We examined whether 21-month-old infants could distinguish between two broad types of social power: respect-based power exerted by a leader (who might be an authority figure with legitimate power, a prestigious individual with merited power, or some combination thereof) and fear-based power exerted by a bully. Infants first saw three protagonists interact with a character who was either a leader (leader condition) or a bully (bully condition). Next, the character gave an order to the protagonists, who initially obeyed; the character then left the scene, and the protagonists either continued to obey (obey event) or no longer did so (disobey event). Infants in the leader condition looked significantly longer at the disobey than at the obey event, suggesting that they expected the protagonists to continue to obey the leader in her absence. In contrast, infants in the bully condition looked equally at the two events, suggesting that they viewed both outcomes as plausible: The protagonists might continue to obey the absent bully to prevent further harm, or they might disobey her because her power over them weakened in her absence. Additional results supported these interpretations: Infants expected obedience when the bully remained in the scene and could harm the protagonists if defied, but they expected disobedience when the order was given by a character with little or no power over the protagonists. Together, these results indicate that by 21 months of age, infants already hold different expectations for subordinates’ responses to individuals with respect-based as opposed to fear-based power.
This blog reports new ideas and work on mind, brain, behavior, psychology, and politics - as well as random curious stuff. (Try the Dynamic Views at top of right column.)
Monday, September 24, 2018
Infants distinguish between leaders and bullies
From Margoni et al:
Friday, September 21, 2018
Giving Ecstasy to Octopuses
Edsinger and Dölen have found out how to make the normally shy and retiring octopus into a party animal. They found that MDMA (phenethylamine (+/−)-3,4-methylendioxymethamphetamine, also known as Ecstasy) has prosocial effects, just as it does in humans. The indicates that the role of the serotonergic neurotransmission (that MDMA acts on) in regulating social behaviors has been evolutionarily conserved over 500 million years.
Human and octopus lineages are separated by over 500 million years of evolution and show divergent anatomical patterns of brain organization. Despite these differences, growing evidence suggests that ancient neurotransmitter systems are shared across vertebrate and invertebrate species and in many cases enable overlapping functions. Sociality is widespread across the animal kingdom, with numerous examples in both invertebrate (e.g., bees, ants, termites, and shrimps) and vertebrate (e.g., fishes, birds, rodents, and primates) lineages [6]. Serotonin is an evolutionarily ancient molecule that has been implicated in regulating both invertebrate and vertebrate social behaviors, raising the possibility that this neurotransmitter’s prosocial functions may be conserved across evolution. Members of the order Octopoda are predominantly asocial and solitary. Although at this time it is unknown whether serotonergic signaling systems are functionally conserved in octopuses, ethological studies indicate that agonistic behaviors are suspended during mating, suggesting that neural mechanisms subserving social behaviors exist in octopuses but are suppressed outside the reproductive period. Here we provide evidence that, as in humans, the phenethylamine (+/−)-3,4-methylendioxymethamphetamine (MDMA) enhances acute prosocial behaviors in Octopus bimaculoides. This finding is paralleled by the evolutionary conservation of the serotonin transporter (SERT, encoded by the Slc6A4 gene) binding site of MDMA in the O. bimaculoides genome. Taken together, these data provide evidence that the neural mechanisms subserving social behaviors exist in O. bimaculoides and indicate that the role of serotonergic neurotransmission in regulating social behaviors is evolutionarily conserved.
Blog Categories:
animal behavior,
evolution/debate,
social cognition
Thursday, September 20, 2018
Building molecular machines.
In an open source PNAS news article, Stephen Ornes describes efforts to build molecular machines modeled on our own biochemical processes - possibly artificial muscles or molecular electronics. It makes a fascinating read. A few clips:
Some of the smallest, most useful machines known to science are the biological molecules that keep living things living. The protein myosin drives the contraction and relaxation of muscle. Kinesin drags cellular cargo around the cell. Motor enzymes unwind, rewind, and maintain DNA, and bacteria use a molecular motor to rotate their whip-like flagella up to 100,000 times per minute, propelling them forward. These machines turn chemical energy into motion. They’re very efficient at their jobs.
