Wagers for work: Decomposing the costs of cognitive effort.

Some aspects of cognition are more taxing than others. Accordingly, many people will avoid cognitively demanding tasks in favor of simpler alternatives. Which components of these tasks are costly, and how much, remains unknown. Here, we use a novel task design in which subjects request wages for completing cognitive tasks and a computational modeling procedure that decomposes their wages into the costs driving them. Using working memory as a test case, our approach revealed that gating new information into memory and protecting against interference are costly. Critically, other factors, like memory load, appeared less costly. Other key factors which may drive effort costs, such as error avoidance, had minimal influence on wage requests. Our approach is sensitive to individual differences, and could be used in psychiatric populations to understand the true underlying nature of apparent cognitive deficits.

Dopamine and serotonin in human substantia nigra track social context and value signals during economic exchange.

Dopamine and serotonin are hypothesized to guide social behaviours. In humans, however, we have not yet been able to study neuromodulator dynamics as social interaction unfolds. Here, we obtained subsecond estimates of dopamine and serotonin from human substantia nigra pars reticulata during the ultimatum game. Participants, who were patients with Parkinson's disease undergoing awake brain surgery, had to accept or reject monetary offers of varying fairness from human and computer players. They rejected more offers in the human than the computer condition, an effect of social context associated with higher overall levels of dopamine but not serotonin. Regardless of the social context, relative changes in dopamine tracked trial-by-trial changes in offer value-akin to reward prediction errors-whereas serotonin tracked the current offer value. These results show that dopamine and serotonin fluctuations in one of the basal ganglia's main output structures reflect distinct social context and value signals.

Barriers to and solutions for representative inclusion across the lifespan and in life course research: The need for structural competency highlighted by the COVID-19 pandemic.

Exclusion of special populations (older adults; pregnant women, children, and adolescents; individuals of lower socioeconomic status and/or who live in rural communities; people from racial and ethnic minority groups; individuals from sexual or gender minority groups; and individuals with disabilities) in research is a pervasive problem, despite efforts and policy changes by the National Institutes of Health and other organizations. These populations are adversely impacted by social determinants of health (SDOH) that reduce access and ability to participate in biomedical research. In March 2020, the Northwestern University Clinical and Translational Sciences Institute hosted the "Lifespan and Life Course Research: integrating strategies" "Un-Meeting" to discuss barriers and solutions to underrepresentation of special populations in biomedical research. The COVID-19 pandemic highlighted how exclusion of representative populations in research can increase health inequities. We applied findings of this meeting to perform a literature review of barriers and solutions to recruitment and retention of representative populations in research and to discuss how findings are important to research conducted during the ongoing COVID-19 pandemic. We highlight the role of SDOH, review barriers and solutions to underrepresentation, and discuss the importance of a structural competency framework to improve research participation and retention among special populations.

PEMCRC anaphylaxis study protocol: a multicentre cohort study to derive and validate clinical decision models for the emergency department management of children with anaphylaxis.

INTRODUCTION: There remain significant knowledge gaps about the management and outcomes of children with anaphylaxis. These gaps have led to practice variation regarding decisions to hospitalise children and length of observation periods following treatment with epinephrine. The objectives of this multicentre study are to (1) determine the prevalence of and risk factors for severe, persistent, refractory and biphasic anaphylaxis, as well as persistent and biphasic non-anaphylactic reactions; (2) derive and validate prediction models for emergency department (ED) discharge; and (3) determine data-driven lengths of ED and inpatient observation prior to discharge to home based on initial reaction severity. METHODS AND ANALYSIS: The study is being conducted through the Pediatric Emergency Medicine Collaborative Research Committee (PEMCRC). Children 6 months to less than 18 years of age presenting to 30 participating EDs for anaphylaxis from October 2015 to December 2019 will be eligible. The primary outcomes for each objective are (1) severe, persistent, refractory or biphasic anaphylaxis, as well as persistent or biphasic non-anaphylactic reactions; (2) safe ED discharge, defined as no receipt of acute anaphylaxis medications or hypotension beyond 4 hours from first administered dose of epinephrine; and (3) time from first to last administered dose of epinephrine and vasopressor cessation. Analyses for each objective include (1) descriptive statistics to estimate prevalence and generalised estimating equations that will be used to investigate risk factors for anaphylaxis outcomes, (2) least absolute shrinkage and selection operator regression and binary recursive partitioning to derive and validate prediction models of children who may be candidates for safe ED discharge, and (3) Kaplan-Meier analyses to assess timing from first to last epinephrine doses and vasopressor cessation based on initial reaction severity. ETHICS AND DISSEMINATION: All sites will obtain institutional review board approval; results will be published in peer-reviewed journals and disseminated via traditional and social media, blogs and online education platforms.

