Friday, June 24, 2022

Magnetic stimulation of the brain can improve cognitive impairment

An open source article from Liu et al. in the journal Cerebral Cortex reports that repetitive transcranial magnetic stimulation (rTMS) over the bilateral angular gyrus in patients with probable Alzheimer’s disease resulted in up to 8 weeks of significantly improved cognitive function.:
Dementia causes a substantial global economic burden, but effective treatment is lacking. Recently, studies have revealed that gamma-band waves of electrical brain activity, particularly 40 Hz oscillations, are closely associated with high-order cognitive functions and can activate microglia to clear amyloid-β deposition. Here, we found that compared with sham stimulation, applying 40-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) over the bilateral angular gyrus in patients with probable Alzheimer’s disease (AD; n = 37) resulted in up to 8 weeks of significantly improved cognitive function. Power spectral density analysis of the resting-state electroencephalography (EEG) demonstrated that 40-Hz rTMS modulated gamma-band oscillations in the left posterior temporoparietal region. Further testing with magnetic resonance imaging and TMS-EEG revealed the following: 40-Hz rTMS 1) prevented gray matter volume loss, 2) enhanced local functional integration within bilateral angular gyrus, as well as global functional integration in bilateral angular gyrus and the left middle frontal gyrus, 3) strengthened information flow from the left posterior temporoparietal region to the frontal areas and strengthened the dynamic connectivity between anterior and posterior brain regions. These findings demonstrate that modulating gamma-band oscillations effectively improves cognitive function in patients with probable AD by promoting local, long-range, and dynamic connectivity within the brain.

Wednesday, June 22, 2022

Effortless training of attention and self-control

I pass on the highlights statement from a fascinating opinion piece by Tang et al. (motivated readers can obtain a copy of the text from me). 

Highlights

A long-held belief in cognitive science is that training attention and self-control must recruit effort. Therefore, various effortful training programs such as attention or working memory training have been developed to improve attention and self-control (or executive function). However, effortful training has limited far-transfer effects.
A growing literature suggests a new way of effortless training for attention and self-control. Effortless training – such as nature exposure, flow experience, and effortless practices – has shown promising effects on improving attention and self-control.
Effortful training requires cognitive control supported by the frontoparietal network to sustain mental effort over the course of training. Effortless training engages autonomic control with less effort, and is supported by the anterior and posterior cingulate cortex, striatum, and parasympathetic nervous system (PNS).
For the past 50 years, cognitive scientists have assumed that training attention and self-control must be effortful. However, growing evidence suggests promising effects of effortless training approaches such as nature exposure, flow experience, and effortless practice on attention and self-control. This opinion article focuses on effortless training of attention and self-control. We begin by introducing our definitions of effortful and effortless training and reviewing the growing literature on these two different forms of training. We then discuss the similarities and differences in their respective behavioral outcomes and neural correlates. Finally, we propose a putative neural mechanism of effortless training. We conclude by highlighting promising directions for research, development, and application of effortless training.
Figure Legend: Core brain regions and their functions during effortless training.
Three colored areas represent the anterior cingulate cortex–posterior cingulate cortex (ACC–PCC)–striatum (APS) and their corresponding functions during training. The broken line arrows indicate that these regions actively communicate with each other during effortless training.

Monday, June 20, 2022

MindBlog in Crypto-Land

Unless you have been hiding in a cave (not a bad place to be these days) you have doubtless been following the current crash of the stock market and the even more dramatic implosion of the cryptocurrency bubble.  From dizzying highs (see The New Get-Rich-Faster Job in Silicon Valley: Crypto Start-Ups) the values of BitCoin, Etherium and other cryptocurrencies have cratered, while critiques of the blockchains and cryptocurrencies have become more numerous (see How ‘Trustless’ Is Bitcoin, Really?Crypto, Houses, Sneakers, Rolexes: How FOMO Drove the EconomyFrom the Big Short to the Big Scam (Krugman)Why bitcoin is worse than a Madoff-style Ponzi scheme.

In this post I’ve decided to pass on a chronicle of my own experience with crypto-world to date - so I know where I can look it up later,  and also as a basis for passing on any further entanglements or results.  [MindBlog has taken a similar tack in reporting its (generally unsuccessful) experiments with dietary supplements meant to enhance our vitality or longevity.]

In early 2021 my techie son (an eCommerce website developer) decided to gamble $1,000 by purchasing two Helium Miners (hotspots) whose antennas connected them to a Helium ‘People’s Network’ - a decentralized wireless infrastructure powered by the Helium Blockchain for use by the IoT  (“Internet of Things” - thermostats, water and gas meters, scooter rentals, etc.).  These miners started generating ‘HNT’ tokens, the Helium cryptocurrency. Tokens valued at over $600,000 soon accumulated, and he cashed out $100,000 of this… for a thousand-fold return on investment! 

I read the hype, drank the kool aid, decided to follow in his footsteps, and put in a bit of ‘mad money’ I was willing to loose...  Here is the Rake’s Progress:

At the end on Nov. 2021 I set up a Coinbase account linked to my real world bank account, bought $1000 of USCD ‘stable coins’ and used them on Dec. 9 to pay for two Bobcat 300 Helium Miners (the step up and down on the left in the Coinbase App screenshot below.)  Then I decided to speculate a bit, and on Dec. 31 bought $1000 of Ethereum (ETH coins), now worth $280.99 (shown by the jagged downward line on the screenshot taken June 18).  Perfect timing!


The Bobcat 300 miners were ordered on Dec. 9….. then came a series of emails describing factory closings in China,  Covid shutdowns, supply chain blockages,  etc….  They finally arrived on June 9 (which seems light years later in cyber-world time) and are being set up now.

 

AND, by now they are being overshined by the appearance of the latest shiny new toy,  the Bobcat 500 (5G) miner, which with a CBRS (Citizens Broadcast Radio Service) operating "Cell" on the 5G cellular network can earn cryptocurrency by providing 5G cellular coverage.  So, naturally I’ve just bought one of these (with “delivery in 4-8 weeks”....we've been there before, see above).  Here are its claims to be a  big deal…


The current Bobcat 300 miners, just about to be setup, will still be grinding away, hopefully earning some HNT,  but their IoT niche is now depicted as occupying 1.2% of this glorious new world.

To be continued.....

 
 

Friday, June 17, 2022

Testerone production in adult men is regulated by an adolescent period sensitive to family experiences.

 From Gettler et al.:

Significance
Testosterone influences how animals devote energy and time toward reproduction, including opposing demands of mating and competition versus parenting. Reflecting this, testosterone often declines in new fathers and lower testosterone is linked to greater caregiving. Given these roles, there is strong interest in factors that affect testosterone, including early-life experiences. In this multidecade study, Filipino sons whose fathers were present and involved with raising them when they were adolescents had lower testosterone when they later became fathers, compared to sons whose fathers were present but uninvolved or were not coresident. Sons’ own parenting behaviors did not explain these patterns. These results connect key social experiences during adolescence to adult testosterone, and point to possible intergenerational effects of parenting style.
Abstract
Across vertebrates, testosterone is an important mediator of reproductive trade-offs, shaping how energy and time are devoted to parenting versus mating/competition. Based on early environments, organisms often calibrate adult hormone production to adjust reproductive strategies. For example, favorable early nutrition predicts higher adult male testosterone in humans, and animal models show that developmental social environments can affect adult testosterone. In humans, fathers’ testosterone often declines with caregiving, yet these patterns vary within and across populations. This may partially trace to early social environments, including caregiving styles and family relationships, which could have formative effects on testosterone production and parenting behaviors. Using data from a multidecade study in the Philippines (n = 966), we tested whether sons’ developmental experiences with their fathers predicted their adult testosterone profiles, including after they became fathers themselves. Sons had lower testosterone as parents if their own fathers lived with them and were involved in childcare during adolescence. We also found a contributing role for adolescent father–son relationships: sons had lower waking testosterone, before and after becoming fathers, if they credited their own fathers with their upbringing and resided with them as adolescents. These findings were not accounted for by the sons’ own parenting and partnering behaviors, which could influence their testosterone. These effects were limited to adolescence: sons’ infancy or childhood experiences did not predict their testosterone as fathers. Our findings link adolescent family experiences to adult testosterone, pointing to a potential pathway related to the intergenerational transmission of biological and behavioral components of reproductive strategies.

Wednesday, June 15, 2022

The brain signature of choosing to accept pain in exchange for future reward

From Coll et al.

