What happens in Vagus - compassion, positive emotion, vagal tone, and respiratory sinus arrhythmia,

The 10th cranial nerve, the vagus nerve, is distinctive to mammals and supports social engagement and nurturing behaviors as well as feeding, digesting, resting, breeding, etc. Its level of activity (tonus, or tension) is reflected in its inhibitory regulation of heartbeat, slowing it during exhalation and increasing it during inhalation. This change is heart rate is called respiratory sinus arrhythmia (RSA). Thus RSA serves as a measure of vagal tone. Dacher Keltner and collaborators have studied the relationship of vagal activity, reflected by RSA, to compassion and other prosocial emotions. I want to pass on the abstract from a preprint that can be downloaded here on studies correlating respiratory sinus arrhythmia with tonic (but not phasic) positive emotionality

Resting respiratory sinus arrhythmia (RSA_REST) indexes important aspects of individual differences in emotionality. In the present investigation, we address whether RSA_REST is associated with tonic positive or negative emotionality, and whether RSA_REST relates to phasic emotional responding to discrete positive emotion-eliciting stimuli. Across an 8-month, multiassessment study of first-year university students (n = 80), individual differences in RSA_REST were associated with positive but not negative tonic emotionality, assessed at the level of personality traits, long-term moods, the disposition toward optimism, and baseline reports of current emotional states. RSA_REST was not related to increased positive emotion, or stimulusspecific emotion, in response to compassion-, awe-, or pride-inducing stimuli. These findings suggest that resting RSA indexes aspects of a person’s tonic positive emotionality.

Reproducability in these studies may be an issue, because there is an apparent conflict between this abstracts report of no relationship between RSA_REST compassion-, awe-, or pride-inducing stimuli and the "increases in RSA during compassion" mentioned in Study 4 of the first link above. I might as well paste in that abstract also:

Compassion is an affective response to another’s suffering and a catalyst of prosocial behavior. In the present studies, we explore the peripheral physiological changes associated with the experience of compassion. Guided by long-standing theoretical claims, we propose that compassion is associated with activation in the parasympathetic autonomic nervous system through the vagus nerve. Across 4 studies, participants witnessed others suffer while we recorded physiological measures, including heart rate, respiration, skin conductance, and a measure of vagal activity called respiratory sinus arrhythmia (RSA). Participants exhibited greater RSA during the compassion induction compared with a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion lacking appraisals of another person’s suffering (Study 3). Greater RSA during the experience of compassion compared with the neutral or control emotion was often accompanied by lower heart rate and respiration but no difference in skin conductance. In Study 4, increases in RSA during compassion positively predicted an established composite of compassion-related words, continuous self-reports of compassion, and nonverbal displays of compassion. Compassion, a core affective component of empathy and prosociality, is associated with heightened parasympathetic activity.

If you simply google "vagus nerve" you will find sites listing means of enhancing vagus activity and tone by self stimulation to improve mood and functioning, as an antidote to anxiety, etc.

The science of mind wandering.

I want to pass on this reference to an Ann. Rev. of Psychology article by Smallwood and Schooler, an extensive review and description of mind wandering, its disengagement from external input, its costs and benefits, its association with medial brain structures of the default mode network, its regulation by more lateral frontal executive control and external attention networks, etc. Here is the abstract, followed by a useful summary graphic:

Conscious experience is fluid; it rarely remains on one topic for an extended period without deviation. Its dynamic nature is illustrated by the experience of mind wandering, in which attention switches from a current task to unrelated thoughts and feelings. Studies exploring the phenomenology of mind wandering highlight the importance of its content and relation to meta-cognition in determining its functional outcomes. Examination of the information-processing demands of the mind-wandering state suggests that it involves perceptual decoupling to escape the constraints of the moment, its content arises from episodic and affective processes, and its regulation relies on executive control. Mind wandering also involves a complex balance of costs and benefits: Its association with various kinds of error underlines its cost, whereas its relationship to creativity and future planning suggest its potential value. Although essential to the stream of consciousness, various strategies may minimize the downsides of mind wandering while maintaining its productive aspects.