The idea of using molecules to build minuscule machines that perform useful tasks dates back at least to a lecture given in 1959 by physicist Richard Feynman titled “There’s Plenty of Room at the Bottom.”* More recently, demonstrations of artificial molecular machines offer good reasons to think that such devices are feasible. Researchers have forged motors, shuttles, elevators, walkers, and pumps out of molecules, and powered them with electrical energy, chemical reactions, or light. Tiny motor by tiny motor, these demonstrations are inching toward future applications that could range from molecular electronics to artificial muscles.
...molecular machines are by nature floppy, like the soft matter that makes up the human body, whereas macroscopic machines are typically made from rigid materials such as metal. But it’s also a consequence of scale. Although the laws of physics don’t change in the nanoworld, their relative influences do. Concepts such as inertia and momentum—critical to the design of machines like cars and planes—become irrelevant. So does gravity, because molecules have such a small mass. Movement at the nanoscale is dominated instead by viscosity and Brownian motion, the random bumbling of individual molecules caused by thermal fluctuations...Katsonis calls this molecular environment a “Brownian storm.” In a 2007 article on the physics of nanoscale machines, physicist R. Dean Astumian at the University of Maine in Orono, ME, likened the challenges to swimming in molasses and walking in a hurricane.The article gives numerous examples of efforts to develop nanoscale motors driven by electrical energy, chemical energy, or light.
Sunday, September 16, 2018
Mapping our subjective feelings.
Nummenmaa et al. do a massive job of data gathering whose purpose left me scratching my head on first sight...wondering why such an effort is useful. But then, if someone asked me how I would describe my subjective experience I wouldn't know where to start. In the introduction to their open source article they "use the word feeling to simply refer to the current, subjectively accessible phenomenological state of an individual...Despite the centrality of subjective feelings to ourselves and our conscious well-being, the relative organization and determinants of different feelings have remained poorly understood. " I pass on their abstract and a summary graphic from the article.
Significance
Significance
Subjective feelings are a central feature of human life, yet their relative organization has remained elusive. We mapped the “human feeling space” for 100 core feelings ranging from cognitive and affective processes to somatic sensations; in the analysis, we combined basic dimension rating, similarity mapping, bodily sensation mapping, and neuroimaging meta-analysis. All feelings were emotionally loaded, and saliencies of bodily and mental experiences were correlated. Feelings formed five groups: positive emotions, negative emotions, cognitive processes, somatic states, and homeostatic states. Feeling space was best explained by emotionality, mental experience, and bodily sensation topographies. Subjectively felt similarity of feelings was associated with basic feeling dimensions and the bodily sensation maps. This shows that subjective feelings are categorical, emotional, and embodied.Abstract
Subjective feelings are a central feature of human life. We defined the organization and determinants of a feeling space involving 100 core feelings that ranged from cognitive and affective processes to somatic sensations and common illnesses. The feeling space was determined by a combination of basic dimension rating, similarity mapping, bodily sensation mapping, and neuroimaging meta-analysis. A total of 1,026 participants took part in online surveys where we assessed (i) for each feeling, the intensity of four hypothesized basic dimensions (mental experience, bodily sensation, emotion, and controllability), (ii) subjectively experienced similarity of the 100 feelings, and (iii) topography of bodily sensations associated with each feeling. Neural similarity between a subset of the feeling states was derived from the NeuroSynth meta-analysis database based on the data from 9,821 brain-imaging studies. All feelings were emotionally valenced and the saliency of bodily sensations correlated with the saliency of mental experiences associated with each feeling. Nonlinear dimensionality reduction revealed five feeling clusters: positive emotions, negative emotions, cognitive processes, somatic states and illnesses, and homeostatic states. Organization of the feeling space was best explained by basic dimensions of emotional valence, mental experiences, and bodily sensations. Subjectively felt similarity of feelings was associated with basic feeling dimensions and the topography of the corresponding bodily sensations. These findings reveal a map of subjective feelings that are categorical, emotional, and embodied.Here is their two dimensional map of feeling space (click to enlarge, or better, click link to original open source article.)
Blog Categories:
emotion,
emotions,
fear/anxiety/stress,
self
Thursday, September 13, 2018
Details of how a fear response is unlearned.
