Proactive response preparation contributes to contingency learning: novel evidence from force-sensitive keyboards.

Contingency learning can involve learning that the identity of one stimulus in a sequence predicts the identity of the next stimulus. It remains unclear, however, whether such learning speeds responses to the next stimulus only by reducing the threshold for triggering the expected response after stimulus onset or also by preparing the expected response before stimulus onset. To distinguish between these competing accounts, we manipulated the probabilities with which each of two prime arrows (Left and Right) were followed by each of two probe arrows (Up and Down) in a prime-probe task while using force-sensitive keyboards to monitor sub-threshold finger force. Consistent with the response preparation account, two experiments revealed greater force just before probe onset on the response key corresponding to the direction in which the probe was more (versus less) likely to point (e.g., Up vs. Down). Furthermore, mirroring sequential contingency effects in behavior, this pre-probe force effect vanished after a single low-probability trial. These findings favor the response preparation account over the threshold only account. They also suggest the possibility that contingency learning in our tasks indexes trial-by-trial expectations regarding the utility of the prime for predicting the upcoming probe.

Measurement of the frequency dependence of four terminal-pair air capacitors with a vector network analyzer.

Four terminal-pair air capacitors are important transfer standards to calibrate LCR meters up to a frequency of 10 MHz. We report a simple and new method to obtain the frequency dependence of the four terminal-pair capacitance of these standards using a four-channel vector network analyzer (VNA). The frequency dependence of the capacitance of an air capacitor and its uncertainty can be obtained from a single set of measurements without changing connections between the standard and the VNA, as has been the case in previously published work. The calculation of the frequency dependency is straightforward and model-independent. Nevertheless, an elementary model is provided to explain the observed frequency dependence. This article allows every laboratory with a four-channel VNA to measure the frequency dependence of these capacitors. Hence, a significant shortening of the traceability chain is achieved.

Interlinguistic conflict: Word-word Stroop with first and second language colour words.

The congruency (or Stroop) effect is a standard observation of slower and less accurate colour identification to incongruent trials (e.g. "red" in green) relative to congruent trials (e.g. "red" in red). This effect has been observed in a word-word variant of the task, when both the distracter (e.g. "red") and target (e.g. "green") are colour words. The Stroop task has also been used to study the congruency effect between two languages in bilinguals. The typical finding is that the congruency effect for L1 words is larger than that for L2 words. For the first time, the present report aims to extend this finding to a word-word variant of the bilingual Stroop task. In two experiments, French monolinguals performed a bilingual word-word Stroop task in which target word language, language match, and congruency between the distracter and target were manipulated. The critical manipulation across two experiments concerned the target language. In Experiment 1, target language was manipulated between groups, with either French (L1) or English (L2) target colour words. In Experiment 2, target words from both languages were intermixed. In both experiments, the congruency effect was larger when the distracter and target were from the same language (language match) than when they were from different languages (language mismatch). Our findings suggested that this congruency effect mostly depends on the language match between the distracter and target, rather than on a target language. It also did not seem to matter whether the language-mismatching distracter was or was not a potential response alternative. Semantic activation of languages in bilinguals and its implications on target identification are discussed.

Pediatric croup with COVID-19.

We describe three previously healthy children, admitted from our emergency department (ED) to our free-standing children's hospital, as the first documented cases of croup as a manifestation of SARS-CoV-2 infection. All three cases (ages 11 months, 2 years, and 9 years old) presented with non-specific upper-respiratory-tract symptoms that developed into a barky cough with associated stridor at rest and respiratory distress. All were diagnosed with SARS-CoV-2 by polymerase chain reaction testing from nasopharyngeal samples that were negative for all other pathogens including the most common etiologies for croup. Each received multiple (≥3) doses of nebulized racemic epinephrine with minimal to no improvement shortly after medication. All had a prolonged period of time from ED presentation until the resolution of their stridor at rest (13, 19, and 21 h). All received dexamethasone early in their ED treatment and all were admitted. All three received at least one additional dose of dexamethasone, an atypical treatment occurrence in our hospital, due to each patient's prolonged duration of symptoms. One child required heliox therapy and admission to intensive care. All patients were eventually discharged. Pathogen testing is usually not indicated in croup, but with "COVID-19 croup," SARS-CoV-2 testing should be considered given the prognostic significance and prolonged quarantine implications. Our limited experience with this newly described COVID-19 croup condition suggests that cases can present with significant pathology and might not improve as rapidly as those with typical croup.

The Use of Coffee to Decrease the Incidence of Postoperative Ileus: A Systematic Review and Meta-Analysis.