Evidence for the default mode network (DMN) as the substrate of the self-generated thought. The DMN is a large-scale brain network defined by the temporal correlation between activity in two core regions on the medial surface of the cortex, known as the posterior cingulate and medial prefrontal cortex. These regions form the core of the DMN (yellow) and interact with subnetworks including the medial temporal lobe subsystem (green) and the dorsal medial subsystem (blue). Meta-analyses using Neurosynth have shown that the core of this system tends to be engaged in self-referential processes, the medial temporal subsystem is engaged by episodic processes, and the dorsal medial subsystem is engaged by social processes. Together, these forms of thought are similar to the content of the self-generated thoughts that often occur during mind wandering, providing important evidence for the involvement of these regions in the mental content that occurs during mind wandering. Studies using experience sampling in conjunction with functional magnetic resonance imaging have shown that these regions show heightened activity during periods of task-unrelated thought (a–c). These brain images show that regions of the core aspects of the DMN exhibited greater activity during periods of task-unrelated thought. Regions: A, dorsal anterior cingulate cortex; B, ventral-medial medial pre-frontal cortex; C, posterior cingulate cortex; D, right temporal-parietal junction; E, dorsal medial prefrontal cortex; F, left rostral-lateral prefrontal cortex.

Manipulating moral decisions by exploiting eye gaze.

Here is a fascinating piece of work from Pärnamets et al.:

Eye gaze is a window onto cognitive processing in tasks such as spatial memory, linguistic processing, and decision making. We present evidence that information derived from eye gaze can be used to change the course of individuals’ decisions, even when they are reasoning about high-level, moral issues. Previous studies have shown that when an experimenter actively controls what an individual sees the experimenter can affect simple decisions with alternatives of almost equal valence. Here we show that if an experimenter passively knows when individuals move their eyes the experimenter can change complex moral decisions. This causal effect is achieved by simply adjusting the timing of the decisions. We monitored participants’ eye movements during a two-alternative forced-choice task with moral questions. One option was randomly predetermined as a target. At the moment participants had fixated the target option for a set amount of time we terminated their deliberation and prompted them to choose between the two alternatives. Although participants were unaware of this gaze-contingent manipulation, their choices were systematically biased toward the target option. We conclude that even abstract moral cognition is partly constituted by interactions with the immediate environment and is likely supported by gaze-dependent decision processes. By tracking the interplay between individuals, their sensorimotor systems, and the environment, we can influence the outcome of a decision without directly manipulating the content of the information available to them.

We hypothesized that participants’ eye gaze reveals their decision process owing to general coupling between sensorimotor decision processes. By using a gaze-contingent probe and selecting when a decision is prompted the resulting choice can be biased toward a randomly predetermined option.

The Apple Watch will be making us more sociable and human??

I enjoy techie stuff (with the recent exception of taking too many hours to figure out wireless network problems that caused my Zeppelin AirPlay speaker to stop working), and like many others, have been wondering why on earth I would want to buy the forthcoming Apple Watch. Manjoo's recent NYTimes review makes an interesting point regarding whether the Watch would push us to new heights of collective narcissism:

...I became intrigued by the opposite possibility — that it could address some of the social angst wrought by smartphones. The Apple Watch’s most ingenious feature is its “taptic engine,” which alerts you to different digital notifications by silently tapping out one of several distinct patterns on your wrist. As you learn the taps over time, you will begin to register some of them almost subconsciously: incoming phone calls and alarms feel throbbing and insistent, a text feels like a gentle massage from a friendly bumblebee, and a coming calendar appointment is like the persistent pluck of a harp. After a few days, I began to get snippets of information from the digital world without having to look at the screen — or, if I had to look, I glanced for a few seconds rather than minutes.

If such on-body messaging systems become more pervasive, wearable devices can become more than a mere flashy accessory to the phone. The Apple Watch could usher in a transformation of social norms just as profound as those we saw with its brother, the smartphone — except, amazingly, in reverse.

Manjoo also notes in a companion article:

There is something magical about having a computer that no one notices right there on your wrist. I first experienced this magic while at lunch with a colleague. I’m usually a wreck at such meetings, because while I try to refrain from looking at my phone, my mind is constantly jonesing for the next digital hit.

Lunch today is different. My iPhone remains hidden deep in my pocket, and to all the world I am the picture of the predigital man. It is the middle of the workday, the busiest time for digital communication. Yet with the Apple Watch on my wrist, my mind remains calm, my compulsion to check the phone suddenly at bay. After spending the last few days customizing my notification settings, my watch is a hornet’s nest of activity. It buzzes every few minutes to indicate incoming email and texts, tweets or Slack messages.

