A central debate in cognitive science concerns the nativist hypothesis, the proposal that universal features of behavior reflect a biologically determined cognitive substrate: For example, linguistic nativism proposes a domain-specific faculty of language that strongly constrains which languages can be learned. An evolutionary stance appears to provide support for linguistic nativism, because coordinated constraints on variation may facilitate communication and therefore be adaptive. However, language, like many other human behaviors, is underpinned by social learning and cultural transmission alongside biological evolution. We set out two models of these interactions, which show how culture can facilitate rapid biological adaptation yet rule out strong nativization. The amplifying effects of culture can allow weak cognitive biases to have significant population-level consequences, radically increasing the evolvability of weak, defeasible inductive biases; however, the emergence of a strong cultural universal does not imply, nor lead to, nor require, strong innate constraints. From this we must conclude, on evolutionary grounds, that the strong nativist hypothesis for language is false. More generally, because such reciprocal interactions between cultural and biological evolution are not limited to language, nativist explanations for many behaviors should be reconsidered: Evolutionary reasoning shows how we can have cognitively driven behavioral universals and yet extreme plasticity at the level of the individual—if, and only if, we account for the human capacity to transmit knowledge culturally. Wherever culture is involved, weak cognitive biases rather than strong innate constraints should be the default assumption.
Thursday, May 26, 2016
From Thompson et al.:
Wednesday, May 25, 2016
I want to pass on the abstract of a forthcoming article in Brain and Behavioral Science for which reviewer's comments are being solicited. (I'm on the mailing list of potential reviewers because I authored an article in the journal in the 1990s). It's model of climate, aggression, and self control makes total sense in terms of my experience of living both in Madison Wisconsin (from May-September) and Fort Lauderdale Florida (October-April). (I returned to Madison two weeks ago and, as usual, have been struck by how much less defensiveness and aggression is exhibited by strangers in public in the more northern Madison location. Strangers at grocery stores are more benign, pleasant, and occasionally even make eye contact!)
Target Article: Aggression and Violence Around the World: A Model of Climate, Aggression, and Self-control in Humans (CLASH)
Authors: Paul A. M. Van Lange, Maria I. Rinderu, and Brad J. Bushman
Deadline for Commentary Proposals: Thursday June 9, 2016
Abstract: Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model of CLimate, Aggression, and Self-control in Humans (CLASH) that seeks to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degrees of seasonal variation in climate, calls for individuals and groups to adopt a slower life history strategy, and exert more focus on the future (versus present), and a stronger focus on self-control. The CLASH model further outlines that slow life strategy, future orientation, and strong self-control are important determinants of inhibiting aggression and violence. We also discuss how CLASH is different from other recently developed models that emphasize climate differences for understanding conflict. We conclude by discussing the theoretical and societal importance of climate in shaping individual and societal differences in aggression and violence.
Tuesday, May 24, 2016
You might have a look at this curious website pointed to by Kevin Randall, an atlas of emotions developed by Paul Ekman and collaborators commissioned by the Dalai Lama (who paid ~$750,000 for the project). After surveying 248 of the most active emotion researchers in the world, Ekman chose to divide emotions into five broad categories (anger, fear, disgust, sadness and enjoyment), each having an elaborate subset of emotional states, triggers, actions and moods. A cartography and data visualization firm was engaged to help depict them in a visual, and hopefully useful, way.
I'm really at a bit of a loss to figure out how the byzantine complexity of the beautiful graphic displays are supposed to be useful. They don't quite do it for me. Maybe this is supposed to be a lookup guide for an emotion one is feeling but not quite categorizing? Sort of a bestiary of emotions? A well-intentioned effort, surely, but many of the descriptions seem quite banal and obvious.
I'm really at a bit of a loss to figure out how the byzantine complexity of the beautiful graphic displays are supposed to be useful. They don't quite do it for me. Maybe this is supposed to be a lookup guide for an emotion one is feeling but not quite categorizing? Sort of a bestiary of emotions? A well-intentioned effort, surely, but many of the descriptions seem quite banal and obvious.
Monday, May 23, 2016
Frodeman and Briggle offer a lament over the irreversible passing of the practice of philosophy as a moral endeavor, one that might offer a view of the good society apart from the prescriptions of religion. Some clips from their essay:
Before its migration to the university, philosophy had never had a central home. Philosophers could be found anywhere — serving as diplomats, living off pensions, grinding lenses, as well as within a university. Afterward, if they were “serious” thinkers, the expectation was that philosophers would inhabit the research university…This purification occurred in response to at least two events. The first was the development of the natural sciences, as a field of study clearly distinct from philosophy, circa 1870, and the appearance of the social sciences in the decade thereafter. ..The second event was the placing of philosophy as one more discipline alongside these sciences within the modern research university. A result was that philosophy, previously the queen of the disciplines, was displaced, as the natural and social sciences divided the world between them.
