Sunday, May 17, 2020

Never smoking, moderate-to-high physical act'y, moderate-to-h. Mediterranean diet, healthy BMI, alcohol moderation, no binge drinking, low TV exposure, short nap, time with friends, & working ≥40 hours/w

Lifestyle-Related Factors and Total Mortality in a Mediterranean Prospective Cohort. Liz Ruiz-Estigarribia et al. American Journal of Preventive Medicine, May 16 2020.

Introduction: Lifestyle-related habits have a strong influence on morbidity and mortality worldwide. This study investigates the association between a multidimensional healthy lifestyle score and all-cause mortality risk, including in the score some less-studied lifestyle-related factors.

Methods: Participants (n=20,094) of the Seguimiento Universidad de Navarra cohort were followed up from 1999 to 2018. The analysis was conducted in 2019. A 10-point healthy lifestyle score previously associated with a lower risk of major cardiovascular events was applied, assigning 1 point to each of the following items: never smoking, moderate-to-high physical activity, moderate-to-high Mediterranean diet adherence, healthy BMI, moderate alcohol consumption, avoidance of binge drinking, low TV exposure, short afternoon nap, time spent with friends, and working ≥40 hours per week.

Results: During a median follow-up of 10.8 years, 407 deaths were documented. In the multivariable adjusted analysis, the highest category of adherence to the score (7–10 points) showed a 60% lower risk of all-cause mortality than the lowest category (0–3 points) (hazard ratio=0.40, 95% CI=0.27, 0.60, p<0.001 for trend). In analyses of the healthy lifestyle score as a continuous variable, for each additional point in the score, a 18% relatively lower risk of all-cause mortality was observed (adjusted hazard ratio=0.82, 95% CI=0.76, 0.88).

Conclusions: Adherence to a healthy lifestyle score, including some less-studied lifestyle-related factors, was longitudinally associated with a substantially lower mortality rate in a Mediterranean cohort. Comprehensive health promotion should be a public health priority.

No strong evidence for a beauty premium is found for either men or women; attractiveness positively associates with the number of fringe benefits of both men and women

Beauty Perks: Physical Appearance, Earnings, and Fringe Benefits. Maryam Dilmaghani. Economics & Human Biology, May 17 2020, 100889.

• This paper examines how attractiveness associates with earnings and fringe benefits.
• No strong evidence for a beauty premium is found for either men or women.
• Attractiveness positively associates with the number of fringe benefits of both men and women.

Abstract: While the existence of a beauty premium is documented for many labour markets, there has been no study on the association of attractiveness with fringe benefits. This is a significant limitation of the extant literature, since fringe benefits are increasingly acknowledged as an integral part of the employees’ compensation, and a main indicator of job quality. Using the Canadian General Social Survey of 2016, the present paper examines how a self-rated measure of attractiveness associates with both labour earnings and fringe benefits. Employing a rich set of controls, no evidence for a beauty premium is found for men, while there is some evidence for a beauty penalty for women. However, attractiveness is found to positively predict the number of fringe benefits of both men and women. Therefore, at equal level of earnings, more attractive individuals appear able to secure higher quality jobs, as measured by the number of fringe benefits. The results, hence, suggest that the effects of attractiveness on labour market outcomes cannot be fully captured by a separate examination of earnings and the hiring process.

Keywords: Physical AppearanceBeauty PremiumEarningsFringe Benefits

Aesthetics & morality judgments share cortical neuroarchitecture: Neural commonalities (sentimentalism & a valuation framework) are more pronounced than predominant philosophical views predict

Aesthetics and morality judgments share cortical neuroarchitecture. Nora C. Heinzelmann, Susanna C. Weber, Philippe N. Tobler. Cortex, May 15 2020.

Abstract: Philosophers have predominantly regarded morality and aesthetics judgments as fundamentally different. However, whether this claim is empirically founded has remained unclear. In a novel task, we measured brain activity of participants judging the aesthetic beauty of artwork or the moral goodness of actions depicted. To control for the content of judgments, participants assessed the age of the artworks and the speed of depicted actions. Univariate analyses revealed whole-brain corrected, content-controlled common activation for aesthetics and morality judgments in frontopolar, dorsomedial and ventrolateral prefrontal cortex. Temporoparietal cortex showed activation specific for morality judgments, occipital cortex for aesthetics judgments. Multivariate analyses revealed both common and distinct whole-brain corrected representations for morality and aesthetics judgments in temporoparietal and prefrontal regions. Overall, neural commonalities are more pronounced than predominant philosophical views would predict. They are compatible with minority accounts that stress commonalities between aesthetics and morality judgments, such as sentimentalism and a valuation framework.

Keywords: valuesmoralityaestheticsdecision-makingMVPA

Moderate amounts of media multitasking are associated with optimal task performance and minimal mind wandering

Moderate amounts of media multitasking are associated with optimal task performance and minimal mind wandering. Myoungju Shin, Astrid Linke, Eva Kemps. Computers in Human. Behavior, Volume 111, October 2020, 106422.

• Media multitasking is an ever-increasing phenomenon in our daily lives.
• A moderate amount of media multitasking is associated with optimal task performance.• Moderate media multitasking is also associated with minimal mind wandering.
• These relationships are more prominent during difficult than easy tasks.

Abstract: The simultaneous engagement in more than one form of media, known as media multitasking, is an ever-increasing phenomenon in our daily lives. Previous studies have associated media multitasking with lower self-control, greater sensation seeking and inattention, which could have detrimental effects on task performance. The current study examined task performance and mind wandering of heavy, intermediate and light media multitaskers as a function of task difficulty in an n-back task. The results showed that intermediate media multitaskers performed better than heavy media multitaskers at the more difficult than easier levels of the task. The performance of heavy and light media multitaskers did not significantly differ across difficulty levels. Intermediate media multitaskers also mind wandered less than heavy media multitaskers; however, their mind wandering did not differ from that of light media multitaskers. Thus, the results indicate an inverted U-shape relationship between media multitasking, task performance and mind wandering. The findings further suggest that the association between frequent media multitasking and greater mind wandering may be due to executive function failures as a result of insufficient cognitive control and distraction.

Keywords: Media multitaskingMind wanderingN-back taskSelf-controlBoredom

Saturday, May 16, 2020

Despite significant partisan splits on most issues, Democrats and Republicans converge on widespread reluctance to use smartphone contact tracing apps

Zhang, Baobao, Sarah E. Kreps, and Nina McMurry. 2020. “Americans' Perceptions of Privacy and Surveillance in the COVID-19 Pandemic.” OSF Preprints. May 13. doi:10.31219/

Abstract: As COVID-19 continues to spread, public health authorities have implemented or plan to implement smartphone apps to supplement traditional contact tracing. Experts suggest that at least 60% of the public would need to use these apps for them to be effective at limiting the spread of COVID-19. Yet fears that these apps would violate users' privacy by expanding governments' and tech companies' surveillance capacity may limit adoption. We study Americans' attitudes toward smartphone contact tracing apps and public health surveillance policies using a large, nationally representative survey of U.S. adults (N=2,612). We find widespread reluctance among the public: support for contact tracing apps is lower than for expanding traditional contact tracing or introducing new measures like temperature checks and centralized quarantine. Using a conjoint analysis experiment embedded in the survey, we find that privacy-preserving features, including non-location tracking and decentralized data storage, increases the public's acceptance of contact tracing apps. Within the population, those with pre-existing health conditions or who know someone who had been COVID-19 positive were more likely to support the tool, suggesting that support will grow as cases increase. Despite significant partisan splits on most issues, Democrats and Republicans converge on levels of support for contact tracing apps, suggesting that bipartisan elite cues could work to augment support. Overall, we found sizable amounts of concern about privacy and misunderstanding about the technology used. Public education campaigns are much needed before states deploy contact tracing apps.

