Thursday, April 26, 2018

Propagation of economic inequality through reciprocity and reputation.

Interesting work from Hackel and Zaki...an excerpt from their introduction, followed by their abstract:
Reciprocity and reputation are cornerstones of both evolutionary accounts of prosociality and evidence-based policy suggestions for amplifying cooperation on a large scale. For instance, people are more likely to vote, donate blood, and conserve energy when their actions are observable by others.
In studies of reciprocity, participants typically start out with an even distribution of wealth By contrast, the real world features enormous and rising economic inequality. We propose that when initial distributions of wealth are unequal, reciprocity and reputation might exacerbate economic inequality.
One possible mechanism is reward-based reinforcement learning, through which people associate actions with rewards Consider two “givers,” one of whom starts with a $100 endowment and the other of whom starts with a $20 endowment. If each giver shares half of his or her resources, each exhibits equal levels of generosity but provides differing levels of reward value, or raw capital, to beneficiaries. When people experience repeated pairings of a stimulus with reward, they are more likely to return to that stimulus . Similarly, we suggest that rewards build positive affect toward another person—even when those rewards do not reflect the giver’s generosity—and these positive associations can color later choices of people with whom to interact.
The abstract:
Reciprocity and reputation are powerful tools for encouraging cooperation on a broad scale. Here, we highlight a potential side effect of these social phenomena: exacerbating economic inequality. In two novel economic games, we manipulated the amount of money with which participants were endowed and then gave them the opportunity to share resources with others. We found that people reciprocated more toward higher-wealth givers, compared with lower-wealth givers, even when those givers were equally generous. Wealthier givers also achieved better reputations than less wealthy ones and therefore received more investments in a social marketplace. These discrepancies were well described by a formal model of reinforcement learning: Individuals who weighted monetary outcomes, rather than generosity, when learning about interlocutors also most strongly helped wealthier individuals. This work demonstrates that reciprocity and reputation—although globally increasing prosociality—can widen wealth gaps and provides a precise account of how inequality grows through social processes.

Wednesday, April 25, 2018

Seeing what you feel - unconscious affect drives perception

Siegle et al. provide yet another example of how it is impossible to separate emotions from cognition and perception:
Affective realism, the phenomenon whereby affect is integrated into an individual’s experience of the world, is a normal consequence of how the brain processes sensory information from the external world in the context of sensations from the body. In the present investigation, we provided compelling empirical evidence that affective realism involves changes in visual perception (i.e., affect changes how participants see neutral stimuli). In two studies, we used an interocular suppression technique, continuous flash suppression, to present affective images outside of participants’ conscious awareness. We demonstrated that seen neutral faces are perceived as more smiling when paired with unseen affectively positive stimuli. Study 2 also demonstrated that seen neutral faces are perceived as more scowling when paired with unseen affectively negative stimuli. These findings have implications for real-world situations and challenge beliefs that affect is a distinct psychological phenomenon that can be separated from cognition and perception.

Tuesday, April 24, 2018

Why exercise alone may not cause weight loss.

Gretchen Reynolds points to work by Lark et al. showing that mice given the opportunity to exercise on a running wheel then are more lazy the rest of the time than mice who don't exercise. Thus the effects of voluntary exercise can be countered by a reduction in nonexercise activity. This may explain why numerous studies in recent years examining exercise and weight loss in both humans and animals have concluded that exercise, by itself, is not an effective way to drop pounds.

Monday, April 23, 2018

How our "I" is like a virtual reality headset.