Learning requires the formation of new nerve connections. When that learning is extinguished are those connections inhibited or lost? Wan Lai et al. provide evidence for the latter:
Significance
Significance
Whether learning-induced changes in neuronal circuits are inhibited or erased during the process of unlearning remains unclear. In this study, we examined the impact of auditory-cued fear conditioning and extinction on the remodeling of synaptic connections in the living mouse auditory cortex. We found that fear conditioning leads to cue-specific formation of new postsynaptic dendritic spines, whereas fear extinction preferentially eliminates these new spines in a cue-specific manner. Our findings suggest that learning-related changes of synaptic connections in the cortex are at least partially reversed after unlearning.Abstract
Fear conditioning-induced behavioral responses can be extinguished after fear extinction. While fear extinction is generally thought to be a form of new learning, several lines of evidence suggest that neuronal changes associated with fear conditioning could be reversed after fear extinction. To better understand how fear conditioning and extinction modify synaptic circuits, we examined changes of postsynaptic dendritic spines of layer V pyramidal neurons in the mouse auditory cortex over time using transcranial two-photon microscopy. We found that auditory-cued fear conditioning induced the formation of new dendritic spines within 2 days. The survived new spines induced by fear conditioning with one auditory cue were clustered within dendritic branch segments and spatially segregated from new spines induced by fear conditioning with a different auditory cue. Importantly, fear extinction preferentially caused the elimination of newly formed spines induced by fear conditioning in an auditory cue-specific manner. Furthermore, after fear extinction, fear reconditioning induced reformation of new dendritic spines in close proximity to the sites of new spine formation induced by previous fear conditioning. These results show that fear conditioning, extinction, and reconditioning induce cue- and location-specific dendritic spine remodeling in the auditory cortex. They also suggest that changes of synaptic connections induced by fear conditioning are reversed after fear extinction.
Blog Categories:
brain plasticity,
fear,
fear/anxiety/stress,
memory/learning
Wednesday, September 12, 2018
Exposure to opposing views on social media can increase political polarization.
A sobering study by Bail et al. (open source) shows that just getting us out of our tribes' social media echo chambers does not have the palliative softening effect commonly supposed, but rather increases political polarization:
Significance
Significance
Social media sites are often blamed for exacerbating political polarization by creating “echo chambers” that prevent people from being exposed to information that contradicts their preexisting beliefs. We conducted a field experiment that offered a large group of Democrats and Republicans financial compensation to follow bots that retweeted messages by elected officials and opinion leaders with opposing political views. Republican participants expressed substantially more conservative views after following a liberal Twitter bot, whereas Democrats’ attitudes became slightly more liberal after following a conservative Twitter bot—although this effect was not statistically significant. Despite several limitations, this study has important implications for the emerging field of computational social science and ongoing efforts to reduce political polarization online.Abstract
There is mounting concern that social media sites contribute to political polarization by creating “echo chambers” that insulate people from opposing views about current events. We surveyed a large sample of Democrats and Republicans who visit Twitter at least three times each week about a range of social policy issues. One week later, we randomly assigned respondents to a treatment condition in which they were offered financial incentives to follow a Twitter bot for 1 month that exposed them to messages from those with opposing political ideologies (e.g., elected officials, opinion leaders, media organizations, and nonprofit groups). Respondents were resurveyed at the end of the month to measure the effect of this treatment, and at regular intervals throughout the study period to monitor treatment compliance. We find that Republicans who followed a liberal Twitter bot became substantially more conservative posttreatment. Democrats exhibited slight increases in liberal attitudes after following a conservative Twitter bot, although these effects are not statistically significant. Notwithstanding important limitations of our study, these findings have significant implications for the interdisciplinary literature on political polarization and the emerging field of computational social science.
Blog Categories:
culture,
culture/politics,
future,
futures,
technology
Tuesday, September 11, 2018
How exercise slows Alzheimer’s disease.
Wow…if I ever needed more encouragement to keep up my exercise routines (mainly swimming, biking, and a few weights) Choi et al. provide it by demonstrating that in a mouse model of Alzheimer's disease, exercise improves memory through a combination of encouraging the generation of new nerve cells in the hippocampus and increasing the levels of brain-derived neurotrophic factor (BDNF) that supports neuronal growth and survival. Their abstract:
Adult hippocampal neurogenesis (AHN) is impaired before the onset of Alzheimer’s disease (AD) pathology. We found that exercise provided cognitive benefit to 5×FAD mice, a mouse model of AD, by inducing AHN and elevating levels of brain-derived neurotrophic factor (BDNF). Neither stimulation of AHN alone, nor exercise, in the absence of increased AHN, ameliorated cognition. We successfully mimicked the beneficial effects of exercise on AD mice by genetically and pharmacologically inducing AHN in combination with elevating BDNF levels. Suppressing AHN later led to worsened cognitive performance and loss of preexisting dentate neurons. Thus, pharmacological mimetics of exercise, enhancing AHN and elevating BDNF levels, may improve cognition in AD. Furthermore, applied at early stages of AD, these mimetics may protect against subsequent neuronal cell death.
