Tuesday, November 24, 2020

Cannabis: 70–85% of users reported increased sexual pleasure/satisfaction, 25–40% prolonged duration of intercourse, 55–70% heightened sensation; & reported more coital frequency; but placebo effect cannot be ruled out

Cannabinoid signalling and effects of cannabis on the male reproductive system. Mauro Maccarrone, Cinzia Rapino, Felice Francavilla & Arcangelo Barbonetti. Nature Reviews Urology, November 19 2020. https://www.nature.com/articles/s41585-020-00391-8

Key points

* Marijuana has the highest consumption rate of any recreational drug in the Western world.

* Endocannabinoids and their receptors, enzymes and transporters, which together form the endocannabinoid system (ECS), are present in various components of the male reproductive tract, including male genital glands, testis and sperm.

* Preclinical studies have shown that the ECS is involved in negative modulation of testosterone secretion by acting at both central and testicular levels.

* As yet, clinical data are insufficient to conclude that cannabinoids have a harmful effect on human male sexual function and fertility.

* Although cannabinoid receptors are present in the testes and sperm, the effects of cannabinoid exposure on spermatogenesis largely remain to be clarified.

* The ECS has the potential to provide new drug targets in male reproductive disorders, and its components might be useful as biomarkers of male infertility.


Abstract: Marijuana is the most widely consumed recreational drug worldwide, which raises concerns for its potential effects on fertility. Many aspects of human male reproduction can be modulated by cannabis-derived extracts (cannabinoids) and their endogenous counterparts, known as endocannabinoids (eCBs). These latter molecules act as critical signals in a variety of physiological processes through receptors, enzymes and transporters collectively termed the endocannabinoid system (ECS). Increasing evidence suggests a role for eCBs, as well as cannabinoids, in various aspects of male sexual and reproductive health. Although preclinical studies have clearly shown that ECS is involved in negative modulation of testosterone secretion by acting both at central and testicular levels in animal models, the effect of in vivo exposure to cannabinoids on spermatogenesis remains a matter of debate. Furthermore, inconclusive clinical evidence does not seem to support the notion that plant-derived cannabinoids have harmful effects on human sexual and reproductive health. An improved understanding of the complex crosstalk between cannabinoids and eCBs is required before targeting of ECS for modulation of human fertility becomes a reality.


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Despite data suggesting that cannabis use can affect human sexual function, its effects remain under debate, as favourable effects on sexual behaviour and motivational, hedonic and/or perceptual aspects of sexual intercourse have been also reported. Some studies77have suggested that 70–85% of marijuana consumers experience increased sexual pleasure and satisfaction, 25–40% prolonged duration of intercourse, and 55–70% heightened orgasmic sensation78,79. Furthermore, the National Survey of Family Growth (NSFG), a representative cross- sectional survey on a well- controlled cohort of almost 23,000 men in the USA, showed that increased frequency of marijuana use was associated with increased coital frequency, even after adjustment for demographic, socio- economic and anthropometric variables80(Table 3). Notably, these data are all self-reported and, therefore, are at risk of both recall bias and exaggeration by participants; thus, they should be interpreted with caution. The authors hypothesized that individuals who engage in marijuana use might be more psychologically disinhibited than those who do not, which could be reflected in their sex life as high coital frequency80. Furthermore, although sexual pleasure could be at least partially attributed to an actual enhancement of sensory experience, especially in terms of an increased sensitivity to touch, which has been reported in cannabis users78, a placebo effect cannot be ruled out, given the anecdotal reputation of cannabis as an aphrodisiac77. These aspects should be taken into account when interpreting the increased sexual pleasure and satisfaction among marijuana consumers reported in previous studies77.





