue a foot stomping refutation of that work:

Fredrickson et al. [Fredrickson BL, et al. (2013) Proc Natl Acad Sci USA 110(33):13684–13689] claimed to have observed significant differences in gene expression related to hedonic and eudaimonic dimensions of well-being. Having closely examined both their claims and their data, we draw substantially different conclusions. After identifying some important conceptual and methodological flaws in their argument, we report the results of a series of reanalyses of their dataset. We first applied a variety of exploratory and confirmatory factor analysis techniques to their self-reported well-being data. A number of plausible factor solutions emerged, but none of these corresponded to Fredrickson et al.’s claimed hedonic and eudaimonic dimensions. We next examined the regression analyses that purportedly yielded distinct differential profiles of gene expression associated with the two well-being dimensions. Using the best-fitting two-factor solution that we identified, we obtained effects almost twice as large as those found by Fredrickson et al. using their questionable hedonic and eudaimonic factors. Next, we conducted regression analyses for all possible two-factor solutions of the psychometric data; we found that 69.2% of these gave statistically significant results for both factors, whereas only 0.25% would be expected to do so if the regression process was really able to identify independent differential gene expression effects. Finally, we replaced Fredrickson et al.’s psychometric data with random numbers and continued to find very large numbers of apparently statistically significant effects. We conclude that Fredrickson et al.’s widely publicized claims about the effects of different dimensions of well-being on health-related gene expression are merely artifacts of dubious analyses and erroneous methodology.

A new compound that ameliorates cognitive dysfunction.

Alzheimer's disease is thought ultimately to be caused by the accumulation of the excess proteins found in plaques and tangles in the brain, but the prior defect that leads to this accumulation is not known. Here is a story about how searching for a drug for that defect led to the serendipitous finding of an impurity that turned out to be very useful...From Robinson's review of Xu et al.:

One implicated pathway involves striatal-enriched protein tyrosine phosphatase, or STEP, a neuron-specific enzyme that, among other jobs, regulates the trafficking of synaptic glutamate receptors and the activity of a group of widely active kinases. STEP is overactive in AD, in part because it isn't degraded fast enough, and its overactivity disrupts the post-synaptic events that underlie learning and memory. In animal models of AD, knocking out STEP improves cognition. Thus, STEP inhibition is a potential target for treatment of AD. In this issue of PLOS Biology, Jian Xu, Paul Lombroso, and colleagues report their discovery of a new class of STEP inhibitor—a discovery that involved a small but significant bit of serendipity—and demonstrate its potential in an AD animal model.

The authors began by conducting a high-throughput screen of 150,000 compounds, testing the ability of each to inhibit STEP's phosphatase activity. As is usual in such screens, a number of good candidates emerged. These were winnowed down to eight, chosen for their high activity at low concentration and favorable properties, such as likely ability to cross the blood-brain barrier and absence of known toxic moieties, all important for developing a centrally active drug. Following standard practice, next, they synthesized the molecules from scratch, and here got a surprise—the compounds displayed little STEP inhibitory activity. Some chemical detective work revealed the true inhibitor was elemental sulfur, S8, present as an impurity in the commercially obtained samples used in the screening. This ring compound doesn't make a good drug, so the authors investigated a structurally related compound, benzopentathiepin, containing a ring of six carbons fused to a ring of five sulfurs. A derivative, TC-2153, was known to have low toxicity and was likely to cross the blood-brain barrier, and, they found, was a potent inhibitor of STEP.

To test whether TC-2153 could reverse some of the cognitive effects of STEP overactivity, the authors turned to the “triple transgenic” mouse model, with mutations in three genes known to cause AD: presenilin 1, amyloid precursor protein, and tau. Compared to vehicle, intraperitoneal injection of TC-2153 improved spatial working memory, novel object recognition, and reference memory, all standard tests of cognitive function in AD models. The treatment had no effect on either a-beta, found in amyloid plaques outside of cortical neurons, or phospho-tau, found in neurofibrillary tangles inside them, indicating that the beneficial effect of TC-2153 was not due to alteration of events upstream of STEP overactivity.