Philosophers needed to embrace the structure of the modern research university, which consists of various specialties demarcated from one another. That was the only way to secure the survival of their newly demarcated, newly purified discipline. “Real” or “serious” philosophers had to be identified, trained and credentialed. Disciplinary philosophy became the reigning standard for what would count as proper philosophy.
Having adopted the same structural form as the sciences, it’s no wonder philosophy fell prey to physics envy and feelings of inadequacy. Philosophy adopted the scientific modus operandi of knowledge production, but failed to match the sciences in terms of making progress in describing the world. Much has been made of this inability of philosophy to match the cognitive success of the sciences. But what has passed unnoticed is philosophy’s all-too-successful aping of the institutional form of the sciences. We, too, produce research articles. We, too, are judged by the same coin of the realm: peer-reviewed products. We, too, develop sub-specializations far from the comprehension of the person on the street. In all of these ways we are so very “scientific.”
The act of purification accompanying the creation of the modern research university was not just about differentiating realms of knowledge. It was also about divorcing knowledge from virtue. Though it seems foreign to us now, before purification the philosopher (and natural philosopher) was assumed to be morally superior to other sorts of people. ..The study of philosophy elevated those who pursued it. Knowing and being good were intimately linked. It was widely understood that the point of philosophy was to become good rather than simply to collect or produce knowledge…The purification made it no longer sensible to speak of nature, including human nature, in terms of purposes and functions…By the late 19th century, Kierkegaard and Nietzsche had proved the failure of philosophy to establish any shared standard for choosing one way of life over another…There was a brief window when philosophy could have replaced religion as the glue of society; but the moment passed. People stopped listening as philosophers focused on debates among themselves.
Once knowledge and goodness were divorced, scientists could be regarded as experts, but there are no morals or lessons to be drawn from their work. Science derives its authority from impersonal structures and methods, not the superior character of the scientist. The individual scientist is no different from the average Joe, with no special authority to pronounce on what ought to be done…philosophy has aped the sciences by fostering a culture that might be called “the genius contest.” Philosophic activity devolved into a contest to prove just how clever one can be in creating or destroying arguments. Today, a hyperactive productivist churn of scholarship keeps philosophers chained to their computers. Like the sciences, philosophy has largely become a technical enterprise, the only difference being that we manipulate words rather than genes or chemicals. Lost is the once common-sense notion that philosophers are seeking the good life — that we ought to be (in spite of our failings) model citizens and human beings. Having become specialists, we have lost sight of the whole. The point of philosophy now is to be smart, not good. It has been the heart of our undoing.
Friday, May 20, 2016
I pass on a few clips from a must-read article in the Washington Post by Robert Kagan, on Donald Trump:
Republican politicians marvel at how he has “tapped into” a hitherto unknown swath of the voting public. But what he has tapped into is what the founders most feared when they established the democratic republic: the popular passions unleashed, the “mobocracy.” Conservatives have been warning for decades about government suffocating liberty. But here is the other threat to liberty that Alexis de Tocqueville and the ancient philosophers warned about: that the people in a democracy, excited, angry and unconstrained, might run roughshod over even the institutions created to preserve their freedoms. As Alexander Hamilton watched the French Revolution unfold, he feared in America what he saw play out in France — that the unleashing of popular passions would lead not to greater democracy but to the arrival of a tyrant, riding to power on the shoulders of the people.
This phenomenon has arisen in other democratic and quasi-democratic countries over the past century, and it has generally been called “fascism.” Fascist movements, too, had no coherent ideology, no clear set of prescriptions for what ailed society. “National socialism” was a bundle of contradictions, united chiefly by what, and who, it opposed; fascism in Italy was anti-liberal, anti-democratic, anti-Marxist, anti-capitalist and anti-clerical. Successful fascism was not about policies but about the strongman, the leader (Il Duce, Der Fuhrer), in whom could be entrusted the fate of the nation. Whatever the problem, he could fix it. Whatever the threat, internal or external, he could vanquish it, and it was unnecessary for him to explain how. Today, there is Putinism, which also has nothing to do with belief or policy but is about the tough man who singlehandedly defends his people against all threats, foreign and domestic.