International Journal of Impotence Research: Sexual desire and its relationship with subjective orgasm experience

Sexual desire and its relationship with subjective orgasm experience. Ana Isabel Arcos-Romero, Dharelys Expósito-Guerra, Juan Carlos Sierra. International Journal of Impotence Research, November 16 2020. https://www.nature.com/articles/s41443-020-00375-7

Rolf Degen's take: https://twitter.com/DegenRolf/status/1331140104400891905

Abstract: Orgasm and sexual desire are components of the human sexual response. The main objective of this study was to examine the relationship between the sexual desire and dimensions of the subjective orgasm experience. A sample composed of 1161 heterosexual adults, distributed into three age groups (18–34, 35–49, and 50 years old or older), completed a background questionnaire, the Orgasm Rating Scale, and the Sexual Desire Inventory. First, the effect that sex and age have on the subjective orgasm experience was analyzed. Second, correlations between sexual desire and orgasm experience were examined. Also, the predictive capacity that dimensions of sexual desire have on the subjective orgasm experience in the context of sexual relationship was examined. Results showed that age had a significant effect on the intensity of the subjective orgasm experience perceived during sexual relationships with a partner and that this experience decreased as people get older. There was an association between the components of sexual desire and the dimensions of subjective orgasm experience. Furthermore, partner-focused sexual desire contributed in a relevant manner to the subjective orgasm experience. Implications for both research and clinical field are also discussed.


Individuals rated as very unattractive actually earned more than those rated unattractive, average looking, or even attractive because they had higher levels of education & higher IQ scores than the other groups

When it comes to earning money, personality may be more important than looks. Satoshi Kanazawaa, Mary C. Still. Research Square, Nov 2020. https://doi.org/10.21203/rs.3.rs-112226/v1

Abstract: Economists have long acknowledged that physical attractiveness affects wages. Highly attractive men and women generally earn more than ordinary people doing comparable work. But it’s not clear _why_ this linkage exists. To answer this question, two scientists recently reported on a study designed to uncover the root cause of this so-called beauty premium. Their results imply that physically attractive people make more money _not_ because they’re beautiful, but rather because they’re healthier, more intelligent, and have more pleasant personalities. Their study tracked the careers and physical attractiveness of over 15,000 people for more than ten years. Participants were interviewed starting around age 16 and again at ages 17, 22, and 29. In each interview, they shared their gross personal earnings over the previous year and described their current occupation and health status. They also completed personality assessments and IQ tests. After each interview, their physical attractiveness was rated on a ve-point scale. The team used the data to test three leading hypotheses for why the beauty premium exists: employer discrimination against physically unattractive employees, the natural tendency of physically attractive employees to pursue jobs in which physical attractiveness is rewarded, and the possibility that more physically attractive workers may genuinely differ from their less attractive counterparts in ways that affect productivity. They found that the final hypothesis was the primary reason for the wage gap. Apparently, very physically attractive people aren’t excelling at work due to their looks, but rather because they more often possess qualities like good health, high intelligence, and extraversion. This conclusion was further supported by a rather unexpected finding: Individuals rated as very unattractive actually earned more than those rated unattractive, average looking, or even attractive. The reason again came down to individual differences. Very unattractive individuals attained higher levels of education and had higher IQ scores than the other groups. In essence, these results suggest that it’s not looks inuencing pay grade, per se. Certain desirable qualities may just be more pronounced in select groups of people, who also happen to be either very attractive _or_ very unattractive.

Keywords: Physical attractiveness, Earnings, Discrimination, Occupational self-selection, Individual differences, Productivity


Why People Distrust Polls: Perceiving respondent dishonesty is a far more robust predictor of distrust in poll than motivated reasoning

Lees, Jeffrey M., Barry Lam, Sara Purinton, and Daniel Wodak. 2020. “Why People Distrust Polls: Meta-cognitive Reasoning, Not Motivated Reasoning.” OSF Preprints. November 23. doi:10.31219/osf.io/53hc7