Upstairs/Downstairs in our Brain – What’s running our show?

Although I mentioned this in Tuesday's post, I wanted to more explicitly point MindBlog readers to this web version of a talk I gave at the Sept. 9, 2014, session of the University of Wisconsin-Madison Chaos and Complexity Seminar Series. The link is also now in the left column of this page under "MindBlog Web Lectures." Here is a description of the talk:

This talk starts with a brief brain 101 elementary anatomy review, and then offers a  cherry picking review of recent trends in brain systems research that correlate what is going on in our brains with our behaviors. We want to know what normally makes us tick, what distortions might underlie addictive, impulsive, aggressive, stressed, depressed, or anxious behaviors, and what therapies might counter these distortions.  I will focus on structure-activity-behavior correlations in three brain state distinctions that are currently being emphasized:  Upstairs/downstairs and attentional/default mode systems that are a spontaneous part of our normal behavioral repertoire, and the cognitive therapy or mediation systems whose training, development, and expression can alter them.

MindBlog's other half - a Sunday afternoon recital at Twin Valley

This past Sunday afternoon my partner Len and I hosted a musical/social event for 50 friends at our Twin Valley home in Middleton Wisconsin. Our good friend Roy Wesley used his iPhone to make a video of the music, and I pass on his clip of one of the pieces in the program I played, the Debussy Nocturne (1892).



The program also included three pieces from Grieg's Lyric Suites and, Poulenc Improvisations #7 and #13 and, Prokofiev Romeo and Juliette

Reboot, reset, your brain - take a break - a walk, or better, a vacation.

I've done a number of posts on the attentional and default modes of our brain (in fact, I'm doing on a talk on this topic today at the Physics Department's chaos and complexity seminar series at the Univ. of Wisconsin.) I wanted to point to a number of recent popular articles pointing out how important it is for us to be able to detach from our attentional mode constantly processing overwhelming input streams of email, media, work demands, etc. While this more focused attentional mode tends to get a better press than the mind-wandering default mode, it is the latter state in which novel, spontaneous, and creative connections are likely to be made. Levitin does a NYTimes essay that notes the real world relevance of his 2008 publication on switching between central executive and default-mode networks, and notes that we should beware of the 'false break' in which we in fact remain attentive to email and other customary inputs, thus blocking real disengagement and mind wandering. Anna North and Gretchen Reynolds each do articles reinforcing this idea and point to articles studying the boosts in creativity and productivity that can accompany just taking a long walk or break.

MDMA (Ecstasy) as an affiliative social drug

Wardle et al. probe an interesting bit of social neurochemistry:

3,4-Methylenedioxymethamphetamine (MDMA, ‘ecstasy’) is used recreationally to improve mood and sociability, and has generated clinical interest as a possible adjunct to psychotherapy. One way that MDMA may produce positive ‘prosocial’ effects is by changing responses to emotional stimuli, especially stimuli with social content. Here, we examined for the first time how MDMA affects subjective responses to positive, negative and neutral emotional pictures with and without social content. We hypothesized that MDMA would dose-dependently increase reactivity to positive emotional stimuli and dampen reactivity to negative stimuli, and that these effects would be most pronounced for pictures with people in them. The data were obtained from two studies using similar designs with healthy occasional MDMA users (total N = 101). During each session, participants received MDMA (0, 0.75 and 1.5 mg/kg oral), and then rated their positive and negative responses to standardized positive, negative and neutral pictures with and without social content. MDMA increased positive ratings of positive social pictures, but reduced positive ratings of non-social positive pictures. We speculate this ‘socially selective’ effect contributes to the prosocial effects of MDMA by increasing the comparative value of social contact and closeness with others. This effect may also contribute to its attractiveness to recreational users.

MDMA primarily triggers transporter-mediated release of serotonin, suggesting that serotonin is a good candidate for being a key regulator of the desire to affiliate and bond with others. It also increases levels of oxytocin in the blood, but recent work indicates that there is no correlation between the changes in oxytocin in the plasma and changes in social behavior.

Does one novelty lead to another?