To understand how such movements take over a democracy, one only has to watch the Republican Party today. These movements play on all the fears, vanities, ambitions and insecurities that make up the human psyche. In democracies, at least for politicians, the only thing that matters is what the voters say they want — vox populi vox dei. A mass political movement is thus a powerful and, to those who would oppose it, frightening weapon. When controlled and directed by a single leader, it can be aimed at whomever the leader chooses. If someone criticizes or opposes the leader, it doesn’t matter how popular or admired that person has been. He might be a famous war hero, but if the leader derides and ridicules his heroism, the followers laugh and jeer. He might be the highest-ranking elected guardian of the party’s most cherished principles. But if he hesitates to support the leader, he faces political death.
This is how fascism comes to America, not with jackboots and salutes (although there have been salutes, and a whiff of violence) but with a television huckster, a phony billionaire, a textbook egomaniac “tapping into” popular resentments and insecurities, and with an entire national political party — out of ambition or blind party loyalty, or simply out of fear — falling into line behind him.
Thursday, May 19, 2016
Suzuki et al. offer a study noting brain areas important in consensus decision-making, with different decision variables being associated with activity in different brain area that are integrated by distributed neural activity (See Network hubs in the human brain for an overall review of domains of cognitive function with some great summary graphics). The summary and abstract:
•A task is used to study how the brain implements consensus decision-making
•Consensus decision-making depends on three distinct computational processes
•These different signals are encoded in distinct brain regions
•Integration of these signals occurs in the dorsal anterior cingulate cortexSummary
Consensus building in a group is a hallmark of animal societies, yet little is known about its underlying computational and neural mechanisms. Here, we applied a computational framework to behavioral and fMRI data from human participants performing a consensus decision-making task with up to five other participants. We found that participants reached consensus decisions through integrating their own preferences with information about the majority group members’ prior choices, as well as inferences about how much each option was stuck to by the other people. These distinct decision variables were separately encoded in distinct brain areas—the ventromedial prefrontal cortex, posterior superior temporal sulcus/temporoparietal junction, and intraparietal sulcus—and were integrated in the dorsal anterior cingulate cortex. Our findings provide support for a theoretical account in which collective decisions are made through integrating multiple types of inference about oneself, others, and environments, processed in distinct brain modules.
Wednesday, May 18, 2016
Reynolds has written a series of articles describing experiments showing the benefits of high-intensity interval training. She now points to a study by Gillen et al. showing that high intensity effort periods of only 1 minute can have a big effect. Twelve weeks of a regime of 3 cycling sessions per week lasting 10 minutes each, with only one minute of that time being strenuous, caused the same 20% increase in aerobic fitness as sessions of 45 min of cycling at a moderate pace.
Tuesday, May 17, 2016
I pass on a few clips from Easterbrook's article, on the prevailing negative depiction (especially by Republican candidates) of America's current state and direction:
...most American social indicators have been positive at least for years, in many cases for decades. The country is, on the whole, in the best shape it’s ever been in. So what explains all the bad vibes?..the core reason for the disconnect between the nation’s pretty-good condition and the gloomy conventional wisdom is that optimism itself has stopped being respectable. Pessimism is now the mainstream, with optimists viewed as Pollyannas. If you don’t think everything is awful, you don’t understand the situation!
Objectively, the glass looks significantly more than half full.
Job growth has been strong for five years, with unemployment now below where it was for most of the 1990s, a period some extol as the “good old days.” The American economy is No. 1 by a huge margin, larger than Nos. 2 and 3 (China and Japan) combined. Americans are seven times as productive, per capita, as Chinese citizens. The dollar is the currency the world craves — which means other countries perceive America’s long-term prospects as very good.
Pollution, discrimination, crime and most diseases are in an extended decline; living standards, longevity and education levels continue to rise. The American military is not only the world’s strongest, it is the strongest ever. The United States leads the world in science and engineering, in business innovation, in every aspect of creativity, including the arts. Terrorism is a serious concern, but in the last 15 years, even taking into account Sept. 11, an American is five times more likely to be hit by lightning than to be killed by a terrorist.Easterbrook continues with a discussion of the dire straits of the middle class, changes in manufacturing jobs ("Manufacturing jobs described by Mr. Trump and Mr. Sanders as “lost” to China cannot be found there, or anywhere."), etc.
...developing the postindustrial economy — while addressing issues such as inequality, greenhouse emissions and the condition of public schools — will require optimism. Pessimists think in terms of rear-guard actions to turn back the clock. Optimists understand that where the nation has faults, it’s time to roll up our sleeves and get to work.
