Antidepressant and nerve growth stimulating effects of exercise - a mechanism.

Yau et al. find that a hormone secreted by fat cells during exercise alleviates depression-like behaviors in mice and boosts new nerve cell synthesis in the hippocampus. The hormone, or compounds that enhance its effectiveness, are potential antidepressant drugs. I copy below their significance section and the abstract with some of the chemical details.

Significance

This study unmasks a previously unidentified functional role of adiponectin (a hormone secreted by adipocytes) in modulating hippocampal neurogenesis and alleviating depression-like behaviors. To our knowledge, this is the first report showing that adiponectin may be an essential factor that mediates the antidepressant effects of physical exercise on the brain by adiponectin receptor 1-mediated activation of AMP-activated protein kinase. Our results reveal a possible mechanism by which exercise increases hippocampal neurogenesis and also suggest a promising therapeutic treatment for depression.

Abstract

Adiponectin (ADN) is an adipocyte-secreted protein with insulin-sensitizing, antidiabetic, anti-inflammatory, and antiatherogenic properties. Evidence is also accumulating that ADN has neuroprotective activities, yet the underlying mechanism remains elusive. Here we show that ADN could pass through the blood–brain barrier, and elevating its levels in the brain increased cell proliferation and decreased depression-like behaviors. ADN deficiency did not reduce the basal hippocampal neurogenesis or neuronal differentiation but diminished the effectiveness of exercise in increasing hippocampal neurogenesis. Furthermore, exercise-induced reduction in depression-like behaviors was abrogated in ADN-deficient mice, and this impairment in ADN-deficient mice was accompanied by defective running-induced phosphorylation of AMP-activated protein kinase (AMPK) in the hippocampal tissue. In vitro analyses indicated that ADN itself could increase cell proliferation of both hippocampal progenitor cells and Neuro2a neuroblastoma cells. The neurogenic effects of ADN were mediated by the ADN receptor 1 (ADNR1), because siRNA targeting ADNR1, but not ADNR2, inhibited the capacity of ADN to enhance cell proliferation. These data suggest that adiponectin may play a significant role in mediating the effects of exercise on hippocampal neurogenesis and depression, possibly by activation of the ADNR1/AMPK signaling pathways, and also raise the possibility that adiponectin and its agonists may represent a promising therapeutic treatment for depression.

Aging: sit less and shape up your attitude

I'm continuing to clean out my queue of aging articles that have been languishing as potential posts...

Reynolds points to two studies. In one, Swedish researchers showed that a group of 68 year old couch potatoes who spent less time sitting and more time in an exercise program had longer telomere caps at the end of their DNA (the caps shorten with aging). The interesting finding was that this was related not to the exercise, but to simply not sitting down as much. A second article reviewed a large database of Canadian adults to find that longer amounts to time spent standing correlated with lower mortality rates.

Span does a review (linking to original articles) of work showing, for example that people who hold more positive views towards aging live 7.5 years longer on average than those who think negatively about aging, and recover more quickly from disabilities. Age stereotypes have a powerful effect, people become what they think. Thinking of older age as a time when one can feel capable, active, full of life, a time of wisdom, self-realization and satisfaction, is rather different from imagining it to be a time of becoming useless, helpless or devalued. A growing body of research shows that people with the latter attitudes are less likely to seek preventive medical care and die earlier, and more likely to suffer memory loss and poor physical functioning.

One interesting bit of work shows that subliminal intervention (flashing positive about aging on a screen so briefly that the brain registers them but they are not perceived) significantly strengthened positive age stereotypes and self-perceptions of age. The abstract:

Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age = 61–99 years, M = 81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention’s impact was greater than the explicit intervention’s impact. The physical-function effect of the implicit intervention surpassed a previous study’s 6-month-exercise-intervention’s effect with participants of similar ages. The current study’s findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time.

Mind wandering that makes effort more efficient.

MindBlog has done numerous posts on our brains' default mode and executive control networks, with the idea usually being that activating the default network or mind wandering during an attention demanding task can impair performance. Spreng et al. now do a study showing that it also can improve performance if the mind wandering is congruent with the task itself. In this case the default and executive control networks appear to relate external goals and internal meaning:

Substantial neuroimaging evidence suggests that spontaneous engagement of the default network impairs performance on tasks requiring executive control. We investigated whether this impairment depends on the congruence between executive control demands and internal mentation. We hypothesized that activation of the default network might enhance performance on an executive control task if control processes engage long-term memory representations that are supported by the default network. Using fMRI, we scanned 36 healthy young adult humans on a novel two-back task requiring working memory for famous and anonymous faces. In this task, participants (1) matched anonymous faces interleaved with anonymous face, (2) matched anonymous faces interleaved with a famous face, or (3) matched a famous faces interleaved with an anonymous face. As predicted, we observed a facilitation effect when matching famous faces, compared with anonymous faces. We also observed greater activation of the default network during these famous face-matching trials. The results suggest that activation of the default network can contribute to task performance during an externally directed executive control task. Our findings provide evidence that successful activation of the default network in a contextually relevant manner facilitates goal-directed cognition.