The buzzes aren’t annoying. They go completely unnoticed by my colleague, while to an addict like me they’re little hits of methadone — just enough contact with the digital world to whet my appetite, but not nearly as immersive, and socially disruptive, as reaching for my phone and eyeing its screen. I not only register the watch’s buzzes, but several times while we’re chatting, I surreptitiously check its screen. I scan some incoming messages and tweets, and even flag a couple of emails for later.

At the end of the meal, I ask my colleague if she’s noticed me checking my watch. She is surprised; she hasn’t seen it.

Fowler's review in the Wall Street Journal suggests that, given the paucity of Apps at startup and the inevitable bug fixes that will be forthcoming, it might be judicious to let the dust settle and buy the Apple Watch 2 when it appears a bit further down the road. Or, if you are a techie addict, you might pay $400 for the 42mm Sport Version when it becomes available.

A drug for compassion?

Sáez et al. enhance human egalitarian behavior in humans with tolcapone - a drug approved for use with Parkinson's disease patients - which prolongs the effect of brain dopamine by inhibiting the enzyme that breaks it down.

Highlights and abstract from their paper:

•Dopamine is causally associated with human prosocial behavior
•Pharmacological dopamine enhancement led to prioritizing of egalitarian motives
•Computational modeling of inequity aversion captures drug-induced changes
•Results support involvement of dopamine in computing prosocial valuation signal 

Summary 

Egalitarian motives form a powerful force in promoting prosocial behavior and enabling large-scale cooperation in the human species. At the neural level, there is substantial, albeit correlational, evidence suggesting a link between dopamine and such behavior. However, important questions remain about the specific role of dopamine in setting or modulating behavioral sensitivity to prosocial concerns. Here, using a combination of pharmacological tools and economic games, we provide critical evidence for a causal involvement of dopamine in human egalitarian tendencies. Specifically, using the brain penetrant catechol-O-methyl transferase (COMT) inhibitor tolcapone, we investigated the causal relationship between dopaminergic mechanisms and two prosocial concerns at the core of a number of widely used economic games: (1) the extent to which individuals directly value the material payoffs of others, i.e., generosity, and (2) the extent to which they are averse to differences between their own payoffs and those of others, i.e., inequity. We found that dopaminergic augmentation via COMT inhibition increased egalitarian tendencies in participants who played an extended version of the dictator game. Strikingly, computational modeling of choice behavior revealed that tolcapone exerted selective effects on inequity aversion, and not on other computational components such as the extent to which individuals directly value the material payoffs of others. Together, these data shed light on the causal relationship between neurochemical systems and human prosocial behavior and have potential implications for our understanding of the complex array of social impairments accompanying neuropsychiatric disorders involving dopaminergic dysregulation.

A natural compound for chilling out?

As I sit here typing this morning, I'm munching on cocoa nibs, inspired by Friedman's review pointing to the work of Dincheva et al. on a gene whose enzyme product (fatty acid amide hydrolase, FAAH) deactivates and thus regulates the action of our endogenous cannabinoid anandamide (which cocoa nibs contain in small amounts).

Individuals with a common human mutation in the FAAH gene have higher brain levels of anandamide and lower levels of background anxiety, due to enhanced connectivity between the frontal lobes and the amygdala. Here is the Dincheva abstract describing actions of the FAAH gene in a mouse model:

Cross-species studies enable rapid translational discovery and produce the broadest impact when both mechanism and phenotype are consistent across organisms. We developed a knock-in mouse that biologically recapitulates a common human mutation in the gene for ​fatty acid amide hydrolase (​FAAH) (C385A; rs324420), the primary catabolic enzyme for the endocannabinoid ​anandamide. This common polymorphism impacts the expression and activity of ​FAAH, thereby increasing ​anandamide levels. Here, we show that the genetic knock-in mouse and human variant allele carriers exhibit parallel alterations in biochemisty, neurocircuitry and behaviour. Specifically, there is reduced ​FAAH expression associated with the variant allele that selectively enhances fronto-amygdala connectivity and fear extinction learning, and decreases anxiety-like behaviours. These results suggest a gain of function in fear regulation and may indicate for whom and for what anxiety symptoms ​FAAH inhibitors or exposure-based therapies will be most efficacious, bridging an important translational gap between the mouse and human.