Rolf Degen's take: https://twitter.com/DegenRolf/status/1331118327343820800

Abstract: Many pollsters and news organizations have expressed growing concerns over public distrust in the accuracy of polls, especially in light of widespread perceived polling failures during the 2016 U.S. Presidential Election. Scholarly investigations into distrust in polls have highlighted motivated reasoning as a source of distrust, where individuals reject or accept polls based on whether their findings conflict with personally held attitudes and desired outcomes. Yet a separate, domain-general explanation for distrust in polls exists that may outweigh the effects of motivated reasoning: meta-cognitive reasoning (i.e., attitudes about the thoughts, attitudes, and motives of others). Here we investigate two distinct domains of meta-cognitive reasoning which may better explain distrust in polls than motivated reasoning: beliefs about whether the pollsters who conducted a poll are biased, and about whether poll respondents are honest in their responses. To examine this hypothesis we utilized a repeated-measures survey with a nationally-representative sample of Americans (N[Observations]=3510, N[Participants]=351) conducted five days prior to the 2020 U.S. Presidential Election. Participants viewed a stimuli set of 56 polls, pretested to be widely distributed across liberal-conservative favorability in results while neutral in aggregate, and responded to measures of motivated reasoning, meta-cognitive reasoning, and political ideology/affiliation. Utilizing mixed-effects modeling to allow for generalizable inferences, we find that meta-cognitive concerns regarding whether pollsters are (un)biased and poll respondents are (dis)honest are much stronger predictors of (dis)trust in polls than motivated reasoning or political ideology/affiliation. Our results are the first to demonstrate that perceiving respondent dishonesty is a far more robust predictor of distrust in poll than motivated reasoning. In general, meta-cognitive reasoning about pollsters and the people polled is the best explanation for why individuals distrust polls.


Recording the microstructure of meal intake in humans—Eating rate decelerated during the course of meals in normal-weight participants but not in participants with obesity

Edograms: recording the microstructure of meal intake in humans—a window on appetite mechanisms. France Bellisle. International Journal of Obesity volume 44, pages 2347–2357 (Aug 25 2020). https://www.nature.com/articles/s41366-020-00653-w

Rolf Degen's take: https://twitter.com/DegenRolf/status/1331104556516839425

Abstract: Early attempts at the objective measurement of food intake in humans followed many heuristic pioneer studies in laboratory animals, which revealed how homeostatic and hedonic factors interact to shape the daily eating patterns. Early studies in humans examined the characteristics of intake responses at discrete ingestive events. Described for the first time in 1969, the edogram consisted of a parallel recording of chewing and swallowing responses during standardized lunches, allowing parameters of the “microstructure of meals” to be quantified under varying conditions of deprivation or sensory stimulation, in parallel with overall meal size, meal duration, and eating rate. Edographic studies showed consistent changes in the microstructure of meals in response to palatability level (increased eating rate, decreased chewing time and number of chews per food unit, shorter intrameal pauses, and increased prandial drinking under improved palatability). Longer premeal deprivation affected the eating responses at the beginning of meals (decreased chewing time and number of chews per food unit) but not at the end. Eating rate decelerated during the course of meals in normal-weight participants but not in participants with obesity. These observations largely agreed with contemporary works using other objective measurement methods. They were confirmed and expanded in later studies, notably in the investigation of satiation mechanisms affecting weight control. Importantly, research has demonstrated that the parameters of the microstructure of meals not only reflect the influence of stimulatory/inhibitory factors but can, per se, exert a causal role in satiation and satiety. The early edographic recording instruments were improved over the years and taken out of laboratory settings in order to address the measurement of spontaneous intake responses in free-living individuals. Much remains to be done to make these instruments entirely reliable under the immense variety of situations where food consumption occurs.


Monday, November 23, 2020

Details freely recalled from one-time real-world experiences can retain high correspondence to the ground truth despite significant forgetting, with higher accuracy than expected after the emphasis on fallibility in the field of memory research

The Truth Is Out There: Accuracy in Recall of Verifiable Real-World Events. Nicholas B. Diamond, Michael J. Armson, Brian Levine. Psychological Science, November 23, 2020. https://doi.org/10.1177/0956797620954812

Abstract: How accurate is memory? Although people implicitly assume that their memories faithfully represent past events, the prevailing view in research is that memories are error prone and constructive. Yet little is known about the frequency of errors, particularly in memories for naturalistic experiences. Here, younger and older adults underwent complex real-world experiences that were nonetheless controlled and verifiable, freely recalling these experiences after days to years. As expected, memory quantity and the richness of episodic detail declined with increasing age and retention interval. Details that participants did recall, however, were highly accurate (93%–95%) across age and time. This level of accuracy far exceeded comparatively low estimations among memory scientists and other academics in a survey. These findings suggest that details freely recalled from one-time real-world experiences can retain high correspondence to the ground truth despite significant forgetting, with higher accuracy than expected given the emphasis on fallibility in the field of memory research.