That’s why the lack of progressive optimism is so keenly felt. In recent decades, progressives drank too deeply of instant-doomsday claims. If their predictions had come true, today petroleum would be exhausted, huge numbers of major animal species would be extinct, crop failures would be causing mass starvation, developing-world poverty would be getting worse instead of declining fast. (In 1990, 37 percent of humanity lived in what the World Bank defines as extreme poverty; today it’s 10 percent.)
Monday, May 16, 2016
I want to thank the anonymous commentator on the “Diversity makes you brighter” post, who sent links to interesting articles by Jonas and by Dinesena and Sønderskov. I pass on just some clips from Jonas, noting work by Putnam and Page:
...a fascinating new portrait of diversity emerging from recent scholarship. Diversity, it shows, makes us uncomfortable -- but discomfort, it turns out, isn't always a bad thing. Unease with differences helps explain why teams of engineers from different cultures may be ideally suited to solve a vexing problem. Culture clashes can produce a dynamic give-and-take, generating a solution that may have eluded a group of people with more similar backgrounds and approaches. At the same time, though, Putnam's work adds to a growing body of research indicating that more diverse populations seem to extend themselves less on behalf of collective needs and goals.
In more diverse communities, he says, there were neither great bonds formed across group lines nor heightened ethnic tensions, but a general civic malaise. And in perhaps the most surprising result of all, levels of trust were not only lower between groups in more diverse settings, but even among members of the same group...So, there is a diversity paradox:
...those in more diverse communities may do more bowling alone, but the creative tensions unleashed by those differences in the workplace may vault those same places to the cutting edge of the economy and of creative culture.
Friday, May 13, 2016
Anna North points to an article by Helzer and Jayawickreme that examines two different control strategies for obtaining short and long term life satisfaction, “primary control” — the ability to directly affect one's circumstances — and “secondary control” — the ability to affect how one responds to those circumstances.
How does a sense of control relate to well-being? We consider two distinguishable control strategies, primary and secondary control, and their relationships with two facets of subjective well-being, daily positive/negative affective experience and global life satisfaction. Using undergraduate and online samples, the results suggest that these different control strategies are associated uniquely with distinct facets of well-being. After controlling for shared variance among constructs, primary control (the tendency to achieve mastery over circumstances via goal striving) was associated more consistently with daily affective experience than was secondary control, and secondary control (the tendency to achieve mastery over circumstances via sense-making) was associated more strongly with life satisfaction than primary control, but only within the student sample and community members not in a committed relationship. The results highlight the importance of both control strategies to everyday health and provide insights into the mechanisms underlying the relationship between control and well-being.It is not clear why relationship status makes a difference. Helzer suggests that having a partner may help people deal with adversity the same way secondary control does, so secondary control may have less of an effect
Thursday, May 12, 2016
Providing some data relevant to debates over affirmative action, Levine et al. show that ethnic diversity can increase intelligent behaviors. Misfits between market prices and the true value of assets (market bubbles) are more likely in ethnically homogeneous than in diverse markets.
Markets are central to modern society, so their failures can be devastating. Here, we examine a prominent failure: price bubbles. Bubbles emerge when traders err collectively in pricing, causing misfit between market prices and the true values of assets. The causes of such collective errors remain elusive. We propose that bubbles are affected by ethnic homogeneity in the market and can be thwarted by diversity. In homogenous markets, traders place undue confidence in the decisions of others. Less likely to scrutinize others’ decisions, traders are more likely to accept prices that deviate from true values. To test this, we constructed experimental markets in Southeast Asia and North America, where participants traded stocks to earn money. We randomly assigned participants to ethnically homogeneous or diverse markets. We find a marked difference: Across markets and locations, market prices fit true values 58% better in diverse markets. The effect is similar across sites, despite sizeable differences in culture and ethnic composition. Specifically, in homogenous markets, overpricing is higher as traders are more likely to accept speculative prices. Their pricing errors are more correlated than in diverse markets. In addition, when bubbles burst, homogenous markets crash more severely. The findings suggest that price bubbles arise not only from individual errors or financial conditions, but also from the social context of decision making. The evidence may inform public discussion on ethnic diversity: it may be beneficial not only for providing variety in perspectives and skills, but also because diversity facilitates friction that enhances deliberation and upends conformity.
Wednesday, May 11, 2016
I pass on some initial and final clips from an essay by Alva Noë that is worth reading in its entirely.
