41 research outputs found
Gaussian multiplicative chaos through the lens of the 2D Gaussian free field
The aim of this review-style paper is to provide a concise, self-contained
and unified presentation of the construction and main properties of Gaussian
multiplicative chaos (GMC) measures for log-correlated fields in 2D in the
subcritical regime. By considering the case of the 2D Gaussian free field, we
review convergence, uniqueness and characterisations of the measures; revisit
Kahane's convexity inequalities and existence and scaling of moments; discuss
the measurability of the underlying field with respect to the GMC measure and
present a KPZ relation for scaling exponents.Comment: 28p, less typos in the 3rd, published version, still no figures, I
remain thankful for comment
A matter of design: priming context and person perception
A matter of considerable debate is whether people spontaneously use categorical knowledge (i.e., stereotypes) to guide their interactions with others. Despite initial evidence for the unconditional automaticity of category activation, recent research has identified a range of factors that moderate this process. Extending this line of inquiry, the current investigation explored the extent to which contextual influences - specifically the order in which priming stimuli are presented to participants - may modulate person categorization. Using a standard semantic-priming paradigm to index category and stereotype activation, participants were presented with priming stimuli that were either intermixed or blocked by sex. The results revealed that: (i) category and stereotype activation are moderated by the order in which priming stimuli are presented; and (ii) priming effects decrease monotonically as a function of category repetition. The theoretical implications of these findings are considered
Investigating the Early Stages of Person Perception: The Asymmetry of Social Categorization by Sex vs. Age
The wealth of information provided by facial cues presents challenges to our understanding of these early stages of person perception. The current study aimed to uncover the dynamics of processing multiply categorizable faces, notably as a function of their gender and age. Using a modified four-choice version of a mouse-tracking paradigm (which assesses the relative dominance of two categorical dimensions), the relative influence that sex and age have on each other during categorization of infant, younger adult, and older adult faces was investigated. Results of these experiments demonstrate that when sex and age dimensions are simultaneously categorized, only for infant faces does age influence sex categorization. In contrast, the sex of both young and older adults was shown to influence age categorization. The functional implications of these findings are discussed in light of previous person perception research
Investigating the Early Stages of Person Perception: The Asymmetry of Social Categorization by Sex vs. Age
The wealth of information provided by facial cues presents challenges to our understanding of these early stages of person perception. The current study aimed to uncover the dynamics of processing multiply categorizable faces, notably as a function of their gender and age. Using a modified four-choice version of a mouse-tracking paradigm (which assesses the relative dominance of two categorical dimensions), the relative influence that sex and age have on each other during categorization of infant, younger adult, and older adult faces was investigated. Results of these experiments demonstrate that when sex and age dimensions are simultaneously categorized, only for infant faces does age influence sex categorization. In contrast, the sex of both young and older adults was shown to influence age categorization. The functional implications of these findings are discussed in light of previous person perception research
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Intergroup contact throughout the lifespan modulates implicit racial biases across perceivers’ racial group
Few researchers have investigated how contact across the lifespan influences racial bias and whether diversity of contact is beneficial regardless of the race of the perceiver. This research aims to address these gaps in the literature with a focus on how diversity in childhood and current contact shapes implicit racial bias across perceivers’ racial group. In two investigations, participants completed an Implicit Association Test and a self-report measure of the racial diversity of their current and childhood contact. In both studies, increased contact with Black compared with White individuals, both in childhood (Study 2) and currently (Studies 1 and 2), was associated with reduced implicit pro-White racial bias. For Black individuals (Study 2) more contact with Black compared with White individuals also was associated with reduced implicit pro-White racial bias. These findings suggest that diversity in contact across the lifespan may be related to reductions in implicit racial biases and that this relationship may generalize across racial groups
Dissociable Neural Substrates for Agentic versus Conceptual Representations of Self
