Ancient Greece's Army of Lovers

This post is under MindBlog's "random and curious stuff" category. A piece by Daniel Mendelsohn in The New Yorker:

Comprising a hundred and fifty male couples, Thebes’s Sacred Band was undefeated until it was wiped out in 338 B.C. In the nineteenth century, the mass grave of the men was found.

Image courtesy Hellenic Ministry of Culture and Sports, Directorate of the Management of the National Archive of Monuments, Department of the Historical Archive of Antiquities and Restorations

In June, 1818, during a visit to central Greece, a young English architect named George Ledwell Taylor went out riding with some friends in order to explore the ruins of an ancient town called Chaeronea. As Taylor’s party neared its destination, his horse took a “fearful stumble,” as he later recalled, on a stone in the roadway; on further inspection, he saw that the stone was, in fact, part of a sculpture. Energetic digging eventually revealed an animal head nearly six feet high—or, as Taylor put it, a “colossal head of the Lion.”

That definite article and the capital “L” are crucial. Taylor realized that he had uncovered a famous monument, mentioned in some historical sources but since lost, known as the Lion of Chaeronea. The Englishman had been studying a work called “The Description of Greece,” by Pausanias, a geographer of the second century A.D., which states that the gigantic figure of the sitting animal had been erected to commemorate a remarkable military unit that had perished there. The lion, Pausa­nias surmised, represented “the spirit of the men.”

The unit to which those men belonged was known as the Sacred Band. Comprising three hundred warriors from the city of Thebes, it was among the most fearsome fighting forces in Greece, undefeated until it was wiped out at the Battle of Chaeronea, in 338 B.C.—an engagement during which Philip of Macedon and his son, the ­future Alexander the Great, crushed a coalition of Greek city-states led by Athens and Thebes. Scholars see Chaeronea as the death knell of the Classi­cal Era of Greek history.

Others might find the story interesting for different reasons. Not the least of these is that the Band was composed entirely of lovers: precisely a hundred and fifty couples, whose valor, so the Greeks thought, was due to the fact that no man would ever exhibit cowardice or act dishonorably in front of his beloved. In Plato’s Symposium, a dialogue about love, a character remarks that an army made up of such lovers would “conquer all mankind.”

Sixty years after George Taylor’s horse stumbled, further excavations revealed a large rectangular burial site near the Lion. Drawings that were made at the site show seven rows of skeletons, two hundred and fifty-four in all. For “The Sacred Band” (Scribner), a forthcoming book by the classicist James Romm, the illustrator Markley Boyer collated those nineteenth-century drawings to produce a reconstruction of the entire mass grave. Black marks indicate wounds. A number of warriors were buried with arms linked; if you look closely, you can see that some were holding hands. ♦

Gamma-frequency oscillations link different brain regions during learning.

Fernández-Ruiz et al. demonstrate that specific, projected gamma-frequency oscillation patterns dynamically engage functionally related cell assemblies across brain regions in a task-specific manner. I pass along their entire structured abstract:  

INTRODUCTION

Learning induces a dynamic reorganization of brain circuits but the neuronal mechanisms underlying this process are not well understood. Interregional gamma-frequency oscillations (~30 to 150 Hz) have been postulated as a mechanism to precisely coordinate upstream and downstream neuronal ensembles, for example, in the hippocampal system. The lateral (LEC) and medial (MEC) entorhinal cortex receive inputs from two distinct streams of cortical hierarchy (the “what” and the “where” pathways) and convey these neuronal messages to the hippocampus. However, the mechanisms by which such messages are packaged and integrated or segregated by hippocampal circuits had yet to be explored.

RATIONALE

Neuronal assemblies firing within gamma time frames in an upstream region can most effectively discharge their downstream partners. This gamma-time-scale organization appears essential for physiological functions because manipulations that impair precision timing of spikes in the hippocampus often affect behavior. However, direct support for distinct gamma-frequency communication in appropriate behavioral situations is missing. To bring physiological operations closer to behavior, we designed “spatial” and “object” learning tasks and examined the selective engagement of gamma-frequency communication between the MEC and LEC inputs and their target neuronal assemblies in the hippocampal dentate gyrus. We combined these correlational observations with optogenetic perturbation of gamma oscillations in LEC and MEC, respectively, to test their roles in pathway-specific neuronal communication and learning.

RESULTS

During spatial learning, fast gamma (100 to 150 Hz) oscillations synchronized MEC and dentate gyrus and entrained predominantly granule cells. During object learning, slow gamma (30 to 50 Hz) oscillations synchronized LEC and dentate gyrus and preferentially recruited mossy cells and CA3 pyramidal neurons, suggesting task-specific routing of MEC and LEC messages in the form of gamma-cycle-spike packets of selected cell types. The low- and high-frequency gamma sub-bands were dominant in the outer and middle third of the dentate molecular layer, respectively, and their amplitude maxima were locked to different phases of theta oscillations.