I pass on some clips from Joshua Rothman's article on the ideas of Metzinger, Blanke and others regarding the actual nature of our experienced selves, ideas that rise from virtual embodiment experiments in which subjects become convinced that they are someone else. The work challenges our understanding of who and what we are.
…reality, as we experience it, might be a mental stage set—a representation of the world, rather than the world itself. Having an O.B.E. (out of body experience) could be like visiting the set at night, when it wasn’t being used…Some internal mental system must function as an invisible, unconscious set dresser, making an itch feel like an itch, coloring the sky blue and the grass green.
It isn’t just that we live inside a model of the external world, Metzinger wrote. We also live inside models of our own bodies, minds, and selves. These “self-models” don’t always reflect reality, and they can be adjusted in illogical ways. They can, for example, portray a self that exists outside of the body—an O.B.E.
Metzinger and Blanke set about hacking the self-model. Along with the cognitive scientists Bigna Lenggenhager and Tej Tadi, they created a virtual-reality system designed to induce O.B.E.-like episodes. In 2005, Metzinger put on a virtual-reality head-mounted display—a headset containing a pair of screens, one for each eye, which together produce the illusion of a 3-D world. Inside, he saw his own body, facing away from him, standing in a room. (It was being filmed by a camera placed six feet behind him.) He watched as Lenggenhager stroked its back. Metzinger could feel the stroking, but the body to which it was happening seemed to be situated in front of him. He felt a strange sensation, as though he were drifting in space, or being stretched between the two bodies. He wanted to jump entirely into the body before him, but couldn’t. He seemed marooned outside of himself. It wasn’t quite an out-of-body experience, but it was proof that, using computer technology, the self-model could easily be manipulated. A new area of research had been created: virtual embodiment.
With a team of various collaborators, Slater and Sanchez-Vives have created many other-body simulations; they show how inhabiting a new virtual body can produce meaningful psychological shifts. In one study, participants are re-embodied as a little girl. Surrounded by a stuffed bear, a rocking horse, and other toys, they watch as their mother sternly demands a cleaner room. Afterward, on psychological tests, they associate themselves with more childlike characteristics. (When I tried it, under the supervision of the V.R. researcher Domna Banakou, I was astonished by my small size, and by the intimidating, Olympian height from which the mother addressed me.) In another, white participants spend around ten minutes in the body of a virtual black person, learning Tai Chi. Afterward, their scores on a test designed to reveal unconscious racial bias shift significantly. “These effects happen fast, and seem to last,” Slater said. A week later, the white participants still had less racist attitudes. (The racial-bias results have been replicated several times in Barcelona, and also by a second team, in London.) Embodied simulations seem to slip beneath the cognitive threshold, affecting the associative, unconscious parts of the mind. “It’s directly experiential,” Slater said. “It’s not ‘I know.’ It’s ‘I am.’ ”
 “I think that, in the human self-model, there are many layers. Some layers are transparent, like your bodily perceptions, which seem absolutely real. You just look”—he gestured toward a chair next to us—“and the chair is there. Others are opaque, like our cognitive layer. When we’re thinking, we know that our thoughts are internal mental constructs, which could be true or false.” As a philosopher, Metzinger’s method has been to see if the transparent can be made opaque. In books such as “Being No One” and “The Ego Tunnel,” he aims to show that aspects of our experience which we take to be real are actually “complex forms of virtual reality” created by our brains.
Imagine that you are sitting in the cockpit of an airplane, surrounded by instruments and controls. It’s a futuristic cockpit, with no windows; where the windshield would be, a computer displays the landscape. Using this cockpit, you can pilot your plane with ease. Still, there are questions you are unable to answer. Exactly what kind of plane are you flying? (It could be a Boeing 777 or an Airbus A380.) How accurate is the landscape on the screen? (Perhaps night-vision software has turned night to day.) When you throttle up the engines, you feel a rumbling and hear a roar. Does this mean the plane is accelerating—or could those effects have been simulated? Both scenarios might be true. You could be using a flight simulator to fly a real plane. This, in Metzinger’s view, is how we live our lives.
The instruments in an airplane cockpit report on pitch, yaw, speed, fuel, altitude, engine status, and so on. Our human instruments report on more complicated variables. They tell us about physical facts: the status of our bodies and limbs. But they also report on mental states: on what we are sensing, feeling, and thinking; on our intentions, knowledge, and memories; on where and who we are. You might wonder who is sitting in the cockpit, controlling everything. Metzinger thinks that no one is sitting there. “We” are the instruments, and our sense of selfhood is the sum of their readouts. On the instrument panel, there is a light with a label that says “Pilot Present.” When the light is on, we are self-conscious; we experience being in the cockpit and monitoring the instruments. It’s easy to assume that, while you’re awake, this light is always on. In fact, it’s frequently off—during daydreams, during much of our mental life, which is largely automatic and unconscious—and the plane still flies.
Two facts about the cockpit are of special importance. The first is that although the cockpit controls the airplane, it is not itself an airplane. It’s only a simulation—a model—of a larger, more complex, and very different machine. The implication of this fact is that the stories we tell about what happens in the cockpit—“I pulled up on the stick”; “I touched my jacket”—are very different from the reality of what is happening to the system as a whole. The second fact, harder to grasp, is that we cannot see the cockpit. Even as we consult its models of the outer and inner worlds, we don’t experience ourselves as doing so; we experience ourselves as simply existing. “You cannot recognize your self-model as a model,” Metzinger writes, in “Being No One.” “It is transparent: you look right through it. You don’t see it. But you see with it.” Our mental models of reality are like V.R. headsets that we don’t know we are wearing. Through them, we experience our own inner lives and have inner sensations that feel as solid as stone. But in truth:
Nobody ever was or had a self. All that ever existed were conscious self-models that could not be recognized as models. . . . You are such a system right now. . . . As you read these sentences, you constantly confuse yourself with the content of the self-model activated by your brain.
Do you know what an ‘illusion of control’ is?” he asked, mischievously. “If people are asked to throw dice, and their task is to throw a high number, they throw the dice harder!” He believes that many experiences of being in control are similarly illusory, including experiences in which we seem to control our own minds. Brain imaging, for example, shows that our thoughts begin before we’re aware of having them. But, Metzinger said, “if a thought crosses the boundary from unconsciousness to consciousness, we feel, ‘I caused this thought.’ ” The sensation of causing our own thoughts is also just another feature of the self-model—a phantom sensation conjured when a readout, labelled “thinking,” switches from “off” to “on.” If you suffer from schizophrenia, this readout may be deactivated inappropriately, and you may feel that someone else is causing your thoughts. “The mind has to explain to itself how it works,” he said, spreading his hands.
Lately, Metzinger has been thinking about his own experience as a meditator. At the center of the meditative experience is the exercise and cultivation of mental autonomy: when the meditator’s mind wanders, he notices and arrests that process, gently returning his mental focus to his breath. “The mind says, ‘I am now re-directing the flashlight of my attention to this,’ ” Metzinger said. “But the thought ‘I am redirecting my mind-wandering’ might itself be another inner story.” He leaned back in his chair and laughed. “It might be that the spiritual endeavor for liberation or detachment can lead to new illusions.”
…you are not the model. You are the whole system—the physical, biological organism in which the self-model is rendered, including its body, its social relationships, and its brain. The model is just a part of that system.” The “I” we experience is smaller than, and different from, the totality of who and what we are.
It turns out that we do, in this sense, possess subtle bodies; we also inhabit subtle selves. While a person exists, he feels that he knows the world and himself directly. In fact, he experiences a model of the world and inhabits a model of himself. These models are maintained by the mind in such a way that their constructed nature is invisible. But it can sometimes be made visible, and then—to a degree—the models can be changed. Something about this discovery is deflating: it turns out that we are less substantial than we thought. Yet it can also be invigorating to understand the constructed, provisional nature of experience. Our perceptions of the world and the self feel real—how could they feel otherwise?—but we can come to understand our own role in the creation of their apparent realness.

Friday, April 20, 2018

Andy Clark on extended mind, A.I., and predictive processing

I want to point to a New Yorker article by Larissa MacFarquhar describing the evolution of the ideas of philosopher of mind Andy Clark.