Pressure testing your research: On the need of having a red team

Pandemic researchers — recruit your own best critics. Daniël Lakens. Nature, May 11 2020.
To guard against rushed and sloppy science, build pressure testing into your research.

As researchers rush to find the best ways to quell the COVID-19 crisis, they want to get results out ultra-fast. Preprints — public but unvetted studies — are getting lots of attention. But even their advocates are seeing a problem. To keep up the speed of research and reduce sloppiness, scientists must find ways to build criticism into the process.

Finding ways to prove ourselves wrong is a scientific ideal, but it is rarely scientific practice. Openness to critiques is nowhere near as widespread as researchers like to think. Scientists rarely implement procedures to receive and incorporate pushback. Most formal mechanisms are tied to the peer-review and publishing system. With preprints, the boldest peers will still criticize the work, but only after mistakes are made and, often, widely disseminated.

An initial version of a recent preprint by researchers at Stanford University in California estimated that COVID-19’s fatality rate was 0.12–0.2% (E. Bendavid et al. Preprint at medrXiv; 2020). This low estimate was removed from a subsequent version, but it had already received widespread attention and news coverage. Many immediately pointed out flaws in how the sample was obtained and the statistics were calculated. Everyone would have benefited if the team had received this criticism before the data were collected and the results were shared.

It is time to adopt a ‘red team’ approach in science that integrates criticism into each step of the research process. A red team is a designated ‘devil’s advocate’ charged to find holes and errors in ongoing work and to challenge dominant assumptions, with the goal of improving project quality. The team has a role similar to that of ‘white-hat hackers’ hired in the software industry to identify security flaws before they can be discovered and exploited by malefactors. Similarly, teams of scientists should engage with red teams at each phase of a research project and incorporate their criticism. The logic is similar to the Registered Report publication system — in which protocols are reviewed before the results are known — except that criticism is not organized by journals. Ideally, there is a larger amount of speedier communication between researchers and their red team than peer review allows, resulting in higher-quality preprints and submissions for publication.

Even scientists who invite criticism from a red team acknowledge that it is difficult not to become defensive. The best time for scrutiny is before you have fallen in love with your results. And the more important the claims, the more scrutiny they deserve. The scientific process needs to incorporate methods to include ‘severe’ tests that will prove us wrong when we really are wrong.

An example of a large-scale collaboration that applies a red-team approach is the Psychological Science Accelerator (PSA), a global network of more than 500 psychology laboratories. The PSA has solicited research projects on questions related to the COVID-19 pandemic and has offered to assist with data collection. Projects range from effective risk communication to cognitive-reappraisal interventions. After researchers develop protocols, the PSA assembles a red team of experts in research ethics, measurement, data analysis and the project’s field to offer criticism and to allow researchers to revise their protocols.

I reviewed one of these protocols after it had been submitted to a journal. I later saw the PSA reviews and learnt that I had repeated many criticisms, such as the generalizability of the stimulus and flexibility of the data analysis, that the red team had made — and that the researchers had opted to ignore.

This shows that assembling a red team isn’t enough: research teams need to commit to addressing criticism from the outset. Sometimes, this is straightforward — items on checklists are absent from a proposal, or an independent statistical analysis yields different results, for example. Usually, it will be less clear whether criticism merits changing a protocol or including a caveat. The key is that, when results are presented, the team transparently communicates the criticism that the red team raised. (Perhaps incorporated criticism could be listed in the methods section of a paper, and unincorporated criticism in the limitations.) This will show how severely a claim has been tested.

Pushback on each step of a research project should be recognized as valuable quality control and adherence to scientific values. Ideally, a research team could recruit their own red team from group members not immediately involved in the project.

Incentives for red teams in science deserve special consideration. A red team might identify major flaws that mean a study should not proceed, so including a team member as a co-author on a future publication by the group would be a conflict of interest. In the computer-security industry, a red team is often paid if it uncovers serious errors. Computer scientist Donald Knuth famously gave out ‘bug bounties’ to people who uncovered technical errors in his published work. (Recipients often kept the small cheques as souvenirs, suggesting that social credit works as an incentive.) To investigate incentivized criticism, my group is now recruiting red-team members and offering financial rewards (

With research moving faster than ever, scientists should invest in reducing their own bias and allowing others to transparently evaluate how much pushback their ideas have been subjected to. A scientific claim is as reliable as only the most severe criticism it has been able to withstand.

This paper examines the impact of the U.S. fracking boom on local STI transmission rates and prostitution activity as measured by online prostitution review counts

Fracking and Risky Sexual Activity. Scott Cunningham, Gregory DeAngelo, Brock Smith. Journal of Health Economics, May 15 2020, 102322.

Abstract: This paper examines the impact of the U.S. fracking boom on local STI transmission rates and prostitution activity as measured by online prostitution review counts. We first document significant and robust positive effects on gonorrhea rates in fracking counties at the national level. But we find no evidence that fracking increases prostitution when using our national data, suggesting sex work may not be the principal mechanism linking fracking to gonorrhea growth. To explore mechanisms, we then focus on remote, high-fracking production areas that experienced large increases in sex ratios due to male in-migration. For this restricted sample we find enhanced gonorrhea transmission effects and moderate evidence of extensive margin effects on prostitution markets. This study highlights public health concerns relating to economic shocks and occupational conditions that alter the local demographic composition.

