Memory reactivation during rest supports upcoming learning of related content.

I have found that a brief period of rest, around 20 minutes or so, after I have worked on learning the notes and fingering of a new piano piece, has a huge effect on the ease of my subsequent learning and consolidation of the difficult passage when I return to practice. Now Schlicting and Preston have looked at the neural basis of this enhancement of subsequent learning of related material. I pass on both their statement of significance and their abstract:

Significance

How our brains capture and store new information is heavily influenced by what we already know. While prior work demonstrates that existing memories are spontaneously reactivated and strengthened in the brain during passive rest periods, the prospective benefits of spontaneous offline reactivation for future learning remain unknown. Here, we use functional MRI to interrogate how reactivation and interregional coupling support the ability to learn related content in later situations. We find that offline processing of prior memories is associated with better subsequent learning. Our results provide a mechanistic account of the circumstances under which prior knowledge can come to facilitate—as opposed to interfere with—new learning, serving as a strong foundation upon which new content is encoded.

Abstract

Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face–object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal–neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal–neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes.

A mechanism underlying our current political paralysis

Thomas Edsall points to the fascinating work of Berkeley graduate students Broockman and Ahler, who puncture the common assumption that a large segment of the electorate is made up of moderates who hunger for centrist compromise. From their September paper, a pessimistic conclusion (slightly edited):

Because each citizen prefers a different mix of policies, there is no one mix a politician could adopt that would broadly satisfy citizens. (For example, a citizen might support liberal tax policies but be opposed to same-sex marriage, but would be defined as moderate if those responses are averaged.) Thus it is natural that many citizens appear frustrated with the choices they have in American elections; yet, given the relatively idiosyncratic nature of citizens’ own preference bundles, it is also unclear that there is dramatic room for improvement.

Because each citizen’s pattern of views across issues appears unique, each citizen is likely to be “disconnected” from the positions their representatives take in his or her own way, a situation which the election of more moderates – or more of any other one particular kind of politician – could not broadly resolve.

The only resolution of this impasse would seem to be for citizens to 'chill out' a bit on the moralistic energy of their 'right way' on a particular issue, and feel more tolerance for other positions. I remember in the 'good old days' of Lyndon Johnson's 1960's presidency, how opponents seemed willing to bend just a bit more and value getting a result, even if it compromised their values. (Even, by the way, though opponents of Medicare were perhaps more virulent than current opponents of The Affordable Care Act.)

Neural and cognitive characteristics of extraordinary altruists.

I pass on this fascinating piece from Marsh et al., who find that a larger than average size of the right amygdala in extreme altruists who are very responsive to fearful faces is the opposite of the smaller than average size and reduced responsiveness found in psychopaths who are usually callous and antisocial:

In this study, we used structural and functional magnetic resonance imaging to assess a population of extraordinary altruists: altruistic kidney donors who volunteered to donate a kidney to a stranger. Such donations meet the most stringent definitions of altruism in that they represent an intentional behavior that incurs significant costs to the donor to benefit an anonymous, nonkin other. Functional imaging and behavioral tasks included face-emotion processing paradigms that reliably distinguish psychopathic individuals from controls. Here we show that extraordinary altruists can be distinguished from controls by their enhanced volume in right amygdala and enhanced responsiveness of this structure to fearful facial expressions, an effect that predicts superior perceptual sensitivity to these expressions. These results mirror the reduced amygdala volume and reduced responsiveness to fearful facial expressions observed in psychopathic individuals. Our results support the possibility of a neural basis for extraordinary altruism. We anticipate that these findings will expand the scope of research on biological mechanisms that promote altruistic behaviors to include neural mechanisms that support affective and social responsiveness.

Anti-aging interventions: from elixirs to fasting.

de Cabo et al. have done a useful review of different approaches to delaying or reversing aging, and I pass on their abstract and two nice summary graphics.