Barbar Jazney summarizes interesting work by Tria et al.:

Life would be boring if things were always the same. Tria and colleagues explore whether novelties—discoveries of things new to us—are independent of each other or whether one novelty leads to another. They analyzed selected text, online music, Wikipedia, and a social tagging site and measured how the number of different elements grew with time. Although two of the data sets contained innovations (items new to everyone) and two contained novelties (items new to individual users), they all showed the same kinetics and probability distributions. Modeling analyses suggested that novelties are not independent of each other. As the authors state, each novelty “comes with a cloud of other potentially new ideas that are thematically adjacent to it and hence can be triggered by it.”

Here is the Tria et al. article abstract:

Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called “expanding the adjacent possible”. The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya's urn, predicts statistical laws for the rate at which novelties happen (Heaps' law) and for the probability distribution on the space explored (Zipf's law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution.

Genetic influence on our valuation of free choice

Cockburn et al. find an interesting correlation: A polymorphism in DARPP-32, a gene linked to dopaminergic striatal plasticity and individual differences in reinforcement learning, predicts how strongly people exhibit preference for options they have freely chosen over equally valued options they have not. Here is their abstract, along with a statement of highlights:

 Highlights

Participants exhibit a biased preference for freely chosen rewarding options

DARPP-32 genotype predicts choice bias as a function of expected value

Bias is mirrored by a model that amplifies positive free-choice learning signals

Choice bias is the byproduct of a mechanism that refines learning signal fidelity

Summary

Humans exhibit a preference for options they have freely chosen over equally valued options they have not; however, the neural mechanism that drives this bias and its functional significance have yet to be identified. Here, we propose a model in which choice biases arise due to amplified positive reward prediction errors associated with free choice. Using a novel variant of a probabilistic learning task, we show that choice biases are selective to options that are predominantly associated with positive outcomes. A polymorphism in DARPP-32, a gene linked to dopaminergic striatal plasticity and individual differences in reinforcement learning, was found to predict the effect of choice as a function of value. We propose that these choice biases are the behavioral byproduct of a credit assignment mechanism responsible for ensuring the effective delivery of dopaminergic reinforcement learning signals broadcast to the striatum.

Morality - how theists and non theists differ

Shariff et al offer an interesting review of the ways in which the moral concerns of theists and nontheists both overlap and are different, as a result of psychological differences in social investment, motivations for prosocial behavior, meta-ethics, and cognitive styles. Some clips:

Many aspects of religions – such as their emphasis on credibility-enhancing displays of commitment – serve to create an ideologically aligned and cohesive ingroup… this tighter social connection may also lead to more parochial moral attitudes – selectively favoring the ingroup and actively derogating the outgroup.

Religious groups exert strong pressure on group members to conform to the requirements and moral ideals of the community. Although the drive to appear virtuous to others is all but universal, it is especially pronounced among theists. An extensive meta-analysis found theists scoring consistently higher than nontheists on measures of socially desirable responding…A recent meta-analysis revealed that nontheists, by contrast, are generally unaffected by invocations of supernatural agents; compared with baseline, nontheists tend to be no more prosocial when primed with god concepts…Nontheists do, however, show increases in prosocial behavior when primed with concepts relating to secular institutions, such as courts and the police.

For believers, God is not just the ultimate arbiter of justice, but the author of morality itself. This meta-ethical belief provides theists with a unique foundation for thinking about moral issues, distinct from their nonreligious counterparts. Recent research suggests that theists are moral objectivists; that is, they tend to believe that when two people disagree about a moral issue, only one person can be correct…religious individuals appear to moralize a wider range of actions beyond those pertaining to harm and injustice, including disobedience of authority, disloyalty to one's ingroup, and sexual impurity… By contrast, nontheists are more inclined than theists to view morality as subjective or culturally relative. Critically, however, this difference is more pronounced with regard to moral issues that have little to do with harm or injustice (e.g., sexual conduct).