Gamma frequency optogenenetic perturbation of MEC and LEC led to learning impairments in a spatial and object learning task, respectively. In the same animals, the dentate layer–specific low- and high-frequency gamma sub-bands and spike-gamma LFP coupling were selectively reduced, coupled with deterioration of spatial and object-related firing of dentate neurons.

CONCLUSION

These findings demonstrate that distinct gamma-frequency-specific communication between MEC and LEC and hippocampal cell assemblies are critical for routing task-relevant information, and our selective gamma-band perturbation experiments suggest that they support specific aspects of learning. We hypothesize that sending neuronal messages by segregated gamma-frequency carriers allows a target “reader” area to disambiguate convergent inputs. In general, these results demonstrate that specific projected gamma patterns dynamically engage functionally related cell assemblies across brain regions in a task-specific manner.

Vision: What’s so special about words?

Readers are sensitive to the statistics of written language. New work by Vidal et al. suggests that this sensitivity may be driven by the same domain-general mechanisms that enable the visual system to detect statistical regularities in the visual environment. 

Highlights

• Readers presented with orthographic-like stimuli are sensitive to bigram frequencies 

• An analogous effect emerges with images of made-up objects and visual gratings 

• These data suggest that the reading system might rely on general-purpose mechanisms 

• This calls for considering reading in the broader context of visual neuroscience

Summary

As writing systems are a relatively novel invention (slightly over 5 kya), they could not have influenced the evolution of our species. Instead, reading might recycle evolutionary older mechanisms that originally supported other tasks and preceded the emergence of written language. Accordingly, it has been shown that baboons and pigeons can be trained to distinguish words from nonwords based on orthographic regularities in letter co-occurrence. This suggests that part of what is usually considered reading-specific processing could be performed by domain-general visual mechanisms. Here, we tested this hypothesis in humans: if the reading system relies on domain-general visual mechanisms, some of the effects that are often found with orthographic material should also be observable with non-orthographic visual stimuli. We performed three experiments using the same exact design but with visual stimuli that progressively departed from orthographic material. Subjects were passively familiarized with a set of composite visual items and tested in an oddball paradigm for their ability to detect novel stimuli. Participants showed robust sensitivity to the co-occurrence of features (“bigram” coding) with strings of letter-like symbols but also with made-up 3D objects and sinusoidal gratings. This suggests that the processing mechanisms involved in the visual recognition of novel words also support the recognition of other novel visual objects. These mechanisms would allow the visual system to capture statistical regularities in the visual environment. We hope that this work will inspire models of reading that, although addressing its unique aspects, place it within the broader context of vision.

Useful Delusions

I want to pass on to MindBlog readers some background information on the recent book "Useful Delusions: The Power and Paradox of the Self-Deceiving Brain" by Shankar Vedantam, host of NPR’s “The Hidden Brain,” and science writer Bill Mesler. It was compiled by a member of the four person program committee of the Austin Rainbow Forum discussion group to which I belong.

This Hidden Brain podcast interview with Shankar Vedantum is a great resource for those up to the challenge of sitting in a comfortable chair for an hour listening to a great conversation while enjoying a pleasant beverage.

And here are a few alternatives for the listening challenged:

A book excerpt at the Hidden Brain website.

And, book reviews from The New York Journal of Books, and The Wall Street Journal.

Why does passion matter more in individualistic cultures?

Tsai does an interesting commentary  (open source) on work noted in MindBlog's recent post on an article by Li et al.  Some clips:

Our research finds that, because achieving independence requires increased arousal and action, cultures that foster these goals value high-arousal positive states like passion, excitement, and enthusiasm. In contrast, because achieving interdependence requires decreased arousal and action, cultures that foster these goals value low-arousal positive states like calm, peacefulness, and balance.

These ideals matter because people use them to judge their own feelings, and, perhaps even more importantly, to judge the feelings of others. For instance, because European Americans value excitement more than Hong Kong Chinese, they rate “excited” faces (with broad toothy smiles) as much friendlier and warmer than “calm” faces (with closed smiles), compared to Hong Kong Chinese. And, because European Americans perceive excited (vs. calm) faces as friendlier and warmer, they share more money with excited vs. calm partners in economic games (e.g., the Dictator Game), compared to East Asians.

Experiencing and expressing cultural ideals can have life-altering consequences in the real world. When deciding whom to lend to on a web-based microlending platform (Kiva.com), people from countries with an excitement ideal loaned more to borrowers who had “excited” smiles in their profile photos and less to borrowers who had “calm” smiles. In a business setting, when selecting an intern, European Americans viewed the “ideal applicant” as being more excited (vs. calm), and chose more excited (vs. calm) applicants than Hong Kong Chinese did. Even in health settings, European Americans chose excitement-focused physicians who promoted dynamic lifestyles (vs. calm-focused physicians who promoted relaxing lifestyles) more than Hong Kong Chinese did. Interestingly, European Americans also recalled and adhered to the recommendations of the excitement- versus calm-focused physician more than East Asian Americans did. These findings suggest that people may also be more receptive to the advice and feedback of people who express their cultural ideal.