The phenomenon of aging is an intrinsic feature of life. Accordingly, the possibility to manipulate it has fascinated humans likely since time immemorial. Recent evidence is shaping a picture where low caloric regimes and exercise may improve healthy senescence, and several pharmacological strategies have been suggested to counteract aging. Surprisingly, the most effective interventions proposed to date converge on only a few cellular processes, in particular nutrient signaling, mitochondrial efficiency, proteostasis, and autophagy. Here, we critically examine drugs and behaviors to which life- or healthspan-extending properties have been ascribed and discuss the underlying molecular mechanisms.

Figure 1.
-Health-Promoting Interventions against Age-Related Diseases
-Three distinct approaches are currently being tested as feasible strategies to counteract a series of disorders, whose risk of emergence is directly linked to increased age: (1) specific antiaging drugs, (2) fasting, which seems best associated to a beneficial diet that includes low protein consumption, and (3) periodic exercise. All of them have been shown to reduce the risk of age-related diseases in mammalian models, including neurodegeneration and cardiovascular disease, among others.

Figure 2.
-Molecular Targets for Caloric Restriction and Pharmacological Interventions against Premature Aging
-Caloric restriction promotes longevity through sirtuin activation as well as through inhibition of the insulin and TOR pathways, which both lead to stress resistance and autophagy activation. Resveratrol, rapamycin, and spermidine exert autophagy-dependent antiaging mechanisms that are exerted both at the cytosolic and nuclear levels. Whether resveratrol directly interacts with the sirtuin family member SIRT1 remains controversial. Metformin promotes AMPK activity and prevents oxidative damage. Ac, acetyl residue; HAT, histone acetyltransferase; AMPK, adenosine monophosphate-activated protein kinase; AKT/PKB, protein kinase B; CR, caloric restriction.

Update on ‘fitness age’ calculators…

The research group that originated the fitness age calculator that I mentioned in a post a year ago has tweaked their online calculator just a bit, so I pass on that link again. (The group has found that a simple list of questions can generate an estimate of peak oxygen intake, a predictor of longevity, that is similar to results obtained with a more exhaustive treadmill test.) I seem to be getting the same result, a fitness age (60) twelve years less than my chronological age (72).

Brain resting state network stimulation for psychiatric and neurological diseases

Fox et al. do a survey of therapy using either invasive approaches, such as deep brain stimulation (DBS), or noninvasive approaches, such as transcranial magnetic stimulation, and find that targets that are most effective in treating the same disease most often are nodes in the same brain network. I pass on their abstract and a summary graphic:

Brain stimulation, a therapy increasingly used for neurological and psychiatric disease, traditionally is divided into invasive approaches, such as deep brain stimulation (DBS), and noninvasive approaches, such as transcranial magnetic stimulation. The relationship between these approaches is unknown, therapeutic mechanisms remain unclear, and the ideal stimulation site for a given technique is often ambiguous, limiting optimization of the stimulation and its application in further disorders. In this article, we identify diseases treated with both types of stimulation, list the stimulation sites thought to be most effective in each disease, and test the hypothesis that these sites are different nodes within the same brain network as defined by resting-state functional-connectivity MRI. Sites where DBS was effective were functionally connected to sites where noninvasive brain stimulation was effective across diseases including depression, Parkinson's disease, obsessive-compulsive disorder, essential tremor, addiction, pain, minimally conscious states, and Alzheimer’s disease. A lack of functional connectivity identified sites where stimulation was ineffective, and the sign of the correlation related to whether excitatory or inhibitory noninvasive stimulation was found clinically effective. These results suggest that resting-state functional connectivity may be useful for translating therapy between stimulation modalities, optimizing treatment, and identifying new stimulation targets. More broadly, this work supports a network perspective toward understanding and treating neuropsychiatric disease, highlighting the therapeutic potential of targeted brain network modulation.