Physical activity's 'modest' effects on cognitive vitality

Prakash et al., in the Annual Review of Psychology, have reviewed the epidemiological literature on physical activity and exercise and their relationship to cognition and age-associated neurodegenerative diseases such as Alzheimer's disease. While the abstract uses the word "modest" to describe the effect of physical activity on preserving or enhancing cognitive vitality, the numerous studies and meta-analyses they cite demonstrate a reduction in all-cause mortality of 20-30% associated with physical activity, and a 38% reduction in risk of cognitive decline in nondemented participants with high physical activity levels, and a 35% reduction in participants with low to moderate levels. Thus there is no evidence for an increase in relative risk reduction in cognitive decline as a function of increasing levels of physical activity. Here is their abstract:

We examine evidence supporting the associations among physical activity (PA), cognitive vitality, neural functioning, and the moderation of these associations by genetic factors. Prospective epidemiological studies provide evidence for PA to be associated with a modest reduction in relative risk of cognitive decline. An evaluation of the PA-cognition link across the life span provides modest support for the effect of PA on preserving and even enhancing cognitive vitality and the associated neural circuitry in older adults, with the majority of benefits seen for tasks that are supported by the prefrontal cortex and the hippocampus. The literature on children and young adults, however, is in need of well-powered randomized controlled trials. Future directions include a more sophisticated understanding of the dose-response relationship, the integration of genetic and epigenetic approaches, inclusion of multimodal imaging of brain-behavior changes, and finally the design of multimodal interventions that may yield broader improvements in cognitive function.

The transparent avatar in your brain.

While doing a review of some recent writing by Thomas Metzinger, I came across this brief and lucid video, which I pass on...

 

Awareness breaks down brain’s network modularity.

Godwin et al. provide an analysis showing that awareness emerges from global changes in the brain’s functional connectivity:

Neurobiological theories of awareness propose divergent accounts of the spatial extent of brain changes that support conscious perception. Whereas focal theories posit mostly local regional changes, global theories propose that awareness emerges from the propagation of neural signals across a broad extent of sensory and association cortex. Here we tested the scalar extent of brain changes associated with awareness using graph theoretical analysis applied to functional connectivity data acquired at ultra-high field while subjects performed a simple masked target detection task. We found that awareness of a visual target is associated with a degradation of the modularity of the brain’s functional networks brought about by an increase in intermodular functional connectivity. These results provide compelling evidence that awareness is associated with truly global changes in the brain’s functional connectivity.

Origins of Narcissism in Children

An interesting study from Brummelman et al. showing that narcissism in children is predicted by parental overvaluation, not by lack of parental warmth, apparently because children internalize parents' inflated views of them:

Narcissism levels have been increasing among Western youth, and contribute to societal problems such as aggression and violence. The origins of narcissism, however, are not well understood. Here, we report, to our knowledge, the first prospective longitudinal evidence on the origins of narcissism in children. We compared two perspectives: social learning theory (positing that narcissism is cultivated by parental overvaluation) and psychoanalytic theory (positing that narcissism is cultivated by lack of parental warmth). We timed the study in late childhood (ages 7–12), when individual differences in narcissism first emerge. In four 6-mo waves, 565 children and their parents reported child narcissism, child self-esteem, parental overvaluation, and parental warmth. Four-wave cross-lagged panel models were conducted. Results support social learning theory and contradict psychoanalytic theory: Narcissism was predicted by parental overvaluation, not by lack of parental warmth. Thus, children seem to acquire narcissism, in part, by internalizing parents’ inflated views of them (e.g., “I am superior to others” and “I am entitled to privileges”). Attesting to the specificity of this finding, self-esteem was predicted by parental warmth, not by parental overvaluation. These findings uncover early socialization experiences that cultivate narcissism, and may inform interventions to curtail narcissistic development at an early age.

Cognitive abilities across the lifespan.

Hartshorne and Germine do a massive analysis of changes in cognitive abilities across the life span, showing that digit symbol coding, digit span, vocabulary, working memory, and facial emotion perception peak and decline at different times, with the last of these continuing to improve into later ages.

For each task, the median (interior line), interquartile range (left and right edges of boxes), and 95% confidence interval (whiskers) are shown. WM = working memory.

