Trypophobia, skin disease, and the visual discomfort of natural textures.

In the last decade, the behavioral sciences have described the phenomenon of trypophobia, which is the discomfort felt by some individuals when viewing images containing clusters of bumps or holes. One evolutionary hypothesis for this phenomenon is that this visual discomfort represents an adaptation which helps organisms avoid skin disease and/or ectoparasites. Even though trypophobic imagery and disease imagery are both examples of visual textures, to date there has been no comparison of the visual discomfort elicited by these two specific kinds of textures within the larger context of the visual comfort elicited by natural texture imagery more generally. In the present study, we administered the Trypophobia Questionnaire (TQ) and recorded the visual comfort ratings elicited by a large set of standard natural texture images, including several trypophobic and skin disease images. In two independent samples, we found that while all observers find skin diseases uncomfortable to view, only those scoring high on the TQ rated trypophobic imagery equally uncomfortable. Comparable effects were observed using both standard ANOVA procedures as well as linear mixed effects modeling. Comparing the ratings of both high-TQ and low-TQ participants to the standard textures, we find remarkably consistent rank-order preferences, with the most unpleasant textures (as rated by both groups) exhibiting qualitative similarities to trypophobic imagery. However, we also find that low-level image statistics which have been previously shown to affect visual comfort are poor predictors of the visual comfort elicited by natural textures, including trypophobic and disease imagery. Our results suggest that a full understanding of the visual comfort elicited by natural textures, including those arising from skin disease, will ultimately depend upon a better understanding of cortical areas specialized for the perception of surface and material properties, and how these visual regions interact with emotional brain areas to evoke appropriate behavioral responses, like disgust.

Evaluating the 'skin disease-avoidance' and 'dangerous animal' frameworks for understanding trypophobia.

ABSTRACTTrypophobia refers to the extreme negative reaction when viewing clusters of circular objects. Two major evolutionary frameworks have been proposed to account for trypophobic visual discomfort. The skin disease-avoidance (SD) framework proposes that trypophobia is an over-generalised response to stimuli resembling pathogen-related skin diseases. The dangerous animal (DA) framework posits that some dangerous organisms and trypophobic stimuli share similar visual characteristics. Here, we performed the first experimental manipulations which directly compare these two frameworks by superimposing trypophobic imagery onto multiple image categories to evaluate changes in comfort. Participants from two countries (United States and Croatia) were evaluated on several measures, including general trypophobia levels, perceived vulnerability to disease, and generalised anxiety. Several analyses showed stronger changes in comfort in the human skin condition (hand, feet, and chest images) compared to the dangerous animal condition (snake and spider images). Furthermore, participants with higher levels of trypophobia showed significantly stronger changes in comfort in the skin condition than the dangerous animal condition, with comparable effects obtained across nationalities. Several variables entered as covariates failed to significantly account for this effect. The present work is the first to experimentally test both evolutionary frameworks of trypophobia, with results supporting the skin disease-avoidance framework.

Demographics, Perceptions, and Use of Medical Marijuana among Patients in Florida.

Medical marijuana (MMJ) is currently legal in 35 US states, with an estimated 3.6 million state-legal medical cannabis patients. Although there are currently over 440,000 MMJ patients in the state of Florida, there are limited data on their demographics, reasons and patterns of use, and successes or failures of treatment. The goal of this study is to examine the demographics, perceptions, and use of medical cannabis among patients in Florida, as well as their perceptions of the quality of information received from physicians and dispensaries. One hundred and fifty-seven MMJ patients completed an online survey regarding their characteristics and use. Patients in Florida shared many characteristics with patients in other states, such as race, use frequency, and administration technique. Patients most commonly used MMJ to treat their symptoms of anxiety, pain, and stress and reported great therapeutic effectiveness. A majority (65%) of patients also reported either a reduction or total discontinuation of at least one prescription or over-the-counter drug. The findings highlight the need to further investigate the use of MMJ as a viable treatment for pain and anxiety and to improve access of quality cannabis information to patients, physicians, and dispensary employees.

Sex Differences in Attitudes Toward Casual Sex: Using STI Contraction Likelihoods to Assess Evolved Mating Strategies.