Fig. 2. Sites for invasive and noninvasive brain stimulation with the best evidence of therapeutic efficacy in each disease are functionally connected. For each disease, the site at which DBS is most effective is shown in red. Resting-state functional connectivity with this site is shown along with the correspondence to the site at which noninvasive stimulation is most effective in each disease (circles). Black circles indicate sites at which noninvasive excitatory stimulation (more than 5 Hz TMS [transcranial magnetic stimulation] or anodal tDCS [transcranial direct current stimulation]) has been reported to be efficacious. White circles indicate sites where inhibitory stimulation (less than 1 Hz TMS or cathodal tDCS) has been reported to be efficacious.

The amygdala as the hub of three brain networks supporting our social life.

I pass on this very useful summary by Bickart et al. that summarizes brain connectivity experiments in rodents, monkeys, and humans to develop a description that has the amygdala as a anchor in three partially distinct brain networks (serving perception, affiliation, and aversion) that each engage a distinct domain of social behavior. Their highlights, followed by the abstract and the main graphic:

Highlights

• We synthesize extant animal and human data to describe networks of the social brain. 

• The amygdala anchors 3 networks, each supporting a distinct social process. 

• People with stronger connectivity in 2 of these networks have larger social networks. 

• People with degeneration in these networks have corresponding social deficits. 

• We discuss future directions and implications for this novel componential framework.

Abstract

A growing body of evidence suggests that the amygdala is central to handling the demands of complex social life in primates. In this paper, we synthesize extant anatomical and functional data from rodents, monkeys, and humans to describe the topography of three partially distinct large-scale brain networks anchored in the amygdala that each support unique functions for effectively managing social interactions and maintaining social relationships. These findings provide a powerful componential framework for parsing social behavior into partially distinct neural underpinnings that differ among healthy people and disintegrate or fail to develop in neuropsychiatric populations marked by social impairment, such as autism, antisocial personality disorder, and frontotemporal dementia.

Here is their central graphic:

Figure: Topographic schematic of amygdala subregions and their affiliated large-scale networks subserving social cognition. A schematic of (a) the amygdala subregions in coronal view that are anchors for (b) three large-scale networks subserving processes important for social cognition. Abbreviations: Ins, insula; SS, somatosensory operculum; STS, superior temporal sulcus; dTP, dorsal temporal pole; OFC, orbitofrontal cortex; cACC, caudal anterior cingulate cortex; rACC, rostral anterior cingulate cortex; sgACC, subgenual anterior cingulate cortex; vmPFC, ventromedial prefrontal cortex; MTL, medial temporal lobe; FG, fusiform gyrus; vTP, ventral temporal pole; vlSt, ventrolateral striatum; vmSt, ventromedial striatum. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article.)

Breath counting as an objective behavioral measure of mindfulness.

Another fascinating piece of work from Richard Davidson's group at the University of Wisconsin, evaluating breath counting as a potential objective and rigorous behavioral measurement of mindfulness. (The technique of indexing mindfulness of breathing by breath counting is referenced as early as 430 AD.) A provisional PDF of the article describing four different studies evaluating this approach can be downloaded from the link.  I recommend that you read the discussion section.  For those who want just the bottom line, here it is from the abstract. They found:

...skill in breath counting associated with more meta-awareness, less mind wandering, better mood, and greater non-attachment (i.e. less attentional capture by distractors formerly paired with reward). We also found in a randomized online training study that 4 weeks of breath counting training improved mindfulness and decreased mind wandering relative to working memory training and no training controls.

The procedure followed was very straightforward:

We instructed 120 participants to “be aware… of the movement of breath” and count their breaths from 1 to 9 repeatedly. With breaths 1-8 they pressed one button, and on breath 9 they pressed another, measuring counting accuracy. Every ~90 sec (60-120 sec range) experience sampling probed state mind wandering and meta-awareness, respectively, with 2 6-point Likert scales, “just now where was your attention? [completely on-task / off task]” and “how aware were you of where your attention was? [completely aware / unaware].” Participants were then probed for their count.