Their abstract:

Understanding how and when cognitive change occurs over the life span is a prerequisite for understanding normal and abnormal development and aging. Most studies of cognitive change are constrained, however, in their ability to detect subtle, but theoretically informative life-span changes, as they rely on either comparing broad age groups or sparse sampling across the age range. Here, we present convergent evidence from 48,537 online participants and a comprehensive analysis of normative data from standardized IQ and memory tests. Our results reveal considerable heterogeneity in when cognitive abilities peak: Some abilities peak and begin to decline around high school graduation; some abilities plateau in early adulthood, beginning to decline in subjects’ 30s; and still others do not peak until subjects reach their 40s or later. These findings motivate a nuanced theory of maturation and age-related decline, in which multiple, dissociable factors differentially affect different domains of cognition.

The Singularity—an Urban Legend?

Clips from an interesting essay by Daniel Dennett:

The Singularity—the fateful moment when AI surpasses its creators in intelligence and takes over the world—is a meme worth pondering. It has the earmarks of an urban legend: a certain scientific plausibility ("Well, in principle I guess it's possible!") coupled with a deliciously shudder-inducing punch line ("We'd be ruled by robots!")

...these alarm calls distract us from a more pressing problem...we are on the verge of abdicating control to artificial agents that can't think, prematurely putting civilization on auto-pilot. The process is insidious because each step of it makes good local sense, is an offer you can't refuse. You'd be a fool today to do large arithmetical calculations with pencil and paper when a hand calculator is much faster and almost perfectly reliable...and why memorize train timetables when they are instantly available on your smart phone? Leave the map-reading and navigation to your GPS system; it isn't conscious; it can't think in any meaningful sense, but it's much better than you are at keeping track of where you are and where you want to go.

What's wrong with turning over the drudgery of thought to such high-tech marvels? Nothing, so long as (1) we don't delude ourselves, and (2) we somehow manage to keep our own cognitive skills from atrophying.

(1) It is very, very hard to imagine (and keep in mind) the limitations of entities that can be such valued assistants, and the human tendency is always to over-endow them with understanding—as we have known since Joe Weizenbaum's notorious Eliza program of the early 1970s. This is a huge risk, since we will always be tempted to ask more of them than they were designed to accomplish, and to trust the results when we shouldn't.

(2) Use it or lose it. As we become ever more dependent on these cognitive prostheses, we risk becoming helpless if they ever shut down. The Internet is not an intelligent agent (well, in some ways it is) but we have nevertheless become so dependent on it that were it to crash, panic would set in and we could destroy society in a few days. That's an event we should bend our efforts to averting now, because it could happen any day.

The real danger, then, is not machines that are more intelligent than we are usurping our role as captains of our destinies. The real danger is basically clueless machines being ceded authority far beyond their competence.

Quiet

From my long queue of potential MindBlog post items, I pull up Judith Warner’s 2012 review of Susan Cain’s Book “Quiet”, which argues for the power of introverts, and pass on a few clips from the review:

The introverts who are the subject of Susan Cain’s new book, “Quiet,” … view their tendency toward solitary activity, quiet reflection and reserve as “a second-class personality trait, somewhere between a disappointment and a pathology,” … Too often denigrated and frequently overlooked in a society that’s held in thrall to an “Extrovert Ideal — the omnipresent belief that the ideal self is gregarious, alpha and comfortable in the spotlight,”

Many of the self-avowed introverts she meets in the course of this book, which combines on-the-scenes reporting with a wide range of social science research and a fair bit of “quiet power” cheerleading, ape extroversion. Though some fake it well enough to make it, going along to get along in a country that rewards the out­going, something precious, the author says, is lost in this masquerade. Unchecked extroversion — a personality trait Cain ties to ebullience, excitability, dominance, risk-taking, thick skin, boldness and a tendency toward quick thinking and thoughtless action — has actually, she argues, come to pose a real menace of late. The outsize reward-seeking tendencies of the hopelessly ­outer-directed helped bring us the bank meltdown of 2008 as well as disasters like Enron, she claims. With our economy now in ruins, Cain writes, it’s time to establish “a greater balance of power” between those who rush to speak and do and those who sit back and think. Introverts — who, according to Cain, can count among their many virtues the fact that “they’re relatively immune to the lures of wealth and fame” — must learn to “embrace the power of quiet.” And extroverts should learn to sit down and shut up.