Previous work shows that males are more likely to pursue casual sex if given the opportunity, compared to females, on average. One component of this strategy is risk-taking, and males have been shown to take more risks than females in a variety of contexts. Here, we investigate the extent to which sex differences exist considering casual sexual encounters involving sexually transmitted infections (STIs) using a hypothetical sexual scenario which attempts to circumvent several factors that may contribute to a female's hesitancy to engage in casual sex encounters. Two hundred and forty-six college students rated their willingness to engage in a satisfying casual sexual encounter with someone judged to be personable as a function of sex, varying STI contraction likelihoods, several STI types, and two levels of hypothetical partner attractiveness. We also assess how individual levels of sociosexuality (as measured by the SOI-R) impact findings. Our findings show that males report higher likelihoods of sexual engagement compared to females in general. This trend continued for lower likelihoods of STI contraction in all four STI types (Cold, Chlamydia, Herpes, HIV), with larger effects shown in the high attractiveness partner condition. For higher STI contraction likelihoods and more severe STI types, along with lower partner attractiveness levels, sex differences shrank. Factoring in participant SOI-R scores attenuated the effects somewhat, although it failed to alter findings substantially with predicted sex differences continuing to exist. These results offer further insight into evolved sex differences in human mating systems and provide an additional framework to test sexual risk-taking among males and females.

Practice Patterns and Training Needs Among Physicians Certifying Patients for Medical Marijuana in Florida.

BACKGROUND: Little is known about the clinical training or practice experiences among physicians who certify patients for medical marijuana. The objective of this study was to determine information sources, factors influencing recommendations, clinical practices in patient assessment, communications, and recommendations, and priority areas for additional training among physicians who certify patients for medical marijuana. METHODS: A cross-sectional state-wide anonymous survey of registered medical marijuana physicians in Florida between June and October 2020 was administered. Numerical responses were quantified using counts and percentages. The frequencies for "often" and "always" responses were aggregated when appropriate. RESULTS: Among 116 respondents, the mean (standard deviation) age was 57 (12) years old, and 70% were male. The most frequently used information sources were research articles (n = 102, 95%), followed by online sources (n = 99, 93%), and discussions with other providers and dispensary staff (n = 84, 90%). Safety concerns were most influential in patient recommendations (n = 39, 39%), followed by specific conditions (n = 30, 30%) and patient preferences (n = 26, 30%). Ninety-three physicians (92%) reported they "often" or "always" perform a patient physical exam. Eighty-four (77%) physicians provided specific administration route recommendations. Half (n = 56) "often" or "always" provided specific recommendations for Δ-9-tetrahydrocannabinol: cannabidiol ratios, while 69 (62%) "often" or "always" provided specific dose recommendations. Online learning/training modules were the most preferred future training mode, with 88 (84%) physicians "likely" or "very likely" to participate. The top 3 desired topics for future training were marijuana-drug interactions (n = 84, 72%), management of specific medical conditions or symptoms (n = 83, 72%), and strategies to reduce opioids or other drugs use (n = 78, 67%). CONCLUSIONS: This survey of over 100 medical marijuana physicians indicates that their clinical practices rely on a blend of research and anecdotal information sources. While physicians report clinical factors as influential during patient recommendation, patient assessment practices and treatment regimen recommendations vary substantially and rely on experimental approaches. More research is needed to inform evidence-based practice and training, especially considering details on drug interactions, risk-benefit of treatment for specific clinical conditions, and strategies to reduce opioid use.

Phylogenetic analysis in the clinical risk management of an outbreak of hepatitis C virus infection among transfused thalassaemia patients in Italy.

BACKGROUND: Occurrence of hepatitis C virus (HCV) infection is reduced by effective risk management procedures, but patient-to-patient transmission continues to be reported in healthcare settings. AIM: To report the use of phylogenetic analysis in the clinical risk management of an HCV outbreak among 128 thalassaemia outpatients followed at a thalassaemia centre of an Italian hospital. METHODS: Epidemiological investigation and root-cause analysis were performed. All patients with acute hepatitis and known chronic infection were tested for HCV RNA, HCV genotyping, and NS3, NS5A, and NS5B HCV genomic region sequencing. To identify transmission clusters, phylogenetic trees were built for each gene employing Bayesian methods. FINDINGS: All patients with acute hepatitis were infected with HCV genotype 1b. Root-cause analysis, including a lookback procedure, excluded blood donors as the source of HCV transmission. The phylogenetic analysis, conducted on seven patients with acute infection and eight patients with chronic infection, highlighted four transmission clusters including at least one patient with chronic and one patient with acute HCV infection. All patients in the same cluster received a blood transfusion during the same day. Two patients with acute hepatitis spontaneously cleared HCV within four weeks and nine patients received ledipasvir plus sofosbuvir for six weeks, all achieving a sustained virological response. CONCLUSION: Combined use of root-cause analysis and molecular epidemiology was effective in ascertaining the origin of the HCV outbreak. Antiviral therapy avoided the chronic progression of the infection and further spread in care units and in the family environment.