Interobserver Agreement in the Assessment of Clinical Findings in Children with Headaches.

OBJECTIVE: To determine the interobserver agreement of history and physical examination findings in children undergoing evaluation in the emergency department (ED) for headaches. STUDY DESIGN: We conducted a prospective, cross-sectional study of children aged 2-17 years evaluated at 3 tertiary-care pediatric EDs for non-traumatic headaches. Two clinicians independently completed a standardized assessment of each child and documented the presence or absence of history and physical examination variables. Unweighted κ statistics were determined for 68 history and 24 physical examination variables. RESULTS: We analyzed 191 paired observations; median age was 12 years, with 19 (9.9%) children younger than 7 years. Interrater reliability was at least moderate (κ ≥ 0.41) for 41 (60.3%) patient history variables. Eleven (61.1%) of 18 physical examination variables for which κ statistics could be calculated had a κ that was at least moderate. CONCLUSIONS: A substantial number of history and physical examination findings demonstrated at least moderate κ statistic values when assessed in children with headaches in the ED. These variables may be generalizable across different types of clinicians for evaluation of children with headaches. If also found to predict the presence or absence of emergent intracranial abnormalities, the more reliable clinical findings may be helpful in the development of clinical prediction rules or risk stratification models that could be used across settings for children with headaches.

Engaging Adolescents With Sexual Health Messaging: A Qualitative Analysis.

PURPOSE: Personalized and interactive text messaging interventions may increase participant engagement; yet, how to design messages that retain adolescent attention and positively affect sexual health behaviors remains unclear. The purpose of this study was to identify the characteristics of sexual health text messages perceived as engaging by sexually active adolescent females. METHODS: We conducted semistructured, open-ended interviews with sexually active females aged 14-19 in one urban emergency department. Participants received automated sexual health information sent via an interactive, two-way texting format. The 343 messages viewed by participants were based on key stakeholder input, relevant theoretical models, and existing evidence-based guidelines. Interviews elicited feedback. Enrollment continued until saturation of themes. Interviews were recorded, transcribed, and coded based on thematic analysis using NVivo 10. RESULTS: Participants (n = 31) were predominantly Hispanic (28; 90%), insured (29; 94%), and recently sexually active (24; 77%). Themes were as follows: (1) Tone: messages should be direct, factual, entertaining, and respect adolescent autonomy; messages should not be intrusive, presumptive, or preachy. (2) Emotion evoked: participants preferred messages that provoked thought, validated feelings, and empowered. Messages from a reliable source felt comforting, making participants feel cared for and special. (3) Interactivity: participants favored messages that offered choices, such as a mini-conversation. (4) Personalization: messages should look similar to adolescent digital preferences but be individually tailored with relatable characters. CONCLUSIONS: This study informs the tone, structure, and style of sexual health text messages directed toward adolescent females in the emergency department. Future work should consider these characteristics when designing digital interventions to engage adolescent females.

A Qualitative Assessment to Understand the Barriers and Enablers Affecting Contraceptive Use Among Adolescent Male Emergency Department Patients.