The first section of the article follows Clark's development of the idea that our minds must be defined as extended beyond our bodies to include the tools in our environment without which they cannot function:
Clark started musing about the ways in which even adult thought was often scaffolded by things outside the head. There were many kinds of thinking that weren’t possible without a pen and paper, or the digital equivalent—complex mathematical calculations, for instance. Writing prose was usually a matter of looping back and forth between screen or paper and mind: writing something down, reading it over, thinking again, writing again. The process of drawing a picture was similar. The more he thought about these examples, the more it seemed to him that to call such external devices “scaffolding” was to underestimate their importance. They were, in fact, integral components of certain kinds of thought. And so, if thinking extended outside the brain, then the mind did, too.
It then describes his moving into artificial intelligence and robotics, encountering the work of Rodney Brooks at M.I.T:
Maybe the way to go was building an intelligence that developed gradually, as in children—seeing and walking first. Perhaps intelligence of many kinds, even the sort that solved theorems and played chess, emerged from the most basic skills—perception, motor control...While constructing a robot that he called Allen, Brooks decided that the best way to build its cognition box was to scrap it altogether. ...It was controlled by three objectives—avoid obstacles, wander randomly, seek distance—layered in a hierarchy, such that the higher could override the lower...It would make no plans. It would simply encounter the world and react.
Robots like Allen... seemed to Clark to represent a fundamentally different idea of the mind. Watching them fumble about, pursuing their simple missions, he recognized that cognition was not the dictates of a high-level central planner perched in a skull cockpit, directing the activities of the body below. Central planning was too cumbersome, too slow to respond to the body’s emergencies. Cognition was a network of partly independent tricks and strategies that had evolved one by one to address various bodily needs. Movement, even in A.I., was not just a lower, practical function that could be grafted, at a later stage, onto abstract reason. The line between action and thought was more blurry than it seemed. A creature didn’t think in order to move: it just moved, and by moving it discovered the world that then formed the content of its thoughts.
Then, how does the brain make sense of the world?
To some people, perception—the transmitting of all the sensory noise from the world—seemed the natural boundary between world and mind. Clark had already questioned this boundary with his theory of the extended mind. Then, in the early aughts, he heard about a theory of perception that seemed to him to describe how the mind, even as conventionally understood, did not stay passively distant from the world but reached out into it. It was called predictive processing.
It appeared that the brain had ideas of its own about what the world was like, and what made sense and what didn’t, and those ideas could override what the eyes (and other sensory organs) were telling it. Perception did not, then, simply work from the bottom up; it worked first from the top down. What you saw was not just a signal from the eye, say, but a combination of that signal and the brain’s own ideas about what it expected to see, and sometimes the brain’s expectations took over altogether.
One major difficulty with perception, Clark realized, was that there was far too much sensory signal continuously coming in to assimilate it all. The mind had to choose. And it was not in the business of gathering data for its own sake: the original point of perceiving the world was to help a creature survive in it. For the purpose of survival, what was needed was not a complete picture of the world but a useful one—one that guided action. A brain needed to know whether something was normal or strange, helpful or dangerous. The brain had to infer all that, and it had to do it very quickly, or its body would die—fall into a hole, walk into a fire, be eaten.
So what did the brain do? It focussed on the most urgent or worrying or puzzling facts: those which indicated something unexpected. Instead of taking in a whole scene afresh each moment, as if it had never encountered anything like it before, the brain focussed on the news: what was different, what had changed, what it didn’t expect...This process was not only fast but also cheap—it saved on neural bandwidth, because it took on only the information it needed—which made sense from the point of view of a creature trying to survive...To Clark, predictive processing described how mind, body, and world were continuously interacting, in a way that was mostly so fluid and smoothly synchronized as to remain unconscious.
And, summarizing paragraphs,
He knew that the roboticist Rodney Brooks had recently begun to question a core assumption of the whole A.I. project: that minds could be built of machines. Brooks speculated that one of the reasons A.I. systems and robots appeared to hit a ceiling at a certain level of complexity was that they were built of the wrong stuff—that maybe the fact that robots were not flesh made more of a difference than he’d realized. Clark couldn’t decide what he thought about this. On the one hand, he was no longer a machine functionalist, exactly: he no longer believed that the mind was just a kind of software that could run on hardware of various sorts. On the other hand, he didn’t believe, and didn’t want to believe, that a mind could be constructed only out of soft biological tissue. He was too committed to the idea of the extended mind—to the prospect of brain-machine combinations, to the glorious cyborg future—to give it up.
In a way, though, the structure of the brain itself had some of the qualities that attracted him to the extended-mind view in the first place: it was not one indivisible thing but millions of quasi-independent things, which worked seamlessly together while each had a kind of existence of its own. “There’s something very interesting about life,” Clark says, “which is that we do seem to be built of system upon system upon system. The smallest systems are the individual cells, which have an awful lot of their own little intelligence, if you like—they take care of themselves, they have their own things to do. Maybe there’s a great flexibility in being built out of all these little bits of stuff that have their own capacities to protect and organize themselves. I’ve become more and more open to the idea that some of the fundamental features of life really are important to understanding how our mind is possible. I didn’t use to think that. I used to think that you could start about halfway up and get everything you needed.”







