New Tests to Measure Individual Differences in Matching and Labelling Facial Expressions of Emotion, and Their Association with Ability to Recognise Vocal Emotions and Facial Identity

Although good tests are available for diagnosing clinical impairments in face expression processing, there is a lack of strong tests for assessing "individual differences"--that is, differences in ability between individuals within the typical, nonclinical, range. Here, we develop two new tests, one for expression perception (an odd-man-out matching task in which participants select which one of three faces displays a different expression) and one additionally requiring explicit identification of the emotion (a labelling task in which participants select one of six verbal labels). We demonstrate validity (careful check of individual items, large inversion effects, independence from nonverbal IQ, convergent validity with a previous labelling task), reliability (Cronbach's alphas of.77 and.76 respectively), and wide individual differences across the typical population. We then demonstrate the usefulness of the tests by addressing theoretical questions regarding the structure of face processing, specifically the extent to which the following processes are common or distinct: (a) perceptual matching and explicit labelling of expression (modest correlation between matching and labelling supported partial independence); (b) judgement of expressions from faces and voices (results argued labelling tasks tap into a multi-modal system, while matching tasks tap distinct perceptual processes); and (c) expression and identity processing (results argued for a common first step of perceptual processing for expression and identity).This research was supported by the Australian Research Council (http://www.arc.gov.au/) grant DP110100850 to RP and EM and the Australian Research Council Centre of Excellence for Cognition and its Disorders (CE110001021) http://www.ccd.edu.au. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Cortisol reactivity and suicidal behavior: investigating the role of hypothalamic-pituitary-adrenal axis responses to stress in suicide attempters and ideators

Every 40 seconds a person dies by suicide somewhere in the world. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. The current study aimed to investigate whether cortisol reactivity to a laboratory stress task differentiated individuals who had previously made a suicide attempt from those who had thought about suicide (suicide ideators) and control participants. One hundred and sixty participants were recruited to a previous attempt, a suicidal ideation or a control group. Participants completed background questionnaires before completing the Maastricht Acute Stress Test (MAST). Cortisol levels were assessed throughout the stress task. Measures of suicide behavior were measured at baseline, 1 month and 6 month follow-up. Participants who had made a previous suicide attempt exhibited significantly lower aggregate cortisol levels during the MAST compared to participants in the control group; suicide ideators were intermediate to both groups. This effect, however, was driven by participants who made an attempt within the past year, and to some degree by those with a family history of attempt. Participants who had made a suicide attempt and had a family history of suicide exhibited the lowest levels of cortisol in response to stress. Finally, lower levels of cortisol in response to the MAST were associated with higher levels of suicidal ideation at 1-month follow-up in the suicide attempter group. These results are consistent with other findings indicating that blunted HPA axis activity is associated with some forms of suicidal behavior. The challenge for researchers is to elucidate the precise causal mechanisms linking stress, cortisol and suicide risk

Significant changes in the skin microbiome mediated by the sport of roller derby

Diverse bacterial communities live on and in human skin. These complex communities vary by skin location on the body, over time, between individuals, and between geographic regions. Culture-based studies have shown that human to human and human to surface contact mediates the dispersal of pathogens, yet little is currently known about the drivers of bacterial community assembly patterns on human skin. We hypothesized that participation in a sport involving skin to skin contact would result in detectable shifts in skin bacterial community composition. We conducted a study during a flat track roller derby tournament, and found that teammates shared distinct skin microbial communities before and after playing against another team, but that opposing teams’ bacterial communities converged during the course of a roller derby bout. Our results are consistent with the hypothesis that the human skin microbiome shifts in composition during activities involving human to human contact, and that contact sports provide an ideal setting in which to evaluate dispersal of microorganisms between people

Trophic interactions modify the temperature dependence of community biomass and ecosystem function

