Monday, August 16, 2021

Rolf Degen summarizing... The brain circuit for pain is different from that for suffering, and the latter adds the bite to the former, and to other kinds of disorder

The anatomy of pain and suffering in the brain and its clinical implications. Dirk De Ridder, Divya Adhia, Sven Vanneste. Neuroscience & Biobehavioral Reviews, August 16 2021 https://doi.org/10.1016/j.neubiorev.2021.08.013

Highlights

• Acute pain is a symptom of acute or potential tissue damage, chronic pain extends beyond the period of healing of the original insult or injury, and hence lacks the acute warning function of physiological nociception.

• Pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral ‘painfulness’ pathway, a medial ‘suffering’ pathway and a descending pain inhibitory pathway.

• In chronic pain the descending pain inhibitory pathway is less activated.

• Pain sensation leads to suffering via a cognitive (insula), emotional (ACC) and autonomic (ACC plus insula) processing, and is expressed as anger, fear, frustration, anxiety and depression, leading to changes in behaviour and functional disability.

• Acute pain transitions into chronic pain under influence of genetic and epigenetic factors.

• The genetic and epigenetic factors modulate neuroinflammation, which is involved in peripheral and central sensitization.

• Chronic pain, with a prevalence of 20-30% is the major cause of human suffering worldwide.

• Perceived pain disability correlates highly with suffering, little with painfulness

• Unpleasantness (and suffering) is transmitted via a phylogenetically old unmyelinated C-fibre network, linked to survival and procreation.

• Pain and suffering depend on salience and context: sadomasochistic erotic behaviour is a clear example.

• The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness.

• Suffering explains the common neurocircuitry of many psychiatric and neurological disorders.

• Women perceive more intense acute and chronic pain and experience more unpleasantness than men.

• Women suffer more than men as evidenced by higher anxiety and depression prevalence.

• The sex-differences in pain perception are genetically encoded and dependent on immunological and hormonal modulation of pain processing.

• The (predictive) Bayesian Brain hypothesis proposes that pain (and suffering) is the consequence of an imbalance between the ascending and descending pain inhibitory pathways. This balance is theorized to be under control of the reward system.

• By categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathways in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.

Abstract: Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Chronic pain, with a prevalence of 20-30% is the major cause of human suffering worldwide, because effective, specific and safe therapies have yet to be developed. It is unevenly distributed among sexes, with women experiencing more pain and suffering. Chronic pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral ‘painfulness’ pathway, a medial ‘suffering’ pathway and a descending pain inhibitory pathway. One may have pain(fullness) without suffering and suffering without pain(fullness). Pain sensation leads to suffering via a cognitive, emotional and autonomic processing, and is expressed as anger, fear, frustration, anxiety and depression. The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness. Genetic and epigenetic influences trigger chronic neuroinflammatory changes which are involved in transitioning from acute to chronic pain. Based on the concept of the Bayesian brain, pain (and suffering) can be regarded as the consequence of an imbalance between the two ascending and the descending pain inhibitory pathways under control of the reward system. The therapeutic clinical implications of this simple pain model are obvious. After categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathways in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.

Keywords: painacutechroniccognitiveemotionalautonomicanterior cingulate cortex


The various disclosure & internal governance rules lead to a total compliance cost of 4.1% of the market capitalization for a median U.S. public firm; these regulatory costs only explain a small fraction of the decline in number of public firms

Regulatory Costs of Being Public: Evidence from Bunching Estimation. Michael Ewens, Kairong Xiao & Ting Xu. NBER Working Paper 29143, August 2021. DOI 10.3386/w29143

Abstract: The increased burden of disclosure and governance regulations is often cited as a key reason for the significant decline in the number of publicly-listed companies in the U.S. We explore the connection between regulatory costs and the number of listed firms by exploiting a regulatory quirk: many rules trigger when a firm’s public float exceeds a threshold. Consistent with firms seeking to avoid costly regulation, we document significant bunching around multiple regulatory thresholds introduced from 1992 to 2012. We present a revealed preference estimation strategy that uses this behavior to quantify regulatory costs. Our estimates show that various disclosure and internal governance rules lead to a total compliance cost of 4.1% of the market capitalization for a median U.S. public firm. Regulatory costs have a greater impact on private firms’ IPO decisions than on public firms’ going private decisions. However, heightened regulatory costs only explain a small fraction of the decline in the number of public firms.