Significance

We often willingly experience pain to reach a goal. However, potential pain can also prevent reckless action. How do we consider future pain when deciding on the best course of action? To date, the precise neural mechanisms underlying the valuation of future pain remain unknown. Using functional MRI, we derive a whole-brain signature of the value of future pain capable of predicting participants’ choices to accept pain in exchange for a reward. We show that this signature is characterized by a distributed pattern of activity with clear contributions from structures encoding reward and salience, notably the ventral and dorsal striatum. These findings highlight how the brain assigns value to future pain when choosing the best course of action.
Abstract
Pain is a primary driver of action. We often must voluntarily accept pain to gain rewards. Conversely, we may sometimes forego potential rewards to avoid associated pain. In this study, we investigated how the brain represents the decision value of future pain. Participants (n = 57) performed an economic decision task, choosing to accept or reject offers combining various amounts of pain and money presented visually. Functional MRI (fMRI) was used to measure brain activity throughout the decision-making process. Using multivariate pattern analyses, we identified a distributed neural representation predicting the intensity of the potential future pain in each decision and participants’ decisions to accept or avoid pain. This neural representation of the decision value of future pain included negative weights located in areas related to the valuation of rewards and positive weights in regions associated with saliency, negative affect, executive control, and goal-directed action. We further compared this representation to future monetary rewards, physical pain, and aversive pictures and found that the representation of future pain overlaps with that of aversive pictures but is distinct from experienced pain. Altogether, the findings of this study provide insights on the valuation processes of future pain and have broad potential implications for our understanding of disorders characterized by difficulties in balancing potential threats and rewards.

Monday, June 13, 2022

Neural signatures of major depressive, anxiety, and stress-related disorders

Some fascintating observation from Zhukovsky et al.,  (open source, nice graphics of brain imaging results) who find that major depressive and anxiety disorders share functional and structural neural signatures, but stress-related disorders are distinct from these. Also, better cognitive function is associated with lower connectivity of specific nodes of the default mode and frontoparietal networks.

Significance
Major depressive, anxiety, and stress-related disorders are highly comorbid and may affect similar neurocircuitry and cognitive processes. However, the neurocircuitry underlying shared dimensions of cognitive impairment is unclear and holds the promise of reimagining psychiatric nosology. Here we leverage population imaging data (n = 27,132) to show that while major depressive and anxiety disorders share functional and structural neural signatures, stress-related disorders are distinct from these two conditions. We report that better cognitive function is associated with lower connectivity of specific nodes of the default mode and frontoparietal networks. These findings provide population benchmarks for brain–cognition associations in healthy participants and those with lifetime major depressive and anxiety disorders, advancing our understanding of intrinsic brain networks underlying cognitive dysfunction.
Abstract
The extent of shared and distinct neural mechanisms underlying major depressive disorder (MDD), anxiety, and stress-related disorders is still unclear. We compared the neural signatures of these disorders in 5,405 UK Biobank patients and 21,727 healthy controls. We found the greatest case–control differences in resting-state functional connectivity and cortical thickness in MDD, followed by anxiety and stress-related disorders. Neural signatures for MDD and anxiety disorders were highly concordant, whereas stress-related disorders showed a distinct pattern. Controlling for cross-disorder genetic risk somewhat decreased the similarity between functional neural signatures of stress-related disorders and both MDD and anxiety disorders. Among cases and healthy controls, reduced within-network and increased between-network frontoparietal and default mode connectivity were associated with poorer cognitive performance (processing speed, attention, associative learning, and fluid intelligence). These results provide evidence for distinct neural circuit function impairments in MDD and anxiety disorders compared to stress disorders, yet cognitive impairment appears unrelated to diagnosis and varies with circuit function.

Friday, June 10, 2022

The Conscious Turing Machine - a blueprint for conscious machines.

I want to point to a paper in the current PNAS by Blum and Blum, "A theory of consciousness from a theoretical computer science perspective: Insights from the Conscious Turing Machine," as well as a copmmentary on it by Oliveira. I do this before diving in to read it and hopefully understand it myself, to alert consciousness mavens of its appearance. A first glance through it makes me think that getting a grip on understanding the model will take considerable effort on my part. Perhaps I will emerge with some commentary, perhaps not.... I pass on the Blum and Blum opening statements:  

Significance

This paper provides evidence that a theoretical computer science (TCS) perspective can add to our understanding of consciousness by providing a simple framework for employing tools from computational complexity theory and machine learning. Just as the Turing machine is a simple model to define and explore computation, the Conscious Turing Machine (CTM) is a simple model to define and explore consciousness (and related concepts). The CTM is not a model of the brain or cognition, nor is it intended to be, but a simple substrate-independent computational model of (the admittedly complex concept of) consciousness. This paper is intended to introduce this approach, show its possibilities, and stimulate research in consciousness from a TCS perspective.
Abstract
This paper examines consciousness from the perspective of theoretical computer science (TCS), a branch of mathematics concerned with understanding the underlying principles of computation and complexity, including the implications and surprising consequences of resource limitations. We propose a formal TCS model, the Conscious Turing Machine (CTM). The CTM is influenced by Alan Turing's simple yet powerful model of computation, the Turing machine (TM), and by the global workspace theory (GWT) of consciousness originated by cognitive neuroscientist Bernard Baars and further developed by him, Stanislas Dehaene, Jean-Pierre Changeux, George Mashour, and others. Phenomena generally associated with consciousness, such as blindsight, inattentional blindness, change blindness, dream creation, and free will, are considered. Explanations derived from the model draw confirmation from consistencies at a high level, well above the level of neurons, with the cognitive neuroscience literature.

Wednesday, June 08, 2022

Stories move the heart - literally

Continuing my thread of heart activity realted posts (here, and here), I'll mention that I've enjoyed reading this open access PNAS Science and Culture article by Carolyn Beans on the meaning and usefulness of heart rate fluctuations. Here are the starting paragraphs:
In June 2019, at the University of Birmingham in England, psychologist Damian Cruse invited 27 young adults to come to the lab, on separate occasions, and listen to the same clips from an audiobook of Jules Verne’s 20,000 Leagues Under the Sea. Sitting alone, each donned headphones and electrocardiogram (EKG) equipment while a voice with a British accent recounted tales of a mysterious monster taking down ships. When researchers later compared volunteers’ heart rates, a curious phenomenon emerged: The heart rates of nearly two-thirds of the participants rose and fell together as the story progressed (1).
“It’s not that the beats align synchronously, but rather the heart rate fluctuations go up and down in unison,” explains Lucas Parra, a biomedical engineer at City College of New York, and co-senior author on the study.
Research has already shown that brain activity can synchronize when listeners pay attention to the same video or story (2). Now, Parra and others are finding that the heart, too, offers insight into who is really paying attention to a story. Potential applications are myriad. With heart rate recordings from smart watches, a webinar host may one day learn whether the audience is engaged, or a doctor could offer a family insight into whether a loved one will recover consciousness.
But the technology is new and researchers are still grappling with how to harness heart rate data responsibly, even as they continue to explore why stories move hearts in synchrony in the first place.

Monday, June 06, 2022

I am not my problem

An explanation of the strange title of this post: Sometimes a new idea spontaneously appears from nowhere as I am waking in the morning. The title of this post - the (apparently nonsensical) sentence "I am not my problem” - is the latest example. The sentence can to be parsed to indicate in this instance that the "I" is referring to the illusory narrative self that our social brains have been designed by evolution to generate, and the "my" refers to our intuition or sensing of the vastly complex underlying interacting body systems (respiratory, circulatory, neuronal, muscular, endocrine, sensory, etc.) from which this veneer of a self rises. The brain is mainly not for thinking. It appears that several styles of meditation practice can expand our awareness of this fundamental generative layer. The "am not my problem" tries to make the point that distinguishing these systems can prove useful in trying to determine the origins of particular feelings or behaviors. 

As I’m writing these words I begin to realize that my “novel” waking insight isn’t so novel, but more an elaboration or restatement of my post of Friday, March 13, 2020, on “the relief of not being yourself,” which described another spontaneous rising of ideas associated with the transition between sleep and wakefulness. I repeat that text here:

What a relief to know that this is not me, it is just the contents of my consciousness, which shift around all the time and are never the same twice. What has changed, after 45 years of doing an introspective personal journal, is that this sentence has become clear and true for me. It is a prying loose from the illusion of the sensing and executive “I”, self, the homunculus inside.
There is a particular feeling of renewal, starting over, in the first moments of the transition to seeing - rather than immersed in being - one of the contents of consciousness. Meditation practice can be seen as training the ability to inhabit this state for longer periods of time, to experience the self or I as co-equal with other contents of consciousness like seeing, hearing, feeling. It is having thoughts without a thinker, having a self without a self.
What is inside is the animal mirror of expanded consciousness, no longer locked into one or another of its contractions. This feels to me like a potentially irreversible quantum bump, a phase or state change in my ongoing awareness (perhaps a long term increase in my brain’s attentional mode activity alongside a decrease its default mode’s mind wandering?...also frontal suppression of amygdalar reactivity?)