Blog Categories:
aging,
brain plasticity,
memory/learning
Monday, September 10, 2018
Robots R Us
Two recent NYTimes pieces - one by Sherry Turtle (professor in the program in Science, Technology and Society at M.I.T.) and the other by Andy Clark (professor of logic and metaphysics at the University of Edinburgh) - lay out starkly opposing views of the desirability of humans moving toward increased interactions with, and possible enhancements by, robots. You should read both. Turtle sees a potential diminution of our humanity:
The narrative begins with the idea that companionate robots would be “better than nothing,” better because there aren’t enough people to teach, love and tend to people. But that idea quickly shifts into another: robots would be better than most anything. Unlike people, they would not abandon you or get sick and die. They might not be capable of love, but they won’t break your heart. From better than nothing to better than anything. These are stations on our voyage to forgetting what it means to be human. But the forgetting begins long before we have a robot companion in place; it begins when we even think of putting one in place. To build the robots, we must first rebuild ourselves as people ready to be their companions.Clark looks towards a glorious enhancement of what it means to be human. He begins with a list that includes improving normal mental functioning and generating a wide spectrum of ways of being:
We now glimpse the next steps in human cultural and cognitive evolution, continuing the trend that started with the arrival of human language and the (much later) invention of writing and the external storage and transmission of ideas. The new steps herald an age of fluidity and demand answers to a host of questions…The two most important such questions are simply: How should we negotiate this dauntingly large space of human possibility? And what costs are we willing to tolerate along the way?
The first is a question of practice, the second of ethics. Practically speaking, it will not be easy to decide in a world of so many possible ways of being, so many enhancements and augmentations, and so many social practices, which ones are for us.
Ethically speaking, we need to ask what new costs and inequalities the freedoms and augmentations of some may mean for others. We need to ask if we are willing to tolerate some inequality as part of the rollout process for a more fluid and interconnected world. Issues of privacy and the right to control (including to trade or sell) our personal information are vividly with us. Not knowing quite where we as protected selves stop and the world around us begins, law and policy struggle to decide if (for example) information stored on our phones is enough like information stored in our heads to warrant the same protections. Law, education and social policy currently lag behind many interacting waves of change. What is up for grabs is what we humans are, and what we will become.(Note,
Blog Categories:
culture/politics,
future,
futures,
human evolution,
self,
technology
Friday, August 31, 2018
MindBlog is on vacation Aug. 31 - Sept. 22
Deric and Len just arrived in Amsterdam today. We will hang out here for a few days before getting on a Viking river boat cruise from Amsterdam to Budapest, Sept. 4 - Sept. 18. MindBlog posts will probably be infrequent or absent until late September. Having banged out 4,522 posts since MindBlog's start in 2006, maybe it's time for a break!
Thursday, August 30, 2018
Collective intelligence is improved by intermittent breaks in interaction.
Interesting work from Bernstein, Shore, and Lazer:
Significance
Significance
Many human endeavors—from teams and organizations to crowds and democracies—rely on solving problems collectively. Prior research has shown that when people interact and influence each other while solving complex problems, the average problem-solving performance of the group increases, but the best solution of the group actually decreases in quality. We find that when such influence is intermittent it improves the average while maintaining a high maximum performance. We also show that storing solutions for quick recall is similar to constant social influence. Instead of supporting more transparency, the results imply that technologies and organizations should be redesigned to intermittently isolate people from each other’s work for best collective performance in solving complex problems.Abstract
People influence each other when they interact to solve problems. Such social influence introduces both benefits (higher average solution quality due to exploitation of existing answers through social learning) and costs (lower maximum solution quality due to a reduction in individual exploration for novel answers) relative to independent problem solving. In contrast to prior work, which has focused on how the presence and network structure of social influence affect performance, here we investigate the effects of time. We show that when social influence is intermittent it provides the benefits of constant social influence without the costs. Human subjects solved the canonical traveling salesperson problem in groups of three, randomized into treatments with constant social influence, intermittent social influence, or no social influence. Groups in the intermittent social-influence treatment found the optimum solution frequently (like groups without influence) but had a high mean performance (like groups with constant influence); they learned from each other, while maintaining a high level of exploration. Solutions improved most on rounds with social influence after a period of separation. We also show that storing subjects’ best solutions so that they could be reloaded and possibly modified in subsequent rounds—a ubiquitous feature of personal productivity software—is similar to constant social influence: It increases mean performance but decreases exploration.