Early fatherhood is common in the United States (U.S.). The emergency department (ED) plays a disproportionate role in serving patients with unmet reproductive and sexual health needs. With 8 million adolescent males visiting U.S. EDs annually, the ED is a potential site to implement interventions to minimize early fatherhood and unintended teenage pregnancy. Little is known about how adolescent male ED patients perceive and behave in sexual relationships and how they influence contraceptive decision making. The objective of this study was to identify the barriers and enablers affecting contraceptive and condom use among adolescent male ED patients. Semistructured interviews were conducted with males aged 14-19 in one urban ED. Enrollment continued until saturation of key themes. Interviews were recorded, transcribed, and coded based on thematic analysis using NVivo 10. The Social Ecological Model was used to organize and understand themes. Participants ( n = 24) were predominantly 18-19 years (63%) and Hispanic (92%). Most (71%) had sex ≤3 months prior but infrequently used a condom at last intercourse (42%). The primary barrier influencing contraceptive use was lack of knowledge of effective contraceptives. Other barriers consisted of perceived gender roles, poor partner communication, and little relationship with a primary provider. Enablers included intention not to get a partner pregnant, school-based sexual health education, normalcy to use condoms, and a trustworthy confidante. The identified barriers and enablers influencing adolescent males' perspectives toward contraceptives should be addressed if designing future ED-based pregnancy prevention interventions targeting teen males.

Early childhood investment impacts social decision-making four decades later.

Early childhood educational investment produces positive effects on cognitive and non-cognitive skills, health, and socio-economic success. However, the effects of such interventions on social decision-making later in life are unknown. We recalled participants from one of the oldest randomized controlled studies of early childhood investment-the Abecedarian Project (ABC)-to participate in well-validated interactive economic games that probe social norm enforcement and planning. We show that in a repeated-play ultimatum game, ABC participants who received high-quality early interventions strongly reject unequal division of money across players (disadvantageous or advantageous) even at significant cost to themselves. Using a multi-round trust game and computational modeling of social exchange, we show that the same intervention participants also plan further into the future. These findings suggest that high quality early childhood investment can result in long-term changes in social decision-making and promote social norm enforcement in order to reap future benefits.

A model of risk and mental state shifts during social interaction.

Cooperation and competition between human players in repeated microeconomic games offer a window onto social phenomena such as the establishment, breakdown and repair of trust. However, although a suitable starting point for the quantitative analysis of such games exists, namely the Interactive Partially Observable Markov Decision Process (I-POMDP), computational considerations and structural limitations have limited its application, and left unmodelled critical features of behavior in a canonical trust task. Here, we provide the first analysis of two central phenomena: a form of social risk-aversion exhibited by the player who is in control of the interaction in the game; and irritation or anger, potentially exhibited by both players. Irritation arises when partners apparently defect, and it potentially causes a precipitate breakdown in cooperation. Failing to model one's partner's propensity for it leads to substantial economic inefficiency. We illustrate these behaviours using evidence drawn from the play of large cohorts of healthy volunteers and patients. We show that for both cohorts, a particular subtype of player is largely responsible for the breakdown of trust, a finding which sheds new light on borderline personality disorder.

Economic Analysis of Diagnostic Imaging in Pediatric Patients With Suspected Appendicitis.

OBJECTIVE: The use of computed tomography (CT) and ultrasound (US) in patients with acute abdominal pain has substantial variation across pediatric emergency departments (EDs). This study compares the cost of diagnosing and treating suspected appendicitis across a multicenter network of children's hospitals. METHODS: This study is a secondary analysis using deidentified data of a prospective, observational study of patients with suspected appendicitis at nine pediatric EDs. The study included patients 3 to 18 years old who presented to the ED with acute abdominal pain of <96 hours' duration. RESULTS: Our data set contained 2,300 cases across nine sites. There was an appendicitis rate of 31.8% and perforation rate of 25.7%. Sites correctly diagnosed appendicitis in over 95% of cases. The negative appendicitis rate ranged from 2.5% to 4.7% while the missed appendicitis rate ranged from 0.3% to 1.1% with no significant differences in these rates across site. Across sites, we found a strong positive correlation (0.95) between CT rate and total cost per case and a strong negative correlation (-0.71) between US rate and cost. The cost per case at US sites was 5.2% ($367) less than at CT sites (p < 0.001). Similarly, costs per case at mixed sites were 3.4% ($244) less than at CT sites (p < 0.001). Comparing costs among CT sites or among US sites, the cost per case generally increased as the images per case increased among both CT sites and US sites, but the costs were universally higher at CT sites. CONCLUSIONS: Our results provide support for US as the primary imaging modality for appendicitis. Sites that preferentially utilized US had lower costs per case than sites that primarily used CT. Imaging rates across sites varied due to practice patterns and resulted in a significant cost consequence without higher rates for negative appendectomies or missed appendicitis cases.