JEL classification: I12 I15 Q33 Q35

Sleepers Selectively Suppress Informative Inputs during REM: Informative speech is selectively processed over meaningless speech, & selectively suppressed during eye movements in REM

Koroma et al., Sleepers Selectively Suppress Informative Inputs during Rapid Eye Movements, Current Biology (2020),

* A neural decoder tracks speech processing in a cocktail party paradigm during sleep
* Speech is encoded in cortical activity during rapid eye movement (REM) sleep
* Informative speech is selectively processed over meaningless speech during REM sleep
* Informative speech is on the contrary selectively suppressed during eye movements within REM

SUMMARY: Sleep leads to a disconnection from the external world. Even when sleepers regain consciousness during rapid eye movement (REM) sleep, little, if any, external information is incorporated into dream content [1–3]. While gating mechanisms might be at play to avoid interference on dreaming activity [4], a total disconnection from an ever-changing environment may prevent the sleeper from promptly responding to informative events (e.g., threat signals). In fact, a whole range of neural responses to external events turns out to be preserved during REM sleep [5–9]. Thus, it remains unclear whether external inputs are either processed or, conversely, gated during REM sleep. One way to resolve this issue is to consider the specific impact of eye movements (EMs) characterizing REM sleep. EMs are a reliable predictor of reporting a dream upon awakening [10, 11], and their absence is associated with a lower arousal threshold to external stimuli [12]. We thus hypothesized that the presence of EMs would selectively prevent the processing of informative stimuli, whereas periods of REM sleep devoid of EMs would be associated with the monitoring of external signals. By reconstructing speech in a multi-talker environment from electrophysiological responses, we show that informative speech is amplified over meaningless speech during REM sleep. Yet, at the precise timing of EMs, informative speech is, on the contrary, selectively suppressed. These results demonstrate the flexible amplification and suppression of sensory information during REM sleep and reveal the impact of EMs on the selective gating of informative stimuli during sleep.

Metaanalysis: Moderate effect of prosocial modeling in eliciting subsequent helping behavior; effect was larger after witnessing the model's generosity & in studies with higher percentage of females

Jung, H., Seo, E., Han, E., Henderson, M. D., & Patall, E. A. (2020). Prosocial modeling: A meta-analytic review and synthesis. Psychological Bulletin, May 2020.

Abstract: Exposure to prosocial models is commonly used to foster prosocial behavior in various domains of society. The aim of the current article is to apply meta-analytic techniques to synthesize several decades of research on prosocial modeling, and to examine the extent to which prosocial modeling elicits helping behavior. We also identify the theoretical and methodological variables that moderate the prosocial modeling effect. Eighty-eight studies with 25,354 participants found a moderate effect (g = 0.45) of prosocial modeling in eliciting subsequent helping behavior. The prosocial modeling effect generalized across different types of helping behaviors, different targets in need of help, and was robust to experimenter bias. Nevertheless, there was cross-societal variation in the magnitude of the modeling effect, and the magnitude of the prosocial modeling effect was larger when participants were presented with an opportunity to help the model (vs. a third-party) after witnessing the model’s generosity. The prosocial modeling effect was also larger for studies with higher percentage of female in the sample, when other people (vs. participants) benefitted from the model’s prosocial behavior, and when the model was rewarded for helping (vs. was not). We discuss the publication bias in the prosocial modeling literature, limitations of our analyses and identify avenues for future research. We end with a discussion of the theoretical and practical implications of our findings.

The meaning of meat: (Un)sustainable eating practices at home and out of home

The meaning of meat: (Un)sustainable eating practices at home and out of home. Gesa Biermann, Henrike Rau. Appetite, May 15 2020, 104730.

• Our findings suggest that few people eat sustainably in all settings.
• Eating practices at home and out of home differ in their environmental impact.
• The normative and emotive expectations of eating out and eating at home diverge.
• Meat and eating out are both associated with ‘special’ and ‘treating oneself’.
• Social setting matters: cooking for others at home coincides with increased use of meat.

Abstract: Many sociological accounts of life in the 21st century include reflections on the dissolution of distinctions between the public and private sphere, aided by social media and information technology. In this paper, we argue that everyday practices around the consumption of food continue to display strong home/out-of-home divisions, especially regarding the consumption of meat and its deeply rooted social meanings. Using data from a German online survey on food preparation and consumption practices, we report and critically examine empirical evidence of significant differences between public and private food consumption. In addition to divergent meanings, we pay particular attention to environmental impacts related to the resource implications of eating in or out. For many, eating out in a restaurant means to treat oneself to something special. Cultural links between eating meat and the celebration of special occasions, the role of meat as a signifier of hospitality, and meat consumption as an expression of high social status leads to considerable resource implications for the practice of eating out and hosting guests. This, in turn, throws up interesting questions regarding the (in)effectiveness of sustainable food campaigns, many of which have hitherto ignored the distinction between public and private consumption. We conclude by arguing for strategies that connect the consumption of plant-based dishes to already established social practices such as hosting guests, barbecuing or celebrating special occasions.

Keywords: Food consumptionMeatSustainable dietSocial meaning of foodPractice theoryBehavior change

Friday, May 15, 2020

Partners’ ability to track mothers’ negative mood dropped during infancy & remained low in toddlerhood; moms' ability to track partners' positive mood dropped in infancy & recovered in toddlerhood

Understanding in transition: The influence of becoming parents on empathic accuracy. Jerica X. Bornstein, Eshkol Rafaeli, Marci E.J. Gleason. Journal of Social and Personal Relationships. May 14, 2020.

Abstract: Empathic accuracy (EA), the ability to understand a close other’s thoughts and feelings, is linked to relationship satisfaction. Yet, it is unclear whether stress interferes with relationship partners’ ability to be empathically accurate. The present study investigates whether a major life stressor, the transition to parenthood (TTP), interferes with EA between partners. In a daily diary study of 78 couples expecting their first child, couples reported on their own and their partners’ daily mood for 3 weeks during three separate time periods across the TTP: pregnancy, infancy, and toddlerhood. Both mothers and their partners demonstrated EA across the TTP. However, there was evidence that the transition interfered with EA: Partners’ ability to track mothers’ negative mood dropped significantly during infancy and remained low in toddlerhood, whereas mothers’ ability to track their partners’ positive mood dropped significantly in infancy and recovered in toddlerhood. This suggests that one way in which a major life stressor, in this case, the TTP, may interfere with relationship functioning is by decreasing couples’ understanding of each other’s mood states.

Keywords: Close relationships, empathic accuracy, mood states, stress, transition to parenthood

In Search of the Appeal of the “DILF”: Why women find DILFs more attractive than otherwise equally attractive men without children

In Search of the Appeal of the “DILF”. Flora Oswald, Shelby Hughes, Amanda Champion & Cory L. Pedersen. Psychology & Sexuality, May 13 2020.

Abstract: Contemporary culture has afforded a new sexualized identity to fatherhood. Fathers are often labeled as nurturing, dominant, and domesticated; attributes demonstrably appealing to females. Colloquially, the sexy dad has come to be referred to as “DILF” (i.e., Dad I’d Like to Fuck), a concept popularized in the media since its debut online in 2011. DILFs are increasingly searched for by women on pornography websites, evidence of an increasing sexual interest in or awareness of the DILF phenomenon. Although sometimes conceptualized as a passing colloquialism, the DILF is reflective of shifts in popular culture pertaining to media, gendered parenting, notions of masculinity, and women’s sexual expression. This unique cultural intersection merits empirically driven investigation. This study explored whether women find DILFs more attractive than otherwise equally attractive men without children. Female participants were randomly assigned to one of two possible male profile conditions of the same attractive man (with children versus without children). Overall, results revealed that women rated the male target with children as possessing more positive attributes relative to the male target without children. Follow-up analyses revealed more positive emotional attributes ascribed to the DILF target condition, whereas more positive social attributes were ascribed to the non-DILF target condition. Results are discussed in reference to the changing landscape of masculinity and fatherhood.