Is there a way of thinking about art that will get us closer to an understanding of its essential nature, and our own?...the trend is to try to answer these questions in the key of neuroscience. I recommend a different approach, but not because I don’t think it is crucial to explore the links between art and our biological nature. The problem is that neuroscience has yet to frame an adequate conception of our nature. You look in vain in the writings of neuroscientists for satisfying accounts of experience or consciousness. For this reason, I believe, we can’t use neuroscience to explain art and its place in our lives. Indeed, if I am right, the order of explanation may go in the other direction: Art can help us frame a better picture of our human nature.
...Design, the work of technology, stops, and art begins, when we are unable to take the background of our familiar technologies and activities for granted, and when we can no longer take for granted what is, in fact, a precondition of the very natural-seeming intelligibility of such things as doorknobs and pictures, words and sounds. When you and are I talking, I don’t pay attention to the noises you are making; your language is a transparency through which I encounter you. Design, at least when it is optimal, is transparent in just this way; it disappears from view and gets absorbed in application. You study the digital image of the shirt on the website, you don’t contemplate its image.
Art, in contrast, makes things strange. You do contemplate the image, when you examine Leonardo’s depiction of the lady with the ermine. You are likely, for example, to notice her jarringly oversized and masculine hand and to wonder why Leonardo draws our attention to that feature of this otherwise beautiful young person. Art disrupts plain looking and it does so on purpose. By doing so it discloses just what plain looking conceals.
Art unveils us ourselves. Art is a making activity because we are by nature and culture organized by making activities. A work of art is a strange tool. It is an alien implement that affords us the opportunity to bring into view everything that was hidden in the background.
If I am right, art isn’t a phenomenon to be explained. Not by neuroscience, and not by philosophy. Art is itself a research practice, a way of investigating the world and ourselves. Art displays us to ourselves, and in a way makes us anew, by disrupting our habitual activities of doing and making.
Tuesday, May 10, 2016
The Science Mazaine precis of Travor et al.:
We all differ in how we perceive, think, and act. What drives individual differences in evoked brain activity? Tavor et al. applied computational models to functional magnetic resonance imaging (fMRI) data from the Human Connectome Project. Brain activity in the “resting” state when subjects were not performing any explicit task predicted differences in fMRI activation across a range of cognitive paradigms. This suggests that individual differences in many cognitive tasks are a stable trait marker. Resting-state functional connectivity thus already contains the repertoire that is then expressed during task-based fMRI.And the article abstract:
When asked to perform the same task, different individuals exhibit markedly different patterns of brain activity. This variability is often attributed to volatile factors, such as task strategy or compliance. We propose that individual differences in brain responses are, to a large degree, inherent to the brain and can be predicted from task-independent measurements collected at rest. Using a large set of task conditions, spanning several behavioral domains, we train a simple model that relates task-independent measurements to task activity and evaluate the model by predicting task activation maps for unseen subjects using magnetic resonance imaging. Our model can accurately predict individual differences in brain activity and highlights a coupling between brain connectivity and function that can be captured at the level of individual subjects.
Monday, May 09, 2016
I pass on clips from this interesting piece, that has been languishing in my queue of potential posts for some time, in which Willer and Feinberg give a more accessible account of their work reported in the Personality and Social Psychology Bulletin.
In business, everyone knows that if you want to persuade people to make a deal with you, you have to focus on what they value, not what you do. If you’re trying to sell your car, you emphasize the features of the sale that appeal to the buyer (the reliability and reasonable price of the vehicle), not the ones that appeal to you (the influx of cash).
This rule of salesmanship also applies in political debate — i.e., you should frame your position in terms of the moral values of the person you’re trying to convince. But when it comes to politics, this turns out to be hard to do. We found that people struggled to set aside their reasons for taking a political position and failed to consider how someone with different values might come to support that same position.
In one study, we presented liberals and conservatives with one of two messages in support of same-sex marriage. One message emphasized the need for equal rights for same-sex couples. This is the sort of fairness-based message that liberals typically advance for same-sex marriage. It is framed in terms of a value — equality — that research has shown resonates more strongly among liberals than conservatives. The other message was designed to appeal to values of patriotism and group loyalty, which have been shown to resonate more with conservatives. (It argued that “same-sex couples are proud and patriotic Americans” who “contribute to the American economy and society.”)
Liberals showed the same support for same-sex marriage regardless of which message they encountered. But conservatives supported same-sex marriage significantly more if they read the patriotism message rather than the fairness one.