...in the context of a European American focus on passion, calm East Asian Americans are often inaccurately judged to be “cold” and “stoic” . This may explain why, compared to European Americans, East Asian Americans are less likely to be promoted to top leadership positions, a problem often described as “the Bamboo Ceiling”. But this might be avoided if teachers, employers, and other decision makers in individualistic cultures understood that in many cultures — as illustrated by the findings of Li et al. — passion matters less. Instead of passion, people are finding, following, and fueling calm, balance, and the other affective states that their cultures value more.

The Psychology of Fake News

Pennycook and Rand do a fascinating open source article in Trends in Cognitive Science on the psychology of fake news.  Their highlights and summary: 

Recent evidence contradicts the common narrative that partisanship and politically motivated reasoning explain why people fall for 'fake news'. 

Poor truth discernment is linked to a lack of careful reasoning and relevant knowledge, as well as to the use of familiarity and source heuristics. 

There is also a large disconnect between what people believe and what they will share on social media, and this is largely driven by inattention rather than by purposeful sharing of misinformation. 

Effective interventions can nudge social media users to think about accuracy, and can leverage crowdsourced veracity ratings to improve social media ranking algorithms.

We synthesize a burgeoning literature investigating why people believe and share false or highly misleading news online. Contrary to a common narrative whereby politics drives susceptibility to fake news, people are ‘better’ at discerning truth from falsehood (despite greater overall belief) when evaluating politically concordant news. Instead, poor truth discernment is associated with lack of careful reasoning and relevant knowledge, and the use of heuristics such as familiarity. Furthermore, there is a substantial disconnect between what people believe and what they share on social media. This dissociation is largely driven by inattention, more so than by purposeful sharing of misinformation. Thus, interventions can successfully nudge social media users to focus more on accuracy. Crowdsourced veracity ratings can also be leveraged to improve social media ranking algorithms.

How dopamine leads to hallucinations

Hallucinations (perceptual experiences without external stimuli) seen in conditions such as schizophrenia are thought to result from giving too much weight to priors, creating an imbalance at the expense of actual sensory evidence. Sustained high-dopamine tone in the striatum has been proposed to contribute to this imbalance; however, it has remained unclear how the dopaminergic perturbation leads to the generation of hallucinations. Schmack et al. have developed a cross-species computational psychiatry approach to directly relate human and rodent behavior and used this approach to study the neural basis of hallucination-like perception in mice. Here is the summary of their results and their conclusion:   

RESULTS

We set up analogous auditory detection tasks for humans and mice. Both humans and mice were presented with an auditory stimulus in which a tone signal was embedded in a noisy background on half of the trials. Humans pressed one of two buttons to report whether or not they heard a signal, whereas mice poked into one of two choice ports. Humans indicated how confident they were in their report by positioning a cursor on a slider; mice expressed their confidence by investing variable time durations to earn a reward. In humans, hallucination-like percepts—high-confidence false alarms—were correlated with the tendency to experience spontaneous hallucinations, as quantified by a self-report questionnaire. In mice, hallucination-like percepts increased with two manipulations known to induce hallucinations in humans: administration of ketamine and the heightened expectation of hearing a signal. We then used genetically encoded dopamine sensors with fiber photometry to monitor dopamine dynamics in the striatum. We found that elevations in dopamine levels before stimulus onset predicted hallucination-like perception in both the ventral striatum and the tail of the striatum. We devised a computational model that explains the emergence of hallucination-like percepts as a consequence of faulty perceptual inference when prior expectations outweigh sensory evidence. Our model clarified how hallucination-like percepts can arise from fluctuations in two distinct types of expectations: reward expectations and perceptual expectations. In mice, dopamine fluctuations in the ventral striatum reflected reward expectations, whereas in the tail of the striatum they resembled perceptual expectations. We optogenetically boosted dopamine in the tail of the striatum and observed that increasing dopamine induced hallucination-like perception. This effect was rescued by the administration of haloperidol, an antipsychotic drug that blocks D2 dopamine receptors.

CONCLUSION

We established hallucination-like perception as a quantitative behavior in mice for modeling the subjective experience of a cardinal symptom of psychosis. We found that hallucination-like perception is mediated by dopamine elevations in the striatum and that this can be explained by encoding different kinds of expectations in distinct striatal subregions. These findings support the idea that hallucinations arise as faulty perceptual inferences due to elevated dopamine producing a bias in favor of prior expectations against current sensory evidence. Our results also yield circuit-level insights into the long-standing dopamine hypothesis of psychosis and provide a rigorous framework for dissecting the neural circuit mechanisms involved in hallucinations. We propose that this approach can guide the development of novel treatments for schizophrenia and other psychotic disorders.

A Dendrite-Focused Framework for Understanding the Actions of Ketamine and Psychedelics

I pass on the highlioght points from an interesting review (open source, with a useful graphic) of how the similar therapeutic effects of ketamine and psychedelics might be explained:

Ketamine can relieve symptoms of depression and anxiety, therefore filling a critically unmet psychiatric need. A few small-scale clinical studies suggest serotonergic psychedelics may have similar therapeutic effects.