Keywords: fatherhood, parenting, DILF, mate choice, evolutionary psychology, Freudian theory mate selection, masculinity

Research says perceivers can accurately diagnose infection using e.g., sight, smell, but these authors find people overperceive pathogen threat in subjectively disgusting sounds

Michalak, Nicholas M., Oliver Sng, Iris Wang, and Joshua Ackerman. 2020. “Sounds of Sickness: Can People Identify Infectious Disease Using Sounds of Coughs and Sneezes?.” PsyArXiv. May 14. doi:10.1098/rspb

Abstract: Cough, cough. Is that person sick, or do they just have a throat tickle? A growing body of research suggests pathogen threats shape key aspects of human sociality. However, less research has investigated specific processes involved in pathogen threat detection. Here, we examine whether perceivers can accurately detect pathogen threats using an understudied sensory modality—sound. Participants in four studies judged whether cough and sneeze sounds were produced by people infected with a communicable disease or not. We found no evidence that participants could accurately identify the origins of these sounds. Instead, the more disgusting they perceived a sound to be, the more likely they were to judge that it came from an infected person (regardless of whether it did). Thus, unlike research indicating perceivers can accurately diagnose infection using other sensory modalities (e.g., sight, smell), we find people overperceive pathogen threat in subjectively disgusting sounds.

Heritability of affectionate communication: A twins study

Heritability of affectionate communication: A twins study. Kory Floyd, Chance York & Colter D. Ray. Communication Monographs, May 13 2020.

ABSTRACT: Using a twin study design, we explored the extent to which affectionate communication is a heritable behavioral trait. Participants (N = 928) were 464 adult twin pairs (229 monozygotic, 235 dizygotic) who provided data on their affectionate communication behaviors. Through ACE modeling, we determined that approximately 45% of the variance in trait expressed affectionate communication is heritable, whereas 21% of the variance in trait received affection was heritable. A bivariate Cholesky decomposition model also revealed that almost 26% of the covariation in expressed and received affection is attributable to additive genetic factors. These estimates were driven primarily by females and those 50 years of age and older. The results suggest the utility of giving greater attention to genetic and biological influences on communicative behaviors by expanding the scope of communication theory beyond consideration of only environmental influences.

KEYWORDS: Affectionate communication, genetics, twin study, ACE model, heritability, affection exchange theory

Thursday, May 14, 2020

COVID-19 social distancing and sexual activity in a sample of the British Public

COVID-19 social distancing and sexual activity in a sample of the British Public. Louis Jacob et al. The Journal of Sexual Medicine, May 14 2020.

Background: On 23rd March 2020 the UK government released self-isolation guidance to reduce the risk of transmission of SARS-Cov-2. The influence such guidance has on sexual activity is not known.

Aim: To investigate levels and correlates of sexual activity during COVID-19 self-isolation in a sample of the UK public.

Methods: This paper presents pre-planned interim analyses of data from a cross-sectional epidemiological study, administered through an online survey.

Outcomes: Sexual activity was measured using the following question: “On average after self-isolating how many times have you engaged in sexual activity weekly?” Demographic and clinical data was collected, including sex, age, marital status, employment, annual household income, region, current smoking status, current alcohol consumption, number of chronic physical conditions, number of chronic psychiatric conditions, any physical symptom experienced during self-isolation, and number of days of self-isolation. The association between several factors (independent variables) and sexual activity (dependent variable) was studied using a multivariable logistic regression model.

Results: 868 individuals were included in this study. There were 63.1% of women, and 21.8% of adults who were aged between 25 and 34 years. During self-isolation, 39.9% of the population reported engaging in sexual activity at least once per week. Variables significantly associated with sexual activity (dependent variable) were being male, a younger age, being married or in a domestic partnership, consuming alcohol, and a higher number of days of self-isolation/social distancing.

Clinical Implications: In this sample of 868 UK adults self-isolating owing to the COVID-19 pandemic the prevalence of sexual activity was lower than 40%. Those reporting particularly low levels of sexual activity included females, older adults, those not married, and those who abstain from alcohol consumption.

Strength and Limitations: This is the first study to investigate sexual activity during the UK COVID-19 self-isolation/social distancing. Participants were asked to self-report their sexual activity potentially introducing self-reporting bias into the findings. Second, analyses were cross-sectional and thus it is not possible to determine trajectories of sexual activity during the current pandemic.

Conclusion: Interventions to promote health and wellbeing during the COVID-19 pandemic should consider positive sexual health messages in mitigating the detrimental health consequences in relation to self-isolation and should target those with the lowest levels of sexual activity.

Key words: Sexual activityCOVID-19SARS-Cov-2Self-isolationUK


In the present study in a sample of 868 individuals residing in the UK during COVID-19 self-isolation/social distancing 39.9% of the sample reported engaging in sexual activity at least once per week. Being male, a younger age, married, consuming alcohol, and a higher number of days in self-isolation/social distancing were all associated with greater sexual activity in comparison to their counter parts.
Findings from the present study for the first-time sheds light on sexual activity during COVID-19 self-isolation/social distancing among the UK public. Importantly, 60.1% of the sample studied reported to not be sexually active during self-isolation/social distancing. The promotion of consensual sexual activity among the UK adult population during self-isolation/social distancing may mitigate some of the detrimental consequences that self-isolation/social distancing may impose, particularly in relation to mental health. However, in order to do this correlates of sexual activity during self-isolation/social distancing need to be identified. The present study sheds light on this.
Indeed, the present study found that being male, a younger age, married, and consuming alcohol were all associated with greater sexual activity in comparison to their counter parts during COVID-19 self-isolation/social distancing. These findings correspond to the existing literature during non-pandemic times. [11,[19][20][21]] These findings suggest that interventions to promote good mental and physical health during the COVID-19 self-isolation/social distancing period should take into account positive sexual health as part of any messaging. Interventions might particularly focus on females, older adults, those not married, and those who abstain from alcohol consumption. A detailed discussion on potential strategies is beyond the scope of this paper. However, would likely include the promotion of respected websites such as [22], as well as platforms to provide advice and support in relation to sexual activity among older adult populations.
Interestingly, the present paper also found that number of days in self-isolation/social distancing was also associated with sexual activity. This may be explained by the simple fact that each day of self-isolation/social distancing would increase ones chances of engaging in sexual activity if they are sexually active or potentially sexual activity is being used for a means to ease stress and anxiety or overcome boredom which is likely to increase with increasing days of isolation. Moreover, in modern times people lead busy lives and may have little discretionary time to spend with their intimate partner. COVID-19 self-isolation may have disrupted daily activities that take time from one’s day, such as commuting to work, this time may be being spent with one’s partner allowing them to reconnect with increasing days of isolation and consequently engage in sexual activity. However, there is no literature to support these hypothesizes and future work of a qualitative nature is required.
This is the first study to investigate sexual activity during the UK COVID-19 self-isolation/social distancing. However, the study findings must be interpreted in light of its limitations. First, participants were asked to self-report their sexual activity and thus potentially introducing self-reporting bias into the findings. Second, analyses were cross-sectional and thus it is not possible to determine trajectories of sexual activity during the current pandemic.
In conclusion, in this sample of 868 UK adults self-isolating/social distancing owing to the COVID-19 pandemic those at particular risk of lower levels of sexual activity included females, older adults, those not married, and those who abstain from alcohol consumption. Interventions to promote sexual activity during the COVID-19 pandemic may mitigate some of the detrimental health consequences in relation to self-isolation and should target those with the lowest levels of sexual activity.