Keywords: false memory, forgetting, aging, autobiographical memory, episodic memory


Regional and network neural activity reflect men’s preference for greater socioeconomic status during impression formation

Regional and network neural activity reflect men’s preference for greater socioeconomic status during impression formation. Denise M. Barth, Bradley D. Mattan, Tzipporah P. Dang & Jasmin Cloutier. Scientific Reports volume 10, Article number: 20302. Nov 20 2020. https://www.nature.com/articles/s41598-020-76847-z

Abstract: Evidence from social psychology suggests that men compared to women more readily display and pursue control over human resources or capital. However, studying how status and gender shape deliberate impression formation is difficult due to social desirability concerns. Using univariate and multivariate fMRI analyses (n = 65), we examined how gender and socioeconomic status (SES) may influence brain responses during deliberate but private impression formation. Men more than women showed greater activity in the VMPFC and NAcc when forming impressions of high-SES (vs. low-SES) targets. Seed partial least squares (PLS) analysis showed that this SES-based increase in VMPFC activity was associated with greater co-activation across an evaluative network for the high-SES versus low-SES univariate comparison. A data-driven task PLS analysis also showed greater co-activation in an extended network consisting of regions involved in salience detection, attention, and task engagement as a function of increasing target SES. This co-activating network was most pronounced for men. These findings provide evidence that high-SES targets elicit neural responses indicative of positivity, reward, and salience during impression formation among men. Contributions to a network neuroscience understanding of status perception and implications for gender- and status-based impression formation are discussed.


Discussion

Across complementary univariate and multivariate analyses, the present findings reveal consistent evidence of greater sensitivity to status (viz., SES) in men than in women. In line with previous findings6,28, we observed greater activity in brain regions indexing positive evaluations of others26 and social reward/salience (e.g., NAcc, amygdala) as men (but not women) formed impressions of high-SES (vs. low-SES) faces. Seed PLS analyses revealed that preferential responses to high (vs. low) SES in the VMPFC were associated with greater co-activation in contrast images reflecting high SES > low SES within an extended network involved in person evaluation and mentalizing, including the precuneus, temporoparietal junction, insula, and orbitofrontal cortex. This co-activation pattern was similar for women and men, suggesting that despite a greater VMPFC preference for high SES in men, both genders show similar patterns of functional connectivity when they do show a pro-high-SES bias in the VMPFC. Beyond our focal regions of interest involved in person evaluation, an exploratory task PLS analysis revealed a coordinated network of brain regions that was sensitive to high-SES (vs. low-SES) faces. Again, this pattern was only reliably observed for men in our sample. The functional network emerging from these analyses is consistent with greater relevance and/or engagement with status cues in men. Taken together, the findings provide evidence that high versus low SES is associated with neural responses indicative of positivity, reward, and salience during impression formation for men. The present findings are noteworthy for their contribution to a network neuroscience understanding of status perception but also for their implications regarding how gender and status interact to shape our impressions of others. We elaborate on these implications in separate sections below. Additionally, by examining both target and perceiver gender, this work provides greater representation in samples than is often used for psychophysiological studies and avoids the potential pitfall of assuming that women respond to status in the same way that men do66. Indeed, as the present and previous work suggest, this is only sometimes the case.

Toward a network neuroscience approach to social hierarchy perception

The present study is among the first to use a multivariate brain network approach to investigate status-based impression formation. This data-driven approach revealed a functional brain network responsive to perceiving high-SES compared to low-SES people, particularly in men. This network shows considerable overlap with a previously identified set of regions involved in status-based attention6,67 and more broadly with networks believed to support salience detection60,62 and attention61,62. However, the observed co-activation network extended beyond these core networks, possibly implicating broader domain-general networks supporting focused task engagement62,63,64,65. Complementing our ROI approach, which focused on brain regions previously shown to support status-based evaluations6,28, the preferential involvement of this large brain network was also driven primarily by men in our sample (see Fig. 5). Taken together, these findings suggest that men may be especially engaged when forming impressions of high-SES people and that these impressions are likely positive14.