Ketamine may both enhance and suppress dendritic excitability, through microcircuit interactions involving disinhibition.

Serotonergic psychedelics may both enhance and suppress excitability, through targeting coexpressed receptors.

Spatial mismatch in the opposing drug actions on dendritic excitability is predicted to steer plasticity actions towards certain synapses and cell types.

We present a dendrite-focused framework as a novel lens to view the actions of ketamine and serotonergic psychedelics on cortical circuits.

False memories can be reversed without damage to true memories.

 Oeberst et al.  demonstrate the effectiveness of source sensitization, which involves alerting participants that their memories could come from external sources, and false memory sensitization, which involves informing individuals that repeatedly being asked to recollect events can produce false memories. The two strategies could be widely implemented in real-world settings and do not require interviewers to know any ground truths.:  

Significance

Human memory is fallible and malleable. In forensic settings in particular, this poses a challenge because people may falsely remember events with legal implications that never actually happened. Despite an urgent need for remedies, however, research on whether and how rich false autobiographical memories can be reversed under realistic conditions (i.e., using reversal strategies that can be applied in real-world settings) is virtually nonexistent. The present study therefore not only replicates and extends previous demonstrations of false memories but, crucially, documents their reversibility after the fact: Employing two ecologically valid strategies, we show that rich but false autobiographical memories can mostly be undone. Importantly, reversal was specific to false memories (i.e., did not occur for true memories).

Abstract

False memories of autobiographical events can create enormous problems in forensic settings (e.g., false accusations). While multiple studies succeeded in inducing false memories in interview settings, we present research trying to reverse this effect (and thereby reduce the potential damage) by means of two ecologically valid strategies. We first successfully implanted false memories for two plausible autobiographical events (suggested by the students’ parents, alongside two true events). Over three repeated interviews, participants developed false memories (measured by state-of-the-art coding) of the suggested events under minimally suggestive conditions (27%) and even more so using massive suggestion (56%). We then used two techniques to reduce false memory endorsement, source sensitization (alerting interviewees to possible external sources of the memories, e.g., family narratives) and false memory sensitization (raising the possibility of false memories being inadvertently created in memory interviews, delivered by a new interviewer). This reversed the false memory build-up over the first three interviews, returning false memory rates in both suggestion conditions to the baseline levels of the first interview (i.e., to ∼15% and ∼25%, respectively). By comparison, true event memories were endorsed at a higher level overall and less affected by either the repeated interviews or the sensitization techniques. In a 1-y follow-up (after the original interviews and debriefing), false memory rates further dropped to 5%, and participants overwhelmingly rejected the false events. One strong practical implication is that false memories can be substantially reduced by easy-to-implement techniques without causing collateral damage to true memories.

The case against reality

Over the past year I've dipped into and out of Donald Hoffman's ideas several times, looking back at Geffer's article in Granta Magazine, Hoffman's TED talk, and sections of his 2019 book "The Case Against Reality: Why Evolution Hid the Truth from Our Eyes." Mainly for my future reference (I forget things, and use my MindBlog posts to go back and look them up), I'm attempting to put down the bare bones of his arguments with a selection of clips from these various sources.

As we go about our daily lives, we tend to assume that our perceptions — sights, sounds, textures, tastes — are an accurate portrayal of the real world...If they were not, wouldn’t evolution have weeded us out by now?...This hunch is wrong. On the contrary, our perceptions of snakes and apples, and even of space and time, do not reveal objective reality...It is a theorem of evolution by natural selection that wallops our hunches.

Does natural selection really favor seeing reality as it is? Fortunately, we don't have to wave our hands and guess; evolution is a mathematically precise theory. We can use the equations of evolution to check this out. We can have various organisms in artificial worlds compete and see which survive and which thrive, which sensory systems are more fit. A key notion in those equations is fitness...Fitness is not the same thing as reality as it is, and it's fitness, and not reality as it is, that figures centrally in the equations of evolution... we have run hundreds of thousands of evolutionary game simulations with lots of different randomly chosen worlds and organisms that compete for resources in those worlds. Some of the organisms see all of the reality, others see just part of the reality, and some see none of the reality, only fitness. Who wins? ...perception of reality goes extinct. In almost every simulation, organisms that see none of reality but are just tuned to fitness drive to extinction all the organisms that perceive reality as it is. So the bottom line is, evolution does not favor veridical, or accurate perceptions. Those perceptions of reality go extinct. Fitness beats truth (This is the "FBT theorem").

A metaphor can help our intuitions. Suppose you’re writing an email, and the icon for its file is blue, rectangular, and in the center of your desktop. Does this mean that the file itself is blue, rectangular, and in the center of your computer? Of course not...The purpose of a desktop interface is not to show you the “truth” of the computer—where “truth," in this metaphor, refers to circuits, voltages, and layers of software. Rather, the purpose of an interface is to hide the “truth” and to show simple graphics that help you perform useful tasks such as crafting emails and editing photos. If you had to toggle voltages to craft an email, your friends would never hear from you. That is what evolution has done. It has endowed us with senses that hide the truth and display the simple icons we need to survive long enough to raise offspring... Perception is not a window on objective reality. It is an interface that hides objective reality behind a veil of helpful icons...Evolution has shaped our senses to keep us alive. We have to take them seriously: if you see a speeding Maserati, don’t leap in front of it; if you see a moldy apple, don’t eat it. But it is a mistake of logic to assume that if we must take our senses seriously then we are required—or even entitled—to take them literally.