Toward a Multidimensional Perspective on Wisdom and Health—An Analogy With Depression Intervention and Neurobiological Research

Toward a Multidimensional Perspective on Wisdom and Health—An Analogy With Depression Intervention and Neurobiological Research. Charles F. Reynolds III, Dan G. Blazer. JAMA Psychiatry, May 13, 2020. doi:10.1001/jamapsychiatry.2020.0642

The article by Lee and colleagues1 in this issue of JAMA Psychiatry explores 3 domains or components of wisdom: prosocial relations, emotional regulation, and spirituality. The authors’ basic hypothesis is that interventions may enhance these domains of wisdom (although they found no eligible studies that addressed wisdom as an inclusive or unitary construct). Interventions ranged widely, from mindfulness to emotional intelligence training. The literature contains many approaches to measuring wisdom as reviewed by the authors.1 One helpful distinction is between theoretical wisdom (understanding the deep nature of reality and humans’ place in it) and practical wisdom (also known as phronesis: making good decisions or doing the right thing, at the right time, for the right reasons), as delineated by Jeste and colleagues in a previous article.2 Both can be measured, yet practical wisdom is perhaps more easily captured via a questionnaire than theoretical wisdom. In the current study, the authors1 combine domains characterized as practical (prosocial behavior and emotional regulation) and theoretical (spirituality). They do not include other domains, such as decisiveness and the tolerance of and ability to deal with uncertainty, because of a dearth of intervention studies in these domains.3 Therefore, the reader should focus on the 3 domains examined as components of a much larger and more complex construct of wisdom, a construct that may be beyond the boundaries of empirical exploration or at least pose considerable challenges thereto.

Regardless, the 3 components measured have been studied frequently in the extant literature, and scales have been developed that provide a foundation for intervention trials. In other words, the data from these intervention trials are fair game for this meta-analysis. However, the serious reader must take advantage of the Supplement to gain a clear understanding of the range of studies included, the scales for measuring outcome, and the approaches to intervention.1 In this spirit, we offer the following perspective and address the importance of defining wisdom as a unitary construct.

In their meta-analysis of 57 published studies, the authors1 found that interventions can enhance prosocial behaviors, emotional regulation, and spirituality. Effect sizes did not vary by component, but for prosocial behaviors and spirituality, larger effect sizes were associated with older mean ages of participants. Estimates of benefits for prosocial behavior and spirituality survived correction for publication bias, but emotional regulation did not. Forty-seven percent of studies reported a significant improvement in one component or another, while the remaining studies did not. Only 40% of studies included an active control group, while many used a waiting list or another inactive control group. The authors suggest that the modern behavioral epidemics of social isolation, loneliness, suicide, and opioid abuse point to a growing need for wisdom-enhancing interventions that promote individual and societal well-being—a behavioral vaccine, as it were.

Part of the heuristic value of the study1 is that it raises important questions. Some pertain to the construct and predictive validity of the wisdom domains analyzed, others to concurrent validity, and still others to scalability and population outcomes. Regarding construct and predictive validity, the authors acknowledge a need to assess well-being and other health-associated measures by objective means (in addition to but not in place of self-reports), such as reports by close associates and hence to determine if enhancements in components of wisdom generalize to everyday life, over longer follow-up periods, to promote individual and population well-being. With respect to concurrent validity, neurobiological assessments with appropriate comparator conditions could examine if there is specific neurocircuitry activation for specific components of wisdom. Using interventional platforms, one could investigate whether there are brain-based mechanisms that mediate improvement in wisdom and/or in its specific components. If so, one could further investigate whether targeted neurostimulation techniques selectively activate neurocircuits associated with components of wisdom, facilitating adaptation as a result of specific, learning-based interventions. This approach bears analogy to emerging research testing the ability of behavioral and neurocognitive interventions to activate specific neurocircuits that in turn relieve depressive symptoms.4 Ultimately, one would like to know if interventions can be simplified, sustained, and scaled up—by analogy with depression, for example, through the use of lay counselors or digital platforms. As with depression, it may be that different interventions better fit the needs and values of individuals depending on sociodemographic, developmental, cultural, and clinical characteristics.

Now to revisit the basic question as to whether wisdom is a unitary construct with multiple components or dimensions: Lee and colleagues1 believe this to be the case and analogize wisdom to a syndrome, that is, a condition characterized by several medical signs and symptoms that more or less consistently occur together and are associated with a common entity (ie, a latent construct). The authors’ San Diego Wisdom Scale (SD-WISE) scale measures individual components, such as prosocial behaviors (empathy and compassion), emotional regulation, and self-reflection.3 In different samples, they have found that subscales of SD-WISE measuring these components correlate with the total composite SD-WISE score, and the total score correlates in cross-sectional studies with measures of overall well-being.1 In their search for the neurobiological correlates of individual components of wisdom (or their opposite, such as with antisocial personality or impulsivity, as in the case of Phineas Gage, or in cases of frontotemporal dementia), the authors have found evidence implicating prefrontal cortex and limbic striatum.5 This is certainly plausible, if relatively nonspecific.

The study1 thus prompts us to ask also which components of wisdom are most important for health and well-being. It is plausible that a combination of wisdom components is more likely to be associated with measures of health and well-being than any individual component. Which specific components should be considered in mechanistic studies to optimize the development of interventions? Our view is that adopting a multidimensional approach to ascertain associations between wisdom and health or well-being may provide greater, more nuanced information about risk for health than the considerations of individual components alone. We suggest another analogy with depression intervention research, where a combination of interventions is often needed to achieve and sustain optimal outcomes.6 Again, it may be that, as with depression treatment or prevention, one size does not fit all. Different interventions or combinations of interventions may better fit the needs of a person depending on sociodemographic, cultural, developmental, and clinical characteristics. By this logic, no single construct (such as prosocial behavior) should automatically be conflated with wisdom as a whole. Higher levels of spirituality, for example, may rate lower in interventions to promote practical wisdom. To be effective against the current epidemics of loneliness, social isolation, opiate addiction, and suicide, a multicomponent, so-called behavioral vaccine, as well as changes in the health care delivery system (to be more collaborative and integrated) may been needed.7

We concur with the authors1 that wisdom is a complex human characteristic with a number of specific components, such as those they have delineated using Delphi methods, resulting in a mixture of pragmatic and theoretical components. More than 1 component may be needed to optimize health effects and elucidate mechanisms of action and underlying neurobiology.

As the authors1 in their wisdom readily acknowledge, the science of wisdom is still at an early stage. Like them, we anticipate that more precise answers will emerge as empirical research, grounded in theory, deepens and widens.