Warner is critical os several aspects of Cain’s book, such as the assumption that most introverts are actually suffering in their self-esteem, also:

...her definition of introversion — a temperamental inner-­directedness first identified as a core personality trait by Carl Jung in 1921 — widens constantly; by the end of the book, it has expanded to include all who are “reflective, cerebral, bookish, unassuming, sensitive, thoughtful, serious, contemplative, subtle, introspective, inner-directed, gentle, calm, modest, solitude-seeking, shy, risk-averse, thin-skinned.” This widening of the definition makes introversion so broad a category, including, basically, all that is wise and good, that it’s largely meaningless, except as yet another vehicle for promoting self-esteem

Altering the oxytocin receptor gene enhances perception of anger and fear.

Puglia et al. find that the epigenetic modification of methylating the DNA of the oxytocin receptor gene (OXTR) decreases the control of amygdala fear responses by brain regions involved in affect appraisal and emotion regulation. Thus individuals with higher levels of OXTR methylation are more reactive to negative emotional facial cues. Clips from their introduction:

A peripheral hormone and central neuromodulator, oxytocin influences a variety of social and affective processes including affiliative behaviors, care-giving, and stress reactivity. Intranasally administered, oxytocin has also been implicated in specialized components of social cognition, such as trust, envy, and mentalizing...One way oxytocin may influence behavior is through anxiety reduction; intranasal oxytocin has been shown to have anxiolytic effects on brain systems supporting affective responses to negatively arousing stimuli. These findings support oxytocin’s role in anxiety reduction and make it an attractive candidate in neurobiological models of psychiatric disorders...Methylation of 5′-Cytosine-phosphate-Guanine-3′ (CpG) dinucleotide pairs in DNA is a highly investigated epigenetic modification that may influence behavioral phenotypes. DNA methylation within the promoter region of OXTR is variable within the population, and methylation of specific OXTR CpG sites reduces transcription of the gene. High levels of OXTR methylation at these same sites have been associated with autism, callous unemotional traits, and anorexia nervosa, suggesting the utility of OXTR methylation as a biomarker of phenotypic variability.

Their abstract:

In humans, the neuropeptide oxytocin plays a critical role in social and emotional behavior. The actions of this molecule are dependent on a protein that acts as its receptor, which is encoded by the oxytocin receptor gene (OXTR). DNA methylation of OXTR, an epigenetic modification, directly influences gene transcription and is variable in humans. However, the impact of this variability on specific social behaviors is unknown. We hypothesized that variability in OXTR methylation impacts social perceptual processes often linked with oxytocin, such as perception of facial emotions. Using an imaging epigenetic approach, we established a relationship between OXTR methylation and neural activity in response to emotional face processing. Specifically, high levels of OXTR methylation were associated with greater amounts of activity in regions associated with face and emotion processing including amygdala, fusiform, and insula. Importantly, we found that these higher levels of OXTR methylation were also associated with decreased functional coupling of amygdala with regions involved in affect appraisal and emotion regulation. These data indicate that the human endogenous oxytocin system is involved in attenuation of the fear response, corroborating research implicating intranasal oxytocin in the same processes. Our findings highlight the importance of including epigenetic mechanisms in the description of the endogenous oxytocin system and further support a central role for oxytocin in social cognition. This approach linking epigenetic variability with neural endophenotypes may broadly explain individual differences in phenotype including susceptibility or resilience to disease.

Individuals with increased methylation of OXTR display elevated amygdala response to angry and fearful faces. Mean Z statistic values are plotted against percent OXTR methylation for each participant (n = 98). Gray shading indicates 95% confidence interval around the best-fit line. (Inset) Z statistic map of voxels shows significant main effect of OXTR methylation depicted in MNI space (y = 0), FDR corrected at q less than 0.05. Region of interest is depicted in blue.

Information overload is filter failure.

I pass on the following brief lucid piece by Jay Rosen.You might also have a look at Peder Zane's "In the Age of Information, Specializing to Survive."

Information Overload

We should retire the idea that goes by the name "information overload." It is no longer useful.

The Internet scholar Clay Shirky puts it well: "There's no such thing as information overload. There's only filter failure." If your filters are bad there is always too much to attend to, and never enough time. These aren't trends powered by technology. They are conditions of life.

Filters in a digital world work not by removing what is filtered out; they simply don't select for it. The unselected material is still there, ready to be let through by someone else's filter. Intelligent filters, which is what we need, come in three kinds:

A smart person who takes in a lot and tells you what you need to know. The ancient term for this is "editor." The front page of the New York Times still works this way.