Blog Categories:
acting/choosing,
culture/politics,
social cognition
Wednesday, August 29, 2018
Robots exert peer pressure on children, but not adults.
From Vollmer et al.:
People are known to change their behavior and decisions to conform to others, even for obviously incorrect facts. Because of recent developments in artificial intelligence and robotics, robots are increasingly found in human environments, and there, they form a novel social presence. It is as yet unclear whether and to what extent these social robots are able to exert pressure similar to human peers. This study used the Asch paradigm, which shows how participants conform to others while performing a visual judgment task. We first replicated the finding that adults are influenced by their peers but showed that they resist social pressure from a group of small humanoid robots. Next, we repeated the study with 7- to 9-year-old children and showed that children conform to the robots. This raises opportunities as well as concerns for the use of social robots with young and vulnerable cross-sections of society; although conforming can be beneficial, the potential for misuse and the potential impact of erroneous performance cannot be ignored.
Blog Categories:
future,
futures,
social cognition,
technology
Tuesday, August 28, 2018
Reversing age related decay of brain plasticity with prozac
Eavri et al. find that treatment of mice with fluoxetine as they are aging slows the decline of several brain plasticity makers. Even if shown to have the same effects in humans, Fluoxetine would probably not be a realistic therapeutic agent for aging humans because it would have to be taken from an early age and is not recommended for use in the elderly due to its side effects. Here is their technical abstract:
Changes in excitatory neuron and synapse structure have been recognized as a potential physical source of age-related cognitive decline. Despite the importance of inhibition to brain plasticity, little is known regarding aging associated changes to inhibitory neurons. Here we test for age-related cellular and circuit changes to inhibitory neurons of mouse visual cortex. We find no substantial difference in inhibitory neuron number, inhibitory neuronal subtypes, or synapse numbers within the cerebral cortex of aged mice as compared to younger adults. However, when comparing cortical interneuron morphological parameters, we find differences in complexity, suggesting that arbors are simplified in aged mice. In vivo two-photon microscopy has previously shown that in contrast to pyramidal neurons, inhibitory interneurons retain a capacity for dendritic remodeling in the adult. We find that this capacity diminishes with age and is accompanied by a shift in dynamics from balanced branch additions and retractions to progressive prevalence of retractions, culminating in a dendritic arbor that is both simpler and more stable. Recording of visually evoked potentials (VEPs) shows that aging-related interneuron dendritic arbor simplification and reduced dynamics go hand in hand with loss of induced stimulus-selective response potentiation (SRP), a paradigm for adult visual cortical plasticity. Chronic treatment with the antidepressant fluoxetine reversed deficits in interneuron structural dynamics and restored SRP in aged animals. Our results support a structural basis for age related impairments in sensory perception, and suggest that declines in inhibitory neuron structural plasticity during aging contribute to reduced functional plasticity.
Monday, August 27, 2018
On the reception and detection of pseudo-profound bullshit
I want to thank MindBlog reader Mike Walterman, who sent me an email pointing me to this article (which won an Ig Nobel Prize) and commented on his experience with "Flow Genome Project" which I reviewed in a Nov. 17, 2017 post titled "Modern flimflam men? - The Flow Genome Project". In commenting on this post, Mike described his experience of signing on for some classes with FGP:
I read your commentary on the Flow Genome Project (FGP) with great interest. Your suspicions about this "effort" are spot on, and I wish that I had your insight before taking two of these classes from the FGP. By the way, Steven Kotler is an alum of UW-Madison!!