Although theists and nontheists disagree whether obedience to authority or sexual impurity are morally relevant concepts, there is much greater consensus about moral issues involving harm and injustice. For example, both religious and nonreligious individuals take a predominantly deontological stance toward torture and both groups find acts of unjust harm (e.g., killing an innocent for no good reason) to be objectively wrong. All world religions defend some version of the Golden Rule, a doctrine that reflects evolved inclinations toward fairness and reciprocity. Recent studies suggest that individuals, independent of religion, exhibit an impulse to behave cooperatively and that they manage to override this immediate prosocial impulse only on further reflection. This universal preference toward prosociality is apparent even in infancy. Thus, although theists and nontheists may be divided through differences in sociality, earthly and supernatural reputational concerns, and meta-ethics, the two groups are united in what could be considered ‘core’ intuitive preferences for justice and compassion. Although the two groups may sometimes disagree about which groups or individuals deserve justice or their compassion, these core moral intuitions form the best basis for mutual understanding and intergroup conciliation.

Intergenerational transmission of emotional trauma.

Interesting work from Debiec and Sullivan on how conditioned fear learning in a parent is transmitted to children:

Despite clinical evidence that specific fear is transmitted across generations, we have little understanding of mechanisms. Here, we model social transmission of mother-to-infant fear in rodents. We show that maternal fear responses to a conditioned fear odor are sufficient to induce robust fear learning throughout infancy, with robust retention. Assessment of mechanism showed that maternal fear expression increases pups’ stress hormone corticosterone and amygdala activation to induce this cue-specific fear learning. Suppressing pups’ amygdala or preventing pups from mounting a stress response blocked this fear learning. Specific fears may thus be transferred across generations through maternal emotional communication and infant’s associative learning mechanisms. Elucidating the mechanisms of this transmission may inform the development of novel therapeutic and preventive approaches.

How could language have evolved?

An eminent group of co-authors (Bolhuis, Tattersall, Chomsky, and Berwick) suggest that a simple core repeatable operation is the basis of all language. This open source article is a "must read" item for anyone interested in the structure and evolution of language, and I pass on just the abstract and a bit on the basic model:

The evolution of the faculty of language largely remains an enigma. In this essay, we ask why. Language's evolutionary analysis is complicated because it has no equivalent in any nonhuman species. There is also no consensus regarding the essential nature of the language “phenotype.” According to the “Strong Minimalist Thesis,” the key distinguishing feature of language (and what evolutionary theory must explain) is hierarchical syntactic structure. The faculty of language is likely to have emerged quite recently in evolutionary terms, some 70,000–100,000 years ago, and does not seem to have undergone modification since then, though individual languages do of course change over time, operating within this basic framework. The recent emergence of language and its stability are both consistent with the Strong Minimalist Thesis, which has at its core a single repeatable operation that takes exactly two syntactic elements a and b and assembles them to form the set {a, b}.

...it appears that human language syntax can be defined in an extremely simple way that makes conventional evolutionary explanations much simpler. In this view, human language syntax can be characterized via a single operation that takes exactly two (syntactic) elements a and b and puts them together to form the set {a, b}. We call this basic operation “merge”. The “Strong Minimalist Thesis” (SMT) holds that merge along with a general cognitive requirement for computationally minimal or efficient search suffices to account for much of human language syntax. The SMT also requires two mappings: one to an internal conceptual interface for thought and a second to a sensory-motor interface that externalizes language as speech, sign, or other modality. The basic operation itself is simple. Given merge, two items such as the and apples are assembled as the set {the, apples}. Crucially, merge can apply to the results of its own output so that a further application of merge to ate and {the, apples} yields the set {ate, {the, apples}}, in this way deriving the full range of characteristic hierarchical structure that distinguishes human language from all other known nonhuman cognitive systems.

The origins of morality.

Mark Johnson has generated some creative and seminal ideas in his books "The Body in the Mind: The Bodily Basis of Meaning, Imagination, and Reason" and, with George Lakoff "Metaphors We Live By." I pass on a few clips from Les Beldo's review of his most recent book, "Morality for Humans Ethical Understanding from the Perspective of Cognitive Science":

Over the past 25 years, a growing number of cognitive scientists have taken it as their mission to find an empirical basis within brain science for the distinctive character of moral judgments. Investigators such as Marc Hauser, Steven Pinker, and Jonathan Haidt have posited the existence of an innate, domain-specific moral faculty in humans, be it a “universal moral grammar,” a “moral instinct,” or an “intuitive ethics.”

