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.