How do people behave when disasters strike? Popular media accounts depict panic and cruelty, but in fact, individuals often cooperate with and care for one another during crises

Catastrophe Compassion: Understanding and Extending Prosociality Under Crisis. Jamil Zaki. Trends in Cognitive Sciences, May 14 2020.

ABSTRACT: How do people behave when disasters strike? Popular media accounts depict panic and cruelty, but in fact, individuals often cooperate with and care for one another during crises. I summarize evidence for such “catastrophe compassion,” discuss its roots, and consider how it might be cultivated in more mundane times.

Roots of Catastrophe Compassion

Psychologists have pinpointed a number of mechanisms that might underlie catastrophe compassion. One pertains to the powerful nature of social identity. Each of us identifies with multiple groups, for instance based on our generation, ideology, and profession , and commonly expresses loyalty, care, and prosociality towards members of our own groups .

Social identity is also malleable. You might be an Ohioan and a tuba player, but those identities will vary in salience depending on whether you’re at band practice or a Buckeyes game. Even new identities created in a lab can take on importance, and shift one’s tendency to act prosocially towards people in novel groups. Identities also tend to matter most when they contain certain characteristics, including shared goals and shared outcome s .

When disasters strike, victims might suddenly be linked in the most important de novo groups to which they’ve ever belonged. Strangers on a bus that is bombed might experience a visceral, existential sense of shared fate, and might thus quickly not be strangers any longer—but rather collaborators in a fight for their lives. As described by Drury [8], an elevated sense of shared identity is indeed common to disaster survivors, and a potent source of cooperative behavior .

A second source of catastrophe compassion is emotional connection. Empathy—sharing, understanding, and caring for others’ emotional experiences —predicts prosocial behavior across a range of settings. Consistent with this connection, a recent study found that individuals’ empathy for those affected by the COVID -19 pandemic tracked their willingness to engage in physical distancing and related protective behaviors, and that inducing empathy for vulnerable people increased intention to socially distance [9].

Emotional connection can also comprise mutual sharing of affect across people. After disclosing emotional experiences with each other, individuals tend to feel more strongly affiliated to one another. Such disclosures are also a powerful way to recruit supportive behavior in during difficult times and thus buffer individuals against stress [10]. However, individuals often avoid disclosing negative experiences —for instance because they imagine others will judge or stigmatize them—and thus miss out on the benefits of affect sharing [11].

Disasters thrust people into a situation where their suffering is obviously shared with others. This could in turn lower psychological barriers to disclosure, thus creating opportunities for deeper connection, mutual help, and community. Consistent with this idea, in the wake of the 1989 Loma Prieta earthquake, individuals frequently talked about the disaster and its effects on them for about two weeks [12]. A similar elevation in emotional conversations was found among Spaniards following a 2004 terrorist bombing in Madrid [5]. Researchers further found that that sharing one week after the attacks predicted increases in solidarity, social support, as well as decreases in loneliness, seven weeks later.

Extending Catastrophe Compassion

As Solnit [2] observes, although few people would want a disaster to befall them, many survivors look back on disasters with a surprising amount of nostalgia. Floods, bombings, and earthquakes are horrific, but in their aftermath individuals glimpse levels of community, interdependence, and altruism that are difficult to find during normal times. Then, normal times return, and often so do the boundaries that typically separate people. Might catastrophe compassion outlast catastrophes themselves, and if so, how?

Some suggestive evidence emerges from the study of individuals who endure personal forms of disaster—adverse events such as severe illness, family loss, and victimization by crime. Such adversity often generates increases in prosocial behavior, which Staub and Vollhardt [13] have termed “altruism born of suffering .” Positive effects of adversity appear to extend in time. For instance, individuals’ experience of lifetime adversity reportedly tracks their willingness to help strangers and their ability to avoid “compassion collapse ,” by maintaining empathy even in the face of numerous victims [14].

Gender and Sexual Orientation of First-Year Philosophy Students in the U.S.

Gender and Sexual Orientation of First-Year Philosophy Students in the U.S. Eric Schwitzgebel, Morgan Thompson, and Eric Winsberg. The Splintered Mind Blog, May 13 2020.

Among these 373,333 students, 0.36% (1132/315158 students, excluding undecided and unanswered) expressed an intention to major in Philosophy. This compares with Philosophy being either the first or second major of 0.39% of students receiving graduate degrees in the most recent available year (2018) in the NCES IPEDS database.[Note 1]

Two gender identity questions are included in the survey:

* Your sex (male, female)
* Are you transgender? (no, yes)

Although men were more likely than women to express an intention to major in philosophy, the ratio was closer to parity than we see among graduates in philosophy: 43% (485/1132) of intended philosophy majors were women (1%, or 7 total, declined to state), compared to 58% of first-year students overall.

Since the latest data from NCES show that among Bachelor's degree recipients, 36% are women, the HERI data are consistent with the "leaky pipeline" hypothesis about women in philosophy. (The leaky pipeline hypothesis holds that over the course of their education, women are more likely than men to leave philosophy.) We plan a more careful time course analysis of these data in the near future, with a close eye on potential non-response bias in the HERI dataset.[Note 2]

Nine percent (105/1132) of the philosophy majors declined to state whether they were transgender. Among philosophy major respondents, 8/1027 (0.8%) identified as transgender. Among students with other majors, 8% did not respond and 0.4% (1172/288989) identified as transgender. Note, however, that with such small proportions, a disproportionate representation of transgender students among those who decline to state (perhaps because they are not sufficiently "out" to want to reveal their transgender status on a questionnaire of this sort), could dramatically affect the results. Similar considerations apply to transgender students who might falsely state that they are not transgender. Given the small number of self-reported transgender students and these resulting interpretative difficulties, we are hesitant to draw conclusions about the proportion of students who are transgender or about whether philosophy students were more likely than other students to be transgender.

We examined five potential concerns related to COVID-19 infection as prospective predictors of social distacing practices over the next two weeks.

Leary, Angelina, Robert Dvorak, Ardhys De Leon, Roselyn Peterson, and Wendy Troop-Gordon. 2020. “COVID-19 Social Distancing.” PsyArXiv. May 13.

Abstract: The current study had two aims. First, we tested three norm-based interventions to increase social distancing practices. Second, we examined five potential concerns related to COVID-19 infection as prospective predictors of social distancing practices over the next two weeks.

Wednesday, May 13, 2020

Does a split-brain harbor a split consciousness or is consciousness unified? The current consensus is that the body of evidence is insufficient to answer this question, maybe the answer is not a simple yes or no

Split-Brain: What We Know Now and Why This is Important for Understanding Consciousness. Edward H. F. de Haan, Paul M. Corballis, Steven A. Hillyard, Carlo A. Marzi, Anil Seth, Victor A. F. Lamme, Lukas Volz, Mara Fabri, Elizabeth Schechter, Tim Bayne, Michael Corballis & Yair Pinto. Neuropsychology Review, May 12 2020.