In Morality for Humans, Mark Johnson introduces an approach he calls “moral naturalism.” It is committed to the idea that moral knowledge does not exist on some separate plane but rather in the everyday habits, practices, institutions, and “bio-regulation” of lived organisms. Johnson is skeptical, however, of claims about the existence of a moral module in the human brain. He notes that “there are simply far too many complexly interacting multifunctional systems … in our intuitive moral judgments for there to be anything remotely resembling a distinct moral faculty.” Although he never uses the term, Johnson argues that moral problem-solving relies entirely on cognitive processes like logic, empathy, or narration. He sees the idea of an innate moral faculty as just another attempt to prove the existence of immutable moral laws, not in divine will or in pure reason but in a strong normative reading of cognitive science and evolutionary biology.

Johnson locates the source of values in our social and biological needs, cultural representations, and personal experiences. Here, Johnson has no qualms about violating the so-called naturalistic fallacy, which suggests that normative statements about how things ought to be cannot be derived from factual statements about what is. He moves freely between descriptions of human needs and human tendencies, on the one hand, and the normative suggestion that we ought to fulfill those needs and support those tendencies. Dismissing the naturalistic fallacy is easy if one thinks of it as an esoteric philosophical concept. But the term refers to a real logical problem of which Johnson is in fact acutely aware: “the fact that we have come to value certain states of affairs,” he writes, “is no guarantee that we should value them in the way we do.” This has been a particular weakness of studies that would make normative claims based on findings in cognitive neuroscience. How can descriptions of how our brains work tell us anything about what we ought to do in particular situations? It is a problem Johnson never resolves.

Morality is typically distinguished from other domains of social judgment by its unconditionality. A moral judgment refers to something that is considered right or wrong in and of itself. Johnson rejects the idea that moral judgments are unconditional, saying instead that the “trumping force” of morality owes to the fact that “certain things tend to matter more for us because they are thought to be necessary for the well-being of ourselves and others.” Individual well-being and societal cohesion are practical ends, however, and concerns about achieving them are matters of prudent conduct and prudent governance. This, along with Johnson's repeated insistence that moral problem-solving is no different in kind from any other form of problem-solving, leads one to wonder why he bothers to retain the concept of “morality” at all. Johnson suggests that values exist only in relation to some predefined or agreed-upon set of goods, feelings, or human needs, but that still creates fertile ground for hypothetical imperatives that are binding upon anyone who accepts the most basic premises of society. Why is this not enough? Is the stigma of moral relativism so frightening? What's so bad about prudence?

The stability of the authoritarian state.

Science Magazine publishes comment on a fascinating article by King et al. who essentially reverse-engineer censorship in China to show that criticisms of the state, its leaders, and their policies are published, whereas posts about real-world events with collective action potential are censored. Criticism on the web, which was thought to be censored, is used by Chinese leaders to determine which officials are not doing their job of mollifying the people and need to be replaced. Here is the structured abstract from the article:

Censorship has a long history in China, extending from the efforts of Emperor Qin to burn Confucian texts in the third century BCE to the control of traditional broadcast media under Communist Party rule. However, with the rise of the Internet and new media platforms, more than 1.3 billion people can now broadcast their individual views, making information far more diffuse and considerably harder to control. In response, the government has built a massive social media censorship organization, the result of which constitutes the largest selective suppression of human communication in the recorded history of any country. We show that this large system, designed to suppress information, paradoxically leaves large footprints and so reveals a great deal about itself and the intentions of the government.

Rationale

Chinese censorship of individual social media posts occurs at two levels: (i) Many tens of thousands of censors, working inside Chinese social media firms and government at several levels, read individual social media posts, and decide which ones to take down. (ii) They also read social media submissions that are prevented from being posted by automated keyword filters, and decide which ones to publish.

To study the first level, we devised an observational study to download published Chinese social media posts before the government could censor them, and to revisit each from a worldwide network of computers to see which was censored. To study the second level, we conducted the first largescale experimental study of censorship by creating accounts on numerous social media sites throughout China, submitting texts with different randomly assigned content to each, and detecting from a worldwide network of computers which ones were censored.