Object Clusters or Spectral Energy? Assessing the Relative Contributions of Image Phase and Amplitude Spectra to Trypophobia.

Trypophobia refers to the visual discomfort experienced by some people when viewing clustered patterns (e.g., clusters of holes). Trypophobic images deviate from the 1/f amplitude spectra typically characterizing natural images by containing excess energy at mid-range spatial frequencies. While recent work provides partial support for the idea of excess mid-range spatial frequency energy causing visual discomfort when viewing trypophobic images, a full factorial manipulation of image phase and amplitude spectra has yet to be conducted in order to determine whether the phase spectrum (sinusoidal waveform patterns that comprise image details like edge and texture elements) also plays a role in trypophobic discomfort. Here, we independently manipulated the phase and amplitude spectra of 31 Trypophobic images using a standard Fast Fourier Transform (FFT). Participants rated the four different versions of each image for levels of visual comfort, and completed the Trypophobia Questionnaire (TQ). Images having the original phase spectra intact (with either original or 1/f amplitude) explained the most variance in comfort ratings and were rated lowest in comfort. However, images with the original amplitude spectra but scrambled phase spectra were rated higher in comfort, with a smaller amount of variance in comfort attributed to the amplitude spectrum. Participant TQ scores correlated with comfort ratings only for images having the original phase spectra intact. There was no correlation between TQ scores and comfort levels when participants viewed the original amplitude / phase-scrambled images. Taken together, the present findings show that the phase spectrum of trypophobic images, which determines the pattern of small clusters of objects, plays a much larger role than the amplitude spectrum in determining visual discomfort.

Fertility-Dependent Acoustic Variation in Women's Voices Previously Shown to Affect Listener Physiology and Perception.

Previous research demonstrates that listeners perceive women's voices as more attractive when recorded at high compared to low fertility phases of the menstrual cycle. This effect has been repeated with multiple voice recording samples, but one stimuli set has shown particularly robust replications. First collected by Pipitone and Gallup (2008), women were recorded counting from 1-10 on approximately the same day and time once a week for 4 weeks. Repeatedly, studies using these recordings have shown that naturally cycling women recorded at high fertility are rated as more attractive compared to voices of the same women at low fertility. Additionally, these stimuli have been shown to elicit autonomic nervous system arousal and precipitate a rise in testosterone levels among listeners. Although previous studies have examined the acoustic properties of voices across the menstrual cycle, they reach little consensus. The current study evaluates Pipitone and Gallup's voice stimuli from an acoustic perspective, analyzing specific vocal characteristics of both naturally cycling women and women taking hormonal contraceptives. Results show that among naturally cycling women, variation in vocal amplitude (shimmer) was significantly lower in high fertility recordings compared to the women's voices at low fertility. Harmonics-to-noise ratio and variation in voice pitch (jitter) also fluctuated systematically across voices sampled at different times during the menstrual cycle, though these effects were not statistically significant. It is possible that these acoustic changes could account for some of the replicated perceptual, hormonal, and physiological changes documented in prior literature using these voice stimuli.