Will this "up to five times" be reproducible?: Exposure to continuous or fluid theories of sexual orientation leads some heterosexuals to embrace less-exclusive heterosexual orientations

Will this "up to five times" be reproducible?: Exposure to continuous or fluid theories of sexual orientation leads some heterosexuals to embrace less-exclusive heterosexual orientations. James S. Morandini, Liam Dacosta & Ilan Dar-Nimrod. Scientific Reports volume 11, Article number: 16546 (2021). https://www.nature.com/articles/s41598-021-94479-9

Abstract: We examined whether heterosexual individuals’ self-reported sexual orientation could be influenced experimentally by manipulating their knowledge of the nature of sexual orientation. In Study 1 (180 university students, 66% female) participants read summaries describing evidence for sexual orientation existing on a continuum versus discrete categories or a control manipulation, and in Study 2 (460 participants in a nationally representative Qualtrics panel, 50% female) additionally read summaries describing sexual orientation as fluid versus stable across the life-course. After reading summaries, participants answered various questions about their sexual orientation. In Study 1, political moderates and progressives (but not conservatives) who read the continuous manipulation subsequently reported being less exclusively heterosexual, and regardless of political alignment, participants reported less certainty about their sexual orientation, relative to controls. In Study 2, after exposure to fluid or continuous manipulations heterosexual participants were up to five times more likely than controls to rate themselves as non-exclusively heterosexual. Additionally, those in the continuous condition reported less certainty about their sexual orientation and were more willing to engage in future same-sex sexual experiences, than those in the control condition. These results suggest that non-traditional theories of sexual orientation can lead heterosexuals to embrace less exclusive heterosexual orientations.

General discussion

These studies show that how heterosexual individuals perceive their sexual orientation can be influenced by exposure to different theories regarding the nature of sexual orientation. In Study 1, exposure to continuous notions of sexual orientation caused political progressive and moderate, but not conservative university students to change how they perceived their sexual orientation to a non-exclusive heterosexual orientation (in support of Hypothesis 2B)—presumably as young progressives were less resistant to accepting that they may have the capacity for same-sex sexuality. Gender did not significantly moderate the effect of the continuous manipulation on sexual orientation change contrary to Hypotheses 2A. Moreover, supporting Hypothesis 1, reading the continuous account caused all participants, regardless of political orientation, to report less certainty about their sexual orientation. Given that college students may be particularly open to sexual identity exploration it was necessary to examine these findings in a heterogeneously-aged community sample. Study 2 failed to directly replicate Study 1 in a nation-wide, more heterogeneously-aged, community sample. Nevertheless, manipulating sexual orientation impacted sexual orientation self-ratings in line with Hypothesis 1. Whereas only 8% of participants in the control condition reported being non-exclusively heterosexual post manipulation, 36% of those who read the continuous account, and 21% who read the fluid account subsequently described themselves as non-exclusively heterosexual post manipulation in this between-subject designed study. These shifts occurred irrespective of political orientation, or gender (contrary to Hypotheses 2A and 2B). Furthermore, in Study 2, the continuous account not only led heterosexuals to report less certainty about their sexual orientation, but also to express greater willingness to engage in sexual or romantic interactions with members of the same-sex. This latter finding may have been significant in Study 2 but not in Study 1 given the substantial difference in power, with the Study 2 sample size offering greater power to find a significant effect for between-subject variables, such as those.

As mentioned, unlike in Study 1, in Study 2 manipulations influenced sexual orientation self-ratings irrespective of the political orientation of participants (contrary to Hypothesis 2B). It is possible that the effects of the continuous condition were stronger in Study 2 (national sample; average age 45) than Study 1 (college sample; average age 19) because these notions of sexual orientation were more novel for the national sample who were on average middle-aged and more politically conservative (i.e., a ceiling effect may have reduced the strength of shifts in the college sample—who were perhaps already well accustomed to continuous notions of sexuality due to young age and political progressivism). Another possibility is that the differences in the design of the studies contributed to the differences in the effect of political orientation. In the first study, a within-subject assessment allowed us to assess actual within-subject changes following the manipulation. As such, it meant that participants were willing to show changes in their self-perceptions following the manipulation. As politically conservative students view same-sex attraction more negatively than their progressive counterparts35, it was arguably less taxing for the progressive (and moderates) to admit that the information in the manipulation (legitimizing gradations of heterosexuality) led them to explicitly recognise some low level of same-sex attraction in themselves. For conservatives, on the other hand, such an admission may have been more taxing and thus, less frequent, leading to the observed differences. In Study 2, on the other hand, no pre-manipulation indication of their Kinsey-type identity label was reported, thus the willingness to show that they accepted the information in the manipulation by changing their identity label immediately following the manipulation was absent, allowing the participants to avoid showing explicit endorsement of the information about continuity (or fluidity) of sexual orientation. Thus, the nature of the studies’ designs may have led conservative individuals to respond differently to the manipulations.