The first class (Flow Fundamentals) was a great community of people, and I learned much from them, and nothing from the FGP personnel. The second class (Flow Performance) was pseudo-profound BS (PPBS.) There is a great paper that won an Ig Nobel Prize titled "On the reception and detection of pseudo-profound bullshit." ... The paper perfectly described every aspect of this class!! The instructor - Jamie Wheal - is more interested in impressing people with PPBS than realaying any useful information. Also, each class is prefaced with the promise that "All the secrets of Stealing Fire will be revealed in this next class." I stopped when this promise was not delivered in Flow Performance; but, was promised for private coaching (at an extremely high price).Here is the abstract from the Pennycook et al. article on pseudo-profound bullshit:
Although bullshit is common in everyday life and has attracted attention from philosophers, its reception (critical or ingenuous) has not, to our knowledge, been subject to empirical investigation. Here we focus on pseudo-profound bullshit, which consists of seemingly impressive assertions that are presented as true and meaningful but are actually vacuous. We presented participants with bullshit statements consisting of buzzwords randomly organized into statements with syntactic structure but no discernible meaning (e.g., “Wholeness quiets infinite phenomena”). Across multiple studies, the propensity to judge bullshit statements as profound was associated with a variety of conceptually relevant variables (e.g., intuitive cognitive style, supernatural belief). Parallel associations were less evident among profundity judgments for more conventionally profound (e.g., “A wet person does not fear the rain”) or mundane (e.g., “Newborn babies require constant attention”) statements. These results support the idea that some people are more receptive to this type of bullshit and that detecting it is not merely a matter of indiscriminate skepticism but rather a discernment of deceptive vagueness in otherwise impressive sounding claims. Our results also suggest that a bias toward accepting statements as true may be an important component of pseudo-profound bullshit receptivity.
Friday, August 24, 2018
The architecture of pride is a cultural universal.
Sznycer et al. provide evidence that the pride system of WEIRD (western-ized, educated, industrialized, rich, and democratic) societies is found in 10 small-scale societies scattered across Central and South America, Africa, and Asia:
Significance
Significance
It has been proposed that one key function of pride is to guide behavior in ways that would increase others’ valuation of the individual. To incline choice, the pride system must compute for a potential action an anticipated pride intensity that tracks the magnitude of the approval or deference that the action would generate among local audiences. Data from industrial mass societies support this expectation. However, it is presently not known whether those data reflect cultural evolutionary processes or a panhuman adaptation. Experiments conducted in 10 traditional small-scale societies with widely varying cultures and subsistence modes replicate the pattern observed in mass societies. This suggests that pride is a universal system that is part of our species’ cooperative biology.Abstract
Becoming valuable to fellow group members so that one would attract assistance in times of need is a major adaptive problem. To solve it, the individual needs a predictive map of the degree to which others value different acts so that, in choosing how to act, the payoff arising from others’ valuation of a potential action (e.g., showing bandmates that one is a skilled forager by pursuing a hard-to-acquire prey item) can be added to the direct payoff of the action (e.g., gaining the nutrients of the prey captured). The pride system seems to incorporate all of the elements necessary to solve this adaptive problem. Importantly, data from western(-ized), educated, industrialized, rich, and democratic (WEIRD) societies indicate close quantitative correspondences between pride and the valuations of audiences. Do those results generalize beyond industrial mass societies? To find out, we conducted an experiment among 567 participants in 10 small-scale societies scattered across Central and South America, Africa, and Asia: (i) Bosawás Reserve, Nicaragua; (ii) Cotopaxi, Ecuador; (iii) Drâa-Tafilalet, Morocco; (iv) Enugu, Nigeria; (v) Le Morne, Mauritius; (vi) La Gaulette, Mauritius; (vii) Tuva, Russia; (viii) Shaanxi and Henan, China; (ix) farming communities in Japan; and (x) fishing communities in Japan. Despite widely varying languages, cultures, and subsistence modes, pride in each community closely tracked the valuation of audiences locally (mean r = +0.66) and even across communities (mean r = +0.29). This suggests that the pride system not only develops the same functional architecture everywhere but also operates with a substantial degree of universality in its content.
Thursday, August 23, 2018
Our divided brains
I just came across an engaging video made by British psychiatrist Iain McGilchrist, and want to pass it on to MindBlog readers:
Wednesday, August 22, 2018
Brain tracking of musical beat is enhanced by low frequency sounds.
Lenc et al. find that that brain activity at the frequency of the perceived beat is selectively enhanced compared with other frequencies in the electroencephalogram (EEG) spectrum when rhythms are conveyed by bass sounds, explaining why across cultures bass instruments are used to induce people to dance to periodic pulse-like beats.