In a parallel experiment, we targeted liberals for persuasion. We presented a group of liberals and conservatives with one of two messages in support of increased military spending. One message argued that we should “take pride in our military,” which “unifies us both at home and abroad.” The other argued that military spending is necessary because, through the military, the poor and disadvantaged “can achieve equal standing,” by ensuring they have “a reliable salary and a future apart from the challenges of poverty and inequality.”
For conservatives, it didn’t matter which message they read; their support for military spending was the same. However, liberals expressed significantly greater support for increasing military spending if they read the fairness message rather than the patriotism one.
If you’re thinking that these reframed arguments don’t sound like ones that conservatives and liberals would naturally be inclined to make, you’re right. In an additional study, we asked liberals to write a persuasive argument in favor of same-sex marriage aimed at convincing conservatives — and we offered a cash prize to the participant who wrote the most persuasive message. Despite the financial incentive, just 9 percent of liberals made arguments that appealed to more conservative notions of morality, while 69 percent made arguments based on more liberal values.
Conservatives were not much better. When asked to write an argument in favor of making English the official language of the United States that would be persuasive to liberals (with the same cash incentive), just 8 percent of conservatives appealed to liberal values, while 59 percent drew upon conservative values.
Why do we find moral reframing so challenging? There are a number of reasons. You might find it off-putting to endorse values that you don’t hold yourself. You might not see a link between your political positions and your audience’s values. And you might not even know that your audience endorses different values from your own. But whatever the source of the gulf, it can be bridged with effort and consideration.
Maybe reframing political arguments in terms of your audience’s morality should be viewed less as an exercise in targeted, strategic persuasion, and more as an exercise in real, substantive perspective taking. To do it, you have to get into the heads of the people you’d like to persuade, think about what they care about and make arguments that embrace their principles. If you can do that, it will show that you view those with whom you disagree not as enemies, but as people whose values are worth your consideration.
Even if the arguments that you wind up making aren’t those that you would find most appealing, you will have dignified the morality of your political rivals with your attention, which, if you think about it, is the least that we owe our fellow citizens.
Friday, May 06, 2016
Here is a neat trick. It works! (I tried it). Ekroll et al. show that illusory visual completion of an object's invisible backside can make you finger feel shorter. Here is their summary and the central graphic from the article.
•The experience of the hidden backsides of things acts as a real percept
•These percepts have causal powers, although they do not correspond to real objects
•They can evoke a bizarre illusion in which the observer’s own finger feels shrunken
•The perceptual representation of body shape is highly malleableSummary
In a well-known magic trick known as multiplying balls, conjurers fool their audience with the use of a semi-spherical shell, which the audience perceives as a complete ball. Here, we report that this illusion persists even when observers touch the inside of the shell with their own finger. Even more intriguingly, this also produces an illusion of bodily self-awareness in which the finger feels shorter, as if to make space for the purely illusory volume of the visually completed ball. This observation provides strong evidence for the controversial and counterintuitive idea that our experience of the hidden backsides of objects is shaped by genuine perceptual representations rather than mere cognitive guesswork or imagery.Figure
A Well-Known Magic Trick and the Shrunken Finger Illusion
(A and B) The multiplying balls routine. The magician first holds what seems to be a single ball between his fingers (A). After a quick flick of the wrist, a second ball seems to materialize (B). In reality, the lower “ball” is a hollow semi-spherical shell, from which the real ball is pulled out.
(C and D) Schematic illustration of the shrunken finger illusion. When a semi-spherical shell is balanced on the observer’s finger as shown in (C) and viewed from above, the observer often reports perceiving the shell as a complete ball (D), while his or her finger is felt to be unusually short, as if to make space for the illusory volume of the complete ball. Note that this drawing is an exaggerated caricature of the perceptual experience. In particular, the real effect may be smaller than depicted here. In the experiments, only the middle finger was extended, while the other fingers were closed to a fist (see Figure below).