Causal relationship of hepatic fat with liver damage and insulin resistance in nonalcoholic fatty liver.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease is epidemiologically associated with hepatic and metabolic disorders. The aim of this study was to examine whether hepatic fat accumulation has a causal role in determining liver damage and insulin resistance. METHODS: We performed a Mendelian randomization analysis using risk alleles in PNPLA3, TM6SF2, GCKR and MBOAT7, and a polygenic risk score for hepatic fat, as instruments. We evaluated complementary cohorts of at-risk individuals and individuals from the general population: 1515 from the liver biopsy cohort (LBC), 3329 from the Swedish Obese Subjects Study (SOS) and 4570 from the population-based Dallas Heart Study (DHS). RESULTS: Hepatic fat was epidemiologically associated with liver damage, insulin resistance, dyslipidemia and hypertension. The impact of genetic variants on liver damage was proportional to their effect on hepatic fat accumulation. Genetically determined hepatic fat was associated with aminotransferases, and with inflammation, ballooning and fibrosis in the LBC. Furthermore, in the LBC, the causal association between hepatic fat and fibrosis was independent of disease activity, suggesting that a causal effect of long-term liver fat accumulation on liver disease is independent of inflammation. Genetically determined hepatic steatosis was associated with insulin resistance in the LBC and SOS. However, this association was dependent on liver damage severity. Genetically determined hepatic steatosis was associated with liver fibrosis/cirrhosis and with a small increase in risk of type 2 diabetes in publicly available databases. CONCLUSION: These data suggest that long-term hepatic fat accumulation plays a causal role in the development of chronic liver disease.

Interactions between observer and stimuli fertility status: Endocrine and perceptual responses to intrasexual vocal fertility cues.

Both men and women find female voices more attractive at higher fertility times in the menstrual cycle, suggesting the voice is a cue to fertility and/or hormonal status. Preference for fertile females' voices provides males with an obvious reproduction advantage, however the advantage for female listeners is less clear. One possibility is that attention to the fertility status of potential rivals may enable women to enhance their own reproductive strategies through intrasexual competition. If so, the response to having high fertility voices should include hormonal changes that promote competitive behavior. Furthermore, attention and response to such cues should vary as a function of the observer's own fertility, which influences her ability to compete for mates. The current study monitored variation in cortisol and testosterone levels in response to evaluating the attractiveness of voices of other women. All 33 participants completed this task once during ovulation then again during the luteal phase. The voice stimuli were recorded from naturally cycling women at both high and low fertility, and from women using hormonal birth control. We found that listeners rated high fertility voices as more attractive compared to low fertility, with the effect being stronger when listeners were ovulating. Testosterone was elevated following voice ratings suggesting threat detection or the anticipation of competition, but no stress response was found.

PNPLA3 rs738409 I748M is associated with steatohepatitis in 434 non-obese subjects with hepatitis C.

BACKGROUND: The PNPLA3/Adiponutrin rs738409 C/G single nucleotide polymorphism is associated with the severity of steatosis, steatohepatitis and fibrosis in patients with non-alcoholic fatty liver disease, as well as the severity of steatosis and fibrosis in patients with chronic hepatitis C (CHC). AIM: To test in genotype 1(G1)-CHC patients, the putative association between the PNPLA3 variant and histological features of steatohepatitis, as well as their impact on the severity of fibrosis. METHODS: Four hundred and thirty-four consecutively biopsied Caucasian G1-CHC patients were genotyped for PNPLA3 rs738409, its effect evaluated by using an additive model. Histological features of steatohepatitis in CHC were assessed using the Bedossa classification. Hepatic expression of PNPLA3 mRNA was evaluated in 63 patients. RESULTS: The prevalence of steatohepatitis increased from 16.5% in patients with PNPLA3 CC, to 23.2% in CG and 29.2% in the GG genotype (P = 0.02). By multiple logistic regression, PNPLA3 genotype (OR 1.54, 95% CI 1.03-2.30, P = 0.03), together with age (OR 1.03, 95% CI 1.00-1.05, P = 0.02), BMI ≥ 30 (OR 2.06, 95% CI 1.04-4.10, P = 0.03) and homoeostasis model assessment (HOMA, OR 1.18, 95% CI 1.04-1.32, P = 0.006) were independently linked to steatohepatitis. When stratifying for obesity, PNPLA3 was associated with NASH in non-obese patients only (12.0% in CC vs. 18.3% in CG vs. 27.3% in GG, P = 0.01), including after correction for metabolic confounders (OR 2.06, 95% CI 1.26-3.36, P = 0.004). We showed an independent association between steatohepatitis (OR 2.05, 95% CI 1.05-4.02, P = 0.003) and severe fibrosis. Higher liver PNPLA3 mRNA was associated both with the severity of steatosis (adjusted P = 0.03) and steatohepatitis after adjusting for gender, age, BMI and HOMA (P = 0.002). CONCLUSION: In patients with genotype 1 hepatitis C, the PNPLA3 G variant is associated with a higher risk of steatosis severity and steatohepatitis, particularly among non-obese subjects.