Interrupting behaviour: Minimizing decision costs via temporal commitment and low-level interrupts.

Ideal decision-makers should constantly assess all sources of information about opportunities and threats, and be able to redetermine their choices promptly in the face of change. However, perpetual monitoring and reassessment impose inordinate sensing and computational costs, making them impractical for animals and machines alike. The obvious alternative of committing for extended periods of time to limited sensory strategies associated with particular courses of action can be dangerous and wasteful. Here, we explore the intermediate possibility of making provisional temporal commitments whilst admitting interruption based on limited broader observation. We simulate foraging under threat of predation to elucidate the benefits of such a scheme. We relate our results to diseases of distractibility and roving attention, and consider mechanistic substrates such as noradrenergic neuromodulation.

The social contingency of momentary subjective well-being.

Although social comparison is a known determinant of overall life satisfaction, it is not clear how it affects moment-to-moment variation in subjective emotional state. Using a novel social decision task combined with computational modelling, we show that a participant's subjective emotional state reflects not only the impact of rewards they themselves receive, but also the rewards received by a social partner. Unequal outcomes, whether advantageous or disadvantageous, reduce average momentary happiness. Furthermore, the relative impacts of advantageous and disadvantageous inequality on momentary happiness at the individual level predict a subject's generosity in a separate dictator game. These findings demonstrate a powerful social influence upon subjective emotional state, where emotional reactivity to inequality is strongly predictive of altruism in an independent task domain.

Monte Carlo Planning Method Estimates Planning Horizons during Interactive Social Exchange.

Reciprocating interactions represent a central feature of all human exchanges. They have been the target of various recent experiments, with healthy participants and psychiatric populations engaging as dyads in multi-round exchanges such as a repeated trust task. Behaviour in such exchanges involves complexities related to each agent's preference for equity with their partner, beliefs about the partner's appetite for equity, beliefs about the partner's model of their partner, and so on. Agents may also plan different numbers of steps into the future. Providing a computationally precise account of the behaviour is an essential step towards understanding what underlies choices. A natural framework for this is that of an interactive partially observable Markov decision process (IPOMDP). However, the various complexities make IPOMDPs inordinately computationally challenging. Here, we show how to approximate the solution for the multi-round trust task using a variant of the Monte-Carlo tree search algorithm. We demonstrate that the algorithm is efficient and effective, and therefore can be used to invert observations of behavioural choices. We use generated behaviour to elucidate the richness and sophistication of interactive inference.

Depression: a decision-theoretic analysis.

The manifold symptoms of depression are common and often transient features of healthy life that are likely to be adaptive in difficult circumstances. It is when these symptoms enter a seemingly self-propelling spiral that the maladaptive features of a disorder emerge. We examine this malignant transformation from the perspective of the computational neuroscience of decision making, investigating how dysfunction of the brain's mechanisms of evaluation might lie at its heart. We start by considering the behavioral implications of pessimistic evaluations of decision variables. We then provide a selective review of work suggesting how such pessimism might arise via specific failures of the mechanisms of evaluation or state estimation. Finally, we analyze ways that miscalibration between the subject and environment may be self-perpetuating. We employ the formal framework of Bayesian decision theory as a foundation for this study, showing how most of the problems arise from one of its broad algorithmic facets, namely model-based reasoning.

The algorithmic anatomy of model-based evaluation.