Across studies, neither the discrete nor stable manipulations demonstrated effects on sexual orientation self-concept—and specifically, contrary to Hypothesis 3—they failed to increase exclusivity of heterosexual feelings or decrease sexual orientation uncertainty or willingness to engage in same-sex encounters. This may be interpreted to suggest that discrete and stable notions of sexual orientation were perhaps the default assumptions in our sample. Furthermore, in Study 2, increased rates of non-exclusive heterosexual identification were observed also among those in the discrete condition (although this was a non-significant trend). On reflection, it is possible that the discrete condition provided scientific evidence that bisexuality exists—which is counter to the binary view of sexual orientation that is still predominant in society—particularly in older generations6 and those who are more politically conservative36. This may have resulted in more self-reports in the bisexual spectrum in some participants. However, the failure to observe this trend in Study 1 may indicate that this finding is spurious and requires future replication.

Contrary to our Hypotheses 2A, women appeared no more likely than men to report non-exclusive heterosexuality following exposure to informational accounts. At face value this is surprising given considerable evidence the female sexual orientation is more malleable than male sexual orientation21,22,37, and given that heterosexual men are likely to experience greater internal resistance28, and greater social backlash24,30, to adopting a non-exclusive heterosexual orientation. However, a closer look at Study 1 may explain why we did not observe gender differences in these effects. Pre-manipulation, men were much more likely than women to report an exclusively heterosexual orientation (91.7% versus 68.3%), and as discussed above, we observed a trend wherein those who were exclusively heterosexual at pre-test demonstrated stronger shifts following exposure to the continuous manipulation than those who were non-exclusively heterosexual at pre-test. Thus, a ceiling effect among the subset of women who already rated themselves as non-exclusively heterosexual at pre-test, may explain why women did not demonstrate stronger increases in non-exclusive heterosexuality than men.

Providing convergent evidence that the continuous account of sexual orientation can influence how heterosexuals view their sexual orientation—participants who read the continuous account were more uncertain of their sexual orientation than those in the control group. This may prove to be a temporary phase as individuals try to make sense of their sexual orientation in light of the new information, or alternatively, it may be a more permanent phenomenon which occurs as individuals move away from categorical and binary understandings of sexual orientation2,38. Moreover, in Study 2, reading the continuous account of sexual orientation increased participant’s willingness to engage in sexual/romantic interactions with members of the same-sex, relative to controls. Whether these behavioral intentions manifest in actual same-sex encounters will require future research. Critically, although those who read continuous and fluid accounts of sexual orientation were more likely to report a non-exclusive heterosexual orientation than controls, it is difficult to assess the generalizability of these effects to a real-world context, including whether the effects of reading these accounts persists over time (i.e., did our brief intervention permanently affect how participants view their sexual orientation?). Longitudinal studies are required to assess the stability of these effects on self-perceived sexual orientation—and thus these findings should be interpreted with caution. Such studies will benefit from integrating elements that can shed light on the mechanisms that are involved in the transitions away from the completely heterosexual descriptors. As perceptions of homogeneity are considered to be central to essentializing social categories based on elements such as sexual orientation39, and this essentialist tendency plays a role in making the members of such groups (e.g., heterosexual vs non-heterosexual individuals) seem more distinct from each others40, the role of perceptions of continuity and fluidity in reducing essentialism-derived taxometric notions offers a promising direction to explore.

Our manipulation of sexual orientation focused on influencing people’s perception of the continuity/discreteness/fluidity/stability of sexual arousal/sexual attraction, which although at the heart of what most people mean by sexual orientation41, is not the only thing which informs people’s sexual orientation. For instance, had our manipulations discussed continuity or fluidity in romantic feelings or pair bonding feelings—these may have impacted sexual orientation self-ratings in different ways. Arguably, as romantic feelings may be less gender specific than sexual arousal/attraction42, at least in males, including romantic themes (e.g., evidence that feelings of emotional intimacy/crushes toward members of the same-sex indicate non-exclusive heterosexuality) in our manipulation may have resulted in larger shifts in self-ratings. Future research may examine this possibility.