It is worth noting that the inferior parietal cortex emerged as one component of the status-based attention network identified through task PLS analysis. This region has been implicated in computing social distances68,69,70,71,72, showing greater activity for difficult comparisons between two closely ranked individuals compared to easy comparisons between very differently ranked individuals71. The involvement of the inferior parietal cortex in the SES-based functional network suggests that men in our sample may dedicate greater attention to differentiating SES when forming impressions of others, particularly when those individuals are high in SES. This interpretation would be consistent with findings from the human and animal literature that high-status (vs. low-status) individuals more readily attract and/or re-direct attention6,73,74,75,76 and are more easily remembered76.

Implications for status and gender of the perceiver

One key takeaway in the present study is that the participant’s gender consistently altered sensitivity to perceived SES. In multiple regions thought to support status-based evaluations6,25,28, men more reliably showed neural responses that were more indicative of positive impressions for high- versus low-status targets. Men also showed greater coordination for increasing target SES in an extended set of regions implicated in salience, attention, and task engagement as discussed in the preceding section. In other words, men more than women showed evidence of positive evaluations and more deliberative engagement with high-SES faces during impression formation. This finding is consistent with evolutionary psychological accounts suggesting that men more readily display, attend to, and/or pursue higher status18,77,78.

Notably, the effect of perceiver gender on neural responses to target SES was not further modulated by target gender. Based in part on predictions derived from theories of sexual selection19, it has been argued that women and men may prefer different dimensions of status, both for themselves77,78 and for potential heterosexual mates19,20,79. Despite some support for this theory in the behavioral literature, it receives little support from the extant albeit sparse neuroimaging literature on gender and status36. One important caveat is that no fMRI study to date has explicitly invoked a context relevant to mating.

Implications for status and gender in person perception

Operationalizing target status

Status can be conveyed along multiple dimensions ranging from commonly studied attributes like dominance36 and finances23,24,80 to social categories such as race21,22,81 and gender36. One important aspect of this study is its focus on SES instead of dominance, which has perhaps received greater attention so far in neuroimaging studies of gender in hierarchical contexts36. As a measure of social rank, SES comprises an individual’s standing in terms of education, income, and occupational prestige82. Although SES may convey dominance in some contexts, these two constructs are not the same6,83. Accordingly, neural responses to perceived dominance may not reflect responses to status when it is operationalized in terms of SES. Indeed, previous work suggests that VMPFC responses to high status depend on the dimension of status in question, with greater responses for high moral status than for high financial status23,24.

In addition to the dimension of status in question, it is also important to consider the means by which status is conveyed. In the present study, status was conveyed through colored cues previously paired with high or low SES. This approach is particularly important for neuroimaging studies of status due to potential confounds that exist in more naturalistic and subtle cues of status such as facial cues84 and clothing81,85,86,87. For example, clothing can shape impressions of dominance85, competence86,87, and attractiveness88, all of which are imperfectly tied to perceptions of status83. This is important for neuroimaging studies of status for two reasons. First, using such cues makes it difficult to distinguish whether purported effects of social rank may instead be due to related but non-equivalent attributes such as competence. Second, this problem would be compounded when comparing the perception of two groups that stereotypically differ in terms of competence87. The present study largely bypasses these limitations by relying on ascribed SES knowledge through color assignment rather than clothing or facial expressions.