Here is their abstract:

Mindfulness practice of present moment awareness promises many benefits, but has eluded rigorous behavioral measurement. To date, research has relied on self-reported mindfulness or heterogeneous mindfulness trainings to infer skillful mindfulness practice and its effects. In four independent studies with over 400 total participants, we present the first construct validation of a behavioral measure of mindfulness, breath counting. We found it was reliable, correlated with self-reported mindfulness, differentiated long-term meditators from age-matched controls, and was distinct from sustained attention and working memory measures. In addition, we employed breath counting to test the nomological network of mindfulness. As theorized, we found skill in breath counting associated with more meta-awareness, less mind wandering, better mood, and greater nonattachment (i.e. less attentional capture by distractors formerly paired with reward). We also found in a randomized online training study that 4 weeks of breath counting training improved mindfulness and decreased mind wandering relative to working memory training and no training controls. Together, these findings provide the first evidence for breath counting as a behavioral measure of mindfulness.

The power of play - Portal2 better than brain training software?

My son, who does what I consider to be magic with his coding of internet commercial websites (see Praxisis.com) has been playing computer games since the first Apple II appeared in my basement office in 1978, and he learned touch typing with the original Mavis Beacon teaches typing program. He is able to look at some extraordinarily difficult coding issue... and poof!, the solution seems to spontaneously materialize in his head. He just sent me this article pointing to one possible underpinning of his abilities, an article on the power of play, a comparison of the Portal 2 game and the Lumosity brain training games (see also my recent post on a critique of brain game claims, and a recent NY Times piece "Can Video Games Fend Off Mental Decline?"):

Highlights

• We tested subjects randomly assigned to play Portal 2 or Lumosity for 8 h.
• All were pre/post tested on problem solving, spatial skills, and persistence.
• Portal 2 players scored higher than Lumosity on all three constructs.
• Portal 2 players also showed significant gains on spatial tests.
• Lumosity subjects showed no gains on any measure.

Abstract

In this study, we tested 77 undergraduates who were randomly assigned to play either a popular video game (Portal 2) or a popular brain training game (Lumosity) for 8 h. Before and after gameplay, participants completed a set of online tests related to problem solving, spatial skill, and persistence. Results revealed that participants who were assigned to play Portal 2 showed a statistically significant advantage over Lumosity on each of the three composite measures—problem solving, spatial skill, and persistence. Portal 2 players also showed significant increases from pretest to posttest on specific small- and large-scale spatial tests while those in the Lumosity condition did not show any pretest to posttest differences on any measure. Results are discussed in terms of the positive impact video games can have on cognitive and noncognitive skills.

Let a Hundred McMansions Bloom

The Dong Dianhu Manor housing development west of Shanghai

How to chill on aggression...get blood glucose levels up.

Here is an interesting and quirky piece by Bushman et al. that has been languishing in my queue of potential posts for quite a while:

People are often the most aggressive against the people to whom they are closest—intimate partners. Intimate partner violence might be partly a result of poor self-control. Self-control of aggressive impulses requires energy, and much of this energy is provided by glucose derived from the food we eat. We measured glucose levels in 107 married couples over 21 days. To measure aggressive impulses, participants stuck 0–51 pins into a voodoo doll that represented their spouse each night, depending how angry they were with their spouse. To measure aggression, participants blasted their spouse with loud noise through headphones. Participants who had lower glucose levels stuck more pins into the voodoo doll and blasted their spouse with louder and longer noise blasts.

This is in line with a body of work (reviewed by Gailliot) suggesting that self-control requires and can deplete a limited energy source, glucose. A relationship between glucose utilization and aggression may be universal, it is also observed in honey bees and fruitflies (Li-Byarlay et al.)

Happiness and well-being sources.

I’m passing on three items from my queue of potential posts that touch on well-being and happiness. First, of course, there’s an App for that! Kit Eaton reviews three of these: Happify, iMoodJournal and Smiling Mind. Basaraba points to a number of sources on the health benefits of gratitude, as does Dashel Keltner’s Greater Good site. Finally, Reynolds points to studies just published in Cell Magazine that delve into the biochemical details of how exercise may protect us against depression.