Aquatic ecosystems worldwide continue to experience unprecedented warming and ecological change. Warming increases metabolic rates of animals, plants, and microbes, accelerating their use of energy and materials, their population growth, and interaction rates. At a much larger biological scale, warming accelerates ecosystem-level processes, elevating fluxes of carbon and oxygen between biota and the atmosphere. Although these general effects of temperature at finer and broader biological scales are widely observed, they can lead to contradictory predictions for how warming affects the structure and function of ecological communities at the intermediate scale of biological organization. We experimentally tested the hypothesis that the presence of predators and their associated species interactions modify the temperature dependence of net ecosystem oxygen production and respiration. We tracked a series of independent freshwater ecosystems (370 L) over 9 weeks, and we found that at higher temperatures, cascading effects of predators on zooplankton prey and algae were stronger than at lower temperatures. When grazing was weak or absent, standing phytoplankton biomass declined by 85%–95% (<1-fold) over the temperature gradient (19–30 °C), and by 3-fold when grazers were present and lacked predators. These temperature-dependent species interactions and consequent community biomass shifts occurred without signs of species loss or community collapse, and only modestly affected the temperature dependence of net ecosystem oxygen fluxes. The exponential increases in net ecosystem oxygen production and consumption were relatively insensitive to differences in trophic interactions among ecosystems. Furthermore, monotonic declines in phytoplankton standing stock suggested no threshold effects of warming across systems. We conclude that local changes in community structure, including temperature-dependent trophic cascades, may be compatible with prevailing and predictable effects of temperature on ecosystem functions related to fundamental effects of temperature on metabolism

Cortisol levels and suicidal behavior: a meta-analysis

Suicide is a major cause of death worldwide, responsible for 1.5% of all mortality. The causes of suicidal behavior are not fully understood. Dysregulated hypothalamic-pituitary-adrenal (HPA) axis activity, as measured by cortisol levels, is one potential risk factor. This meta-analytic review aimed i) to estimate the strength and variability of the association between naturally fluctuating cortisol levels and suicidal behavior and ii) to identify moderators of this relationship. A systematic literature search identified 27 studies (N = 2226; 779 suicide attempters & 1447 non-attempters) that met the study eligibility criteria from a total of 417 unique records initially examined. Estimates of effect sizes (r) obtained from these studies were analysed using Comprehensive Meta-Analysis. In these analyses, we compared participants identified as having a past history of suicide attempt(s) to those with no such history. Study quality, mean age of sample and percentage of male participants were examined as potential moderators. Overall, there was no significant effect of suicide group on cortisol. However, significant associations between cortisol and suicide attempts were observed as a function of age. In studies where the mean age of the sample was below 40 years the association was positive (i.e., higher cortisol was associated with suicide attempts; r = .234, p < .001), and where the mean age was 40 or above the association was negative (i.e., lower cortisol was associated with suicide attempts; r = - .129, p < .001). These findings confirm that HPA axis activity, as indicated by age-dependent variations in cortisol levels, is associated with suicidal behavior. The challenge for theory and clinical practice is to explain the complete reversal of the association with age and to identify its clinical implications

Community health workers can improve child growth of antenatally-depressed, South African mothers : a cluster randomized controlled trial

CITATION: Tomlinson, M., et al. 2015. Community health workers can improve child growth of antenatally-depressed, South African mothers : a cluster randomized controlled trial. BMC Psychiatry, 15:225, doi:10.1186/s12888-015-0606-7.The original publication is available at https://bmcpsychiatry.biomedcentral.comBackground: Maternal antenatal depression has long-term consequences for children’s health. We examined if home visits by community health workers (CHW) can improve growth outcomes for children of mothers who are antenatally depressed. Methods: A cluster randomized controlled trial of all pregnant, neighbourhood women in Cape Town, South Africa. Almost all pregnant women (98 %, N = 1238) were recruited and assessed during pregnancy, two weeks post-birth (92 %) and 6 months post-birth (88 %). Pregnant women were randomized to either: 1) Standard Care (SC), which provided routine antenatal care; or 2) an intervention, The Philani Intervention Program (PIP), which included SC and home visits by CHW trained as generalists (M = 11 visits). Child standardized weight, length, and weight by length over 6 months based on maternal antenatal depression and intervention condition. Results: Depressed mood was similar across the PIP and SC conditions both antenatally (16.5 % rate) and at 6 months (16.7 %). The infants of depressed pregnant women in the PIP group were similar in height (height-forage Z scores) to the children of non-depressed mothers in both the PIP and the SC conditions, but significantly taller at 6 months of age than the infants of pregnant depressed mothers in the SC condition. The intervention did not moderate children’s growth. Depressed SC mothers tended to have infants less than two standard deviations in height on the World Health Organization’s norms at two weeks post-birth compared to infants of depressed PIP mothers and non-depressed mothers in both conditions. Conclusions: A generalist, CHW-delivered home visiting program improved infant growth, even when mothers’ depression was not reduced. Focusing on maternal caretaking of infants, even when mothers are depressed, is critical in future interventions.https://bmcpsychiatry.biomedcentral.com/articles/10.1186/s12888-015-0606-7Publisher's versio