What is literature good for?

I pass on this fetching clutch of points on the usefulness of reading literature (rather than brief tweets, and blog posts like this) from Alain de Botton's School of Life, via Maria Popova's "Brain Pickings" (both are sites well worth checking out). Literature:

SAVES YOU TIME

It looks like it's wasting time, but literature is actually the ultimate time-saver – because it gives us access to a range of emotions and events that it would take you years, decades, millennia to try to experience directly. Literature is the greatest reality simulator – a machine that puts you through infinitely more situations than you can ever directly witness.

MAKES YOU NICER

Literature performs the basic magic of what things look like though someone else's point of view; it allows us to consider the consequences of our actions on others in a way we otherwise wouldn't; and it shows us examples of kindly, generous, sympathetic people.

Literature deeply stands opposed to the dominant value system – the one that rewards money and power. Writers are on the other side – they make us sympathetic to ideas and feelings that are of deep importance but can't afford airtime in a commercialized, status-conscious, and cynical world.

IS A CURE FOR LONELINESS

We're weirder than we like to admit. We often can't say what's really on our minds. But in books we find descriptions of who we genuinely are and what events, described with an honesty quite different from what ordinary conversation allows for. In the best books, it's as if the writer knows us better than we know ourselves – they find the words to describe the fragile, weird, special experiences of our inner lives... Writers open our hearts and minds, and give us maps to our own selves, so that we can travel in them more reliably and with less of a feeling of paranoia or persecution...

PREPARES YOU FOR FAILURE

All of our lives, one of our greatest fears is of failure, of messing up, of becoming, as the tabloids put it, "a loser." Every day, the media takes us into stories of failure. Interestingly, a lot of literature is also about failure – in one way or another, a great many novels, plays, poems are about people who messed up... Great books don't judge as harshly or as one-dimensionally as the media...

Why do we like sad music?

I have earlier noted work on how, in both Eastern and Western music and vocalization, major modes are associated with positive emotions, and minor modes with darker emotions, and I've also mentioned Kawakami's work on how music can be perceived as sad, but yet be accompanied by the experience of positive emotions. Now Taruffi and Koelsch have done an online survey with both Western and Eastern participants (N = 772) that probes the rewarding aspects of music-evoked sadness. Their results suggest four different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no “real-life” implications:

This study explores listeners’ experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no “real-life” implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

Positive thinking can sabotage desired outcomes.

The point is a simple one - imagining success in attaining a goal can make one strive less diligently towards it. Gabriele Oettingen has summarized her research over the past 15-20 years on how this plays out in different areas of endeavour, in a new book “Rethinking Positive Thinking: Inside the New Science of Motivation.” (I know this because she has done what now seems imperative for for getting one's ideas to briefly rise about the noise level facing readers in the general public: she has done a marketing piece in The New York Times - another example of this is Graziano's piece on his theory of consciousness also in the "Gray Matter" NYTimes series - to which I devoted an extended MindBlog post ).

Oettingen's NYTimes piece gives links to her studies showing that women in a weight reduction program who imaged successful completion of the program lost fewer pounds than those who imagined themselves less positively, and that students instructed to imagine a great week ahead report feeling less energized and accomplish less than students instructed to write down any thoughts about the coming week. She then notes experiments on what she suggests as the most effective strategy, combining positive thinking with realism by mentally contrasting them.

A mechanism underlying intractable political conflicts.

Waytz et al. do an interesting piece of work directly relevant to the polarized mid-term election that just occurred, finding a cognitive bias that drives conflict between American Democrats and Republicans and ethnoreligious conflict between Israelis and Palestinians. (Note, "ingroup love" refers to compassion and empathy toward one's own group, and "outgroup hate" refers to dislike and animosity toward the opposing group.) I pass on both the significance statement and the abstract:

Significance

Political conflict between American Democrats and Republicans and ethnoreligious conflict between Israelis and Palestinians seem intractable, despite the availability of reasonable compromise solutions in both cases. This research demonstrates a fundamental cognitive bias driving such conflict intractability: Adversaries attribute their ingroup’s actions to ingroup love more than outgroup hate and attribute their outgroup’s actions to outgroup hate more than ingroup love. This biased attributional pattern increases beliefs and intentions associated with conflict intractability, including unwillingness to negotiate and unwillingness to vote for compromise solutions. In addition, offering financial incentives for accuracy in evaluating one’s outgroup mitigates this biased attributional pattern and its consequences. Understanding this bias and how to alleviate it can contribute to conflict resolution on a global scale.