Friday, June 03, 2022

Beginnings

The title of this post is the title of one of the mini-essays in a piece on my website, written 20 years ago, called "MINDSTUFF: BONBONS FOR THE CURIOUS USER." I re-discovered it while working on a lecture I'm giving this fall, and find the writing much more engaging than what I am currently generating!

 

BEGINNINGS

We are forever barred from recalling the buzzing cacophony that greeted our entry into this world. Our remembering brains had not formed, they had not begun to construct a world for themselves outside the womb. And yet, they had a very ancient kind of knowledge formed over millions of years. They knew to look for a face, they knew to direct muscles of the mouth to draw milk from a mother's breast. From a very rudimentary beginning repertoire they began fashioning a network of sensing and acting to finally generate the extraordinary machines that can read a page like this one.
In both the womb and with the growing baby, the story is a record of sensuality, of kinesthetic, visual, auditory, tasting and smelling histories that form themselves into a predictable order. A sense of past and of anticipation of the predictable future form a base non verbal imaged story line on which the layers of human language begin to build themselves. A smooth continuity informs the transformation of communication from gestures and simple sounds to strings of words with subjects, objects and verbs that form into stories about why, what, how, where. This transformation does not occur in feral children raised by surrogate animal parents, they appear to remain locked in the more present centered mental space of animals - a space that gives no flicker of reflectivity. The requirement is for not only our distinctively human genes but also a cultural context of human communication through gesture and language kept alive, altered, and transmitted by successive generations. We are tools of our our tools.
The programming of our brain regions central to social interactions is just as biological as the workings of a liver or kidney. It involves involuntary linkages of our primitive mammalian or limbic brain and its neuroendocrinology to status, sex, affiliation, power - mechanisms whose fundamental aspects we share with prairie voles and cichlid fish. Unique to humans is the self conscious confabulator or self-constructor that provides a new level of nudging, specification, control over these processes. It is this confabulator that generates what we take to be the world, what we take to be social sources of validation. All are in fact internal self creations that are assayed by their utility.

Wednesday, June 01, 2022

Heart rate variability as a marker of stress and health - measurements with the 'magic ring'

This post is a follow-up to the previous post on brain-heart interplay in emotional arousal, and points to Thayer et al.'s meta-analysis of heart rate variability (HRV) and neuroimaging studies to evaluate HRV as a marker of stress and health. I'm curious about the practical usefulness of the heart rate (HR) and heart rate variability (HRV) measurements that have been reported by the Oura Ring bio-monitor I purchased over six months ago, and has been measuring my sleep, heart rate, activity, and body temperature (I call it the 'magic ring'). I'm finding an allmost complete correlation between the ring's HRV overnight measurements and my subjective sense of robustness and health on waking in the mornings. HRV is lower after a previous day of physical, social, (or gastronomic!) stress, and higher after a day of rest and relaxation. Here I pass on just one clip from the text:
Resting HRV, in our view, is a marker for flexible dynamic regulation of autonomic activity; thus, higher HRV signals the availability of context- and goal-based control of emotions. We have investigated the role of HRV in emotional regulation at two different levels of analysis. One level is at the trait or tonic level where individual differences in resting HRV have been associated with differences in emotional regulation. We have shown that individuals with higher levels of resting HRV, compared to those with lower resting levels, produce context appropriate emotional responses as indexed by emotion-modulated startle responses, fear-potentiated startle responses, and phasic heart rate responses in addition to behav- ioral and self-reported emotional responses (Melzig et al., 2009; Ruiz-Padial et al., 2003; Thayer and Brosschot, 2005). In addition, we have recently shown that individuals with low resting HRV show delayed recovery from psychological stressors of cardiovascular, endocrine, and immune responses compared to those with higher levels of resting HRV (Weber et al., 2010). Thus, individuals with higher resting levels of HRV appear more able to produce context appropriate responses including appropriate recovery after the stressor has ended.
And here is the article's abstract:
The intimate connection between the brain and the heart was enunciated by Claude Bernard over 150 years ago. In our neurovisceral integration model we have tried to build on this pioneering work. In the present paper we further elaborate our model and update it with recent results. Specifically, we per- formed a meta-analysis of recent neuroimaging studies on the relationship between heart rate variability and regional cerebral blood flow. We identified a number of regions, including the amygdala and ventro- medial prefrontal cortex, in which significant associations across studies were found. We further propose that the default response to uncertainty is the threat response and may be related to the well known neg- ativity bias. Heart rate variability may provide an index of how strongly ‘top–down’ appraisals, mediated by cortical-subcortical pathways, shape brainstem activity and autonomic responses in the body. If the default response to uncertainty is the threat response, as we propose here, contextual information repre- sented in ‘appraisal’ systems may be necessary to overcome this bias during daily life. Thus, HRV may serve as a proxy for ‘vertical integration’ of the brain mechanisms that guide flexible control over behavior with peripheral physiology, and as such provides an important window into understanding stress and health.

Monday, May 30, 2022

Brain-Heart interplay in emotional arousal - resolving a hundred year old debate

Candia-Rivera et al. do a fascinating piece of work that answers some long-standing issues in the century old debate on the role of the autonomic nervous system in feelings. I will be slowly re-reading this paper a number of times. The introduction provides an excellent review of contrasting theories of what emotions are.
...The debate about the role of the ANS in emotions can be condensed into two views: specificity or causation. The specificity view is related to the James–Lange theory, which states that bodily responses precede emotions’ central processing, meaning that bodily states would be a response to the environment, followed by an interpretation carried out by the CNS that would result in the feeling felt. However, causation theories represent an updated view of the James–Lange theory, suggesting that peripheral changes influence the conscious emotional experience....While more “classical” theories point to emotions as “the functional states of the brain that provide causal explanations of certain complex behaviors—like evading a predator or attacking prey”, other theories suggest how they are constructions of the world, not reactions to it (see MindBlog posts on Lisa Feldman Barretts work). Namely, emotions are internal states constructed on the basis of previous experiences as predictive schemes to react to external stimuli.
Here is a clip from the discussion of their open source paper, followed by the significance and abstract sections at the begninning of the article:
....To the best of our knowledge, major novelties of the current study with respect to prior state of the art are related to 1) the uncovering of the directed functional interplay between central and peripheral neural dynamics during an emotional elicitation, using ad-hoc mathematical models for synchronized EEG and ECG time series; 2) the uncovering of temporal dynamics of cortical and cardiovascular neural control during emotional processing in both ascending, from the heart to the brain, and descending, from the brain to the heart, functional directions; and 3) the experimental support for causation theories of physiological feelings.
In the frame of investigating the visceral origin of emotions, main findings of this study suggest that ascending BHI (brain-heart interplay) coupling initiates emotional processing and is mainly modulated by the subjective experience of emotional arousal. Such a relationship between arousal and ascending BHI may not be related to the attention levels, as controlled with two different neural correlates of attention. The main interactions begin through afferent vagal pathways (HF power) sustaining EEG oscillations, in which the theta band was repeatedly found related to major vagal modulations. In turn, with a later onset, this ascending modulation actually triggers a cascade of cortical neural activations that, in turn, modulate directed neural control onto the heart, namely from-brain-to-heart interplay. Concurrent bidirectional communication between the brain and body occurs throughout the emotional processing at specific timings, reaching a maximum coupling around 15 to 20 s from the elicitation onset, involving both cardiac sympathetic and vagal activity.

From the beginning of the article;  

Significance

We investigate the temporal dynamics of brain and cardiac activities in healthy subjects who underwent an emotional elicitation through videos. We demonstrate that, within the first few seconds, emotional stimuli modulate heartbeat activity, which in turn stimulates an emotion intensity (arousal)–specific cortical response. The emotional processing is then sustained by a bidirectional brain–heart interplay, where the perceived arousal level modulates the amplitude of ascending heart-to-brain neural information flow. These findings may constitute fundamental knowledge linking neurophysiology and psychiatric disorders, including the link between depressive symptoms and cardiovascular disorders.
Abstract
A century-long debate on bodily states and emotions persists. While the involvement of bodily activity in emotion physiology is widely recognized, the specificity and causal role of such activity related to brain dynamics has not yet been demonstrated. We hypothesize that the peripheral neural control on cardiovascular activity prompts and sustains brain dynamics during an emotional experience, so these afferent inputs are processed by the brain by triggering a concurrent efferent information transfer to the body. To this end, we investigated the functional brain–heart interplay under emotion elicitation in publicly available data from 62 healthy subjects using a computational model based on synthetic data generation of electroencephalography and electrocardiography signals. Our findings show that sympathovagal activity plays a leading and causal role in initiating the emotional response, in which ascending modulations from vagal activity precede neural dynamics and correlate to the reported level of arousal. The subsequent dynamic interplay observed between the central and autonomic nervous systems sustains the processing of emotional arousal. These findings should be particularly revealing for the psychophysiology and neuroscience of emotions.