Thursday, April 19, 2018

Baby Boomers reaching the end of their To-Do list

A few clips from an engaging piece by Patricia Hampl on the maturing of the baby boomer generation, those born in 1946 or later - who came of age during the Vietnam War era. (Born in 1942, I qualify as being on the leading edge of this generation.)
Life, if you’re lucky, is divided into thirds, my father used to say: youth, middle age and “You look good.”...By the time you’ve worked long enough, hard enough, real life begins to reveal itself as something other than effort, other than accomplishment...It’s a late-arriving awareness of consciousness existing for its own sake...in this latter stage of existence, to have only one task: to waste life in order to find it.
...now the boomers are approaching the other side...the other side of striving...The battle between striving and serenity may be distinctly American. The struggle between toil and the dream of ease is an American birthright, the way a Frenchman expects to have decent wine at a reasonable price, and the whole month of August on vacation...The essential American word isn’t happiness. It’s pursuit.
But how about just giving up? What about wasting time? Giving up or perhaps giving over. To what? Perhaps what an earlier age called “the life of the mind,” the phrase that describes the sovereign self at ease, at home in the world. This isn’t the mind of rational thought, but the lost music of wondering, the sheer value of looking out the window, letting the world float along...That’s what that great American lounger Whitman did. “I loaf and invite my soul,” he wrote. “I lean and loaf at my ease, observing a spear of summer grass.” In this way he came to his great conception of national citizenship for Americans, “the dear love of comrades.” His loafing led to solidarity.
Loafing is not a prudent business plan, not even a life plan, not a recognizably American project. But it begins to look a little like happiness, the kind that claims you, unbidden. Stay put and let the world show up? Or get out there and be a flâneur? Which is it? Well, it’s both.
Maybe this is what my father’s third stage of life is about — wondering, rather than pursuing. You look good — meaning, hey, you’re still alive, you’re still here, and for once you don’t really need to have a to-do list.

Wednesday, April 18, 2018

Basal forebrain and default mode network regulation.

The basal forebrain is an ascending, activating, neuromodulatory system involved in wake–sleep regulation, memory formation, and regulation of sensory information processing. Nair et al. show that it also influences (in mice) the default mode brain network that is active (as in mind wandering) when the brain's attention is not directed externally, as during tasks or exploration. They suggest that basal forebrain nuclei might be target regions for up or down regulation during default mode dysfunction during epilepsy or major depressive disorder.


The default mode network (DMN) is a collection of cortical brain regions that is active during states of rest or quiet wakefulness in humans and other mammalian species. A pertinent characteristic of the DMN is a suppression of local field potential gamma activity [~ 40 Hz brain waves] during cognitive task performance as well as during engagement with external sensory stimuli. Conversely, gamma activity is elevated in the DMN during rest. Here, we document that the rat basal forebrain (BF) exhibits the same pattern of responses, namely pronounced gamma oscillations during quiet wakefulness in the home cage and suppression of this activity during active exploration of an unfamiliar environment. We show that gamma oscillations are localized to the BF and that gamma-band activity in the BF has a directional influence on a hub of the rat DMN, the anterior cingulate cortex, during DMN-dominated brain states. The BF is well known as an ascending, activating, neuromodulatory system involved in wake–sleep regulation, memory formation, and regulation of sensory information processing. Our findings suggest a hitherto undocumented role of the BF as a subcortical node of the DMN, which we speculate may be important for switching between internally and externally directed brain states. We discuss potential BF projection circuits that could underlie its role in DMN regulation and highlight that certain BF nuclei may provide potential target regions for up- or down-regulation of DMN activity that might prove useful for treatment of DMN dysfunction in conditions such as epilepsy or major depressive disorder.

Tuesday, April 17, 2018

Scared by the news? Take the long view.

I tell everyone I meet or chat with to read Steven Pinker's new book "Enlightenment Now." It was the subject of a series of recent MindBlog posts, starting on 3/1/18. I want to pass on a few nice quotes from a recent interview of Pinker by David Bornstein, starting with Pinker's answer to "Why did you write the book?"
The first impetus was coming across data sets showing that the state of humanity has been improving. It’s a conclusion one can’t appreciate from the news — because journalism covers the disasters, crises, dangers and injustices that remain. And until the Messiah comes, there will always be enough of them to fill Page One.
Improvements, in contrast, are gradual, and often consist of things that don’t happen — an absence of war, or famine or crime in much of the world. One can spot them only by looking at data, which tally both the occurrences and the non-occurrences. When I came across data showing plunges in extreme poverty, illiteracy, war, violent crime, racism, sexism, homophobia, domestic violence, disease, lethal accidents and just about every other scourge, I thought these improvements deserved to be better known.
...denying progress can make us fatalistic: If all our efforts at improving the human condition have failed, why throw good money after bad? More generally, people are so jaded by the narrative of decline that they can’t think coherently about progress; the concept just doesn’t compute. I’m regularly confronted with an example of something that has gone wrong, like the opioid epidemic or a rampage shooting, as a refutation of progress — as if progress meant that everything gets better for everyone everywhere always. That wouldn’t be progress; that would be magic. Progress consists of solving problems, and problems are inevitable. So of course things can get worse for some people sometimes.
We live longer: Life expectancy at birth worldwide is now 71 years, and in the developed world, 80 years; through most of human existence it was around 30. Global extreme poverty has declined to 9.6 percent of the world population; 200 years ago, it was at 90 percent. In just the last 30 years, extreme poverty has declined by 75 percent — a stupendous achievement that is almost entirely unappreciated. Equally unappreciated is the fact that 90 percent of the world’s population under the age of 25 can read and write, including girls. In most of the history of Europe, no more than 15 percent could read and write, mostly men.
...liberals, ... in joining the chorus of decline have unilaterally disarmed in the fight for judicious regulation and social spending. Take pollution. Since the formation of the Environmental Protection Agency in 1970, air pollution (aside from carbon dioxide) has fallen by 60 percent, even as Americans have become more populous and richer and have driven more miles. But because many liberals today can’t bring themselves to acknowledge progress, they have cleared the field for opponents of regulation like Scott Pruitt to claim that the regulations have done no good and have only cramped our lives and dragged down the economy. Rather than saying “Environmental regulation has improved the environment while allowing the economy to grow,” they have said, ineffectually, “If you oppose regulation, you’re a bad person.”
The same is true with poverty. Ronald Reagan famously wisecracked, “Some years ago, the federal government declared war on poverty, and poverty won.” Few liberals would disagree. But Reagan was mistaken. If you factor in government social spending, such as the earned-income tax credit, rates of poverty have declined significantly. But here again liberals hand their opponents a weapon: the conclusion that all social programs are ineffective.
If I were an editor, I’d impose a rule that before a pundit writes about any putative change or trend, he or she must compare the present to the past. Commentators should be more data-oriented, especially now that data are so much more widely available. Also, I’d put the kibosh on a pernicious journalistic habit: reporting a small reversal in a trend (because it’s “news”) while ignoring the far more numerous year-by-year improvements (because they’re not news). This is journalistic malpractice, because it gives readers an impression that is opposite to reality.
Like many cognitive psychologists, I think that curriculums that aim at de-biasing and statistical literacy should begin early, including an explicit awareness of the fallacies we’re vulnerable to. It should be part of our conventional wisdom never to trust our intuitions about risk and danger, and to try to circumvent them by seeking data and reasoning about them probabilistically.
Some psychologists despair that it’s naïve to hope that we can overcome our illusions and biases. But history shows that we can outgrow our collective irrationality. We don’t explain disease by miasmas or evil spirits — most people with a sinus infection take antibiotics rather than calling in an exorcist. We don’t engage in human sacrifice to bribe gods for better weather or victory on the battlefield. Not even the most know-nothing politician today would appeal to astrology. So upgrading our intellectual culture can in fact allow us to outgrow our irrationality and delusions.