An intriguing possibility is that heterosexuals who hold a continuous or fluid view of sexual orientation are less prejudiced toward gay, lesbian, or bisexual peoples. Such a prediction is supported by evidence that indicates that perceiving sexual orientation as discrete is associated with greater anti-gay prejudice8. On the other hand, a recent study found that when heterosexual men are exposed to information that blurs the distinction between themselves and homosexual men, they enact greater homophobia, to re-establish their distinctiveness28. Future research clarifying how continuous and fluid notions of sexual orientation impact sexual prejudice is therefore of the upmost importance. Further, although the present research focused solely on heterosexual populations, future research may also examine how exposure to continuous and fluid notions of sexual orientation influences how gay men and lesbian women conceive of their sexual orientation. The potential effects of such exposure on shifts in reported sexual orientation and on levels of internalized homophobia are valuable, needed explorations.

Our findings also bring into question the meaning of “mostly” (e.g., “mostly same-sex attracted”, mostly opposite-sex attracted”) ratings on Kinsey-type measures. As commonly interpreted by researchers and lay people alike, individuals who report different positions on a Kinsey-type scale are thought to possess different sexual orientations43. But how then do we make sense of the present findings—in which participants’ self-ratings changed following our manipulations? Did we change the sexual orientation of our participants? Surely not. To make sense of the shifts observed we need to recognize that measures such as the Kinsey scale can only possibly assess “self-perceived sexual orientation”44. Although self-perceived sexual orientation is partly informed by actual sexual/romantic experiences (which gender/s we find sexually arousing, crush on, fantasize about, have sex with) these experiences are filtered through appraisals of these thoughts, feelings, and behaviours based on a range of personal beliefs and attitudes. This means that two individuals, with identical sexual experiences, could report quite different sexual orientations. The present study found that manipulating participants beliefs about sexual orientation changed how they interpreted their sexual/romantic experiences and the subsequent global assessment they made when rating their sexual orientation. As considerable effort has been undertaken to understand mental health45,46, substance use47,48, sexual health49,50,51, discrimination52, and even physiological differences43,53,54,55,56,57 between exclusive and non-exclusive heterosexual individuals, clarifying the cognitive and attitudinal variables that may predispose a heterosexual person to adopt respective labels is surely important if we are interested in the causes of differences (e.g., mental health, sexual health) between exclusive heterosexual and non-exclusive heterosexual populations.

Our findings suggest that non-exclusive heterosexual orientations might become more prevalent as continuous and fluid notions of sexuality become more culturally mainstream and provide currently-identified heterosexuals with more nuanced ways of describing themselves. We should stress that present findings do not support the contention that sexual orientation (the underlying compass that directs our sexual/romantic feelings) can be changed. Rather we show that how people understand and label their experiences can influenced by exposure to certain theories of sexual orientation, which arguably more accurately reflect their underlying feelings.

Bureaucracy adaptation: Why Didn't the 2009 Recovery Act Improve the Nation's Highways and Bridges?

From 2017... Dupor, William Daniel, So, Why Didn't the 2009 Recovery Act Improve the Nation's Highways and Bridges? (2017). SSRN: http://dx.doi.org/10.20955/r.2017.169-182

Abstract: Although the American Recovery and Reinvestment Act of 2009 (the Recovery Act) provided nearly $28 billion to state governments for improving U.S. highways, the highway system saw no significant improvement. For example, relative to the years before the act, the number of structurally deficient or functionally obsolete bridges was nearly unchanged, the number of workers on highway and bridge construction did not significantly increase, and the annual value of construction put in place for public highways barely budged. The author shows that as states spent Recovery Act highway grants, many simultaneously slashed their own contributions to highway infrastructure, freeing up state dollars for other uses. Next, using a cross-sectional analysis of state highway spending, the author shows that a state?s receipt of Recovery Act highway dollars had no statistically significant causal impact on that state?s total highway spending. Thus, the amount of actual highway infrastructure investment following the act?s passage was likely very similar to that under a no-stimulus counterfactual.

JEL Classification: E62, E65, H54, H77