Thursday, May 05, 2016
I want to mention an interesting article by Easterbrook that has been languishing in my queue of potential posts for more than a year. It notes numerous studies on aging and life extension, and the question of how long the eerily linear rise in life expectancy since 1840 (from the 40's to the 80's) can continue. Two clips:
No specific development or discovery has caused the rise: improvements in nutrition, public health, sanitation, and medical knowledge all have helped, but the operative impetus has been the “stream of continuing progress.”One view is that increases will continue at least until life expectancy at birth surpasses 100. Jay Olshansky, a professor of public health at the University of Illinois at Chicago disagrees, saying:
...the rise in life expectancy will “hit a wall soon, if it hasn’t already....Most of the 20th-century gains in longevity came from reduced infant mortality, and those were one time gains.” Infant mortality in the United States trails some other nations’, but has dropped so much—down to one in 170—that little room for improvement remains. “There’s tremendous statistical impact on life expectancy when the young are saved,” Olshansky says. “A reduction in infant mortality saves the entire span of a person’s life. Avoiding mortality in a young person—say, by vaccine—saves most of the person’s life. Changes in medicine or lifestyle that extend the lives of the old don’t add much to the numbers.” Olshansky calculates that if cancer were eliminated, American life expectancy would rise by only three years, because a host of other chronic fatal diseases are waiting to take its place. He thinks the 21st century will see the average life span extend “another 10 years or so,” with a bonus of more health span. Then the increase will slow noticeably, or stop.Easterbrook's discussion of the social, economic, and political aspects of our graying future is well worth reading. The number of Americans 65 or older could reach 108 million by 2050, like adding three more Floridas inhabited entirely by seniors.
The nonpartisan think tank Third Way has calculated that at the beginning of the Kennedy presidency, the federal government spent $2.50 on public investments—infrastructure, education, and research—for every $1 it spent on entitlements. By 2022, Third Way predicts, the government will spend $5 on entitlements for every $1 on public investments. Infrastructure, education, and research lead to economic growth; entitlement subsidies merely allow the nation to tread water.
Wednesday, May 04, 2016
Huth et al. have performed functional MRI on subjects listening to hours of narrative stories to find semantic domains that seem to be consistent across individuals. This interactive 3D viewer (a preliminary version with limited data that takes a while to download and requires a fairly fast computer) shows a color coding of areas with different semantic selectivities (body part, person, place, time, outdoor, visual, tactile, violence, etc.) Here is their Nature abstract:
The meaning of language is represented in regions of the cerebral cortex collectively known as the ‘semantic system’. However, little of the semantic system has been mapped comprehensively, and the semantic selectivity of most regions is unknown. Here we systematically map semantic selectivity across the cortex using voxel-wise modelling of functional MRI (fMRI) data collected while subjects listened to hours of narrative stories. We show that the semantic system is organized into intricate patterns that seem to be consistent across individuals. We then use a novel generative model to create a detailed semantic atlas. Our results suggest that most areas within the semantic system represent information about specific semantic domains, or groups of related concepts, and our atlas shows which domains are represented in each area. This study demonstrates that data-driven methods—commonplace in studies of human neuroanatomy and functional connectivity—provide a powerful and efficient means for mapping functional representations in the brain.
Tuesday, May 03, 2016
Continuing the MindBlog thread on brain games (cf. here), I pass on the introduction to a brief review by Mishra, Anguera, and Gazzaley on designing the next generation of closed-loop video games (CLVGs) that offer the prospect of enhancing cognition:
Humans of all ages engage deeply in game play. Game-based interactive environments provide a rich source of enjoyment, but also generate powerful experiences that promote learning and behavioral change (Pellegrini, 2009). In the modern era, software-based video games have become ubiquitous. The degree of interactivity and immersion in these video games can now be further enhanced like never before with the advent of consumer-accessible technologies like virtual reality, augmented reality, wearable physiological devices, and motion capture, all of which can be readily integrated using accessible game engines. This technological revolution presents a huge opportunity for neuroscientists to design targeted, novel game-based tools that drive positive neuroplasticity, accelerate learning, and strengthen cognitive function, and thereby promote mental wellbeing in both healthy and impaired brains.
In fact, there is now a burgeoning brain-training industry that already claims to have achieved this goal. However, many commercial claims are unsubstantiated and dismissed by the scientific community (Max Planck Institute for Human Development/Stanford Center on Longevity, 2014, Underwood, 2016). It seems prudent for us to slow down and approach this opportunity with scientific rigor and conservative optimism. Enhancing brain function should not be viewed as a clever, profitable start-up idea that can be conquered with a large marketing budget. If the field continues to be led by overinflated claims, we will jeopardize the careful and iterative process of evidence-based innovations in brain training and thereby risk throwing out the baby with the bathwater.