Abstract: Recently, the discussion regarding the consequences of cutting the corpus callosum (“split-brain”) has regained momentum (Corballis, Corballis, Berlucchi, & Marzi, Brain, 141(6), e46, 2018; Pinto et al., Brain, 140(5), 1231–1237, 2017a; Pinto, Lamme, & de Haan, Brain, 140(11), e68, 2017; Volz & Gazzaniga, Brain, 140(7), 2051–2060, 2017; Volz, Hillyard, Miller, & Gazzaniga, Brain, 141(3), e15, 2018). This collective review paper aims to summarize the empirical common ground, to delineate the different interpretations, and to identify the remaining questions. In short, callosotomy leads to a broad breakdown of functional integration ranging from perception to attention. However, the breakdown is not absolute as several processes, such as action control, seem to remain unified. Disagreement exists about the responsible mechanisms for this remaining unity. The main issue concerns the first-person perspective of a split-brain patient. Does a split-brain harbor a split consciousness or is consciousness unified? The current consensus is that the body of evidence is insufficient to answer this question, and different suggestions are made with respect to how future studies might address this paucity. In addition, it is suggested that the answers might not be a simple yes or no but that intermediate conceptualizations need to be considered.


Thus, it seems that in split-brain patients perceptual processing is largely split, yet response selection and action control appear to be unified under certain conditions. This, by itself, does not prove whether a split-brain houses one or two conscious agents. One explanation could be that the split-brain houses two agents, each having their own experiences, who synchronize their behavioral output through various means. Another possible explanation is that a split-brain houses one agent who experiences an unintegrated stream of information who controls the entire body, comparable to watching a movie where sight and sound are out-of-sync. At any rate, these findings challenge the previously mentioned classic split-brain description, which is still found in reviews and text books (Gray, 2002; Wolman, 2012). In this classic characterization the patient indicates that they saw nothing when a stimulus appeared in the left visual field. Yet, to their own verbal surprise, the left hand correctly draws the stimulus. The aforementioned examples of unity in action control suggests that these effects may depend on the type and complexity of the response that is required.


There are three, not-mutually exclusive, hypotheses concerning the mechanisms involved in, seemingly, preserved unity in the split-brain. The first notion is that information is transferred subcortically. The second idea is that ipsilateral motor control underlies unity in action control. The third idea claims that information transfer is based on varies forms of inter-hemispheric collaboration, including subtle behavioral cues. The first proposal (Corballis Corballis, Berlucchi, & Marzi, 2018; de Haan et al., 2019; Pinto, Lamme, & de Haan, 2017b; Pinto et al., 2017a; Savazzi et al., 2007; Mancuso, Uddin, Nani, Costa, & Cauda, 2019) suggests that the multitude of subcortical connections that are spared during surgery are responsible for the transfer of information. As was initially pointed out by Trevarthen (1968) and Trevarthen and Sperry (1973) and recently stressed by Pinto, de Haan, and Lamme (2017a) and Corballis et al. (2018), there are many commissures (white matter tracts that connect homologous structures on both sides of the central nervous system) and decussations (bundles that connect different structures on both sides) that link nuclei that are known to be involved in perceptual processing. The importance of these commisural connections for transferring visual information in split-brain patients has been highlighted by Trevarthen and Sperry (1973). Moreover, the role of these connections in a split-brain has recently been demonstrated by bilateral fMRI activations in the first somatosensory cortex, after unilateral stimulation of trunk midline touch receptors (Fabri et al., 2006) and in the second somatic sensory area after unilateral stimulation of hand pain receptors (Fabri, Polonara, Quattrini, & Salvolini, 2002). Uddin and colleagues used low-frequency BOLD fMRI resting state imaging to investigate functional connectivity between the two hemispheres in a patient in whom all major cerebral commissures had been cut (Uddin et al., 2008). Compared to control subjects, the patient’s interhemispheric correlation scores fell within the normal range for at least two symmetrical regions. In addition, Nomi and colleagues suggested that split-brain patients might rely particularly on dorsal and ventral pontine decussations of the cortico-cerebellar interhemispheric pathways as evidenced by increased fractional anisotropy (FA) on diffusion weighted imaging (Nomi, Marshall, Zaidel, Biswal, Castellanos, Dick, Uddin & Mooshagian, 2019). Interhemispheric exchange of information also seems to occur in the domain of taste sensitivity, activation of primary gustatory cortex in the fronto-parietal operculum was reported in both hemispheres after unilateral gustatory stimulation of the tongue receptors (Mascioli, Berlucchi, Pierpaoli, Salvolini, Barbaresi, Fabri, & Polonara, 2015). Note that patients may differ with respect to how many of these connections have been cut, and this might also explain some of the individual variance among patients. Moreover, in all patients subcortical structures remain intact. For instance, the superior colliculus is known to integrate visual information from both hemispheres and project information to both hemispheres (Meredith & Stein, 1986; Comoli et al., 2003). Such structures may support attentional networks, and may enable the right hemisphere to attend to the entire visual field. In turn, attentional unity could help in unifying cognitive and motor control, which may subserve ipsilateral motor control.
The second point concerns the ipsilateral innervation of the arms. Manual action is not strictly lateralized, and the proximal (but not the distal) parts of the arm are controlled bilaterally, although the ipsilateral contribution remains undetermined. This could explain why split-brain patients may respond equally well with both hands in certain experimental conditions (Corballis, 1995; Gazzaniga, Bogen, & Sperry, 1967; Pinto, de Haan, & Lamme, 2017a). First, there is substantial evidence that bilateral cortical activations can be observed during unilateral limb movements in healthy subjects. In addition, ipsilesional motor problems in arm control have been observed in patients with unilateral cortical injuries, and finally there is evidence from electrocorticography with implanted electrodes for localization of epileptic foci showing similar spatial and spectral encoding of contralateral and ipsilateral limb kinematics (Bundy, Szrama, Pahwa, & Leuthardt, 2018). While these observations argue convincingly for a role in action control by the ipsilateral hemisphere, they do not prove that a hemisphere on it’s own can purposefully control the movements of the ipsilateral hand. Thus, the role of ipsilateral arm-hand control in explaining split-brain findings is currently not settled.
The third hypothesis argues that in addition to whatever direct neural communication may exist between the hemispheres, they may inform one another via strategic cross-cueing processes (Volz & Gazzaniga, 2017; Volz et al., 2018). The split-brain patients underwent surgery many years prior to testing, and the separated perceptual systems have had ample time to learn how to compensate for the lack of commissural connections. For example, subtle cues may be given by minimal movements of the eyes or facial muscles, which might not even be visible to an external observer but are capable of encoding, for example, the location of a stimulus for the hemisphere that did not “see” it. A cross-cueing mechanism might also allow one hemisphere to convey to the other which one of a limited set of known items had been shown (Gazzaniga & Hillyard, 1971; Gazzaniga, 2013).
Finally, it is possible to entertain combinations of the different explanations. For instance, it is conceivable that in the subacute phase following split-brain surgery the hemispheres are ineffective in communicating with each other. During this initial phase, phenomena such as an “alien hand” - that is a hand moving outside conscious control of the (verbal) person - may be present. In the ensuing period, the patients may have learned to utilize the information that is exchanged via subcortical connections, ipsilateral motor control or cross-cueing to coordinate the processing of the two hemispheres. In such a way, the patient may counteract some of the effects of losing the corpus callosum.