Physiological changes in response to hearing female voices recorded at high fertility.

The human voice transmits pertinent information regarding health status and age, with recent evidence suggesting that it plays an important role in mate selection. However, the mechanism that drives preferences for voices of fertile females has yet to be elucidated. The current study examined the physiological changes that occur when listening to voices recorded from naturally cycling females at high and low fertility phases of the menstrual cycle, as well as from females using hormonal contraception. We found the voices of naturally cycling females recorded during a high fertility phase were rated as more attractive and produced the greatest increase in galvanic skin response (GSR). Heart rate (HR) also showed a trend towards the highest increase when listening to naturally cycling, high fertility female voices. There were no differences in ratings of voice attractiveness, GSR, or HR between the voices recorded from females using hormonal contraception. Analyzed separately, male and female listeners both showed a preference for naturally cycling, high fertility voices. Female listeners additionally showed increased GSR and HR responses to naturally cycling, high fertility voices. We discuss the adaptive benefits of detecting vocal changes for male as well as female listeners, and also discuss the role that the nervous system plays during human mate assessments.

Association of vitamin D serum levels and its common genetic determinants, with severity of liver fibrosis in genotype 1 chronic hepatitis C patients.

Lower 25-hydroxyvitamin D [25(OH)D] serum levels have been associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients (G1CHC). In addition, a recent genome-wide study identified genetic variants (rs12785878, near dehydrocholesterol reductase, DHCR7; rs10741657, near CYP2R1; and rs7041, near vitamin D-binding protein, GC) affecting 25(OH)D serum levels in healthy populations. We aimed to assess the association between vitamin D serum levels and its genetic determinants, with the severity of liver fibrosis. Two hundred and sixty patients with biopsy-proven G1CHC were consecutively evaluated. The 25(OH)D serum levels were measured by high-pressure liquid chromatography. All patients were genotyped for DHCR7 rs12785878, CYP2R1 rs10741657 and GC rs7041 single nucleotide polymorphisms. DHCR7 GG genotype (P = 0.003) and the severity of fibrosis (P = 0.03) were independent factors associated with lower 25(OH)D serum levels in multiple linear regression analysis. Interestingly, 53.8% (7/13) of patients with DHCR7 GG genotype had severe liver fibrosis, compared to 27.1% (67/247) of those with DHCR7 TT/TG genotype (P = 0.03). By multivariate logistic regression analysis, severe fibrosis was independently associated with older age (OR, 1.056; 95% CI, 1.023-1.089, P = 0.001), low cholesterol (OR, 0.984; 95% CI, 0.974-0.994, P = 0.002), high triglycerides (OR, 1.008; 95% CI, 1.002-1.015, P = 0.01), low 25(OH)D (OR, 0.958; 95% CI, 0.919-0.999, P = 0.04), DHCR7 GG genotype (OR, 4.222; 95% CI, 1.106-16.120; P = 0.03), moderate-severe steatosis (OR, 2.588; 95% CI, 1.355-4.943; P = 0.004) and moderate-severe necroinflammatory activity (grading) (OR, 2.437; 95% CI, 1.307-4.763; P = 0.001). No associations were found between liver fibrosis and both CYP2R1 and GC genotypes. In patients with G1CHC, GG homozygosis for DHCR7 gene and lower 25(OH)D levels are independently associated with the severity of liver fibrosis.

In vivo liver expression of TLR2, TLR3 and TLR7 in chronic hepatitis C.

