Monday, June 17, 2019

Why can we read only one word at a time?

Fascinating work from White et al.:

Significance
Because your brain has limited processing capacity, you cannot comprehend the text on this page all at once. In fact, skilled readers cannot even recognize just two words at once. We measured how the visual areas of the brain respond to pairs of words while participants attended to one word or tried to divide attention between both. We discovered that a single word-selective region in left ventral occipitotemporal cortex processes both words in parallel. The parallel streams of information then converge at a bottleneck in an adjacent, more anterior word-selective region. This result reveals the functional significance of subdivisions within the brain’s reading circuitry and offers a compelling explanation for a profound limit on human perception.
Abstract
In most environments, the visual system is confronted with many relevant objects simultaneously. That is especially true during reading. However, behavioral data demonstrate that a serial bottleneck prevents recognition of more than one word at a time. We used fMRI to investigate how parallel spatial channels of visual processing converge into a serial bottleneck for word recognition. Participants viewed pairs of words presented simultaneously. We found that retinotopic cortex processed the two words in parallel spatial channels, one in each contralateral hemisphere. Responses were higher for attended than for ignored words but were not reduced when attention was divided. We then analyzed two word-selective regions along the occipitotemporal sulcus (OTS) of both hemispheres (subregions of the visual word form area, VWFA). Unlike retinotopic regions, each word-selective region responded to words on both sides of fixation. Nonetheless, a single region in the left hemisphere (posterior OTS) contained spatial channels for both hemifields that were independently modulated by selective attention. Thus, the left posterior VWFA supports parallel processing of multiple words. In contrast, activity in a more anterior word-selective region in the left hemisphere (mid OTS) was consistent with a single channel, showing (i) limited spatial selectivity, (ii) no effect of spatial attention on mean response amplitudes, and (iii) sensitivity to lexical properties of only one attended word. Therefore, the visual system can process two words in parallel up to a late stage in the ventral stream. The transition to a single channel is consistent with the observed bottleneck in behavior.

Friday, June 14, 2019

Why high-class people get away with incompetence.

Belmi et al. do four experiments suggesting that people who come from a higher social class are more likely to have an inflated sense of their skills — even when tests proved that they are average. This unmerited overconfidence is interpreted by strangers as competence. This highlights yet another way that family wealth and parents' education confers an advantage in getting ahead in life.
Understanding how socioeconomic inequalities perpetuate is a central concern among social and organizational psychologists. Drawing on a collection of findings suggesting that different social class contexts have powerful effects on people’s sense of self, we propose that social class shapes the beliefs that people hold about their abilities, and that this, in turn, has important implications for how status hierarchies perpetuate. We first hypothesize that compared with individuals with relatively low social class, individuals with relatively high social class are more overconfident. Then, drawing on research suggesting that overconfidence can confer social advantages, we further hypothesize that the overconfidence of higher class individuals can help perpetuate the existing class hierarchy: It can provide them a path to social advantage by making them appear more competent in the eyes of others. We test these ideas in four large studies with a combined sample of 152,661 individuals. Study 1, a large field study featuring small-business owners from Mexico, found evidence that individuals with relatively high social class are more overconfident compared with their lower-class counterparts. Study 2, a multiwave study in the United States, replicated this result and further shed light on the underlying mechanism: Individuals with relatively high (vs. low) social class tend to be more overconfident because they have a stronger desire to achieve high social rank. Study 3 replicated these findings in a high-powered, preregistered study and found that individuals with relatively high social class were more overconfident, even in a task in which they had no performance advantages. Study 4, a multiphase study that featured a mock job interview in the laboratory, found that compared with their lower-class counterparts, higher-class individuals were more overconfident; overconfidence, in turn, made them appear more competent and more likely to attain social rank.

Wednesday, June 12, 2019

Policy evaluation by randomized trials may provoke greater objections than implementing them untested.

Meyer et al. find that experiments comparing two unobjectionable policies or treatments can generate more objections than simply proceeding to implement them.