We used to think that the Earth is flat because it looks that way. Then we thought that the Earth is the unmoving center of reality because it looks that way. We were wrong. We had misinterpreted our perceptions. Now we believe that spacetime and objects are the nature of reality as it is. The theory of evolution is telling us that once again, we're wrong. We're misinterpreting the content of our perceptual experiences. There's something that exists when you don't look, but it's not spacetime and physical objects. It's...hard for us to let go of spacetime and objects...we're blind to our own blindnesses...By peering through the lens of a telescope we discovered that the Earth is not the unmoving center of reality, and by peering through the lens of the theory of evolution we discovered that spacetime and objects are not the nature of reality. When I have a perceptual experience that I describe as a red tomato, I am interacting with reality, but that reality is not a red tomato and is nothing like a red tomato...And here's the kicker: When I have a perceptual experience that I describe as a brain, or neurons, I am interacting with reality, but that reality is not a brain or neurons and is nothing like a brain or neurons. And that reality, whatever it is, is the real source of cause and effect in the world -- not brains, not neurons. Brains and neurons have no causal powers. They cause none of our perceptual experiences, and none of our behavior. Brains and neurons are a species-specific set of symbols, a hack.

Plasticity during our development of mapping time on to space.

A previous mindblog post has pointed to work showing how culture shapes our spatial conceptions of time. Starr and Srinivasan now address the development of spatial representations of time in three dimension in children from different cultures.:

Across cultures, people frequently communicate about time in terms of space. English speakers in the United States, for example, might “look forward” to the future or gesture toward the left when talking about the past. As shown by these examples, different dimensions of space are used to represent different temporal concepts. Here, we explored how cultural factors and individual differences shape the development of two types of spatiotemporal representations in 6- to 15-year-old children: the horizontal/vertical mental timeline (in which past and future events are placed on a horizontal or vertical line that is external to the body) and the sagittal mental timeline (in which events are placed on a line that runs through the front-back axis of the body). We tested children in India because the prevalence of both horizontal and vertical calendars there provided a unique opportunity to investigate how calendar orientation and writing direction might each influence the development of the horizontal/vertical mental timeline. Our results suggest that the horizontal/vertical mental timeline and the sagittal mental timeline are constructed in parallel throughout childhood and become increasingly aligned with culturally-conventional orientations. Additionally, we show that experience with calendars may influence the orientation of children's horizontal/vertical mental timelines, and that individual differences in children's attitudes toward the past and future may influence the orientation of their sagittal mental timelines. Taken together, our results demonstrate that children are sensitive to both cultural and personal factors when building mental models of time.

Measuring happiness in small steps.

I find this Brook's self help essay - that I came across while browsing the news during this morning's coffee - to be a nice brief tonic. His basic message is that small steps are more likely to make you happier than hard-to-achieve lifelong goals. I pass on his three summary nostrums here and recommend that you scan his list of brief essays on "How to build a life" in the Atlantic Magazine.  

1. Live in “day-tight compartments.”

The scientific literature is clear that goals can bring a lot of happiness when they are short term, achievable, and leading us toward ultimate success—in other words, when achieving them indicates that we are making progress...set an end goal, then break it into manageable steps: one year, one month, one week, one day.

2. Focus on the journey.

...see major goals not as the only way to achieve happiness but as points of navigation that set a direction for your lifelong journey. That way, when storms arise and new opportunities present themselves, you can set a new goal and gracefully let go of your old one, thereby avoiding disappointment and missed opportunities.

3. Set intrinsic goals.

Extrinsic goals — money, power, and prestige — can be the hardest to achieve because they are inherently zero-sum: In the pursuit of scarce resources, we crowd one another out. By contrast, intrinsic goals—based on love and personal growth—are positive-sum, and thus more likely to lead to success: My efforts to love and grow as a person are not crowded by your efforts; on the contrary, they can be complementary...they are the goals most associated with happiness...intrinsic goals are akin to what the writer David Brooks calls “eulogy virtues”: the things you would want people to remember you for at the end of your life.

Brain mechanism by which testosterone reduces generosity

 Interesting work from Jianxin Ou et al.:

Significance

Testosterone is associated with aggressive behavior in both animals and humans. Here, we establish a link between increased testosterone and selfishness in economic decision making and identify the neural mechanisms through which testosterone reduces generosity in a double-blind, placebo-controlled, between-participant study. We find that testosterone induces more selfish choices, particularly when distant others are concerned. Moreover, it disrupts the representation of other-regarding value in local activity and functional connectivity involving the temporoparietal junction and subcortical regions involved in reward processing. Our study provides causal evidence for a testosterone-mediated neurohormonal link between generosity and the valuation system.