Friday, May 27, 2022

Experiential appreciation as a pathway to meaning in life

I have resumed cruising journals' tables of contents after a lapse due to shifting my attention elsewhere, and just came across this interesting open source paper in Nature Human Biology. This work resonates with me because I sometimes feel that my experience of listening to and performing music (piano) provides me with more than sufficient "MIL"...here is the abstract from Kim et al.:  

Abstract

A key research program within the meaning in life (MIL) literature aims to identify the key contributors to MIL. The experience of existential mattering, purpose in life and a sense of coherence are currently posited as three primary contributors to MIL. However, it is unclear whether they encompass all information people consider when judging MIL. Based on the ideas of classic and contemporary MIL scholars, the current research examines whether valuing one’s life experiences, or experiential appreciation, constitutes another unique contributor to MIL. Across seven studies, we find support for the idea that experiential appreciation uniquely predicts subjective judgements of MIL, even after accounting for the contribution of mattering, purpose and coherence to these types of evaluations. Overall, these findings support the hypothesis that valuing one’s experiences is uniquely tied to perceptions of meaning. Implications for the incorporation of experiential appreciation as a fundamental antecedent of MIL are discussed.

Wednesday, May 25, 2022

Why is a moving hand less sensitive to touch than a stationary hand?

Fuehrer et al. do a nice piece showing how our brains' predictive processing can alter our sensory experience:  

Significance

Tactile sensations on a moving hand are perceived weaker than when presented on the same but stationary hand. There is an ongoing debate about whether this weaker perception is based on sensorimotor predictions or is due to a blanket reduction in sensitivity. Here, we show greater suppression of sensations matching predicted sensory feedback. This reinforces the idea of precise estimations of future body sensory states suppressing the predicted sensory feedback. Our results shine light on the mechanisms of human sensorimotor control and are relevant for understanding clinical phenomena related to predictive processes.
Abstract
The ability to sample sensory information with our hands is crucial for smooth and efficient interactions with the world. Despite this important role of touch, tactile sensations on a moving hand are perceived weaker than when presented on the same but stationary hand. This phenomenon of tactile suppression has been explained by predictive mechanisms, such as internal forward models, that estimate future sensory states of the body on the basis of the motor command and suppress the associated predicted sensory feedback. The origins of tactile suppression have sparked a lot of debate, with contemporary accounts claiming that suppression is independent of sensorimotor predictions and is instead due to an unspecific mechanism. Here, we target this debate and provide evidence for specific tactile suppression due to precise sensorimotor predictions. Participants stroked with their finger over textured objects that caused predictable vibrotactile feedback signals on that finger. Shortly before touching the texture, we probed tactile suppression by applying external vibrotactile probes on the moving finger that either matched or mismatched the frequency generated by the stroking movement along the texture. We found stronger suppression of the probes that matched the predicted sensory feedback. These results show that tactile suppression is specifically tuned to the predicted sensory states of a movement.

Saturday, May 21, 2022

Mozart and Brahms Piano Trios at an 80th birthday house concert

This post falls in the 'random curious stuff' category mentioned under MindBlog's title. On May 15, one day before my 80th birthday, my piano trio invited friends and family to a Sunday afternoon house concert at the home of our cellist on Cat Mountain in the Northwest Hills of Austin Texas. I have posted the individual movements of the Mozart Piano Trio No. 2 in B flat major, K. 502 and the Brahms Piano Trio No. 1 in B major, Op. 8 on my YouTube channel, as well as in playlists that play through all the movements of each piece. 

To give you a sample, this post passes on the last movements of the two trios. 

The allegretto of the Mozart Trio.

 

The allegro of the Brahms trio. 

Thursday, May 19, 2022

Harmonics of the social brain

Interesting work from Mague et al. on the brain-wide network in mice that encodes rewarding social experience: 

Highlights

• Machine learning model discovers and integrates circuits into affective brain network 
• Brain-wide network encodes rewarding social experience of individual mice 
• Causal activation of network sub-circuits selectively induces social behavior 
• Social brain network fails to encode individual behavior in a mouse model of autism
Summary
The architecture whereby activity across many brain regions integrates to encode individual appetitive social behavior remains unknown. Here we measure electrical activity from eight brain regions as mice engage in a social preference assay. We then use machine learning to discover a network that encodes the extent to which individual mice engage another mouse. This network is organized by theta oscillations leading from prelimbic cortex and amygdala that converge on the ventral tegmental area. Network activity is synchronized with cellular firing, and frequency-specific activation of a circuit within this network increases social behavior. Finally, the network generalizes, on a mouse-by-mouse basis, to encode individual differences in social behavior in healthy animals but fails to encode individual behavior in a ‘high confidence’ genetic model of autism. Thus, our findings reveal the architecture whereby the brain integrates distributed activity across timescales to encode an appetitive brain state underlying individual differences in social behavior.

Monday, May 16, 2022

How stress might help reduce dementia and alzheimer’s.

The post today (my 80th birthday) points to experimental results relevant to my interest in not losing my marbles anytime soon. Fauzia points to work by Avezov and collaborators (open source) showing that the accumulation of aggregates of misfolded proteins in the endoplasmic reticulum of brain cells that is associated with dementia and Alzheimer's can be reversed by stressing cells with chemicals or heat, activating molecular chaperones that in turn untangle or remove protein aggregates. How much stress is just enough, but not to much, isn't clear. The abstract of the work:
Protein synthesis is supported by cellular machineries that ensure polypeptides fold to their native conformation, whilst eliminating misfolded, aggregation prone species. Protein aggregation underlies pathologies including neurodegeneration. Aggregates’ formation is antagonised by molecular chaperones, with cytoplasmic machinery resolving insoluble protein aggregates. However, it is unknown whether an analogous disaggregation system exists in the Endoplasmic Reticulum (ER) where ~30% of the proteome is synthesised. Here we show that the ER of a variety of mammalian cell types, including neurons, is endowed with the capability to resolve protein aggregates under stress. Utilising a purpose-developed protein aggregation probing system with a sub-organellar resolution, we observe steady-state aggregate accumulation in the ER. Pharmacological induction of ER stress does not augment aggregates, but rather stimulate their clearance within hours. We show that this dissagregation activity is catalysed by the stress-responsive ER molecular chaperone – BiP. This work reveals a hitherto unknow, non-redundant strand of the proteostasis-restorative ER stress response.

Friday, May 13, 2022

The tabula sapiens consortium - mapping cell types in the human body

It is hard to keep up with the mind boggling advances that pop up in almost every issue of Science Magazine. In a perspective article Liu and Zhang describe the findings of the “Tabula Sapiens Consortium” that has now provided a molecular reference atlas for more than 400 cell types of the human body by measuring the messenger RNA molecules in each of nearly 500,000 cells from 24 tissues and organs. Multiple laboratories used single-cell transcriptomics to measure the messenger RNA molecules in each of nearly 500,000 cells from 24 tissues and organs Here is a single clip summary clip from Liu and Zhang:
...the Tabula Sapiens Consortium discovered that endothelial cells from lung, heart, uterus, liver, pancreas, fat, and muscle exhibit the most distinct transcriptional signatures, suggesting highly specialized functions, whereas endothelial cells from the thymus, vasculature, prostate, and eye resemble one another. The pan-tissue approach led to the discovery of SLC14A1 (solute carrier family 14 member 1) as a marker for heart endothelial cells, likely reflecting specialized metabolism in cardiac blood vessels. Eraslan et al. also found rare cell types, such as neuroendocrine cells in the prostate and enteric neurons in the esophagus. Additionally, the corroborative use of both high-throughput 10X and full-length SMART-seq2 single-cell transcriptome data allowed the quantification of splicing isoform usage at the single-cell level, thereby revealing differential exon usage patterns for genes, including MYL6 (myosin light chain 6) and CD47, in different cell-type compartments.

Wednesday, May 11, 2022

Increases and decreases in affective polarization over the past 40 years in advanced democracies

An interesting study from Boxell et al. shows that across 12 advanced democracies, affective polarization, the degree to which people feel more negatively toward other political parties than toward their own, has increased the most since the 1980s in the United States and to a lesser extent in Canada, Denmark, France, New Zealand, and Switzerland, and has decreased in Australia, Britain, (West) Germany, Japan, Norway, and Sweden. The authors derived theses conclusions from harmonizing results from 149 surveys and assembled data on economic, media, demographic, and political trends. Trends in the nonwhite share of the population and in the polarization of political elites were most strongly associated with trends in polarization of the general public.