Although humans generally experience a coherent sense of selfhood, we can nevertheless articulate different aspects of self. Recent research has demonstrated that one such aspect of self—conceptual knowledge of one's own personality traits—is subserved by ventromedial prefrontal cortex (vMPFC). Here, we examined whether an alternative aspect of “self”—being an agent who acts to achieve one's own goals—relies on cognitive processes that overlap with or diverge from conceptual operationalizations of selfhood. While undergoing fMRI, participants completed tasks of both conceptual self-reference, in which they judged their own or another person's personality traits, and agentic self-reference, in which they freely chose an object or watched passively as one was chosen. The agentic task failed to modulate vMPFC, despite producing the same memory enhancement frequently observed during conceptual self-referential processing (the “self-reference” effect). Instead, agentic self-reference was associated with activation of the intraparietal sulcus (IPS), a region previously implicated in planning and executing actions. Experiment 2 further demonstrated that IPS activity correlated with later memory performance for the agentic, but not conceptual, task. These results support views of the “self” as a collection of distinct mental operations distributed throughout the brain, rather than a unitary cognitive system
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Intraparietal Sulcus Activity During Explicit Self-Referential Social Status Judgments about Others
Previous research has suggested that the intraparietal sulcus (IPS) supports judgments of social distance, with greater activity observed in response to targets judged to be closer to each other (Yamakawa, Kanai, Matsumura, & Naito, 2009). Amongst other stimuli, activity in the IPS appears to be responsive to targets varying in social status (Chiao et al., 2009; Cloutier, Ambady, Meagher, & Gabrieli, 2012). The current project examined brain responses during explicit self-referential social status judgments of targets varying in either financial or moral status. Using an event-related fMRI design, participants viewed photographs of male faces paired with distinct levels of financial or moral status. During the task, participants were asked to explicitly identify each target’s status in relation to their own. Focusing on IPS activity, results from whole-brain and region of interest analyses revealed an interaction between social status types and levels. The implications of these results are discussed with respect to our current understanding of the impact of social status on the neural substrates of person perception.Investigación previa ha sugerido que el surco intraparietal (IPS) respalda juicios de distancia social, con mayor actividad observada en respuesta a objetivos juzgados para estar más cerca de otros (Yamakawa, Kanai, Matsumura, & Naito, 2009). Entre otros estímulos, la actividad en el surco intraparietal parece ser receptiva a objetivos variando en estatus sociales (Chiao et al., 2009; Cloutier, Ambady, Meagher, & Gabrieli, 2012). El presente proyecto examinó las respuestas cerebrales durante juicios de estatus sociales auto-referenciales de objetivos variando tanto en estatus morales como financieros. Usando un diseño de resonancia magnética asociada a evento, los participantes observaron fotografías de rostros masculinos emparejadas con distintos niveles de estatus financieros o morales. Durante la tarea, se les pidió a los participantes identificar explícitamente el estatus de cada objetivo en relación al de ellos. Enfocándose en la actividad del surco intraparietal, los resultados de los análisis del cerebro entero y de regiones de interés revelaron una interacción entre los tipos y niveles de estatus sociales. Las implicaciones de estos resultados son discutidas con respecto a nuestro entendimiento actual del impacto del estatus social en los substratos neuronales de la percepción de las personas
Actividad del Surco Intraparietal Durante Juicios de Estatus Sociales Auto-Referenciales De Otros
Previous research has suggested that the intraparietal sulcus (IPS) supports judgments of social distance, with greater activity observed in response to targets judged to be closer to each other (Yamakawa, Kanai, Matsumura, & Naito, 2009). Amongst other stimuli, activity in the IPS appears to be responsive to targets varying in social status (Chiao et al., 2009; Cloutier, Ambady, Meagher, & Gabrieli, 2012). The current project examined brain responses during explicit self-referential social status judgments of targets varying in either financial or moral status. Using an event-related fMRI design, participants viewed photographs of male faces paired with distinct levels of financial or moral status. During the task, participants were asked to explicitly identify each target’s status in relation to their own. Focusing on IPS activity, results from whole-brain and region of interest analyses revealed an interaction between social status types and levels. The implications of these results are discussed with respect to our current understanding of the impact of social status on the neural substrates of person perception.Investigación previa ha sugerido que el surco intraparietal (IPS) respalda juicios de distancia social, con mayor actividad observada en respuesta a objetivos juzgados para estar más cerca de otros (Yamakawa, Kanai, Matsumura, & Naito, 2009). Entre otros estímulos, la actividad en el surco intraparietal parece ser receptiva a objetivos variando en estatus sociales (Chiao et al., 2009; Cloutier, Ambady, Meagher, & Gabrieli, 2012). El presente proyecto examinó las respuestas cerebrales durante juicios de estatus sociales auto-referenciales de objetivos variando tanto en estatus morales como financieros. Usando un diseño de resonancia magnética asociada a evento, los participantes observaron fotografías de rostros masculinos emparejadas con distintos niveles de estatus financieros o morales. Durante la tarea, se les pidió a los participantes identificar explícitamente el estatus de cada objetivo en relación al de ellos. Enfocándose en la actividad del surco intraparietal, los resultados de los análisis del cerebro entero y de regiones de interés revelaron una interacción entre los tipos y niveles de estatus sociales. Las implicaciones de estos resultados son discutidas con respecto a nuestro entendimiento actual del impacto del estatus social en los substratos neuronales de la percepción de las personas