Significance
Randomized experiments—long the gold standard in medicine—are increasingly used throughout the social sciences and professions to evaluate business products and services, government programs, education and health policies, and global aid. We find robust evidence—across 16 studies of 5,873 participants from three populations spanning nine domains—that people often approve of untested policies or treatments (A or B) being universally implemented but disapprove of randomized experiments (A/B tests) to determine which of those policies or treatments is superior. This effect persists even when there is no reason to prefer A to B and even when recipients are treated unequally and randomly in all conditions (A, B, and A/B). This experimentation aversion may be an important barrier to evidence-based practice.
Abstract
Randomized experiments have enormous potential to improve human welfare in many domains, including healthcare, education, finance, and public policy. However, such “A/B tests” are often criticized on ethical grounds even as similar, untested interventions are implemented without objection. We find robust evidence across 16 studies of 5,873 participants from three diverse populations spanning nine domains—from healthcare to autonomous vehicle design to poverty reduction—that people frequently rate A/B tests designed to establish the comparative effectiveness of two policies or treatments as inappropriate even when universally implementing either A or B, untested, is seen as appropriate. This “A/B effect” is as strong among those with higher educational attainment and science literacy and among relevant professionals. It persists even when there is no reason to prefer A to B and even when recipients are treated unequally and randomly in all conditions (A, B, and A/B). Several remaining explanations for the effect—a belief that consent is required to impose a policy on half of a population but not on the entire population; an aversion to controlled but not to uncontrolled experiments; and a proxy form of the illusion of knowledge (according to which randomized evaluations are unnecessary because experts already do or should know “what works”)—appear to contribute to the effect, but none dominates or fully accounts for it. We conclude that rigorously evaluating policies or treatments via pragmatic randomized trials may provoke greater objection than simply implementing those same policies or treatments untested.

Monday, June 10, 2019

Is technology really reshaping our consciousness?

My first reaction on reading a recent Op-Ed piece by David Brooks "When Trolls and Crybullies Rule the Earth" was to say 'Yes!', and think I should immediately fire off some selected clips in a MindBlog post. I'm glad I waited a bit, because as I look at it again I feel he has erred on the side of being an alarmist drama queen to grab our attention. The article begins with:
Over the past several years, teenage suicide rates have spiked horrifically....What's going on?
Several sources show an increasing rate from 2010 to 2017, but a look at Centers for Disease Control data shows higher rates for the late 1980's and early 1990's. He continues:
My answer starts with technology but is really about the sort of consciousness online life induces.
Brooks then describes transformations of human consciousness as if they have replaced, rather than adding to and enhancing, older forms of consciousness:  the shift from an oral to a printed culture centuries ago and the current shift from printed to electronic communication.
Attention and affection have gone from being private bonds to being publicly traded goods...up until recently most of the attention a person received came from family and friends and was pretty stable. But now most of the attention a person receives can come from far and wide and is tremendously volatile...your online post can go viral and get massively admired or ridiculed, while other times your post can leave you alone and completely ignored. Communication itself, once mostly collaborative, is now often competitive, with bids for affection and attention. It is also more manipulative — gestures designed to generate a response.
But... were not the old fashioned kinds of attention exchanged personally or in crowds of people, rather than electronically, labile and competitive with constant bids for affection and attention? Electronics may have amplified what was happening, but it didn't fundamentally transform it. Vicious gossip can be exchanged in old fashioned personal or newer less personal electronic ways. Online platforms may be an amplifier of our traits, but they don't basically transform them. Trolls and crybullies have always been with us. Still, Brooks makes good points, even if a bit exaggerated:
The internet has become a place where people communicate out of their competitive ego: I’m more fabulous than you (a lot of Instagram). You’re dumber than me (much of Twitter). It’s not a place where people share from their hearts and souls.
Of course, people enmeshed in such a climate are more likely to feel depressed, to suffer from mental health problems. Of course, they are more likely to see human relationship through the abuser/victim frame, and to be acutely sensitive to any power imbalance. Imagine you’re 17 and people you barely know are saying nice or nasty things about your unformed self. It creates existential anxiety and hence fanaticism.

Friday, June 07, 2019

The wisdom of partisan crowds.

Fascinating and counterintuitive findings from Becker et al., who find that the wisdom of crowds is robust to partisan bias:

Significance
Normative theories of deliberative democracy are based on the premise that social information processing can improve group beliefs. Research on the “wisdom of crowds” has found that information exchange can increase belief accuracy in many cases, but theories of political polarization imply that groups will become more extreme—and less accurate—when beliefs are motivated by partisan political bias. While this risk is not expected to emerge in politically heterogeneous networks, homogeneous social networks are expected to amplify partisan bias when people communicate only with members of their own political party. However, we find that the wisdom of crowds is robust to partisan bias. Social influence not only increases accuracy but also decreases polarization without between-group network ties.
Abstract
Theories in favor of deliberative democracy are based on the premise that social information processing can improve group beliefs. While research on the “wisdom of crowds” has found that information exchange can increase belief accuracy on noncontroversial factual matters, theories of political polarization imply that groups will become more extreme—and less accurate—when beliefs are motivated by partisan political bias. A primary concern is that partisan biases are associated not only with more extreme beliefs, but also with a diminished response to social information. While bipartisan networks containing both Democrats and Republicans are expected to promote accurate belief formation, politically homogeneous networks are expected to amplify partisan bias and reduce belief accuracy. To test whether the wisdom of crowds is robust to partisan bias, we conducted two web-based experiments in which individuals answered factual questions known to elicit partisan bias before and after observing the estimates of peers in a politically homogeneous social network. In contrast to polarization theories, we found that social information exchange in homogeneous networks not only increased accuracy but also reduced polarization. Our results help generalize collective intelligence research to political domains.