Music makes us move, and using bass instruments to build the rhythmic foundations of music is especially effective at inducing people to dance to periodic pulse-like beats. Here, we show that this culturally widespread practice may exploit a neurophysiological mechanism whereby low-frequency sounds shape the neural representations of rhythmic input by boosting selective locking to the beat. Cortical activity was captured using electroencephalography (EEG) while participants listened to a regular rhythm or to a relatively complex syncopated rhythm conveyed either by low tones (130 Hz) or high tones (1236.8 Hz). We found that cortical activity at the frequency of the perceived beat is selectively enhanced compared with other frequencies in the EEG spectrum when rhythms are conveyed by bass sounds. This effect is unlikely to arise from early cochlear processes, as revealed by auditory physiological modeling, and was particularly pronounced for the complex rhythm requiring endogenous generation of the beat. The effect is likewise not attributable to differences in perceived loudness between low and high tones, as a control experiment manipulating sound intensity alone did not yield similar results. Finally, the privileged role of bass sounds is contingent on allocation of attentional resources to the temporal properties of the stimulus, as revealed by a further control experiment examining the role of a behavioral task. Together, our results provide a neurobiological basis for the convention of using bass instruments to carry the rhythmic foundations of music and to drive people to move to the beat.
Tuesday, August 21, 2018
The false idols of wellness.
Jen Gunter does an engaging take-down of the wellness-industrial complex in a NYTimes piece. She suggests that the wellness industry is exploiting rather than filling the gaps left by normal medical practice.:
Wellness used to mean a blend of health and happiness...it has become a false antidote to the fear of modern life and death...The wellness industry takes medical terminology, such as “inflammation” or “free radicals,” and levigates it to the point of incomprehension. The resulting product is a D.I.Y. medicine for longevity that comes with a confidence that science can only aspire to achieve.
...take the trend of adding a pinch of activated charcoal to your food or drink...it’s sold as a supposed “detox.”..It has the same efficacy as a spell from the local witch...“Toxins,” as defined by the peddlers of these dubious cures, are the harmful effluvia of modern life that supposedly roam our bodies...for without these toxins there can be no search for purity — “clean” tampons, “clean” food, “clean” makeup. There are also sacred acts and rituals to follow...Medicine and religion have long been deeply intertwined, and it’s only relatively recently that they have separated. The wellness-industrial complex seeks to resurrect that connection. It’s like a medical throwback, as if the halcyon days of health were 5,000 years ago. Ancient cleansing rituals with a modern twist — supplements, useless products and scientifically unsupported tests.
The dietary supplements that are the backbone of wellness make up a $30 billion a year business despite studies showing they have no value for longevity...So what’s the harm of spending money on charcoal for nonexistent toxins or vitamins for expensive urine or grounding bedsheets to better connect you with the earth’s electrons?..Here’s what: the placebo effect or “trying something natural” can lead people with serious illnesses to postpone effective medical care.
Moving the kind of product that churns the wheels of the wellness-industrial complex requires a constant stream of fear and misinformation. Look closer at most wellness sites and at many of their physician partners, and you’ll find a plethora of medical conspiracy theories: Vaccines and autism. The dangers of water fluoridation. Bras and breast cancer. Cellphones and brain cancer. Heavy metal poisoning. AIDS as a construct of Big Pharma.
There are symptoms that I believe have been with us since the beginning of time, so common that they are likely part of the human experience: fatigue, bloat, low libido, episodic pain, loss of vigor. When medicine can only offer a therapy, not a cure, or when doctors give undesired answers — suggesting attention to sleep hygiene, for instance — it isn’t hard to see how the intoxicating confidence and theater of wellness could beckon.
I admit that doctors can learn something from wellness. It’s clear that some people are looking for healers, so we must find ways to serve that need that are medically ethical...We doctors can do more to provide factual information about hazardous substances, such as carcinogens and endocrine disrupting chemicals, in products and the environment from medically vetted sites with no products to sell, such as the National Cancer Institute and the Endocrine Society...Many people — women especially — have long been marginalized and dismissed by medicine, but the answer does not lie in predatory conspiracy theories, a faux religion or expensive magic.
Blog Categories:
culture,
culture/politics,
happiness
Monday, August 20, 2018
Mesolimbic reward circuitry influences valuation of knowledge versus ignorance.