Speaking out in a group correlates with gender.

The effectiveness of group decision-making depends on whether the best informed members actually contribute to the discussion. Coffman does a laboratory experiment to examine factors that influence an individual's propensity to contribute, finding that in general undergraduate women contribute less than men, but show the least reluctance for more female-stereotyped subject areas such as art and the most for male-stereotyped subject such as sports:

We use a lab experiment to explore the factors that predict an individual's decision to contribute her idea to a group. We find that contribution decisions depend upon the interaction of gender and the gender stereotype associated with the decision-making domain: conditional on measured ability, individuals are less willing to contribute ideas in areas that are stereotypically outside of their gender's domain. Importantly, these decisions are largely driven by self-assessments, rather than fear of discrimination. Individuals are less confident in gender incongruent areas and are thus less willing to contribute their ideas. Because even very knowledgeable group members under-contribute in gender incongruent categories, group performance suffers and, ex post, groups have difficulty recognizing who their most talented members are. Our results show that even in an environment where other group members show no bias, women in male-typed areas and men in female-typed areas may be less influential. An intervention that provides feedback about a woman's (man's) strength in a male-typed (female-typed) area does not significantly increase the probability that she contributes her ideas to the group. A back-of-the-envelope calculation reveals that a “lean in” style policy that increases contribution by women would significantly improve group performance in male-typed domains.

And, a related bit of work from Eddy et al. shows that although females outnumber males in biology, does a study of 23 different introductory biology classrooms that reveals systematic gender disparities in student performance on exams and student participation when instructors ask students to volunteer answers to instructor-posed questions.

Scientific evidence does not support anti-aging claims of the brain game industry.

MindBlog has done numerous posts on brain training games as possible antidotes to cognitive decline in the elderly. (I've played with both Merzenich's BrainHQ exercises and Luminosity exercises). The Stanford Center for Longevity and the Max Planck Institute for Human Development have together just issued a joint statement skeptical about the effectiveness of "brain game" products such as these (the full statement, with references, is here), signed by 69 prominent psychologists and cognitive scientists from around the world,  even including Adam Gazzaley at UCSF, who has a financial interest in the brain gaming industry (and whose PT Barnum approach to publicizing his work I have criticized - see also a a recent NY Times piece on Gazzaley "Can Video Games Fend Off Mental Decline?"). Daniel Schacter at Harvard is among the other prominent signatories.

I pass on their closing recommendations and summary:

Much more research needs to be done before we understand whether and what types of challenges and engagements benefit cognitive functioning in everyday life. In the absence of clear evidence, the recommendation of the group, based largely on correlational findings, is that individuals lead physically active, intellectually challenging, and socially engaged lives, in ways that work for them. Before investing time and money on brain games, consider what economists call opportunity costs: If an hour spent doing solo software drills is an hour not spent hiking, learning Italian, making a new recipe, or playing with your grandchildren, it may not be worth it. But if it replaces time spent in a sedentary state, like watching television, the choice may make more sense for you.

Physical exercise is a moderately effective way to improve general health, including brain fitness. Scientists have found that regular aerobic exercise increases blood flow to the brain, and helps to support formation of new neural and vascular connections. Physical exercise has been shown to improve attention, reasoning, and components of memory. All said, one can expect small but noticeable gains in cognitive performance, or attenuation of loss, from taking up aerobic exercise training.

A single study, conducted by researchers with financial interests in the product, or one quote from a scientist advocating the product, is not enough to assume that a game has been rigorously examined. Findings need to be replicated at multiple sites, based on studies conducted by independent researchers who are funded by independent sources. Moreover, participants of training programs should show evidence of significant advantage over a comparison group that does not receive the treatment but is otherwise treated exactly the same as the trained group.

No studies have demonstrated that playing brain games cures or prevents Alzheimer’s disease or other forms of dementia.