The role of innate immune response mediated by Toll-like receptors in HCV infection, is not yet well understood and there is a lack of data regarding liver tissue expression of these molecules in chronic hepatitis C (CHC). Our study is aimed to investigate ex vivo, liver expression of TLR2, TLR3 and TLR7, which are more involved in the immune-pathogenesis of CHC, and to explore possible correlations with features of disease. We obtained liver biopsies and collected peripheral blood mononuclear cells (PBMC) from 23 consecutive patients with CHC and from 6 patients of control, without liver disease, undergoing surgery for cholecystectomy. The levels of TLRs mRNA in the samples were determined using a real-time reverse transcription quantitative PCR (RT-qPCR). We found a significant high expression of TLR3 in the liver of CHC patients respect to controls (also higher than expression in the PBMC). Conversely no differences emerged in the TLR2 and TLR7 levels between cases and controls. Also we found a correlation of TLR2 and TLR7 levels with the grade of necro-inflammation in the liver. Furthermore TLR7 hepatic levels resulted related to a more advanced stage of liver fibrosis. Ours is the first study to provide data on tissue expression of TLRs during chronic hepatitis C and we believe that it could lead to a better understanding of the role of these molecules in the HCV-mediated liver damage.

Role of IL-28B and inosine triphosphatase polymorphisms in efficacy and safety of Peg-Interferon and ribavirin in chronic hepatitis C compensated cirrhosis with and without oesophageal varices.

Genetic factors can influence the outcome of antiviral therapy in chronic hepatitis C (HCV). We evaluated the role of interleukin-28B single nucleotide polymorphisms (SNPs) and inosine triphosphatase (ITPA) gene variants in HCV cirrhosis treated with Peg-Interferon and ribavirin. A prospective cohort of 233 patients with compensated cirrhosis received 1-1.5 µg/kg/week of Peg-Interferon alpha-2b plus 1000-1200 mg/day of RBV for 48 weeks. A sustained virologic response (SVR) was achieved in 27% of patients. On multivariate logistic analysis, the absence of oesophageal varices (OR 3.64 CI 95% 1.27-10.44 P = 0.016), infection with genotype 2 or 3 (OR 4.06, CI 95% 1.08-15.26, P = 0.038), C/C alleles of rs12979860 SNP (OR 7.04, CI 95% 2.40-20.72, P < 0.001) and rapid virologic response (RVR) (OR 78.29, CI 95% 16.07-381.29, P < 0.001) were independently associated with SVR. Patients who experienced post-treatment relapse received lower total doses of Peg-Interferon (52.0 ± 15.8 µg/kg vs 65.7 ± 13.3 µg/kg, P < 0.001) and lower total dose of RBV (3829 ± 1210 mg vs 4709 ± 954 mg, P < 0.001) than patients who achieved an SVR. ITPA variants predictive of high ITPase activity were associated with reduction of haemoglobin ≥3 g/dL in the first 4 weeks (P < 0.001), and with reduction of haemoglobin <10 g/dL (P = 0.03) on treatment. In conclusion, combination therapy with Peg-Interferon and RBV in patients with HCV cirrhosis must be guided by virus genotype, severity of portal hypertension, favourable IL-28B polymorphisms and ITPA variants, and RVR on treatment.

Voice and handgrip strength predict reproductive success in a group of indigenous African females.

Evolutionary accounts of human traits are often based on proxies for genetic fitness (e.g., number of sex partners, facial attractiveness). Instead of using proxies, actual differences in reproductive success is a more direct measure of darwinian fitness. Certain voice acoustics such as fundamental frequency and measures of health such as handgrip strength correlate with proxies of fitness, yet there are few studies showing the relation of these traits to reproduction. Here, we explore whether the fundamental frequency of the voice and handgrip strength account for differences in actual reproduction among a population of natural fertility humans. Our results show that both fundamental frequency and handgrip strength predict several measures of reproductive success among a group of indigenous Namibian females, particularly amongst the elderly, with weight also predicting reproductive outcomes among males. These findings demonstrate that both hormonally regulated and phenotypic quality markers can be used as measures of darwinian fitness among humans living under conditions that resemble the evolutionary environment of Homo sapiens. We also argue that these findings provide support for the Grandmother Hypothesis.

Bottle feeding simulates child loss: postpartum depression and evolutionary medicine.

At the level of a mother's basic biology, the decision to bottle feed unwittingly mimics conditions associated with the death of an infant. Child loss is a well documented trigger for depression particularly in mothers, and growing evidence shows that bottle feeding is a risk factor for postpartum depression. The implications of this hypothesis for infant feeding practices, hospital procedures that lead to intermittent separation between mothers and infants during the immediate postpartum period, parallels between an increased desire to hold infants by mothers who bottle feed and responses to infant death among nonhuman primates, and the relationship between weaning and depression are discussed in the context of an emerging discipline known as evolutionary medicine.