Results of the Sukuma Ndoda (“Stand up, Man”) HIV Self-Screening and Assisted Linkage to Care Project in Johannesburg: A Quasi-Experimental Pre–Post Evaluation

BackgroundHIV testing rates among South African men lag behind rates for women and national targets. Community-based HIV self-screening (HIVSS) distribution and follow-up by community health workers (CHWs) is a scalable option to increase testing coverage, diagnosis, and treatment initiation. We provided HIVSS and assisted linkage to care to men not recently tested (within the past 12 months) residing in high-HIV-burden areas of Johannesburg.MethodsCHWs distributed HIVSS in 6 clinic catchment areas. Follow-up to encourage confirmatory testing and antiretroviral therapy initiation was conducted through personal support (PS) or an automated short message service (SMS) follow-up and linkage system in 3 clinic areas each. Using a quasi-experimental pre-post design, we compared differences in the proportion of men testing in the clinic catchment areas during the HIVSS campaign (June-August 2019) to the 3 months prior (March-May 2019) and compared treatment initiations by assisted linkage strategy.ResultsAmong 4793 participants accepting HIVSS, 62% had never tested. Among 3993 participants with follow-up data, 90.6% reported using their HIVSS kit. Testing coverage among men increased by 156%, from under 4% when only clinic-based HIV testing services were available to 9.5% when HIVSS and HIV testing services were available (z = -11.6; P &lt; 0.01). Reported test use was higher for men followed through PS (99% vs. 68% in SMS); however, significantly more men reported reactive self-test results in the SMS group compared with PS (6.4% vs. 2.0%), resulting in more antiretroviral therapy initiations in the SMS group compared with PS (23 vs. 9; P &lt; 0.01).ConclusionsCHW HIVSS distribution significantly increases testing among men. While PS enabled personalized follow-up, reporting differences indicate SMS is more acceptable and better aligned with expectations of privacy associated with HIVSS

Relationship Between Hispanic Nativity, Residential Environment, and Productive Activity Among Individuals With Traumatic Brain Injury: A TBI Model Systems Study

Objective: To examine the influence of nativity and residential characteristics on productive activity among Hispanics at 1 year after traumatic brain injury (TBI). Setting: Acute rehabilitation facilities and community follow-up. Participants: A total of 706 Hispanic individuals in the TBI Model Systems National Database. Design: Secondary data analysis from a multicenter longitudinal cohort study. Main Measures: Nativity (foreign born or US native), productive activity derived from interview questions regarding employment status, and other demographic information. Census data were extracted by zip code to represent residential characteristics of aggregate household income and proportion of foreign language speakers (FLS). Results: Among foreign-born individuals with TBI, those living in an area with a higher proportion of FLS were 2.8 times more likely to be productive than those living in areas with a lower proportion of FLS. Among individuals living in an area with a lower proportion of FLS, US-born Hispanics were 2.7 times more likely to be productive compared with Hispanic immigrants. Conclusion: The relationship between nativity and productive activity at 1 year post-TBI was moderated by the residential proportion of FLS. Findings underscore the importance of considering environmental factors when designing vocational rehabilitation interventions for Hispanics after TBI