An algorithm that sifts through the choices other smart people have made, ranks them, and presents you with the top results. That's how Google works— more or less.

A machine learning system that over time gets to know your interests and priorities and filters the world for you in a smarter and smarter way. Amazon uses systems like that. Here's the best definition of information that I know of: information is a measure of uncertainty reduced. It's deceptively simple. In order to have information, you need two things: an uncertainty that matters to us (we're having a picnic tomorrow, will it rain?) and something that resolves it (weather report.) But some reports create the uncertainty that is later to be solved.

Suppose we learn from news reports that the National Security Agency "broke" encryption on the Internet. That's information! It reduces uncertainty about how far the U.S. government was willing to go. (All the way.) But the same report increases uncertainty about whether there will continue to be a single Internet, setting us up for more information when that larger picture becomes clearer. So information is a measure of uncertainty reduced, but also of uncertainty created. Which is probably what we mean when we say: "well, that raises more questions than it answers."

Filter failure occurs not from too much information but from too much incoming "stuff" that neither reduces existing uncertainty nor raises questions that count for us. The likely answer is to combine the three types of filtering: smart people who do it for us, smart crowds and their choices, smart systems that learn by interacting with us as individuals. It's at this point that someone usually shouts out: what about serendipity? It's a fair point. We need filters that listen to our demands, but also let through what we have no way to demand because we don't know about it yet. Filters fail when they know us too well and when they don't know us well enough.

Expert listening to music alters gene transcription...So?

I can't resist comment on a piece generated by PsyBlog, "Classical Music's Surprising Effect on Genes Vital to Memory and Learning." ..."How 20 minutes of Mozart affects the expression of genes vital to learning, memory and more…" that points to work of Järvelä​ and collaborators, whose abstract states:

To verify whether listening to classical music has any effect on human transcriptome, we performed genome-wide transcriptional profiling from the peripheral blood of participants after listening to classical music (n = 48), and after a control study without music exposure (n = 15). As musical experience is known to influence the responses to music, we compared the transcriptional responses of musically experienced and inexperienced participants separately with those of the controls. Comparisons were made based on two subphenotypes of musical experience: musical aptitude and music education. In musically experienced participants, we observed the differential expression of 45 genes (27 up- and 18 down-regulated) and 97 genes (75 up- and 22 down-regulated) respectively based on subphenotype comparisons...

Apart from issues of control and sample sizes, there is the problem that almost distinctive behavior (athletic engagement, meditation, whatever, can be shown to alter genes transcription. Presenting a trained (versus a naive) person with stimuli in the trained area of expertise would be expected to alter the “transcriptome” to support the brain processing required for that expertise, regardless of what the area is (music, visual art, literature, athletics). We're a long way from being able to make much sense of or interpret the statements that conclude the abstract:

...the up-regulated genes are primarily known to be involved in the secretion and transport of dopamine, neuron projection, protein sumoylation, long-term potentiation and dephosphorylation. Down-regulated genes are known to be involved in ATP synthase-coupled proton transport, cytolysis, and positive regulation of caspase, peptidase and endopeptidase activities. One of the most up-regulated genes, alpha-synuclein (SNCA), is located in the best linkage region of musical aptitude on chromosome 4q22.1 and is regulated by GATA2, which is known to be associated with musical aptitude. Several genes reported to regulate song perception and production in songbirds displayed altered activities, suggesting a possible evolutionary conservation of sound perception between species. We observed no significant findings in musically inexperienced participants.

To be sure, primitive first steps such as these are useful, but it is unfortunate when their popularization by blogs vying for attention proceeds to overinterpretation and hyperbole.

Thought for the day: America devolving into a plutocracy...

A clip from Tom Engelhardt writing in Salon:

...let me be as clear as I can be about something that seems murky indeed: this period doesn’t represent a version, no matter how perverse or extreme, of politics as usual; nor is the 2016 campaign an election as usual; nor are we experiencing Washington as usual. Put together our 1% elections, the privatization of our government, the de-legitimization of Congress and the presidency, as well as the empowerment of the national security state and the U.S. military, and add in the demobilization of the American public (in the name of protecting us from terrorism), and you have something like a new ballgame.

While significant planning has been involved in all of this, there may be no ruling pattern or design. Much of it may be happening in a purely seat-of-the-pants fashion. In response, there has been no urge to officially declare that something new is afoot, let alone convene a new constitutional convention. Still, don’t for a second think that the American political system isn’t being rewritten on the run by interested parties in Congress, our present crop of billionaires, corporate interests, lobbyists, the Pentagon, and the officials of the national security state.