Despite many debates in the first half of the twentieth century, it is now largely a truism that humans and other animals build models of their environments and use them for prediction and control. However, model-based (MB) reasoning presents severe computational challenges. Alternative, computationally simpler, model-free (MF) schemes have been suggested in the reinforcement learning literature, and have afforded influential accounts of behavioural and neural data. Here, we study the realization of MB calculations, and the ways that this might be woven together with MF values and evaluation methods. There are as yet mostly only hints in the literature as to the resulting tapestry, so we offer more preview than review.

Use of the focused assessment with sonography for trauma (FAST) examination and its impact on abdominal computed tomography use in hemodynamically stable children with blunt torso trauma.

BACKGROUND: The aim of this study was to evaluate the variability of clinician-performed Focused Assessment with Sonography for Trauma (FAST) examinations and its impact on abdominal computed tomography (AbCT) use in hemodynamically stable children with blunt torso trauma (BTT). The FAST is used with variable frequency in children with BTT. METHODS: We performed a planned secondary analysis of children (<18 years) with BTT. Patients with a Glasgow Coma Scale (GCS) score of less than 9, those with hypotension, and those taken directly to the operating suite were excluded. Clinicians documented their suspicion for intra-abdominal injury (IAI) as very low, less than 1%; low, 1% to 5%; moderate, 6% to 10%; high, 11% to 50%; or very high, greater than 50%. We determined the relative risk (RR) for AbCT use based on undergoing a FAST examination in each of these clinical suspicion strata. RESULTS: Of 6,468 (median age, 11.8 years; interquartile range, 6.3-15.5 years) children who met eligibility, 887 (13.7%) underwent FAST examination before CT scan. A total of 3,015 (46.6%) underwent AbCT scanning, and 373 (5.8%) were diagnosed with IAI. Use of the FAST increased as clinician suspicion for IAI increased, 11.0% with less than 1% suspicion for IAI, 13.5% with 1% to 5% suspicion, 20.5% with 6% to 10% suspicion, 23.2% with 11% to 50% suspicion, and 30.7% with greater than 50% suspicion. The patients in whom the clinicians had a suspicion of IAI of 1% to 5% or 6% to 10% were significantly less likely to undergo a CT scan if a FAST examination was performed: RR, 0.83 (0.67-1.03); RR, 0.81 (0.72-0.91); RR, 0.85 (0.78-0.94); RR, 0.99 (0.94-1.05); and RR, 0.97 (0.91-1.05) for patients with clinician suspicion of IAI of less than 1%, 1% to 5%, 6% to 10%, 11% to 50%, and greater than 50%, respectively. CONCLUSION: The FAST examination is used in a relatively small percentage of children with BTT. Use increases as clinician suspicion for IAI increases. Patients with a low or moderate clinician suspicion of IAI are less likely to undergo AbCT if they receive a FAST examination. A randomized controlled trial is required to more precisely determine the benefits and drawbacks of the FAST examination in the evaluation of children with BTT. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, II.

Optimal indolence: a normative microscopic approach to work and leisure.

Dividing limited time between work and leisure when both have their attractions is a common everyday decision. We provide a normative control-theoretic treatment of this decision that bridges economic and psychological accounts. We show how our framework applies to free-operant behavioural experiments in which subjects are required to work (depressing a lever) for sufficient total time (called the price) to receive a reward. When the microscopic benefit-of-leisure increases nonlinearly with duration, the model generates behaviour that qualitatively matches various microfeatures of subjects' choices, including the distribution of leisure bout durations as a function of the pay-off. We relate our model to traditional accounts by deriving macroscopic, molar, quantities from microscopic choices.

Nurse and physician agreement in the assessment of minor blunt head trauma.