From Charpentier et al.:
The pursuit of knowledge is a basic feature of human nature. However, in domains ranging from health to finance people sometimes choose to remain ignorant. Here, we show that valence is central to the process by which the human brain evaluates the opportunity to gain information, explaining why knowledge may not always be preferred. We reveal that the mesolimbic reward circuitry selectively treats the opportunity to gain knowledge about future favorable outcomes, but not unfavorable outcomes, as if it has positive utility. This neural coding predicts participants’ tendency to choose knowledge about future desirable outcomes more often than undesirable ones, and to choose ignorance about future undesirable outcomes more often than desirable ones. Strikingly, participants are willing to pay both for knowledge and ignorance as a function of the expected valence of knowledge. The orbitofrontal cortex (OFC), however, responds to the opportunity to receive knowledge over ignorance regardless of the valence of the information. Connectivity between the OFC and mesolimbic circuitry could contribute to a general preference for knowledge that is also modulated by valence. Our findings characterize the importance of valence in information seeking and its underlying neural computation. This mechanism could lead to suboptimal behavior, such as when people reject medical screenings or monitor investments more during bull than bear markets.
Friday, August 17, 2018
Meditation quiets the ego? ….maybe just the opposite.
From Gebauer et al.. In their abstract "self-enhancement bias" refers to exaggerated self views or valuations.
Mind-body practices enjoy immense public and scientific interest. Yoga and meditation are highly popular. Purportedly, they foster well-being by curtailing self-enhancement bias. However, this “ego-quieting” effect contradicts an apparent psychological universal, the self-centrality principle. According to this principle, practicing any skill renders that skill self-central, and self-centrality breeds self-enhancement bias. We examined those opposing predictions in the first tests of mind-body practices’ self-enhancement effects. In Experiment 1, we followed 93 yoga students over 15 weeks, assessing self-centrality and self-enhancement bias after yoga practice (yoga condition, n = 246) and without practice (control condition, n = 231). In Experiment 2, we followed 162 meditators over 4 weeks (meditation condition: n = 246; control condition: n = 245). Self-enhancement bias was higher in the yoga (Experiment 1) and meditation (Experiment 2) conditions, and those effects were mediated by greater self-centrality. Additionally, greater self-enhancement bias mediated mind-body practices’ well-being benefits. Evidently, neither yoga nor meditation fully quiet the ego; to the contrary, they boost self-enhancement.
Thursday, August 16, 2018
The neuroscience of pessimism.
Ann Graybiel and collaborators offer a fascinating study showing that stimulation of the brain's caudate nucleus induces persistent and repetitive negative decision making. They devised a cost-benefit situation in which monkeys were offered a reward of juice paired with an unpleasant puff of air to the face. When the caudate nucleus was stimulated the animals began to avoid choosing the reward, when previously they would have put up with the unpleasant stimulus. This suggests that pessimistic decision-making can be tied to an overactive caudate nucleus. Work is now beginning with human patients suffering from anxiety and depression to find out whether abnormal activity in the caudate nucleus can be seen during negative decision making.
Highlights
Highlights
Caudate nucleus stimulation induces persistent state change affecting value evaluation
CN stimulation produces repetitive choices, whereas pACC stimulation does not
CN beta oscillations parallel negative states influencing repetitive decisions
Abnormal CN beta oscillations are correlated with persistency in OCD-like statesSummary P
ersistent thoughts inducing irrationally pessimistic and repetitive decisions are often symptoms of mood and anxiety disorders. Regional neural hyperactivities have been associated with these disorders, but it remains unclear whether there is a specific brain region causally involved in these persistent valuations. Here, we identified potential sources of such persistent states by microstimulating the striatum of macaques performing a task by which we could quantitatively estimate their subjective pessimistic states using their choices to accept or reject conflicting offers. We found that this microstimulation induced irrationally repetitive choices with negative evaluations. Local field potentials recorded in the same microstimulation sessions exhibited modulations of beta-band oscillatory activity that paralleled the persistent negative states influencing repetitive decisions. These findings demonstrate that local striatal zones can causally affect subjective states influencing persistent negative valuation and that abnormal beta-band oscillations can be associated with persistency in valuation accompanied by an anxiety-like state.
Blog Categories:
acting/choosing,
fear/anxiety/stress
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