Monday, April 16, 2018

Cracking the code relating speech prosody to social judgements.

Ponsot et al. use an ingenious method to determine prosodic prototypes that govern social judgments in speech. Clips from their introduction:
In social encounters with strangers, human beings are able to form high-level social representations from very thin slices of expressive behavior and quickly determine whether the other is a friend or a foe and whether they have the ability to enact their good or bad intentions. While much is already known about how facial features contribute to such evaluations, determinants of social judgments in the auditory modality remain poorly understood.
Anthropologists, linguists, and psychologists have noted regularities of pitch contours in social speech for decades. Notably, patterns of high or rising pitch are associated with social traits such as submissiveness or lack of confidence, and low or falling pitch with dominance or self-confidence, a code that has been proposed to be universal across species. Unfortunately, because these observations stem either from acoustic analysis of a limited number of actor-produced utterances or from the linguistic analysis of small ecological corpora, it has remained difficult to attest of their generality and causality in cognitive mechanisms, and we still do not know what exact pitch contour maximally elicits social percepts.
Inspired by a recent series of powerful data-driven studies in visual cognition in which facial prototypes of social traits were derived from human judgments of thousands of computer-generated visual stimuli, we developed a voice-processing algorithm able to manipulate the temporal pitch dynamics of arbitrary recorded voices in a way that is both fully parametric and realistic and used this technique to generate thousands of novel, natural-sounding variants of the same word utterance, each with a randomly manipulated pitch contour. We then asked human listeners to evaluate the social state of the speakers for each of these manipulated stimuli and reconstructed their mental representation of what speech prosody drives such judgments, using the psychophysical technique of reverse correlation.
Here is their full abstract:
Human listeners excel at forming high-level social representations about each other, even from the briefest of utterances. In particular, pitch is widely recognized as the auditory dimension that conveys most of the information about a speaker’s traits, emotional states, and attitudes. While past research has primarily looked at the influence of mean pitch, almost nothing is known about how intonation patterns, i.e., finely tuned pitch trajectories around the mean, may determine social judgments in speech. Here, we introduce an experimental paradigm that combines state-of-the-art voice transformation algorithms with psychophysical reverse correlation and show that two of the most important dimensions of social judgments, a speaker’s perceived dominance and trustworthiness, are driven by robust and distinguishing pitch trajectories in short utterances like the word “Hello,” which remained remarkably stable whether male or female listeners judged male or female speakers. These findings reveal a unique communicative adaptation that enables listeners to infer social traits regardless of speakers’ physical characteristics, such as sex and mean pitch. By characterizing how any given individual’s mental representations may differ from this generic code, the method introduced here opens avenues to explore dysprosody and social-cognitive deficits in disorders like autism spectrum and schizophrenia. In addition, once derived experimentally, these prototypes can be applied to novel utterances, thus providing a principled way to modulate personality impressions in arbitrary speech signals.

Friday, April 13, 2018

Locus Coeruleus integrity and memory in aging adults

The locus coeruleus is a deep brain nucleus whose cells synthesize noradrenaline that is sent via its axonal projections to other parts of the brain. Hämmerer et al. show that its integrity is critical in maintaining memory performance:

Significance
Locus coeruleus (LC) integrity in cognitively normal older adults is a potentially important preclinical marker in dementia. Our study establishes a link between variability in LC integrity and cognitive decline related to noradrenergic modulation in old age. We find that in older adults, reduced LC integrity explains lower memory performance. This effect was more pronounced for memory related to negative events, and accompanied by increased pupil diameter size in response to negative events. The study provides a strong motivation for future research investigating the role of LC integrity in healthy, as well as in pathological, aging.
Abstract
The locus coeruleus (LC) is the principal origin of noradrenaline in the brain. LC integrity varies considerably across healthy older individuals, and is suggested to contribute to altered cognitive functions in aging. Here we test this hypothesis using an incidental memory task that is known to be susceptible to noradrenergic modulation. We used MRI neuromelanin (NM) imaging to assess LC structural integrity and pupillometry as a putative index of LC activation in both younger and older adults. We show that older adults with reduced structural LC integrity show poorer subsequent memory. This effect is more pronounced for emotionally negative events, in accord with a greater role for noradrenergic modulation in encoding salient or aversive events. In addition, we found that salient stimuli led to greater pupil diameters, consistent with increased LC activation during the encoding of such events. Our study presents novel evidence that a decrement in noradrenergic modulation impacts on specific components of cognition in healthy older adults. The findings provide a strong motivation for further investigation of the effects of altered LC integrity in pathological aging.