Out of the chaos of this prolonged moment and inside the shell of the old system, a new culture, a new kind of politics, a new kind of governance is being born right before our eyes. Call it what you want. But call it something. Stop pretending it’s not happening.

Transcranial direct current stimulation increases propensity to mind-wander

Alelrod et al. show that stimulation of the frontal lobe areas involved in our attentional network increase mind wandering associated with our default mode network (see previous posts here and here for discussion of these networks).

Humans mind-wander quite intensely. Mind wandering is markedly different from other cognitive behaviors because it is spontaneous, self-generated, and inwardly directed (inner thoughts). However, can such an internal and intimate mental function also be modulated externally by means of brain stimulation? Addressing this question could also help identify the neural correlates of mind wandering in a causal manner, in contrast to the correlational methods used previously (primarily functional MRI). In our study, participants performed a monotonous task while we periodically sampled their thoughts to assess mind wandering. Concurrently, we applied transcranial direct current stimulation (tDCS). We found that stimulation of the frontal lobes [anode electrode at the left dorsolateral prefrontal cortex (DLPFC), cathode electrode at the right supraorbital area], but not of the occipital cortex or sham stimulation, increased the propensity to mind-wander. These results demonstrate for the first time, to our knowledge, that mind wandering can be enhanced externally using brain stimulation, and that the frontal lobes play a causal role in mind-wandering behavior. These results also suggest that the executive control network associated with the DLPFC might be an integral part of mind-wandering neural machinery.

Impulse control with weak currents applied to the head - a new therapy?

Spieser et al. apply a very small current (1 milliamp) using the electrodes shown in the figure to slightly hyperpolarize, or make less excitable, the supplementary motor cortex, and find that this inhibits impulsive responses in a reaction time task.

To err is human. However, an inappropriate urge does not always result in error. Impulsive errors thus entail both a motor system capture by an urge to act and a failed inhibition of that impulse. Here we show that neuromodulatory electrical stimulation of the supplementary motor complex in healthy humans leaves action urges unchanged but prevents them from turning into overt errors. Subjects performed a choice reaction-time task known to trigger impulsive responses, leading to fast errors that can be revealed by analyzing accuracy as a function of poststimulus time. Yet, such fast errors are only the tip of the iceberg: electromyography (EMG) revealed fast subthreshold muscle activation in the incorrect response hand in an even larger proportion of overtly correct trials, revealing covert response impulses not discernible in overt behavior. Analyzing both overt and covert response tendencies enables to gauge the ability to prevent these incorrect impulses from turning into overt action errors. Hyperpolarizing the supplementary motor complex using transcranial direct current stimulation (tDCS) preserves action impulses but prevents their behavioral expression. This new combination of detailed behavioral, EMG, and tDCS techniques clarifies the neurophysiology of impulse control, and may point to avenues for improving impulse control deficits in various neurologic and psychiatric disorders.

Losing the music - Aging affects the perception of musical harmony

An open access article from Bones and Plack:

When two musical notes with simple frequency ratios are played simultaneously, the resulting musical chord is pleasing and evokes a sense of resolution or “consonance”. Complex frequency ratios, on the other hand, evoke feelings of tension or “dissonance”. Consonance and dissonance form the basis of harmony, a central component of Western music. In earlier work, we provided evidence that consonance perception is based on neural temporal coding in the brainstem (Bones et al., 2014). Here, we show that for listeners with clinically normal hearing, aging is associated with a decline in both the perceptual distinction and the distinctiveness of the neural representations of different categories of two-note chords. Compared with younger listeners, older listeners rated consonant chords as less pleasant and dissonant chords as more pleasant. Older listeners also had less distinct neural representations of consonant and dissonant chords as measured using a Neural Consonance Index derived from the electrophysiological “frequency-following response.” The results withstood a control for the effect of age on general affect, suggesting that different mechanisms are responsible for the perceived pleasantness of musical chords and affective voices and that, for listeners with clinically normal hearing, age-related differences in consonance perception are likely to be related to differences in neural temporal coding.

By the way, the same issue of J. Neuroscience has another interesting article by Vaden et al. on noting cingulo-opercular cortical activity that predicts how well older adults recognize speech in noise.