Monday, May 09, 2022

Graziano's conceptual framework for consciousness

I would like to pass on this link to Graziano's latest (open source) explication of his theory of consciousness, continuing a MindBlog thread that started with a 2014 post on his 2013 book "Consciousness and the Social Brain." Here is his abstact:
This article argues that consciousness has a logically sound, explanatory framework, different from typical accounts that suffer from hidden mysticism. The article has three main parts. The first describes background principles concerning information processing in the brain, from which one can deduce a general, rational framework for explaining consciousness. The second part describes a specific theory that embodies those background principles, the Attention Schema Theory. In the past several years, a growing body of experimental evidence—behavioral evidence, brain imaging evidence, and computational modeling—has addressed aspects of the theory. The final part discusses the evolution of consciousness. By emphasizing the specific role of consciousness in cognition and behavior, the present approach leads to a proposed account of how consciousness may have evolved over millions of years, from fish to humans. The goal of this article is to present a comprehensive, overarching framework in which we can understand scientifically what consciousness is and what key adaptive roles it plays in brain function.
The article is worth a read, and here is Graziano's bottom line, from the last paragraph of his article:
If you start your search for consciousness by assuming the existence of a subjective feeling—a private component that cannot be measured and can only be felt and attested to, experienceness itself—then you are assuming the literal accuracy of an internal model. By principle 1, your conviction that you have consciousness depends on an information set in your brain. By principle 2, the brain’s models are never accurate. You have accepted the literal truth of a caricature, and you will never find the answer to your ill-posed question. When the police draw a sketch of a suspect, and you set yourself the task of finding a flat man made of graphite, you will fail. Yet at the same time, if you take the opposite approach and insist that the sketch is an empty illusion, you are missing the point. Instead, understand the sketch for what it is: a schematic representation of something real. We can explain physical processes in the brain; we can explain the models constructed by the brain to represent those physical processes; we can explain the way those models depict reality in a schematic, imperfect manner; we can explain the cognitive beliefs that stem from those imperfect models; and most importantly, we can explain the adaptive, cognitive benefits served by those models. AST is not just a theory of consciousness. It is a theory of adaptive mechanisms in the brain.

The prosocial effect of touching - the Midas touch effect.

Schaefer et al. (open source) examine the neural underpinnings of how light touching enhances prosocial behavior. Their abstract:
Giving and receiving touch are some of the most important social stimuli we exchange in daily life. By touching someone, we can communicate various types of information. Previous studies have also demonstrated that interpersonal touch may affect our altruistic behavior. A classic study showed that customers give bigger tips when they are lightly touched by a waitress, which has been called the Midas touch effect. Numerous studies reported similar effects of touch on different kinds of helping or prosocial behaviors. Here, we aim to examine the neural underpinnings of this effect by employing a functional magnetic resonance imaging approach. While lying in the scanner, participants played different rounds of the dictator game, a measure of prosocial behavior. Before each round, participants were touched (or not touched in the control condition) by an experimenter. We found that touching the hand increased the likeliness to behave prosocial (but not the general liking of control stimuli), thereby confirming the Midas touch effect. The effect was predicted by activity in the primary somatosensory cortex, indicating that the somatosensory cortex here plays a causal role in prosocial behavior. We conclude that the tactile modality in social life may be much more important than previously thought.

Thursday, May 05, 2022

Questioning common claims about human brain evolution

From DeCasien et al.:

Highlights
New research has questioned or contradicted multiple long-standing claims about human brain evolution.
Contrary to the social brain hypothesis, new work suggests that ecological factors, rather than social complexity, best predict relative brain size across primate species.
Brain size does not have similar effects or cognitive implications in different phylogenetic lineages since it is associated with different mosaic structural changes.
Although the human prefrontal cortex is proportionally large, this may not represent an adaptive specialization and research emphasis on this region has distracted attention from the importance of wider neural networks.
Functional and anatomical integration, rather than developmental constraints, may primarily explain patterns of brain region size covariation across species.
Abstract
Human brains are exceptionally large, support distinctive cognitive processes, and evolved by natural selection to mediate adaptive behavior. Comparative biology situates the human brain within an evolutionary context to illuminate how it has been shaped by selection and how its structure relates to evolutionary function, while identifying the developmental and molecular changes that were involved. Recent applications of powerful phylogenetic methods have uncovered new findings, some of which overturn conventional wisdom about how and why brains evolve. Here, we focus on four long-standing claims about brain evolution and discuss how new work has either contradicted these claims or shown the relevant phenomena to be more complicated than previously appreciated. Throughout, we emphasize studies of non-human primates and hominins, our close relatives and recent ancestors.
The authors dispute the following common claims about human brain evolution: (Motivated readers can obtain the whole text with their detailed arguments from me.)
Claim 1. Social complexity is the primary driver of non-human primate and human brain evolution
Claim 2. Brain size has similar effects and cognitive implications across a wide range of species
Claim 3. The proportionally large human PFC reflects selection on PFC-specific functions
Claim 4. Developmental constraints play a major role in the evolution of brain structure

Tuesday, May 03, 2022

Older adults store too much information.

From Amer et al.:  

Highlights

Healthy aging is accompanied by declines in control of attention.
These reductions in the control of attention, result in older adults processing too much information, creating cluttered memory representations.
Cluttered representations can impair memory by interfering with the retrieval of target information, but can also provide an advantage on tasks that benefit from extensive knowledge.

Abstract

Declines in episodic memory in older adults are typically attributed to differences in encoding strategies and/or retrieval processes. These views omit a critical factor in age-related memory differences: the nature of the representations that are formed. Here, we review evidence that older adults create more cluttered (or richer) representations of events than do younger adults. These cluttered representations might include target information along with recently activated but no-longer-relevant information, prior knowledge cued by the ongoing situation, as well as irrelevant information in the current environment. Although these representations can interfere with the retrieval of target information, they can also support other memory-dependent cognitive functions.

Monday, May 02, 2022

The human fear paradox: Affective origins of cooperative care

On the same morning last week that I read a NYTimes essay by Thomas Edsall "The Politics of Fear Show No Sign of Abating" I received an email from the journal Behavioral and Brain Science soliciting reviews on an upcoming article by Tobias Grossmann with an interesting hypothesis on why we humans are so fearful: "The human fear paradox: Affective origins of cooperative care." His 'fearful ape hypothesis' proposes that, in the context of the strong interdependence reflected in cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. Here I pass on the abstract of Grossmann's piece, and motivated readers can obtain the whole text from me.
Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal and health implications, as it challenges the predominant view in WEIRD societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions.

Thursday, April 28, 2022

The cultural evolution of love in literary history

An interesting article from Baumard et al. in Nature Human Behaviour:
Since the late nineteenth century, cultural historians have noted that the importance of love increased during the Medieval and Early Modern European period (a phenomenon that was once referred to as the emergence of ‘courtly love’). However, more recent works have shown a similar increase in Chinese, Arabic, Persian, Indian and Japanese cultures. Why such a convergent evolution in very different cultures? Using qualitative and quantitative approaches, we leverage literary history and build a database of ancient literary fiction for 19 geographical areas and 77 historical periods covering 3,800 years, from the Middle Bronze Age to the Early Modern period. We first confirm that romantic elements have increased in Eurasian literary fiction over the past millennium, and that similar increases also occurred earlier, in Ancient Greece, Rome and Classical India. We then explore the ecological determinants of this increase. Consistent with hypotheses from cultural history and behavioural ecology, we show that a higher level of economic development is strongly associated with a greater incidence of love in narrative fiction (our proxy for the importance of love in a culture). To further test the causal role of economic development, we used a difference-in-difference method that exploits exogenous regional variations in economic development resulting from the adoption of the heavy plough in medieval Europe. Finally, we used probabilistic generative models to reconstruct the latent evolution of love and to assess the respective role of cultural diffusion and economic development.

Tuesday, April 26, 2022

Are we seeing the beginning of World War III?

Below, I am passing on some links to background reading for this Sunday's Austin Rainbow Forum (email forumaustin@gmail.com for information), whose discussion topic is "The War in Ukraine: Start of World War III?." 

David Brooks - Globalization Is Over. The Global Culture Wars Have Begun

Thomas Friedman - Putin Had No Clue How Many of Us Would Be Watching 

Yuval Harari - What’s at stake in Ukraine is the direction of human history 

Fareed Zakaria - Russia is the last multinational empire, fighting to keep its colonies  

Ezra Klein - The Enemies of Liberalism Are Showing Us What It Really Means  

 

Thursday, April 21, 2022

Insight from Jonathan Haidt - "After Babel"

This article by Jonathan Haidt in the May 2022 print edition of The Atlantic is a long, frightening, and rewarding read. It lays out the mechanisms by which social media have catalyzed civil society's world wide disintegration over the past 10 years. I will not presume to do my usual extracting of summary chunks apart from passing on the first few paragraphs to whet your appetite:
The story of Babel is the best metaphor I have found for what happened to America in the 2010s, and for the fractured country we now inhabit. Something went terribly wrong, very suddenly. We are disoriented, unable to speak the same language or recognize the same truth. We are cut off from one another and from the past.
It’s been clear for quite a while now that red America and blue America are becoming like two different countries claiming the same territory, with two different versions of the Constitution, economics, and American history. But Babel is not a story about tribalism; it’s a story about the fragmentation of everything. It’s about the shattering of all that had seemed solid, the scattering of people who had been a community. It’s a metaphor for what is happening not only between red and blue, but within the left and within the right, as well as within universities, companies, professional associations, museums, and even families.
Babel is a metaphor for what some forms of social media have done to nearly all of the groups and institutions most important to the country’s future—and to us as a people. How did this happen? And what does it portend for American life?