Wednesday, June 05, 2019

Inequality brokered

Public opinion about sexual minorities has improved dramatically in recent years, but Sun and Gao do an analysis showing that discriminatory behavior in lending practices has been ongoing and gone unchecked.

Significance
We propose a method to infer people’s sexual orientation indirectly through gender disclosure of the borrower and coborrower in a mortgage. Furthermore, we examine lending practices toward same-sex borrowers and its spillover effects. We attempt to extend the research on race/gender discrimination by systematically investigating the potentially different lending treatment toward same-sex borrowers. The data reveal that, compared with otherwise similar different-sex applicants, same-sex applicants are 73.12% more likely to be denied, and they tend to be charged up to 0.2% higher fees/interest. Furthermore, neighborhoods’ higher same-sex population density adversely affects both same-sex and different-sex borrowers’ lending experiences. Our method might approximately measure the US homosexual population distribution up to the census tract level annually over decades.
Abstract
Using massive US mortgage lending data, we propose a method to infer a borrower’s sexual orientation indirectly without a self-identification requirement and demonstrate the method’s potential to approximately measure the sexual orientation of the US population at the local level annually over decades. We continue to examine the lending practices to same-sex borrowers and its spillover effects. The persistent results since 1990 reveal that, in contrast with otherwise comparable different-sex loan applicants, the approval rate for same-sex applicants is ∼3–8% lower. Furthermore, conditional on approval, lenders, on average, charge about 0.02–0.2% higher interest to same-sex borrowers, which is equivalent to an annual total of $8.6 million to $86 million in additional interest/fees nationwide. Meanwhile, we find that same-sex borrowers are less risky overall, as they exhibit similar default risk but lower prepayment risk. Finally, we document findings of spillover effects. That is, when the share of a neighborhood’s same-sex population increases, both same-sex and different-sex borrowers seem to experience more unfavorable lending outcomes overall. The findings should raise enough concerns to warrant further investigations.

Monday, June 03, 2019

Blueprint - Nicholas Christakis' new book on evolutionary origins of a good society

This opinion piece by Frank Bruni in the NYTimes motivated me to download and read Nicholas Christakis' Magnum Opus “Blueprint” (very much in the 'everything you need to know about humans' spirit of Sapolsky's "Behave" and Harari's "Sapiens," and "Homo Deus," and "21 Lessons," all books that I have made the subject of previous posts.). It echoes Pinker's emphasis on the more positive aspects of human nature and progress. It is a very engaging read, and not amenable to a simple summary, but here is a bit from his introduction:
How can people be so different from—even go to war with—one another and yet also be so similar? The fundamental reason is that we each carry within us an evolutionary blueprint for making a good society.
Genes do amazing things inside our bodies, but even more amazing to me is what they do outside of them. Genes affect not only the structure and function of our bodies; not only the structure and function of our minds and, hence, our behaviors; but also the structure and function of our societies. This is what we recognize when we look at people around the world. This is the source of our common humanity.
Natural selection has shaped our lives as social animals, guiding the evolution of what I call a “social suite” of features priming our capacity for love, friendship, cooperation, learning, and even our ability to recognize the uniqueness of other individuals. Despite all the trappings and artifacts of modern invention—our tools, agriculture, cities, nations—we carry within us innate proclivities that reflect our natural social state, a state that is, as it turns out, primarily good, practically and even morally. Humans can no more make a society that is inconsistent with these positive urges than ants can suddenly make beehives.
I believe that we come to this sort of goodness just as naturally as we come to our bloodier inclinations. We cannot help it. We feel great when we help others. Our good deeds are not just the products of Enlightenment values. They have a deeper and prehistoric origin. The ancient tendencies that form the social suite work together to bind communities, specify their boundaries, identify their members, and allow people to achieve individual and collective objectives while at the same time minimizing hatred and violence. For too long, in my opinion, the scientific community has been overly focused on the dark side of our biological heritage: our capacity for tribalism, violence, selfishness, and cruelty. The bright side has been denied the attention it deserves.