What do We Need to Know?

This paper aims to contribute to the agenda for the next decade of split-brain research. Full split-brain surgery is rare these days, and it is important that we try to answer the central questions while these patients are still available for study. In order to examine the variations between patients it would be useful to test as many of the available patients as possible with the same tests.
One important goal is to map out precisely how much functionality and information is still integrated across hemispheres in the split-brain, and what the underlying principles are. For instance, in some cases the two hemispheres seem to carry out sensory-motor tasks, such as visual search, independently from one another (Arguin et al., 2000; Franz, Eliassen, Ivry, & Gazzaniga, 1996; Hazeltine, Weinstein, & Ivry, 2008; Luck, Hillyard, Mangun, & Gazzaniga, 1994; Luck et al., 1989), while in other cases functions such as attentional blink, or attentional cueing, seem to be integrated across hemispheres (Giesbrecht & Kingstone, 2004; Holtzman, Volpe, & Gazzaniga, 1984; Holtzman, Sidtis, Volpe, Wilson, & Gazzaniga, 1981; Pashler et al., 1994; Ptito, Brisson, Dell’Acqua, Lassonde, & Jolicœur, 2009). An important challenge is to unveil why some cognitive functions can be carried out independently in the separated hemispheres while other functions engage both hemispheres. Furthermore, it is now clear that accurate detection and localization is possible across the whole visual field, and there is some evidence that even more information concerning visual images can be transferred between hemispheres. Although we have some understanding of what types of information can be transferred in the visual domain, our knowledge base in the somatosensory domain is much more limited. This is probably due to a bias throughout cognitive neuroscience and psychology, leading to a strong focus on vision in split-brain research. It is important to collect converging evidence by investigating the somatosensory system which is also strongly lateralized. Note that in somatosensory processing transfer between hemispheres (about 80% correct for the bimanual conditions) has been observed for basic same-different matching of real objects (Fabri, Del Pesce et al., 2005).
Another important goal is to obtain a more detailed description of the perceptual, cognitive and linguistic capabilities of the disconnected right hemisphere. For understanding unity of mind, two capabilities specifically are crucial. First, experiments investigating aspects of the conscious mind often go beyond simple visual processing, and future studies will thus critically depend on testing high-level cognitive abilities of both hemispheres. Specifically, language abilities, crucial for understanding questions and instructions, will likely play a pivotal role. Thus, the first question is to what extent the right hemisphere is capable of language processing. Note that complicated instructions (Gazzaniga, Smylie, Baynes, Hirst, & McCleary, 1984; Pinto et al., 2017a; Zaidel, 1983), for instance relating to mental imagery (Johnson, Corballis, & Gazzaniga, 2001; Kosslyn, Holtzman, Farah, & Gazzaniga, 1985; Sergent & Corballis, 1990), seem to be well within the reach of the right hemisphere. Moreover, right hemisphere language capabilities seem to improve over time (Gazzaniga, Volpe, Smylie, Wilson, & LeDoux, 1979; Gazzaniga et al., 1996). Longitudinal language tests (for instance with a Token test: De Renzi & Vignolo, 1962) would further illuminate the extent of right hemisphere language processing.
Second, unveiling to what extent each hemisphere is capable of subserving consciousness at all seems relevant for unity of mind as well. If the disconnected right hemisphere can produce full-blown consciousness, then questions regarding unity of mind are clearly more pertinent then if the right hemisphere only produces minimal amounts of consciousness. Right hemisphere consciousness can be studied through novel neural paradigms (Bekinschtein et al., 2009; Casali et al., 2013; Pitts, Metzler, & Hillyard, 2014; Shafto & Pitts, 2015). For instance, Bekinschtein et al. employed EEG to measure if the brain detected irregularities (as indicated by an event-related potential [ERP] signal called the P3) in different states of consciousness. They found that when consciousness was reduced, local irregularities were still detected - for instance after three high auditory tones a low tone evoked a P3. However, global irregularities - several times a low tone followed three high tones, then on the critical trial three high tones were followed by another high tone - did not evoke a P3 when consciousness was reduced. Crucially, when consciousness was unimpaired both local and global irregularities evoked a P3 response. Right hemisphere consciousness may also be studied in other patient groups where interhemispheric communication is hampered. One particularly interesting group are post-hemispherotomy patients (Lew, 2014). These patients have been surgically treated to disconnect an entire hemisphere (usually for intractable epilepsy), but unlike hemispherectomy patients the disconnected hemisphere remains in place in the cranium and remains vascularized.
Clearly, the central question, whether each hemisphere supports an independent conscious agent, is not settled yet. Novel paradigms in this respect could lead to progress. For instance, a pivotal question is whether each hemisphere makes its own decisions independent of the other hemisphere. If each hemisphere produces its own autonomous conscious agent then this should be the case. That is, if two agents are asked to freely choose a random number, then the odds that they consistently pick the same number are small. And vice versa, if each hemisphere makes its own conscious decisions, independent of the other hemisphere, then this seems to rule out unity of mind. Note that each hemisphere making its own decisions is different from information processing occurring independently per hemisphere. Unconscious information processing is almost certainly split across hemispheres in a split-brain. However, this does not prove that consciousness is split or unified. Even in a healthy brain, where consciousness is unified, many unconscious processes run independently, and in parallel.
One way to tackle the central question is by having the hemispheres respond to questions in parallel. Overt behavior most likely does not allow for this, due to bilateral motor control processes sketched earlier. However, perhaps parallel responding is possible if the hemispheres produce covert responses. For instance, the patient could be asked to pick one of four options and indicate their choice by carrying out certain content-specific mental imagery tasks. This imagery can then be decoded in parallel from each hemisphere using neuroimaging techniques (see Owen et al., 2006 for a similar approach with vegetative state patients). If each hemisphere harbors an autonomous conscious agent, then it is highly unlikely that the two hemispheres will consistently make the same choices. Thus, if the choices are uncorrelated across hemispheres, then this may critically challenge the unified mind view.
Another way to tackle the question of unified consciousness in the split-brain is to employ ERPs as markers of concurrent conscious processing in the left and right hemispheres. For instance, in one study (Kutas, Hillyard, Volpe, & Gazzaniga, 1990) visual targets were presented either separately to the left or right visual field or to both visual fields simultaneously. It was found that the P300 - a signal possibly reflecting conscious processing of a visual target (Dehaene & Changeux, 2011; Dehaene, Charles, King, & Marti, 2014; Salti, Bar-Haim, & Lamy, 2012) - was reduced for bilateral targets. This suggests some type of integration of conscious processing. Studies employing ERPs may indicate whether conscious processing is unified, while unconscious processing is split, which would be suggestive of unified consciousness.