Monday, April 18, 2022

How the gut talks to the brain.

Gabanyi et al. show that bacterial cell wall molecules that travel to the brain could trigger a host of behaviors. Here is the abstract of a Perspectives essay on this work by Adamantidis:
The mammalian gastrointestinal tract hosts a community of diverse micro-organisms, including bacteria, archea, fungi, and viruses. Bacterial products, such as metabolites and cell wall fragments, are implicated in host metabolic functions. In addition, the gut microbiota influences the immune and central nervous systems, and it has emerged as a key regulator of brain development and the modulation of behaviors, including stress and anxiety, often in a sex-specific manner. Disruption of gut microbiota–brain interactions contribute to the pathogenesis of neurodevelopmental and psychiatric disorders in animal models. ...Gabanyi et al. show that bacterial peptidoglycans, a by-product of bacterial cell wall degradation during cell division and cell death, directly inhibit the activity of feeding-promoting neurons in the hypothalamus and ultimately decrease appetite and body temperature, mostly in female mice. This finding may open new approaches for the treatment of metabolic disorders, including obesity.

Friday, April 15, 2022

A magisterial summary of the new world disorder by David Brooks

A few clips that attempt to summarize a David Brooks essay that does a beautiful job of putting all the pieces together:
I can remember a time — about a quarter-century ago — when the world seemed to be coming together. The great Cold War contest between communism and capitalism appeared to be over. Democracy was still spreading. Nations were becoming more economically interdependent. The internet seemed ready to foster worldwide communications. It seemed as if there would be a global convergence around a set of universal values — freedom, equality, personal dignity, pluralism, human rights...it was sometimes assumed that nations all around the world would admire the success of the Western democracies and seek to imitate us...They’d be more driven by the desire to settle down into suburban homes than by the fanatical ideologies or the sort of hunger for prestige and conquest that had doomed humanity to centuries of war.
...this vision does not describe the world we live in today. The world is not converging anymore; it’s diverging...The 2008 financial crisis delegitimized global capitalism for many people...Global flows of long-term investment fell by half between 2016 and 2019...All manner of antiglobalization movements have arisen: those of the Brexiteers, xenophobic nationalists, Trumpian populists, the antiglobalist left...The world economy seems to be gradually decoupling into, for starters, a Western zone and a Chinese zone. Foreign direct investment flows between China and America were nearly $30 billion per year five years ago. Now they are down to $5 billion...Economic rivalries have now merged with political, moral and other rivalries into one global contest for dominance. Globalization has been replaced by something that looks a lot like global culture war.
The fact is that human behavior is often driven by forces much deeper than economic and political self-interest, at least as Western rationalists typically understand these things...First, human beings are powerfully driven by what are known as the thymotic desires. These are the needs to be seen, respected, appreciated. If you give people the impression that they are unseen, disrespected and unappreciated, they will become enraged, resentful and vengeful. They will perceive diminishment as injustice and respond with aggressive indignation...Global politics over the past few decades functioned as a massive social inequality machine. In country after country, groups of highly educated urban elites have arisen to dominate media, universities, culture and often political power. Great swaths of people feel looked down upon and ignored.
Second, most people have a strong loyalty to their place and to their nation. But over the past few decades many people have felt that their places have been left behind and that their national honor has been threatened. In the heyday of globalization, multilateral organizations and global corporations seemed to be eclipsing nation-states...In country after country, highly nationalistic movements have arisen to insist on national sovereignty and to restore national pride: Modi in India, Recep Tayyip Erdogan in Turkey, Trump in the United States, Boris Johnson in Britain.
Third, people are driven by moral longings — by their attachment to their own cultural values, by their desire to fiercely defend their values when they seem to be under assault. For the past few decades, globalization has seemed to many people to be exactly this kind of assault...The problem is that Western values are not the world’s values. In fact, we in the West are complete cultural outliers. In his book “The WEIRDest People in the World,” Joseph Henrich amasses hundreds of pages of data to show just how unusual Western, Educated, Industrialized, Rich and Democratic values are...Many people around the world look at our ideas about gender roles and find them foreign or repellent...The idea that it’s up to each person to choose one’s own identity and values — that seems ridiculous to many. The idea that the purpose of education is to inculcate critical thinking skills so students can liberate themselves from the ideas they received from their parents and communities — that seems foolish to many.
Finally, people are powerfully driven by a desire for order. Nothing is worse than chaos and anarchy...Today, many democracies appear less stable than they did and many authoritarian regimes appear more stable. American democracy, for example, has slid toward polarization and dysfunction. Meanwhile, China has shown that highly centralized nations can be just as technologically advanced as the West. Modern authoritarian nations now have technologies that allow them to exercise pervasive control of their citizens in ways that were unimaginable decades ago...Autocratic regimes are now serious economic rivals to the West. They account for 60 percent of patent applications. In 2020, the governments and businesses in these countries invested $9 trillion in things like machinery, equipment and infrastructure, while democratic nations invested $12 trillion. If things are going well, authoritarian governments can enjoy surprising popular support.
...something bigger is happening today that is different from the great power struggles of the past, that is different from the Cold War. This is not just a political or an economic conflict. It’s a conflict about politics, economics, culture, status, psychology, morality and religion all at once. More specifically, it’s a rejection of Western ways of doing things by hundreds of millions of people along a wide array of fronts...To define this conflict most generously, I’d say it’s the difference between the West’s emphasis on personal dignity and much of the rest of the world’s emphasis on communal cohesion. But that’s not all that’s going on here. What’s important is the way these longstanding and normal cultural differences are being whipped up by autocrats who want to expand their power and sow chaos in the democratic world. Authoritarian rulers now routinely weaponize cultural differences, religious tensions and status resentments to mobilize supporters, attract allies and expand their own power. This is cultural difference transmogrified by status resentment into culture war.
...rejection of Western liberalism, individualism, pluralism, gender equality and all the rest is not only happening between nations but also within nations. The status resentment against Western cultural, economic and political elites that flows from the mouths of illiberal leaders like Putin and Modi and Jair Bolsonaro of Brazil sounds quite a lot like the status resentment that flows from the mouths of the Trumpian right, from the French right, from the Italian and Hungarian right...How do you win a global culture war in which differing views on secularism and gay rights parades are intertwined with nuclear weapons, global trade flows, status resentments, toxic masculinity and authoritarian power grabs?
The critiques that so many people are making about the West, and about American culture — for being too individualistic, too materialistic, too condescending — these critiques are not wrong. We have a lot of work to do if we are going to be socially strong enough to stand up to the challenges that are coming over the next several years, if we are going to persuade people in all those swing countries across Africa, Latin America and the rest of the world that they should throw their lot in with the democracies and not with the authoritarians — that our way of life is the better way of life.
At the end of the day, only democracy and liberalism are based on respect for the dignity of each person. At the end of the day, only these systems and our worldviews offer the highest fulfillment for the drives and desires I’ve tried to describe here...I have faith in the ideas and the moral systems that we have inherited. What we call “the West” is not an ethnic designation or an elitist country club. The heroes of Ukraine are showing that at its best, it is a moral accomplishment, and unlike its rivals, it aspires to extend dignity, human rights and self-determination to all. That’s worth reforming and working on and defending and sharing in the decades ahead.

Wednesday, April 13, 2022

The Dance of Sleep

Sleep and wakefulness are characterized by unique intrinsic activity patterns and are usually thought to be two distinct global states, with the preoptic area of the hypothalamus being the regulator of brain state changes. Yamagata et al. find that this area also affects within-state changes of sleep and wake intensity.  

Significance

Our current understanding of how sleep is regulated is based upon the model of sleep homeostasis, which defines a variable called Process S as a measure of sleep need, and a so-called “flip-flop” model of state switching, which builds on a notion of a mutually antagonistic relationship between subcortical sleep-promoting and wake-promoting circuits. The neurobiological substrates of the interaction between the sleep switch and Process S are unknown. Our study identifies a previously unrecognized role of hypothalamic circuitry in tuning within-state brain activity or levels of arousal, which in turn determine the homeostatic drive for sleep.
Abstract
Sleep and wakefulness are not simple, homogenous all-or-none states but represent a spectrum of substates, distinguished by behavior, levels of arousal, and brain activity at the local and global levels. Until now, the role of the hypothalamic circuitry in sleep–wake control was studied primarily with respect to its contribution to rapid state transitions. In contrast, whether the hypothalamus modulates within-state dynamics (state “quality”) and the functional significance thereof remains unexplored. Here, we show that photoactivation of inhibitory neurons in the lateral preoptic area (LPO) of the hypothalamus of adult male and female laboratory mice does not merely trigger awakening from sleep, but the resulting awake state is also characterized by an activated electroencephalogram (EEG) pattern, suggesting increased levels of arousal. This was associated with a faster build-up of sleep pressure, as reflected in higher EEG slow-wave activity (SWA) during subsequent sleep. In contrast, photoinhibition of inhibitory LPO neurons did not result in changes in vigilance states but was associated with persistently increased EEG SWA during spontaneous sleep. These findings suggest a role of the LPO in regulating arousal levels, which we propose as a key variable shaping the daily architecture of sleep–wake states.