OBJECTIVE: The Pediatric Emergency Care Applied Research Network (PECARN) traumatic brain injury (TBI) clinical prediction rules identify children with minor blunt head trauma who are at low risk for clinically important traumatic brain injuries. We measured the agreement between the registered nurse (RN) and physician (MD) assessments. METHODS: We performed a cross-sectional study of all children <18 years of age with minor blunt head trauma who presented to a single emergency department. RNs and MDs independently assessed each child and recorded age-based PECARN predictors. As symptoms can change over time, we included cases only when both evaluations were completed within 60 minutes. We used the κ statistic to measure RN-MD agreement, with the main analysis focusing on the overall PECARN rule agreement. RESULTS: Of the 1624 eligible children, 1191 (73%) had evaluations completed by both RN and ED providers, of which 437 (37%) were in children <2 years of age. The median time between completions of the provider forms was 12 minutes (interquartile range 4-25 minutes). The overall agreement between the RN and MD was higher for the older children (κ 0.55, 95% confidence interval 0.49-0.61 for children 2-18 years versus κ 0.32, 95% confidence interval 0.23-0.41 for children <2 years). CONCLUSIONS: The overall agreement between RN and MD for the PECARN TBI prediction rules was moderate for older children and fair for younger children. Initial RN assessments should be verified by the MD before clinical application, especially for the youngest children.

Variation in resource utilization across a national sample of pediatric emergency departments.

OBJECTIVE: To describe variations in emergency department (ED) quality measures and determine the association between ED costs and outcomes for 3 pediatric conditions: asthma, gastroenteritis, and simple febrile seizure. STUDY DESIGN: This cross-sectional analysis of ED visits used the Pediatric Health Information System database. Children aged ≤ 18 years who were evaluated in an ED between July 2009 and June 2011 and had a discharge diagnosis of asthma, gastroenteritis, or simple febrile seizure were included. Two quality of care metrics were evaluated for each target condition, and Spearman correlation was applied to evaluate the relationship between ED costs (reflecting overall resource utilization) and admission and revisit rates among institutions. RESULTS: More than 250,000 ED visits at 21 member hospitals were analyzed. Among children with asthma, the median rate of chest radiography utilization was 35.1% (IQR, 31.3%-41.7%), and that of corticosteroid administration was 82.6% (IQR, 78.5%-86.5%). For children with gastroenteritis, the median rate of ondansetron administration was 52% (IQR, 43.2%-57.0%), and that of intravenous fluid administration was 18.1% (IQR, 15.3%-21.3%). Among children with febrile seizures, the median rate of computed tomography utilization was 3.1% (IQR, 2.7%-4.3%), and that of lumbar puncture was 4.0% (IQR, 2.3%-5.6%). Increased costs were not associated with lower admission rate or 3-day ED revisit rate for the 3 conditions. CONCLUSION: We observed variation in quality measures for patients presenting to pediatric EDs with common conditions. Higher costs were not associated with lower hospitalization or ED revisit rates.

Identifying adolescent females at high risk of pregnancy in a pediatric emergency department.

PURPOSE: Emergency departments (EDs) care for adolescent females with unmet reproductive health care needs. Our objective was, among adolescents presenting to a pediatric ED, to estimate pregnancy risk, describe pregnancy intentions, and identify potentially modifiable factors associated with pregnancy risk. METHODS: Using a paper-based questionnaire, we surveyed females aged 15-19 years presenting to our ED, assessing health care access, sexual behaviors, pregnancy intentions, and receptivity to interventions. We calculated the pregnancy risk index (PRI), which estimates pregnancy risk in the subsequent 12 months, by assessing recent sexual activity, contraception at last intercourse, and known contraceptive failure rates. Independent sample t tests and analysis of variance were used to identify risk factors associated with increased PRI. RESULTS: Of 459 females enrolled, 13% were pregnant and 20% reported prior pregnancy. Among 399 nonpregnant females, 238 (60%) had intercourse in the prior 3 months and 73 (31%) used no contraception at last intercourse. Among nonpregnant adolescents, the PRI was 19.5, which equates to 19.5 expected pregnancies per 100 females per year. Factors associated with higher PRI included lacking a primary provider, prior ED visits, wanting a baby now, and reported partner wantedness of pregnancy. Half believed ED doctors should discuss pregnancy prevention, and one-quarter were interested in starting contraception in the ED. CONCLUSIONS: Nearly one-third of adolescent females in a pediatric ED were either pregnant or could be expected to become pregnant within a year. Screening questions can identify adolescents at high risk of pregnancy in the ED setting. These females should be the target for future pregnancy prevention interventions.