Do not expect that cognitively challenging activities will work like one-shot treatments or vaccines; there is little evidence that you can do something once (or even for a concentrated period) and be inoculated against the effects of aging in an enduring way. In all likelihood, gains won’t last long after you stop the challenge.

In summary: We object to the claim that brain games offer consumers a scientifically grounded avenue to reduce or reverse cognitive decline when there is no compelling scientific evidence to date that they do. The promise of a magic bullet detracts from the best evidence to date, which is that cognitive health in old age reflects the long-term effects of healthy, engaged lifestyles. In the judgment of the signatories, exaggerated and misleading claims exploit the anxiety of older adults about impending cognitive decline. We encourage continued careful research and validation in this field.

Humans and robots.

A recent issue of Science magazine has a special section of articles on the social life of robots. The introduction by Stone and Lavine provides links to the abstracts of the articles (full text is not open access). I pass on their introduction:

Autonomous machines have gripped our imagination ever since the first robot flickered on the silver screen, Maria (left) in the 1927 film Metropolis. Most of the robots we know today—unglamorous devices like robotic welders on car assembly lines and the Roomba vacuum cleaner—fall short of those in science fiction. But our relationship with robots is about to become far more intimate. Would you be comfortable with a robot butler, or a self-driving car? How about a robo-scientist toiling away next to you at the bench, not only pipetting but also formulating hypotheses and designing experiments?

As robots become more sophisticated, psychological paradoxes are coming into sharper relief. Robots that look human strike many of us as downright creepy (as this week's cover attests), while robots that act human—when they are programmed, for example, to cheat at cards—somehow put us at ease. And no matter how uncannily lifelike some of today's robots may seem, the resemblance is skin-deep. A stubborn challenge has been endowing robots with not only the capability to sense their environment, but also the wits to make sense of it. Robots will get there eventually, and when that happens we'll be confronted with a new array of ethical and moral questions. Questions like: Should robots be accorded rights as sentient beings? The rise of the machines will be anything but predictable.

And here is the abstract to one of the articles, "In our own image" by Dennis Normile:

For 2 decades, Hiroshi Ishiguro's teams have deployed various robots—some with vaguely human forms, others crafted to look indistinguishable from people—as customers in cafes, clerks in stores, guides in malls and museums, teachers in schools, and partners in recreational activities. The roboticists, who use robots both operating autonomously and under human remote control, have come to some startling conclusions. In some situations, people prefer to speak with an android instead of another person, and they feel that robots should be held accountable for mistakes and treated fairly. And humans can quickly form deep emotional bonds with robots. Some find the implications of the work worrisome. But with a wave of more sophisticated social robots about to hit the mass market, the debate is no longer academic.

Pianists’ brains are different from everyone else...

Because I'm a pianist who started lessons at age 6 and now usually give two concerts a year, I'm always fascinated by articles like this one from a music site (pointed out to me by my artistic daughter-in-law, who does improvisation theater), that points to several interesting studies on brain changes that are caused by high level music training, most pronounced if training is begun before age 7. Because the hands of pianists must negotiate 88 keys with ten fingers, sometimes playing 10 notes at once, the normal asymmetry of hand motor area of the brain associated with being right or left handed is reduced. (Usually the brain's central sulcus that contains the hand motor area is deeper on the dominant side.) Watson summarizes a number of other differences in hand and motor coordination. Also, high level music training enhances ability to integrate sensory information from hearing, touch, and sight. Brain circuits involved in musical improvisation are shaped by systematic training, leading to less reliance on working memory and more extensive connectivity within the brain. Finally, when experienced pianists play and improvise, they literally switch off the part of the brain associated with providing stereotypical responses, ensuring that they play with their own unique voice and not the voices of others.