Abstract

Recent evidence has linked testosterone, a major sex hormone, to selfishness in economic decision-making. Here, we aimed to investigate the neural mechanisms through which testosterone reduces generosity by combining functional MRI with pharmacological manipulation among healthy young males in a double-blind, placebo-controlled, between-subject design. After testosterone or placebo gel administration, participants performed a social discounting task in which they chose between selfish options (benefiting only the participant) and generous options (providing also some benefit to another person at a particular social distance). At the behavioral level, testosterone reduced generosity compared to the placebo. At the neural level (n = 60), the temporoparietal junction (TPJ) encoded the other-regarding value of the generous option during generous choices, and this effect was attenuated by testosterone, suggesting that testosterone reduced the consideration of other’s welfare as underpinned by TPJ activity. Moreover, TPJ activity more strongly reflected individual differences in generosity in the placebo than the testosterone group. Furthermore, testosterone weakened the relation between the other-regarding value of generous decisions and connectivity between the TPJ and a region extending from the insula into the striatum. Together, these findings suggest that a network encompassing both cortical and subcortical components underpins the effects of testosterone on social preferences.

Four distinct patterns of aging - what is your 'ageotype'?

An interesting piece from Lanese describs work showing how aging unfolds at different rates in different tissues:

The research team behind the study sorted 43 people into aging categories, or "ageotypes," based on biological samples collected over the course of two years. The samples included blood, inflammatory substances, microbes, genetic material, proteins and by-products of metabolic processes. By tracking how the samples changed over time, the team identified about 600 so-called markers of aging — values that predict the functional capacity of a tissue and essentially estimate its "biological age."

So far, the team has identified four distinct ageotypes: Immune, kidney, liver and metabolic. Some people fit squarely in one category, but others may meet the criteria for all four, depending on how their biological systems hold up with age.

Expanding the study will surely reveal more than four categories. One of the study participants was clearly a cardiovascular ager, whose cardiac muscle was accumulating damage at a greater rate than other parts of their body. 

This reminds me of Atul Gawande's great description of how complex systems wear down and crash:

...complex systems—power plants, say—have to survive and function despite having thousands of critical components. Engineers therefore design these machines with multiple layers of redundancy: with backup systems, and backup systems for the backup systems. The backups may not be as efficient as the first-line components, but they allow the machine to keep going even as damage accumulates...within the parameters established by our genes, that’s exactly how human beings appear to work. We have an extra kidney, an extra lung, an extra gonad, extra teeth. The DNA in our cells is frequently damaged under routine conditions, but our cells have a number of DNA repair systems. If a key gene is permanently damaged, there are usually extra copies of the gene nearby. And, if the entire cell dies, other cells can fill in.

Nonetheless, as the defects in a complex system increase, the time comes when just one more defect is enough to impair the whole, resulting in the condition known as frailty. It happens to power plants, cars, and large organizations. And it happens to us: eventually, one too many joints are damaged, one too many arteries calcify. There are no more backups. We wear down until we can’t wear down anymore.

Points on having a self and free will.

 A recent podcast by Sam Harris summarizing his ideas on the question of whether we have free will motivates me to do a further summary here…

There is a broad consensus among many disciplines that our experience of having a self or “I” is an illusion (see for example my lecture “The I-Illusion” and subsequent web lectures).  This self illusion is what has the experience of ‘free will,’ of being free to make choices. Having a self is other side of the coin of having free will.

Here is my one paragraph paraphrase of points that Sam Harris’ makes in his ‘Waking Up’ App, and book of that title, as well as his recent podcast:

We all are concatenations of previous causes with the most recent proximal cause rising from this subconscious mist.  What we take to be our 'self' or 'I' is actually the archive of our past actions and experiences, stored in long term declarative and procedural memory systems from which thoughts and actions of the present instant  seem to rise from nowhere - 'we' don't 'choose' them, they just seem to appear.  Having morality doesn't require free will, it is accomplished by having a historical coltlective record of what actions do or don't work out well, with respect to holding society together and passing on our genes. Thinking that 2 + 2 = 5 or killing other humans have bad consequences.  It is from this history of actions and expectations in our brain that the moral choices of the moment arise, again as if from nowhere.

Still, most of us, even if granting the above, can’t imagine losing our feeling of having a self, it seems too useful, we couldn’t get along without it.  This problem is addressed at the end of my “I-Illusion” talk with text based on points Wegner makes at the end of his classic 2002 book “The Illusion of Conscious Will” : 

…..the important point is that we have the experience of having free will, and it must be there for something, even if it is not an adequate theory of behavior causation....perhaps we have conscious will because it helps us to appreciate and remember what we are doing, the experience of will marks our actions for us, its embodied quality our actions from those of other agents in our environment.

We have evolved emotions of anger, sadness, fear, happiness related to survival. We can think of the emotion of agency, or conscious will, as the same sort of evolved emotion, obviously a useful capability in sorting out our physical and social world. 