To find out the details of how the system works, we supplemented the typical current approach (conducting uncertain and potentially unsafe confidential interviews with insiders) with a participant observation study, in which we set up our own social media site in China. While also attempting not to alter the system we were studying, we purchased a URL, rented server space, contracted with Chinese firms to acquire the same software as used by existing social media sites, and—with direct access to their software, documentation, and even customer service help desk support—reverseengineered how it all works.

Results

Criticisms of the state, its leaders, and their policies are routinely published, whereas posts with collective action potential are much more likely to be censored—regardless of whether they are for or against the state (two concepts not previously distinguished in the literature). Chinese people can write the most vitriolic blog posts about even the top Chinese leaders without fear of censorship, but if they write in support of or opposition to an ongoing protest—or even about a rally in favor of a popular policy or leader—they will be censored.

We clarify the internal mechanisms of the Chinese censorship apparatus and show how changes in censorship behavior reveal government intent by presaging their action on the ground. That is, it appears that criticism on the web, which was thought to be censored, is used by Chinese leaders to determine which officials are not doing their job of mollifying the people and need to be replaced.

Conclusion

Censorship in China is used to muzzle those outside government who attempt to spur the creation of crowds for any reason—in opposition to, in support of, or unrelated to the government. The government allows the Chinese people to say whatever they like about the state, its leaders, or their policies, because talk about any subject unconnected to collective action is not censored. The value that Chinese leaders find in allowing and then measuring criticism by hundreds of millions of Chinese people creates actionable information for them and, as a result, also for academic scholars and public policy analysts.

Early life anxiety in monkeys and humans correlates with connectivity between prefrontal cortex and amygdala.

A group of collaborators, mainly at the University of Wisconsin, including Ned Kalin and Richard Davidson, provide new information about the evolutionarily conserved brain network underlying extreme early-life anxiety:

Some individuals are endowed with a biology that renders them more reactive to novelty and potential threat. When extreme, this anxious temperament (AT) confers elevated risk for the development of anxiety, depression and substance abuse. These disorders are highly prevalent, debilitating and can be challenging to treat. The high-risk AT phenotype is expressed similarly in children and young monkeys and mechanistic work demonstrates that the central (Ce) nucleus of the amygdala is an important substrate. Although it is widely believed that the flow of information across the structural network connecting the Ce nucleus to other brain regions underlies primates’ capacity for flexibly regulating anxiety, the functional architecture of this network has remained poorly understood. Here we used functional magnetic resonance imaging (fMRI) in anesthetized young monkeys and quietly resting children with anxiety disorders to identify an evolutionarily conserved pattern of functional connectivity relevant to early-life anxiety. Across primate species and levels of awareness, reduced functional connectivity between the dorsolateral prefrontal cortex, a region thought to play a central role in the control of cognition and emotion, and the Ce nucleus was associated with increased anxiety assessed outside the scanner. Importantly, high-resolution 18-fluorodeoxyglucose positron emission tomography imaging provided evidence that elevated Ce nucleus metabolism statistically mediates the association between prefrontal-amygdalar connectivity and elevated anxiety. These results provide new clues about the brain network underlying extreme early-life anxiety and set the stage for mechanistic work aimed at developing improved interventions for pediatric anxiety.

Homologous dorsolateral prefrontal cortex (dlPFC) subdivisions show decreased intrinsic connectivity with the central (Ce) nucleus in anxious children and monkeys. (a) Children with anxiety disorders at rest. Bottom-left panel shows the Ce nucleus seed (cyan in red ring). Upper-left panel depicts a coronal slice through the human dlPFC cluster (dark orange; corrected for the combined volume of the mPFC and right dlPFC; n.s. when corrected for the volume of the whole brain). The intermediate frontal sulcus (IFS) is shown in dark red. Upper-right panel shows the IFS with the location of the coronal slice indicated by the blue vertical line. Bottom-right panel shows the location of the dlPFC cluster relative to the architectonic subdivisions of the human dlPFC. (b) Young monkeys with high levels of anxious temperament (AT) under anesthesia. Conventions are similar to a; dark red indicates the location of the sulcus principalis. The bottom-right panels of this figure were adapted with permission from Badre and D'Esposito.74 L, left hemisphere; R, right hemisphere.