Absence of effects of target gender

Although the gender of perceivers shaped neural responses to target status during impression formation, these responses did not differ based on the gender of targets. This is noteworthy for a few reasons. First, participants did explicitly rate women are more likeable than men after scanning, suggesting that they did attend to gender to some extent. Additionally, previous work has revealed distinct neural correlates of target gender, regardless of whether gender is explicitly processed36,89. Given the relative salience of social category cues such as gender90,91, we anticipated that gender might interact with target status. Indeed, Marsh and colleagues36 observed greater responses in the VMPFC and right amygdala for increasingly dominant body postures of only the woman targets. However, as previously mentioned, the fact that status was based on different dimensions (SES vs. dominance) and antecedents (perceptual attributes vs. person knowledge) may explain these differences. Furthermore, neuroimaging work examining status-based impression formation in the presence of another salient social category (viz., race) also only found effects of status21,22. One possibility is that participants disregarded initial impressions based on gender information by focusing on the available status knowledge to form more individuated impressions92.

The absence of effects of target gender is also noteworthy from the perspective of some proposals arising from evolutionary psychology. Due in part to a lower minimal male investment in child-rearing93, evolutionary psychologists argue that males were frequently engaged in ancestral conflicts within and between groups, resulting in greater natural selection of physical and psychological characteristics associated with dominance in males than in females18. This relationship between sex and social hierarchy cues may also extend to social constructions such as the clothes we wear. For example, previous work has shown that men wearing high-status attire are more readily attended94 and rated as more competent87 than women wearing high-status attire. In contrast with this previous work, the present study showed no unique effects of SES for faces depicting men compared to women. One possibility is that conveying status through person knowledge rather than appearance eliminates potential gender bias in how status shapes social attention and evaluations6.

Alternative interpretation

Prior to concluding, it is worth considering an alternative interpretation of the present work. Given that the impression formation task did not include a control task condition, one could argue that our findings are not related to the status information ascribed to each target during impression formation. In this perspective, one could imagine obtaining similar findings if the faces of women and men were grouped based on other social information than social status such as their preference for different kinds of food. If so, then our findings might mean that men are more sensitive than women to social information in general rather than social status, per se.

Notwithstanding existing research suggesting that, in some instances, women may be more sensitive to social information than men95,96,97, we believe it is more parsimonious to focus our interpretation in the context of status sensitivity, rather than sensitivity to social information more generally, for three reasons. (1) Given that the face stimuli were equated across various dimensions and counterbalanced across participants within gender, we think it would be prudent not to over-generalize our findings to other social information. (2) The present findings are consistent with the literature suggesting greater status-driven perception and behaviors in men10,14,15,16,17,18,98. (3) Assuming that men were more sensitive to social information in general, it is unclear why men didn’t also show greater neural sensitivity to perceived gender, a dimension that has demonstrable biological and psychological relevance as a function of perceiver gender19,20. The present study was focused primarily on SES as the perceived status dimension, finding evidence of greater neural sensitivity to high (vs. low) SES in men compared to women. Importantly, SES is but one possible dimension of social status, being composed of subcomponents (e.g., income, education, occupational prestige) that may or may not elicit the same kinds of evaluations6,28,83. Other social hierarchies that have been studied using fMRI include hierarchies based on dominance/ability/competence31,99, power80,100, and moral character23,24. With few exceptions23,24, these studies have focused on just one hierarchy dimension and often just one gender, usually men. In general, these studies frequently find the VMPFC and NAcc are responsive to high-ranking individuals. Other work by Kumaran and colleagues suggests that the VMPFC in particular may be implicated in updating social hierarchy knowledge in hierarchies involving the self100. However, it is unclear whether these effects are similarly driven by men as they were for SES in the present study. In future research, it will be important to replicate and extend the present work to determine whether men also show greater neural sensitivity to high status compared to women for other status dimensions as well as for social dimensions that are potentially ordinal but not frequently used to delineate hierarchies (e.g., age).

In sum, we believe our present findings can be interpreted as a gender-specific differential in sensitivity to perceived status. However, we do not believe that men’s greater sensitivity to SES in this study precludes the possibility that women (or men) might be more responsive to other social information in other contexts. For example, it is possible that subsequent studies may uncover a preference in women for other dimensions of status such as communal/moral character23,24,77 or that women may value high-SES individuals more than men in certain contexts. These questions among others are ripe for future inquiry and consistent with recent calls to explore how perceiver gender may differentially shape sensitivity to other dimensions of social information66. We hope that this study will pave the way for future work exploring gender differences in sensitivity to different forms of social information.