Monday, April 11, 2022

The road to our larger brains

Bertrand et al. address the question of how and why mammals evolved large brain sizes relative to their body mass by characterizing the timing and pattern of mammal brain development across the Early Jurassic to the middle Cenozoic (∼200 million to 30 million years ago) when the ecological niches vacated by the extinction of large reptiles were being filled by large mammals. Here is their abstract:
Mammals are the most encephalized vertebrates, with the largest brains relative to body size. Placental mammals have particularly enlarged brains, with expanded neocortices for sensory integration, the origins of which are unclear. We used computed tomography scans of newly discovered Paleocene fossils to show that contrary to the convention that mammal brains have steadily enlarged over time, early placentals initially decreased their relative brain sizes because body mass increased at a faster rate. Later in the Eocene, multiple crown lineages independently acquired highly encephalized brains through marked growth in sensory regions. We argue that the placental radiation initially emphasized increases in body size as extinction survivors filled vacant niches. Brains eventually became larger as ecosystems saturated and competition intensified.

Friday, April 08, 2022

Humans don’t have culture because we’re smart, we’re smart because we have culture.

The title of this post is a sentence taken from the final paragraph of Henrich's Perspective article in Science on the work of Thompson et al. which notes that Thompson et al.'s results
...highlight a deeper point: Humans don’t have culture because we’re smart, we’re smart because we have culture. The selective processes of cultural evolution not only generate more sophisticated practices and technologies but also produce new cognitive tools—algorithms—that make humans better adapted to the ecological and institutional challenges that we confront. Thompson et al.’s results underline the need for the psychological sciences to abandon their implicit reliance on a digital computer metaphor of the mind (hardware versus software) and transform into a historical science that considers not just how cultural evolution shapes what we think (our mental contents) but also how we think [our cognitive processes].
Here I pass on the introductory paragraphs and then the abstract of the Thompson et al. article. Motivated readers can obtain the full text by emailing me.
Reading, counting, cooking, and sailing are just some of the human abilities passed from generation to generation through social learning... Complex abilities like these often depend on learned cognitive algorithms: procedural representations of a problem that coordinate memory, attention, and perception into sequences of useful computations and actions. Accumulation of complex algorithms—from ancient tool-making techniques to bread making, boat building, or horticulture—is central to human adaptation yet challenging to explain because algorithmic concepts can be difficult to discover, communicate, and learn from observation, making them vulnerable to loss. Theories of cultural evolution suggest that human social learning may help overcome this fragility. For example, mathematical models predict that choosing to learn from successful or prestigious individuals can prevent the loss of rare innovations. However, this potential link between sociality and complex abilities is challenging to establish.
We conducted large-scale simulations of cultural evolution with human participants to assess how selective social learning influenced the evolution of cognitive algorithms. Prior research shows that social learning can improve decisions in multiple-choice tasks, perceptual judgments, and search problems and can improve artifacts such as physical structures or computer programs. However, the evolution of cognitive algorithms at the population level has been difficult to study. We developed custom software to recruit large numbers of participants online and organize them into evolving societies facing a common problem. Twenty populations tackled a sequential decision problem... Presented with six images, participants attempted to establish hidden arbitrary orderings using pairwise comparisons. Out-of-order pairs swapped positions when compared. Participants were rewarded for establishing the ordering using fewer comparisons. This task poses a sorting problem, requiring a strategy for executing appropriate sequences of actions, analogous to culturally evolved strategies for making tools or food.
Abstract:
Many human abilities rely on cognitive algorithms discovered by previous generations. Cultural accumulation of innovative algorithms is hard to explain because complex concepts are difficult to pass on. We found that selective social learning preserved rare discoveries of exceptional algorithms in a large experimental simulation of cultural evolution. Participants (N = 3450) faced a difficult sequential decision problem (sorting an unknown sequence of numbers) and transmitted solutions across 12 generations in 20 populations. Several known sorting algorithms were discovered. Complex algorithms persisted when participants could choose who to learn from but frequently became extinct in populations lacking this selection process, converging on highly transmissible lower-performance algorithms. These results provide experimental evidence for hypothesized links between sociality and cognitive function in humans.

Wednesday, April 06, 2022

The Science of Consciousness - Tucson 2022

For junkies of consciousness and altered states thereof, as in anesthesia or psychedelic-induced states, a browsing of the abstracts submitted for The Science of Consciousness 2022 in Tucson April 18-22 makes for stimulating reading (though I found pauses to recover from input overload to be necessary.) I attended the first “Towards a Science of Consciousness” - now known as TSC “The Science of Consciousness” - in 1994, as well as a number of subsequent meetings, and it was encouragement from several then luminaries in the field that emboldened me to turn the lecture notes from my “Biology of Mind” course at the University of Wisconsin into a book of that title which was published in 1999. There are numerous bon-bons to be found in this year's set of abstracts, one example from many being Huang’s noting of his work on how the anterior insula, situated between unimodal and transmodal cortical areas along the brain’s primary functional gradient, regulates the default mode – dorsal attention network transitions, and gates conscious access of sensory information.

Monday, April 04, 2022

Magic mind therapy….. Moving your body.

Gretchen Reynolds interviews Jennifer Heisz about the contents of her new book "Move the Body, Heal the Mind," which details the latest science about exercise and mental health, especially its potential to reduce anxiety and stress. The brief reprieve from anxiety than can sometimes be experienced after a workout is due to the release of neuropeptide Y, known to dampen hyperactivity of the anxious amygdala. Exercise also can reduce stress-induced body inflammation that damages cells and affects mood. These effects require only about a quarter of the normally recommended 150 minutes of moderate to vigorous exercise a week, so the exercise prescription for mental health seems to be less than that for physical health.

Friday, April 01, 2022

Losing sleep with age.

Jacobson and Hoyer summarize experiments of Li et al.:
Humans spend approximately one-third of their lives asleep, but this is not distributed equally across their life span. Sleep quantity and quality decline as age advances, and insomnia and sleep fractionation are common in older people. Sleep is essential for vitality and health. At any age, chronic sleep deprivation causes a range of issues, including disrupted cognition and memory. Correspondingly, sleep complaints in older people are associated with increased risks of impaired physical and mental health and with mortality. Beyond evidence of degenerating subcortical nuclei in age-associated sleep disturbances, the underlying mechanisms remain unclear despite decades of awareness of the problem and its consequences...Li et al.report the hyperexcitability of hypocretin neurons as a core mechanism underlying sleep disruption in aged mice, explaining why sleep is punctuated by intruding wakefulness despite the loss of wake-promoting neurons.

A few clips from the Li et al. article: 

RATIONALE

We hypothesized that the decline in sleep quality could be due to malfunction of the neural circuits associated with sleep/wake control. It has been established that hypocretin/orexin (Hcrt/OX) neuronal activity is tightly associated with wakefulness and initiates and maintains the wake state. In this study, we investigated whether the intrinsic excitability of Hcrt neurons is altered, leading to a destabilized control of sleep/wake states during aging.
RESULTS
Aged mice exhibited sleep fragmentation and a significant loss of Hcrt neurons. Hcrt neurons manifested a more frequent firing pattern, driving wake bouts and disrupting sleep continuity in aged mice. Aged Hcrt neurons were capable of eliciting more prolonged wake bouts upon optogenetic stimulations. These results suggested that hyperexcitability of Hcrt neurons emerges with age. Patch clamp recording in genetically identified Hcrt neurons revealed distinct intrinsic properties between the young and aged groups. Aged Hcrt neurons were hyperexcitable with depolarized membrane potentials (RMPs) and a smaller difference between RMP and the firing threshold.
CONCLUSION
Aged mice exhibited sleep fragmentation and a significant loss of Hcrt neurons. Hcrt neurons manifested a more frequent firing pattern, driving wake bouts and disrupting sleep continuity in aged mice. Aged Hcrt neurons were capable of eliciting more prolonged wake bouts upon optogenetic stimulations. These results suggested that hyperexcitability of Hcrt neurons emerges with age. Patch clamp recording in genetically identified Hcrt neurons revealed distinct intrinsic properties between the young and aged groups. Aged Hcrt neurons were hyperexcitable with depolarized membrane potentials (RMPs) and a smaller difference between RMP and the firing threshold.