Abstract

Five studies across cultures involving 661 American Democrats and Republicans, 995 Israelis, and 1,266 Palestinians provide previously unidentified evidence of a fundamental bias, what we term the “motive attribution asymmetry,” driving seemingly intractable human conflict. These studies show that in political and ethnoreligious intergroup conflict, adversaries tend to attribute their own group’s aggression to ingroup love more than outgroup hate and to attribute their outgroup’s aggression to outgroup hate more than ingroup love. Study 1 demonstrates that American Democrats and Republicans attribute their own party’s involvement in conflict to ingroup love more than outgroup hate but attribute the opposing party’s involvement to outgroup hate more than ingroup love. Studies 2 and 3 demonstrate this biased attributional pattern for Israelis and Palestinians evaluating their own group and the opposing group’s involvement in the current regional conflict. Study 4 demonstrates in an Israeli population that this bias increases beliefs and intentions associated with conflict intractability toward Palestinians. Finally, study 5 demonstrates, in the context of American political conflict, that offering Democrats and Republicans financial incentives for accuracy in evaluating the opposing party can mitigate this bias and its consequences. Although people find it difficult to explain their adversaries’ actions in terms of love and affiliation, we suggest that recognizing this attributional bias and how to reduce it can contribute to reducing human conflict on a global scale.

Aging - predictors of cognitive abilities.

The Oct. 31 issue of Science Magazine has a special section of articles on the aging brain. I point in particular to Underwood's article, "Starting young", which describes the followup on a Scottish national intelligence test performed on every 11 year old in the country in 1932 and 1947. The finding was that an individual's level of intelligence at age 11 is the most powerful predictor of late-life cognitive ability — not diet, social engagement, or any other virtuous activity. Scores at age 11 predicted about 50% of the variance in the IQs at age 77 in a cohort of individuals living in the Lothian region near Edinburgh (1641 of the original 5000 people tested were assessed.) Note the bottom line indicated in the final clip below:

By having an intelligence measure from even earlier in life, the Lothian studies are helping distinguish glitter from gold in the vast literature on factors correlated with cognition. A good recent example is Deary's analysis of the potential benefits of drinking, Thompson says. A smattering of correlational studies suggest that drinking small amounts of wine has positive effects on cognition late in life—indeed, Deary initially found a similar result when he first looked for a relationship between alcohol consumption and cognitive performance in the Lothian cohort. When he accounted for the participants' IQ scores on the Scottish Mental Survey, however, the perceived benefit dissolved. Rather than gaining cognitive benefit from drinking wine when they were older, “people who drank more were already likely to be smart,” Deary says.

The Lothian cohort has similarly challenged other reported influences on cognition, such as diet, body mass index, and caffeine consumption. None of those factors seems to have any effect on cognitive skills in the Lothian cohort when childhood intelligence is accounted for, Deary says. Even the effects of social and intellectual activity disappeared when he took into account how bright children were at age 11, possibly because those children are more likely to end up being socially and intellectually engaged.

And a final clip:

...the growing body of data from the Lothian Birth Cohort studies and other aging research supports a theory that some describe irreverently, and a little brutally, as the “water tank hypothesis”: The better put-together your brain is early on, thanks to good genes and, to some extent, a favorable early life environment, the more cognitive reserves you have to lose to neurodegeneration. In other words, Martin says, “the more you start out with in the tank, the longer it takes to draw down.”

Liberals and conservatives have different smell preferences.

A post faintly appropriate to this election day that is deciding the outcomes of very polarized contests of liberals and conservatives...Arthur Brooks points to an interesting article by McDermott et al. suggesting that our human mate preference - known to influenced more by political attitudes more than any other social, behavioral, or physical trait except religion - may be reflected in our smell preferences! Some clips from McDermott et al.:

Here we integrate extant studies of attraction, ideology, and olfaction and explore the possibility that assortation on political attitudes may result, in part, from greater attraction to the scent of those with shared ideology. We conduct a study in which individuals evaluated the body odor of unknown others, observing that individuals are more attracted to their ideological concomitants.

We conducted a study where participants rated the attractiveness of the body odor of unknown strong liberals and strong conservatives, hereafter referred to as “target” subjects; all “evaluator” subjects remained blind to the ideology of the target samples. One hundred forty-six participants between 18–40 years old were drawn from a large city in the northeast United States... Twenty-one target participants were selected for their high scores on opposite ends of the political spectrum (10 liberals and 11 conservatives) and provided body odor samples...Eleven of these target participants were female and 10 were male. Ideology was measured using the standard 7-point (strongly liberal to strongly conservative) American National Election Studies (ANES) self-report measure.

... individuals find the smell of those who are more ideologically similar to themselves more attractive than those endorsing opposing ideologies; recall that participants never saw the individuals whose smells they were evaluating, and the order of target subjects was randomized for each evaluator. Thus, the recognition of political alignment occurred through the medium of attraction, not recognition.

Some insight on the potency of odor might be gained from the participants’ comments and physical reactions during the study... a participant asked the experimenter if she could take one of the vials home with her because she thought it was “the best perfume I ever smelled”; the vial was from a male who shared an ideology similar to the evaluator. She was preceded by another respondent with an ideology opposite to the person who provided the exact same sample; this participant reported that that vial had “gone rancid” and suggested it needed to be replaced. In this way, different participants experienced the exact same stimulus in radically different ways only moments apart.

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.)