Vitamin D prevents cognitive decline

...in aging rats, to be sure. Work like the following piece from my colleagues at the University of Wisconsin reinforces my determination to continue my vitamin D supplements (over the objection of my internist). At the risk of TMI (too much information), I can also report that I sense the association of my vitamin D (25-hydroxyvitamin D) levels with androgen (testosterone) levels that has been reported. Latimer et al.:

Significance

Higher blood levels of vitamin D are associated with better health outcomes. Vitamin D deficiency, however, is common among the elderly. Despite targets in the brain, little is known about how vitamin D affects cognitive function. In aging rodents, we modeled human serum vitamin D levels ranging from deficient to sufficient and tested whether increasing dietary vitamin D could maintain or improve cognitive function. Treatment was initiated at middle age, when markers of aging emerge, and maintained for ∼6 mo. Compared with low- or normal-dietary vitamin D groups, only aging rats on higher vitamin D could perform a complex memory task and had blood levels considered in the optimal range. These results suggest that vitamin D may improve the likelihood of healthy cognitive aging.

Abstract

Vitamin D is an important calcium-regulating hormone with diverse functions in numerous tissues, including the brain. Increasing evidence suggests that vitamin D may play a role in maintaining cognitive function and that vitamin D deficiency may accelerate age-related cognitive decline. Using aging rodents, we attempted to model the range of human serum vitamin D levels, from deficient to sufficient, to test whether vitamin D could preserve or improve cognitive function with aging. For 5–6 mo, middle-aged F344 rats were fed diets containing low, medium (typical amount), or high (100, 1,000, or 10,000 international units/kg diet, respectively) vitamin D3, and hippocampal-dependent learning and memory were then tested in the Morris water maze. Rats on high vitamin D achieved the highest blood levels (in the sufficient range) and significantly outperformed low and medium groups on maze reversal, a particularly challenging task that detects more subtle changes in memory. In addition to calcium-related processes, hippocampal gene expression microarrays identified pathways pertaining to synaptic transmission, cell communication, and G protein function as being up-regulated with high vitamin D. Basal synaptic transmission also was enhanced, corroborating observed effects on gene expression and learning and memory. Our studies demonstrate a causal relationship between vitamin D status and cognitive function, and they suggest that vitamin D-mediated changes in hippocampal gene expression may improve the likelihood of successful brain aging.

How culture shapes spatial conceptions of time - Is your past in front of, or behind you?

A interesting perspective from Fuente et al. on spatial conceptions of time. Some clips from their article:

Across many of the world’s languages, the future is “ahead” of the speaker, and the past is “behind.” In English, people can look “forward” to their retirement or look “back” on their childhood....yet some languages exhibit the opposite space-time mapping. In the Andean language Aymara, for example, metaphors place the past in front (e.g., nayra mara, tr. “front year,” means last year) and the future behind (e.g., qhipa marana, tr. “back year,” means next year)...In the research reported here, we investigated this question by exploring a surprising discovery about temporal language and thought in speakers of Darija, a Moroccan dialect of modern Arabic. Front-back time metaphors in Arabic are similar to metaphors in English and other future-in-front languages.

We compared how native Spanish and Darija speakers gesture when talking about past and future events. Whereas Spaniards showed a weak tendency to gesture according to the future-in-front mapping, Moroccans showed a strong tendency to gesture according to the past-in-front mapping—despite using future-in-front metaphors in speech. On the basis of their co-speech gestures, it appears that Darija speakers think about time like the Aymara do, even though they talk about it like speakers of English, Spanish, and other familiar future-in-front languages.

Since existing theories cannot explain the pattern of space-time mappings observed across cultures, we proposed an alternative explanation, the temporal-focus hypothesis: People’s implicit associations of “past” and “future” with “front” and “back” should depend on their temporal focus. That is, in people’s mental models, they should place in front of them whichever pole of the space-time continuum they tend to “focus on” metaphorically—locating it where they could focus on it literally with their eyes if events in time were visible objects. Consistent with the temporal-focus hypothesis, our results showed that, compared with Moroccans, Spaniards tend to be future focused, attributing more importance to social change, economic and technological progress, and modernization. By contrast, compared with Spaniards, Moroccans tend to be past focused, attributing more importance to older generations and respect for traditional practices.

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.