Thursday, April 12, 2018

A.I. quantifies 100 years of gender and ethnic stereotypes.

Hutson points to work of Garg et al. that uses artificial intelligence to demonstrate how racial and gender stereotypes have changed over time.
They designed their program to use word embeddings, strings of numbers that represent a word’s meaning based on its appearance next to other words in large bodies of text. If people tend to describe women as emotional, for example, “emotional” will appear alongside “woman” more frequently than “man,” and word embeddings will pick that up...Going decade by decade, they found that words related to competence—such as “resourceful” and “clever”—were slowly becoming less masculine. But words related to physical appearance—such as “alluring” and ”homely”—were stuck in time...their embeddings were still distinctly “female.”...Asian names became less tightly linked to terms for outsiders...words related to terrorism became more closely associated with words related to Islam...
Here is the Carg et al. abstract:
Word embeddings are a powerful machine-learning framework that represents each English word by a vector. The geometric relationship between these vectors captures meaningful semantic relationships between the corresponding words. In this paper, we develop a framework to demonstrate how the temporal dynamics of the embedding helps to quantify changes in stereotypes and attitudes toward women and ethnic minorities in the 20th and 21st centuries in the United States. We integrate word embeddings trained on 100 y of text data with the US Census to show that changes in the embedding track closely with demographic and occupation shifts over time. The embedding captures societal shifts—e.g., the women’s movement in the 1960s and Asian immigration into the United States—and also illuminates how specific adjectives and occupations became more closely associated with certain populations over time. Our framework for temporal analysis of word embedding opens up a fruitful intersection between machine learning and quantitative social science.

Wednesday, April 11, 2018

The contract with authoritarianism

Thomas Edsall offers yet another of his thoughtful well referenced essays, from which I want to pass on a few clips. You should read the entire article. He begins by citing a quote from George Lakoff’s writing, done just after the 1994 Newt Gingrich Republican revolution that led to our current era of conservative ascendancy:
Deeply embedded in conservative and liberal politics are two different models of the family. Conservatism is based on a Strict Father model, while liberalism is centered on a Nurturant Parent model. These two models of the family give rise to different moral systems.
…The crucial word now… is authoritarianism.
The election of Donald Trump — built as it was on several long-term trends that converged in 2016 — has created an authoritarian moment. 
…traits like closed mindedness, along with aversion to change and discomfort with diversity, are linked to authoritarianism:
As these social and cultural conflicts have become a bigger part of our political debates, citizens have sorted into different parties based on personality, with citizens high in openness much more likely to be liberals and Democrats than those low in openness. This psychological sorting process does not line up perfectly with older partisan differences based on class, because those higher in income and education also tend to be higher in openness.
With the rise of cultural and lifestyle politics, Democrats and Republicans are now sharply distinguished by a set of psychological dispositions related to experiential openness — a general dimension of personality tapping tolerance for threat and uncertainty in one’s environment.
Edall cites Marc Hetherington and Jonathan Weiler:
...preferences about many of the new issues on the American political agenda, such as gay rights, the war in Iraq, the proper response to terrorism, and immigration are likely structured by authoritarianism.
Those with a fixed worldview tend to see “American Carnage,” while those with fluid worldviews see the world as a big, beautiful place that is safe to explore. The fixed tend to be wary of what they perceive as constant threats to their physical security specifically and of social change in general. The fluid are much more open to change and, indeed, see it as a strength. For them, anger lies in holding on to old ideas and rejecting diversity.
Matt Grossmann and Daniel Thaler of Michigan State University further expand on the role of psychological traits in voter decision-making in their forthcoming paper, “Mass-Elite Divides in Aversion to Social Change and Support for Donald Trump.” They found that aversion to change “is strongly predictive of support for Trump” among regular voters, but much less so among Republican political elites.
Smith and Hanley used what they call a “domineering leader scale” to measure the wish for a strong leader who will force others to submit. The premise is that evil is afoot; that money, the media and government authority — and even “politically correct” moral authority — have been usurped by undeserving interlopers. The desire for a domineering leader is the desire to see this evil crushed.
If an aggressive, domineering authoritarianism is a prime motivator for many Trump supporters, as Smith and Hanley contend, the clash between Republicans and Democrats is likely to become more hostile and warlike.
Federico, Feldman and Weber note that:
...since the early 2000s, many especially acrimonious political debates have focused on threats to social stability and order — debates surrounding abortion, transgender rights, immigration, and the role of the federal government in protecting the rights of marginalized social groups.
The rising “salience of these debates,” they write, “has contributed to a growing ‘authoritarian divide’ within the United States, at least among White Americans.”
Trump has purposefully exacerbated the “many especially acrimonious political debates” now dominating public discourse, deepening not only the authoritarian divide, but the divide between open and closed mindedness, between acceptance and racial resentment, and between toleration of and aversion to change. He evidently believes that this is the best political strategy for presiding in the White House and winning re-election, but it is an extraordinarily destructive strategy for governing the country and for safeguarding America’s interests in the world.

Tuesday, April 10, 2018

A small molecule for stroke therapy

The small 'magic molecule,' a neural plasticity enhancer, found by Abe et al. to accelerate motor function recovery from brain damage is edonerpic maleate, whose complicated formal name I won't spell out here, but instead show you the structure:



Here is their abstract:
Brain damage such as stroke is a devastating neurological condition that may severely compromise patient quality of life. No effective medication-mediated intervention to accelerate rehabilitation has been established. We found that a small compound, edonerpic maleate, facilitated experience-driven synaptic glutamate AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic-acid) receptor delivery and resulted in the acceleration of motor function recovery after motor cortex cryoinjury in mice in a training-dependent manner through cortical reorganization. Edonerpic bound to collapsin-response-mediator-protein 2 (CRMP2) and failed to augment recovery in CRMP2-deficient mice. Edonerpic maleate enhanced motor function recovery from internal capsule hemorrhage in nonhuman primates. Thus, edonerpic maleate, a neural plasticity enhancer, could be a clinically potent small compound with which to accelerate rehabilitation after brain damage.
And, Rumpel offers a nice summary graphic in his perspectives piece describing the work (click to enlarge):





Monday, April 09, 2018

Why senior adults get lost more frequently than younger adults.