The authorship emotion, an emotion that authenticates the action's owner as the self, is something we would miss if it were gone... it would not be very satisfying to go through life causing things, making discoveries, helping people, whatever.. if we had no personal recognition of those achievements.

And, this view doesn't really need to conflict with notions of responsibility and morality, because what people intend and consciously will is a basis for how the moral rightness or wrongness of an act judged. This is why mental competence is an issue in criminal trials.

So, just as in theater, art, used car sales ...and in the scientific analysis of conscious will..how things seem is more important than what they are. It seems to us that we have selves, have conscious will, have minds, are agents. While it is sobering and ultimately accurate to call all this an illusion, it is incorrect to call the illusion a trivial one, its invention has an obvious evolutionary rationale (along with long list of cognitive biases we seem to be hardwired with). Illusions piled on top of apparent mental causation are the building blocks of human psychology, social life, and our dominance as a species on this planet.

Passion matters but not equally everywhere.

From Li et al.:  

Significance

In three large-scale datasets representing adolescents from 59 societies across the globe, we find evidence of a systematic cultural variation in the relationship between passion and achievement. In individualistic societies, passion better predicts achievement and explains more variance in achievement outcomes. In collectivistic societies, passion still positively predicts achievement, but it is a much less powerful predictor. There, parents’ support predicts achievement as much as passion. One implication of these findings is that if admission officers, recruiters, and managers rely on only one model of motivation, a Western independent one, they may risk passing over and mismanaging talented students and employees who increasingly come from sociocultural contexts where a more interdependent model of motivation is common and effective.

Abstract

How to identify the students and employees most likely to achieve is a challenge in every field. American academic and lay theories alike highlight the importance of passion for strong achievement. Based on a Western independent model of motivation, passionate individuals—those who have a strong interest, demonstrate deep enjoyment, and express confidence in what they are doing—are considered future achievers. Those with less passion are thought to have less potential and are often passed over for admission or employment. As academic institutions and corporations in the increasingly multicultural world seek to acquire talent from across the globe, can they assume that passion is an equally strong predictor of achievement across cultural contexts? We address this question with three representative samples totaling 1.2 million students in 59 societies and provide empirical evidence of a systematic, cross-cultural variation in the importance of passion in predicting achievement. In individualistic societies where independent models of motivation are prevalent, relative to collectivistic societies where interdependent models of motivation are more common, passion predicts a larger gain (0.32 vs. 0.21 SD) and explains more variance in achievement (37% vs. 16%). In contrast, in collectivistic societies, parental support predicts achievement over and above passion. These findings suggest that in addition to passion, achievement may be fueled by striving to realize connectedness and meet family expectations. Findings highlight the risk of overweighting passion in admission and employment decisions and the need to understand and develop measures for the multiple sources and forms of motivation that support achievement.

Hierarchical dynamics as a macroscopic organizing principle of the human brain

Raut, Snyder, and Raichle do a open source description of general principles describing the functional organization of brain activity timescales that vary according to anatomical hierarchy:  

Significance

Accumulating evidence suggests that, during task performance, information is encoded at shorter timescales in primary sensory regions as compared to longer timescales in higher-order cortical regions. These encoding timescales correlate with the timescales of activity within these regions. Here, we test the hypothesis that a hierarchy of activity timescales represents a general organizing principle of brain function. Using functional imaging of the human brain in the eyes-open resting state, we find that the timescales of ongoing activity are hierarchically organized as gradients across the entire cerebral cortex. Further, whole-brain coverage permitted examination of subcortical structures, which exhibited hierarchical timescale gradients parallel to cerebral cortex. Altogether, our results support the existence of hierarchical gradients that globally organize human brain dynamics.

Abstract

Multimodal evidence suggests that brain regions accumulate information over timescales that vary according to anatomical hierarchy. Thus, these experimentally defined “temporal receptive windows” are longest in cortical regions that are distant from sensory input. Interestingly, spontaneous activity in these regions also plays out over relatively slow timescales (i.e., exhibits slower temporal autocorrelation decay). These findings raise the possibility that hierarchical timescales represent an intrinsic organizing principle of brain function. Here, using resting-state functional MRI, we show that the timescale of ongoing dynamics follows hierarchical spatial gradients throughout human cerebral cortex. These intrinsic timescale gradients give rise to systematic frequency differences among large-scale cortical networks and predict individual-specific features of functional connectivity. Whole-brain coverage permitted us to further investigate the large-scale organization of subcortical dynamics. We show that cortical timescale gradients are topographically mirrored in striatum, thalamus, and cerebellum. Finally, timescales in the hippocampus followed a posterior-to-anterior gradient, corresponding to the longitudinal axis of increasing representational scale. Thus, hierarchical dynamics emerge as a global organizing principle of mammalian brains.

How about another global conspiracy theory?..... Multinational mega-corporations are a global oligarchy maintaining world peace.

I pass on this great clip from Mark Manson's weekly newletter:

Watch any cheesy Hollywood action flick from the 90s or early 2000s and the villain is likely some mega-billionaire who’s about to destroy half a nation and all the baby seals along with it because it’ll add a few more percentage points to his bottom line.