To strike the right balance, the path to commercialization needs to be accomplished via cutting-edge, neuroscientifically informed video game development tightly coupled with refinement and validation of the software in well-controlled empirical studies. Additionally, to separate the grain from the chaff, these studies and the claims based on them need verification and approval by independent regulatory agencies and the broader scientific community. High-level video game development and rigorous scientific validation need to become the twin pillar foundations of the next generation of closed-loop video games (CLVGs). Here, we define CLVGs as interactive video games that incorporate rapid, real-time, performance-driven, adaptive game challenges and performance feedback. The time is ideal for intensified effort in this important endeavor; CLVGs that are methodically developed and validated have the potential to benefit a broad array of disciplines in need of effective tools to enhance brain function, including education, medicine, and wellness.
Monday, May 02, 2016
Andy Clark does a fascinating discussion and analysis of predictive processing, which turns the traditional picture of perception on its head. The embodied mind model, which seems to me completely compelling, shows the stark inadequacy of most brain centered models of mind and cognition. I pass on the end of his introduction and the closing paragraph of the essay. (This essay is just one of many on a fascinating website , Open Mind, that has posted 39 essays (edited by Thomas Metzinger and Jennifer Windt) by contributors who are both junior and senior members of the academic philosophy of mind field.
Predictive processing plausibly represents the last and most radical step in a retreat from the passive, input-dominated view of the flow of neural processing. According to this emerging class of models, naturally intelligent systems (humans and other animals) do not passively await sensory stimulation. Instead, they are constantly active, trying to predict the streams of sensory stimulation before they arrive. Before an “input” arrives on the scene, these pro-active cognitive systems are already busy predicting its most probable shape and implications. Systems like this are already (and almost constantly) poised to act, and all they need to process are any sensed deviations from the predicted state. It is these calculated deviations from predicted states (known as prediction errors) that thus bear much of the information-processing burden, informing us of what is salient and newsworthy within the dense sensory barrage. The extensive use of top-down probabilistic prediction here provides an effective means of avoiding the kinds of “representational bottleneck” feared by early opponents of representation-heavy—but feed-forward dominated—forms of processing. Instead, the downward flow of prediction now does most of the computational “heavy-lifting”, allowing moment-by-moment processing to focus only on the newsworthy departures signified by salient prediction errors. Such economy and preparedness is biologically attractive, and neatly sidesteps the many processing bottlenecks associated with more passive models of the flow of information.
Action itself...then needs to be reconceived. Action is not so much a response to an input as a neat and efficient way of selecting the next “input”, and thereby driving a rolling cycle. These hyperactive systems are constantly predicting their own upcoming states, and actively moving so as to bring some of them into being. We thus act so as to bring forth the evolving streams of sensory information that keep us viable (keeping us fed, warm, and watered) and that serve our increasingly recondite ends. PP thus implements a comprehensive reversal of the traditional (bottom-up, forward-flowing) schema. The largest contributor to ongoing neural response, if PP is correct, is the ceaseless anticipatory buzz of downwards-flowing neural prediction that drives both perception and action. Incoming sensory information is just one further factor perturbing those restless pro-active seas. Within those seas, percepts and actions emerge via a recurrent cascade of sub-personal predictions forged from unconscious expectations spanning multiple spatial and temporal scales.
Conceptually, this implies a striking reversal, in that the driving sensory signal is really just providing corrective feedback on the emerging top-down predictions. As ever-active prediction engines, these kinds of minds are not, fundamentally, in the business of solving puzzles given to them as inputs. Rather, they are in the business of keeping us one step ahead of the game, poised to act and actively eliciting the sensory flows that keep us viable and fulfilled. If this is on track, then just about every aspect of the passive forward-flowing model is false. We are not passive cognitive couch potatoes so much as proactive predictavores, forever trying to stay one step ahead of the incoming waves of sensory stimulation.Conclusion: Towards a mature science of the embodied mind
By self-organizing around prediction error, and by learning a generative rather than a merely discriminative (i.e., pattern-classifying) model, these approaches realize many of the goals of previous work in artificial neural networks, robotics, dynamical systems theory, and classical cognitive science. They self-organize around prediction error signals, perform unsupervised learning using a multi-level architecture, and acquire a satisfying grip—courtesy of the problem decompositions enabled by their hierarchical form—upon structural relations within a domain. They do this, moreover, in ways that are firmly grounded in the patterns of sensorimotor experience that structure learning, using continuous, non-linguaform, inner encodings (probability density functions and probabilistic inference). Precision-based restructuring of patterns of effective connectivity then allow us to nest simplicity within complexity, and to make as much (or as little) use of body and world as task and context dictate. This is encouraging. It might even be that models in this broad ballpark offer us a first glimpse of the shape of a fundamental and unified science of the embodied mind.