Strang et al. identify the brain area whose degeneration with aging underlies the loss of our navigational abilities:

Highlights
•Grid-cell-like representations in human entorhinal cortex are compromised in old age 
•This effect is predominantly driven by a lack of representational stability over time 
•Path integration ability in old age is associated with grid-cell-like representations
Summary
A progressive loss of navigational abilities in old age has been observed in numerous studies, but we have only limited understanding of the neural mechanisms underlying this decline. A central component of the brain’s navigation circuit are grid cells in entorhinal cortex, largely thought to support intrinsic self-motion-related computations, such as path integration (i.e., keeping track of one’s position by integrating self-motion cues). Given that entorhinal cortex is particularly vulnerable to neurodegenerative processes during aging and Alzheimer’s disease, deficits in grid cell function could be a key mechanism to explain age-related navigational decline. To test this hypothesis, we conducted two experiments in healthy young and older adults. First, in an fMRI experiment, we found significantly reduced grid-cell-like representations in entorhinal cortex of older adults. Second, in a behavioral path integration experiment, older adults showed deficits in computations of self-position during path integration based on body-based or visual self-motion cues. Most strikingly, we found that these path integration deficits in older adults could be explained by their individual magnitudes of grid-cell-like representations, as reduced grid-cell-like representations were associated with larger path integration errors. Together, these results show that grid-cell-like representations in entorhinal cortex are compromised in healthy aging. Furthermore, the association between grid-cell-like representations and path integration performance in old age supports the notion that grid cells underlie path integration processes. We therefore conclude that impaired grid cell function may play a key role in age-related decline of specific higher-order cognitive functions, such as spatial navigation.

Friday, April 06, 2018

We choose what we want to hear.

Billig et al. provide a nice example of how we can consciously influence what we perceive, in this case hearing a sequence of pure tones either as individual sounds or as an integrated percept: 

SIGNIFICANCE STATEMENT
Can we consciously influence our perception of the external world? We address this question using sound sequences that can be heard either as coming from a single source or as two distinct auditory streams. Listeners reported spontaneous changes in their perception between these two interpretations while we recorded neural activity to identify signatures of such integration and segregation. They also indicated that they could, to some extent, choose between these alternatives. This claim was supported by corresponding changes in responses in auditory cortex. By linking neural and behavioral correlates of perception, we demonstrate that the number of objects that we perceive can depend not only on the physical attributes of our environment, but also on how we intend to experience it.
Abstract
Auditory signals arrive at the ear as a mixture that the brain must decompose into distinct sources based to a large extent on acoustic properties of the sounds. An important question concerns whether listeners have voluntary control over how many sources they perceive. This has been studied using pure high (H) and low (L) tones presented in the repeating pattern HLH-HLH-, which can form a bistable percept heard either as an integrated whole (HLH-) or as segregated into high (H-H-) and low (-L-) sequences. Although instructing listeners to try to integrate or segregate sounds affects reports of what they hear, this could reflect a response bias rather than a perceptual effect. We had human listeners (15 males, 12 females) continuously report their perception of such sequences and recorded neural activity using MEG. During neutral listening, a classifier trained on patterns of neural activity distinguished between periods of integrated and segregated perception. In other conditions, participants tried to influence their perception by allocating attention either to the whole sequence or to a subset of the sounds. They reported hearing the desired percept for a greater proportion of time than when listening neutrally. Critically, neural activity supported these reports; stimulus-locked brain responses in auditory cortex were more likely to resemble the signature of segregation when participants tried to hear segregation than when attempting to perceive integration. These results indicate that listeners can influence how many sound sources they perceive, as reflected in neural responses that track both the input and its perceptual organization.

Thursday, April 05, 2018

Reprogramming fear responses outside of conscious awareness.

Fascinating work by Taschereau-Dumouchel et al. suggests that our 'hard wired' fear responses can be reprogrammed or attenuated by an unconscious manipulation, offering an alternative to the common exposure therapies that are often aversive to patients.

Significance
Conventional therapies for the treatment of anxiety disorders are aversive, and as a result, many patients terminate treatment prematurely. We have developed an unconscious method to bypass the unpleasantness in conscious exposure using functional magnetic resonance imaging neural reinforcement. Using this method, participants learn to generate brain patterns similar to the multivariate brain pattern of a feared animal. We demonstrate in a double-blind placebo-controlled experiment that neural reinforcement can lead to reliable reductions in physiological fear responses. Crucially, this intervention can be achieved completely unconsciously and without any aversive reaction. Extending our approach to other forms of psychopathologies, such as posttraumatic stress disorders, might eventually provide another means of intervention for patients currently receiving insufficient exposure treatments.
Abstract
Can “hardwired” physiological fear responses (e.g., for spiders and snakes) be reprogramed unconsciously in the human brain? Currently, exposure therapy is among the most effective treatments for anxiety disorders, but this intervention is subjectively aversive to patients, causing many to drop out of treatment prematurely. Here we introduce a method to bypass the subjective unpleasantness in conscious exposure, by directly pairing monetary reward with unconscious occurrences of decoded representations of naturally feared animals in the brain. To decode physiological fear representations without triggering excessively aversive reactions, we capitalize on recent advancements in functional magnetic resonance imaging decoding techniques, and use a method called hyperalignment to infer the relevant representations of feared animals for a designated participant based on data from other “surrogate” participants. In this way, the procedure completely bypasses the need for a conscious encounter with feared animals. We demonstrate that our method can lead to reliable reductions in physiological fear responses, as measured by skin conductance as well as amygdala hemodynamic activity. Not only do these results raise the intriguing possibility that naturally occurring fear responses can be “reprogrammed” outside of conscious awareness, importantly, they also create the rare opportunity to rigorously test a psychological intervention of this nature in a double-blind, placebo-controlled fashion. This may pave the way for a new approach combining the appealing rationale and proven efficacy of conventional psychotherapy with the rigor and leverage of clinical neuroscience.