More on better living through zapping your brain.

Anna Altman has done an entertaining piece on transcranial direct-current stimulation, or tDCS, which I have mentioned in numerous previous mindblog posts (enter tDCS in the mindblog search box). You can make your own tDCS machine from parts obtained at Radio Shack for ~ $20 or buy one off the web for $90. Various reports have shown enhanced alertness and learning, and palliative medical effect on chronic pain, stroke rehabilitation, and depressive disorders. Researchers go to lengths to warm of the potential downside effect of DIY (do it yourself) public experimentation. And indeed, so what if tDCS gives a bit of a boost?..

“Is brain boosting a fair addition to the cognitive enhancement arms race? Will it create a Morlock/Eloi-like social divide where the rich can afford to be smarter and leave everyone else behind? Will Tiger Moms force their lazy kids to strap on a zappity helmet during piano practice?” Or, she asks, “Could school-age girls use the zappy cap while studying math to drown out the voices that tell them they can’t do math because they’re girls?”

Origins of good and evil in human babies.

Felix Warneken does a review in TICS (Trends in Cognitive Sciences) of Paul Bloom new book "Just Babies: The Origins of Good and Evil," which argues that humans, already in the first year of life, have a basic moral sense that is shaped by innate evolved processes.

Bloom...reviews studies in which babies can choose to touch one of two geometrically shaped agents with googly eyes – and they prefer to touch one who helps a struggling fellow up a hill rather than one who pushes that fellow down. This indicates that babies like helping and despise harming others, even if they are only a third party who observes how other people treat each other. Beyond their judgments of the actions of others, young children also display helpful tendencies in their own behavior. Bloom reviews the extensive work on toddlers as young as 18 months of age who display a tendency to comfort others who are in distress, and spontaneously help clumsy people by picking up dropped objects and holding doors open. Last but not least, preschool children seem to have a sense of fairness when faced with the task of divvying up desirable resources, with equality already serving as a guiding principle.

...although our basic, parochially bound moral sentiments come naturally to us without much effort, applying these principles to strangers takes some mental effort. It requires that we employ perspective-taking in our interactions with others...Expanding our moral circle to include strangers thus depends on socialization and abilities that develop only in late childhood...our evolutionarily evolved morality is prepared for kin and friends, but not for strangers. This can be seen in young children's ingroup biases and toddlers’ stranger anxiety.

Still,

...human children depend more on interactions beyond the immediate family than do our closest evolutionary relatives... Infants thus have to tolerate being handed around and interact with many unfamiliar people from early on. We might therefore expect infants to be open-minded and vigilant at the same time, creating their social circles in a more sophisticated manner than ducklings who follow either white feathers or men with white beards, whichever they see first. And it seems as if they do so, not in a naïve fashion, but in a sophisticated way that balances risk and opportunity.

OhMyGawd...now MRI measurement are going to tell us how happy we are??

Dolan and collaborators come up with yet another clever use of MRI measurements. (If you enter "Dolan" in the mindblog search box, you will find numerous posts on his work.) The article appears to be open-source, which means I'm not going to pass on some of the eye-catching graphics (showing predictive activity in the striatum and right anterior insula) that you should be able to check out, along with the details of the experiment that recruited over 18,000 participants to play a smartphone gambling game and report their subjective happiness when queried.

A common question in the social science of well-being asks, “How happy do you feel on a scale of 0 to 10?” Responses are often related to life circumstances, including wealth. By asking people about their feelings as they go about their lives, ongoing happiness and life events have been linked, but the neural mechanisms underlying this relationship are unknown. To investigate it, we presented subjects with a decision-making task involving monetary gains and losses and repeatedly asked them to report their momentary happiness. We built a computational model in which happiness reports were construed as an emotional reactivity to recent rewards and expectations. Using functional MRI, we demonstrated that neural signals during task events account for changes in happiness.