Wednesday, March 30, 2022

Re-energizing the aged brain

Alderton does a brief summary of work by Brakedal et al.:
Nicotinamide adenine dinucleotide (NAD) is an important cofactor in numerous metabolic reactions. NAD concentrations decline with age, which may contribute to age-associated conditions such as Parkinson’s disease. Preclinical studies show that replenishing NAD by supplementation with nicotinamide riboside (NR), a biosynthetic precursor to NAD, can promote health span and neuroprotection. Brakedal et al. performed a randomized, double-blind phase 1 clinical trial of NR supplementation in 30 patients newly diagnosed with Parkinson’s disease. They found that NR supplementation was safe and that concentrations of NAD in the brain increased in most patients receiving NR. These patients had signs of altered cerebral metabolism and mild clinical improvement, although further testing is needed with a larger cohort to confirm any clinical benefit.
Added note: I realized I had bought a jar of nicotinamide riboside some time ago ("TRU - Niagen" at an outrageious price), decided not to take it after reading about possible side effects, but relented after reading the Brakedal et al. article. I've been taking a 150 mg capsule daily for the past 10 days, half the recommended dosage. I haven't detected any noticable effects on my general energy levels.

Monday, March 28, 2022

Abnormal hemispheric interactions of Autism Spectrum Disorder present in 1st year of life.

From Rolison et al.:
Autism spectrum disorder (ASD) is characterized by atypical connectivity lateralization of functional networks. However, previous studies have not directly investigated if differences in specialization between ASD and typically developing (TD) peers are present in infancy, leaving the timing of onset of these differences relatively unknown. We studied the hemispheric asymmetries of connectivity in children with ASD and infants later meeting the diagnostic criteria for ASD. Analyses were performed in 733 children with ASD and TD peers and in 71 infants at high risk (HR) or normal risk (NR) for ASD, with data collected at 1 month and 9 months of age. Comparing children with ASD (n = 301) to TDs (n = 432), four regions demonstrated group differences in connectivity: posterior cingulate cortex (PCC), posterior superior temporal gyrus, extrastriate cortex, and anterior prefrontal cortex. At 1 month, none of these regions exhibited group differences between ASD (n = 10), HR-nonASD (n = 15), or NR (n = 18) infants. However, by 9 months, the PCC and extrastriate exhibited atypical connectivity in ASD (n = 11) and HR-nonASD infants (n = 24) compared to NR infants (n = 22). Connectivity did not correlate with symptoms in either sample. Our results demonstrate that differences in network asymmetries associated with ASD risk are observable prior to the age of a reliable clinical diagnosis.

Friday, March 25, 2022

Trust is needed to run the world, and crypto can make trusting easier

I want to pass on a few clips from a recent screed by Mark Manson in his usual explitive-rich style. I regret that he doesn't make clear the central point that it is the blockchain concept underlying various cryptocurrencies that is responsible for generating trustworthy transactions, without requiring the intervention of third parties like banks, inspectors, and regulators to certify trustworthiness. Here are my clips and pastings:
The problem is that trust-building institutions are human. And humans are, uh, not really trustworthy....there are millions of people in the world whose entire jobs are to verify trustworthiness. Insurance companies, banks, legal firms, universities, regulatory agencies, and government programs have massive office buildings full of nothing but people doing this trustworthy verification thing, all day every day... because we have not other better way to do it...and the process is corruptible because it is human.
The way Uber automated away taxi drivers, crypto will automate away millions of these trust verifiers...you can shake your fist and make please about job security and income inequality or whatever, but at the end of the day...we will all love it and use it for the same reason we love and use Uber...because it makes our lives a hundred times easier...dealing with human-led institution to constantly verify trust is a never-ending nightmare...submissionsw of hundreds of pages of paperwork...All it takes is one pissed off guy at the DMV to literally prevent you from being able to legally drive. All it takes is one asshoel banker on a power trip to fuck up your ability to buy a home.
That is why I believe crypto is inevitable...but messy...crypto is market-testing hundreds of different types of governance models, security protocols, capitalization allocations, wealth redistribution, brand-building. What happend in 100 years in the real world happens in a couple months in the crypto world...eventually, it will catch up. The governance systems will be better, faster, more reliable, more secure, and censorship-proof. But part of that market-testing is subjecting itself to hundreds of hacks, ponzis, rug pulls, saboteurs, scam artists, rip-offs, and dum dog coins. ...in order to automate and upgrade trust-verifying institutions, you must rebuild and/or replace those institutions. And those institutions are unlikely to go quietly.

Wednesday, March 23, 2022

Neurons in the brain that respond mainly to singing

New work from Norman-Haignere et al. describes a population of cells in our auditory cortex, located between the music and speech-selective areas, that is responsive to singing, but not to instrumental music or speech. (Their experiments were done on patients who were in hospital with electrodes implanted into their heads for epilepsy treatment, allowing more precise location data than can be obtained from fMRI scans.) Their result is consonant with a popular theory that singing has an important role in the evolution of music and language. Their abstract:  

Highlights

• Neural population responsive to singing, but not instrumental music or speech 
• New statistical method infers neural populations from human intracranial responses 
• fMRI used to map the spatial distribution of intracranial responses 
• Intracranial responses replicate distinct music- and speech-selective populations
Summary
How is music represented in the brain? While neuroimaging has revealed some spatial segregation between responses to music versus other sounds, little is known about the neural code for music itself. To address this question, we developed a method to infer canonical response components of human auditory cortex using intracranial responses to natural sounds, and further used the superior coverage of fMRI to map their spatial distribution. The inferred components replicated many prior findings, including distinct neural selectivity for speech and music, but also revealed a novel component that responded nearly exclusively to music with singing. Song selectivity was not explainable by standard acoustic features, was located near speech- and music-selective responses, and was also evident in individual electrodes. These results suggest that representations of music are fractionated into subpopulations selective for different types of music, one of which is specialized for the analysis of song.

Monday, March 21, 2022

Mellow Mice - Why deep breathing can keep us calm

How we are breathing is usally a good indicator of whether we are calm or aroused. When we become anxious or aroused, usually the best thing we can do is stop and take a deep breath. Gretchen Reynolds points to interesting work in mice that suggests that taking deep breaths is calming because it does not activate neurons in the brain's breathing center that communicate with the brain's arousal center (breathing pacemakers in humans closely resemble those in mice). Here is the abstract from Yackle et al.:
Slow, controlled breathing has been used for centuries to promote mental calming, and it is used clinically to suppress excessive arousal such as panic attacks. However, the physiological and neural basis of the relationship between breathing and higher-order brain activity is unknown. We found a neuronal subpopulation of about 350 neurons in the mouse preBötzinger complex (preBötC), the primary breathing rhythm generator, which regulates the balance between calm and arousal behaviors. Conditional, bilateral genetic ablation of the ~175 Cdh9/Dbx1 double-positive preBötC neurons in adult mice left breathing intact but increased calm behaviors and decreased time in aroused states. These neurons project to, synapse on, and positively regulate noradrenergic neurons in the locus coeruleus, a brain center implicated in attention, arousal, and panic that projects throughout the brain.

Friday, March 18, 2022

Difference in knowledge production by global north and south

Torres et al. do an interesting analysis:

Significance
Contemporary social sciences aim to be diverse and inclusive, but traces of the historical dominance of Western European and North American academic institutions persist in scientific practices. One such practice is the phrasing of article titles. Our analysis shows that articles studying the global North are systematically less likely to mention the name of the country they study in their title compared to articles on the global South. This constitutes, potentially, an unwarranted claim on universality and may lead to lesser recognition of global South studies. Social and behavioral scientists must reflect on the phrasing of their article titles to avoid reproducing harmful relations of intellectual domination which limit inclusivity and constitute a barrier to the generalizability of scientific knowledge.
Abstract
The legacy of Eurocentrism continues to affect knowledge production in the social sciences. Evidence produced in and about the global North is assumed to be more “universal,” whereas evidence from or produced in the global South is considered valid only for specific contexts (i.e., “localized”). We argue that these dynamics are evident in the phrasing of articles’ titles based on the examination of more than half a million social science research articles indexed by Scopus (1996 to 2020). We find that empirical articles written by authors affiliated to institutions of the global North, using data from these countries, are less likely to include a concrete geographical reference in their titles. When authors are affiliated to global South institutions, and use evidence from global South countries, the names of these countries are more likely to be part of the article’s title. We confirm this overarching pattern by looking at 1) differences between world regions, 2) differences within world regions, and 3) patterns in 23 social science subfields. These gaps are large and consistent, yet article naming conventions are merely the “tip of the iceberg” of the imbalances in knowledge production between the global North and South.