Wednesday, April 04, 2018

If resources are scarce infants choose ingroup support over fairness.

From Bian et al:

Significance
Recent research suggests that infants possess principles of fairness and ingroup support. We examined whether 1.5- and 2.5-y-olds would prioritize fairness or ingroup support when the two were pitted against each other. Children watched mixed-recipients resource-allocation events in which a puppet distributor faced two potential recipients, an ingroup and an outgroup puppet. Expectations about the distributor’s actions depended on how many allocation items were available. When there were as many items as puppets, children expected fairness to prevail; when there were fewer items than puppets, however, children expected ingroup support to prevail. Thus, beginning early in life, children expect fairness in mixed-recipients scenarios unless there is a shortage of resources, in which case they expect ingroup support to override fairness.
Abstract
Recent research suggests that the foundations of human moral cognition include abstract principles of fairness and ingroup support. We examined which principle 1.5-y-old infants and 2.5-y-old toddlers would prioritize when the two were pitted against each other. In violation-of-expectation tasks, a puppet distributor brought in either two (two-item condition) or three (three-item condition) items and faced two potential recipients, an ingroup and an outgroup puppet. In each condition, the distributor allocated two items in one of three events: She gave one item each to the ingroup and outgroup puppets (equal event), she gave both items to the ingroup puppet (favors-ingroup event), or she gave both items to the outgroup puppet (favors-outgroup event). Children in the two-item condition looked significantly longer at the equal or favors-outgroup event than at the favors-ingroup event, suggesting that when there were only enough items for the group to which the distributor belonged, children detected a violation if she gave any of the items to the outgroup puppet. In the three-item condition, in contrast, children looked significantly longer at the favors-ingroup or favors-outgroup event than at the equal event, suggesting that when there were enough items for all puppets present, children detected a violation if the distributor chose to give two items to one recipient and none to the other, regardless of which recipient was advantaged. Thus, infants and toddlers expected fairness to prevail when there were as many items as puppets, but they expected ingroup support to trump fairness otherwise.

Tuesday, April 03, 2018

Is loneliness a health epidemic?

Two recent bits of writing on loneliness:

Klinenberg suggests that the 'loneliness epidemic' that has been promoted by numerous recent articles (Britain has appointed its first "minister for loneliness") is an illusion. Loneliness exists as a feature of modern societies, but the best data do not show increase in either loneliness or social isolation between ~1950 and the present.

Pinker, in Figure 18-2 of his new book actually shows data tracking the subjective loneliness of college and high school students over the period 1978-2012, and showing that a small decrease reported loneliness has occurred. His summary comment:
Modern life, then, has not crushed our minds and bodies, turned us into atomized machines suffering from toxic levels of emptiness and isolation, or set us drifting apart without human contact or emotion. How did this hysterical misconception arise? Partly it came out of the social critic’s standard formula for sowing panic: Here’s an anecdote, therefore it’s a trend, therefore it’s a crisis. But partly it came from genuine changes in how people interact. People see each other less in traditional venues like clubs, churches, unions, fraternal organizations, and dinner parties, and more in informal gatherings and via digital media. They confide in fewer distant cousins but in more co-workers. They are less likely to have a large number of friends but also less likely to want a large number of friends.51 But just because social life looks different today from the way it looked in the 1950s, it does not mean that humans, that quintessentially social species, have become any less social.

Monday, April 02, 2018

Predicting the effectiveness of cognitive therapy with functional MRI

Reggente et al. do interesting work showing that MRI measurement of functional connectivity patterns in the default mode and visual networks of obsessive-compulsive disorder (OCD) individuals before entering cognitive therapy predict post treatment OCD severity. Such information could prove useful in choosing between behavioral and drug therapy for a given individual.

Significance
The ability to predict an individual’s potential response to treatment would permit clinicians to more prudently allocate resources that support cognitive behavioral therapy for obsessive–compulsive disorder (OCD), an often stressful and time-consuming treatment. The current study lays important groundwork for an exciting advance toward personalized medicine in psychiatry that up to this point has eluded the field. This study marks a success in using multivariate pattern recognition to identify neurobiological predictors of treatment response. In addition, it advances knowledge of the neurophysiology of OCD and of mechanistic processes involved in the therapeutic response, which could be used to refine existing treatments or to develop novel treatments based on identified potential brain targets.
Abstract
Cognitive behavioral therapy (CBT) is an effective treatment for many with obsessive–compulsive disorder (OCD). However, response varies considerably among individuals. Attaining a means to predict an individual’s potential response would permit clinicians to more prudently allocate resources for this often stressful and time-consuming treatment. We collected resting-state functional magnetic resonance imaging from adults with OCD before and after 4 weeks of intensive daily CBT. We leveraged machine learning with cross-validation to assess the power of functional connectivity (FC) patterns to predict individual posttreatment OCD symptom severity. Pretreatment FC patterns within the default mode network and visual network significantly predicted posttreatment OCD severity, explaining up to 67% of the variance. These networks were stronger predictors than pretreatment clinical scores. Results have clinical implications for developing personalized medicine approaches to identifying individual OCD patients who will maximally benefit from intensive CBT.