Peruse any conspiracy theory forum or YouTube channel (note: please don’t actually do this) and you’ll come across dozens of half-baked theories about how governments are secretly controlled by the Big Evil Corporation and all these people are being killed on purpose so that Bill Gates can like, add a third wing to his mansion… or something.

(Sidenote: If I ever start another business, I’m totally going to call it “Big Evil Corporation.”)

But what if I told you these same too-big-to-fail companies might be the best thing happening for global peace? The idea is not as crazy as you think.

Some version of this idea was first proposed in 1995 by the economist Thomas Friedman in what he initially called “The Golden Arches Theory of Conflict.” The theory was simple: two countries with McDonald’s restaurants had, until then, never gone to war with one another and Friedman aruged that they would rarely, if ever, go to war in the future.

His reasoning was that two countries that enjoy the fruits of globalized, American-exported schlop would never jeopardize such luxuries by opting to kill each other instead.

Unfortunately for Friedman, it only took a few years for two ethnic groups to discover that they hated each other way more than they liked Big Macs, as the Bosnia and Serbia war quickly put an end to that theory.

But like any good human, Friedman learned from his mistakes and updated his theory in 2005 to the new and improved “Dell Theory of Conflict.” The Dell Theory says that any two countries who share supply chains for major industries with one another would never go to war, as the economic disruption would make any conflict too costly to pursue.

Unlike its cheap McDonald’s cousin, The Dell Theory of Conflict seems to have some legs to it. It explains why India and Pakistan keep backing down from each other, why China always says it’s going to invade Taiwan but never does, and why the US really has only seemed interested in invading countries that don’t have anything interesting to sell them.

People rarely believe this, but we live in the most peaceful period of human history. The world has not experienced a large-scale war between two major powers in over 50 years. Wars have been declining for so long and have become so rare that foreign policy experts have come to refer to the last fifty years as “The Long Peace.”

Last year, I wrote that a company like Apple is likely more responsible for peace between the US and China than any US president. Neither country wants to fuck with a $2 trillion dollar cash cow in both their backyards.

We’ve more recently seen this with the pandemic. Pharmaceutical companies who were once at each other’s throats came together and shared research and manufacturing capacity because they all realized that a world in enforced lockdowns isn’t good for anybody.

Hell, you want to get into conspiracies? Blackrock, the largest financial asset management in the world, with over $8 trillion dollars in assets, and tentacles in every industry and almost every country, has allegedly picked up the phone before and politely asked various groups and countries to knock it off and start selling to each other. And, well, I guess there’s something to that?

Economic self-interest may be soulless. But perhaps by removing people’s group affinities and emotional biases from the equation, at scale, it does make for a better, safer world.

Traces of psychedelics make you feel good, but so does placebo.

From Balázs Szigeti et al.:

Microdosing is the practice of regularly using low doses of psychedelic drugs. Anecdotal reports suggest that microdosing enhances well-being and cognition; however, such accounts are potentially biased by the placebo effect. This study used a ‘self-blinding’ citizen science initiative, where participants were given online instructions on how to incorporate placebo control into their microdosing routine without clinical supervision. The study was completed by 191 participants, making it the largest placebo-controlled trial on psychedelics to-date. All psychological outcomes improved significantly from baseline to after the 4 weeks long dose period for the microdose group; however, the placebo group also improved and no significant between-groups differences were observed. Acute (emotional state, drug intensity, mood, energy, and creativity) and post-acute (anxiety) scales showed small, but significant microdose vs. placebo differences; however, these results can be explained by participants breaking blind. The findings suggest that anecdotal benefits of microdosing can be explained by the placebo effect.

Further descriptions and discussions of this work are offered by Cameron and by O'Grady.

You should probably end a conversation sooner than you think.

From Mastroianni et al.: 

Significance

Social connection is essential to physical and psychological well-being, and conversation is the primary means by which it is achieved. And yet, scientists know little about it—about how it starts, how it unfolds, or how it ends. Our studies attempted to remedy this deficit, and their results were surprising: conversations almost never end when anyone wants them to! At a moment in history when billions of people have been forced to curtail their normal social activities and to reimagine this one, a scientific understanding of conversation could hardly be timelier.

Abstract

Do conversations end when people want them to? Surprisingly, behavioral science provides no answer to this fundamental question about the most ubiquitous of all human social activities. In two studies of 932 conversations, we asked conversants to report when they had wanted a conversation to end and to estimate when their partner (who was an intimate in Study 1 and a stranger in Study 2) had wanted it to end. Results showed that conversations almost never ended when both conversants wanted them to and rarely ended when even one conversant wanted them to and that the average discrepancy between desired and actual durations was roughly half the duration of the conversation. Conversants had little idea when their partners wanted to end and underestimated how discrepant their partners’ desires were from their own. These studies suggest that ending conversations is a classic “coordination problem” that humans are unable to solve because doing so requires information that they normally keep from each other. As a result, most conversations appear to end when no one wants them to.