PURPOSE: To investigate the efficacy of providing coffee to elective abdominal surgery patients, immediately postoperatively, to lessen postoperative ileus. DESIGN: A systematic review with meta-analysis of six randomized controlled trials published since 2012. METHODS: Methodological quality was evaluated using the Cochrane guidelines. The Grading of Recommendations, Assessment, Development, and Evaluations assessment tool evaluated the quality of the evidence. Subgroup analyses were completed if the I2 statistic demonstrated heterogeneity (greater than 50%). FINDINGS: Coffee was statistically significant in shortening the time between surgery and the first passage of stool (mean difference, -9.38; 95% confidence interval, -17.60 to -1.16; P = .03). Although not statistically significant (P = .20), the overall effect favored shorter hospital stays for those patients receiving coffee. CONCLUSIONS: The current systematic review and meta-analysis suggests that coffee given as early as 2 hours postoperatively decreases time to first bowel movement. In addition, patients tolerated solid food faster and were discharged sooner when given coffee immediately postoperatively.

High salt diet impairs cerebral blood flow regulation via salt-induced angiotensin II suppression.

OBJECTIVES: This study sought to determine whether salt-induced ANG II suppression contributes to impaired CBF autoregulation. METHODS: Cerebral autoregulation was evaluated with LDF during graded reductions of blood pressure. Autoregulatory responses in rats fed HS (4% NaCl) diet vs LS (0.4% NaCl) diet were analyzed using linear regression analysis, model-free analysis, and a mechanistic theoretical model of blood flow through cerebral arterioles. RESULTS: Autoregulation was intact in LS-fed animals as MAP was reduced via graded hemorrhage to approximately 50 mm Hg. Short-term (3 days) and chronic (4 weeks) HS diet impaired CBF autoregulation, as evidenced by progressive reductions of laser Doppler flux with arterial pressure reduction. Chronic low dose ANG II infusion (5 mg/kg/min, i.v.) restored CBF autoregulation between the pre-hemorrhage MAP and 50 mm Hg in rats fed short-term HS diet. Mechanistic-based model analysis showed a reduced myogenic response and reduced baseline VSM tone with short-term HS diet, which was restored by ANG II infusion. CONCLUSIONS: Short-term and chronic HS diet lead to impaired autoregulation in the cerebral circulation, with salt-induced ANG II suppression as a major factor in the initiation of impaired CBF regulation.

Propofol Versus Dexmedetomidine for Procedural Sedation in a Pediatric Population.

OBJECTIVES: Frequently, infants and children require sedation to facilitate noninvasive procedures and imaging studies. Propofol and dexmedetomidine are used to achieve deep procedural sedation in children. The objective of this study was to compare the clinical safety and efficacy of propofol versus dexmedetomidine in pediatric patients undergoing sedation in a pediatric sedation unit. METHODS: A retrospective analysis of patients sedated with either propofol or dexmedetomidine in a pediatric sedation unit by pediatric emergency physicians was performed. Both medications were dosed per protocol with propofol 2 mg/kg induction and 150 µg · kg-1 · min-1 maintenance and dexmedetomidine 3 µg/kg induction for 10 minutes and 2 µg · kg-1 · h-1maintenance. The variables collected included drug dose, sedation time (time that the drug was given to the completion of the procedure), recovery time (end of the study to the return to the presedation sedation score for 15 minutes), need for dose rate changes, airway management, and adverse events. RESULTS: A total of 2432 children were included- 1503 who received propofol and 929 who received dexmedetomidine. Propofol and dexmedetomidine resulted in successful completion of the study in 98.8% and 99.7%, respectively (P = 0.02). The mean recovery time for propofol was 34.3 minutes, compared with 65.6 minutes for dexmedetomidine (P < 0.001). The need for unexpected airway management was 9.7% for propofol and 2.2% for dexmedetomidine (P < 0.001). Adverse events occurred in 8.6% and 6% of patients in the propofol and dexmedetomidine groups, respectively (P = 0.02). CONCLUSIONS: Propofol use led to significantly shorter recovery times, with an increased need for airway management, but rates of bag-mask ventilation (2.3%), airway obstruction (1.1%), and desaturation (1.6%) were low. No patients required intubation. Propofol is a reasonable alternative to dexmedetomidine, with a clinically acceptable safety profile.

Best not to bet on the horserace: A comment on Forrin and MacLeod (2017) and a relevant stimulus-response compatibility view of colour-word contingency learning asymmetries.

One powerfully robust method for the study of human contingency learning is the colour-word contingency learning paradigm. In this task, participants respond to the print colour of neutral words, each of which is presented most often in one colour. The contingencies between words and colours are learned, as indicated by faster and more accurate responses when words are presented in their expected colour relative to an unexpected colour. In a recent report, Forrin and MacLeod (2017b, Memory & Cognition) asked to what extent this performance (i.e., response time) measure of learning might depend on the relative speed of processing of the word and the colour. With keypress responses, learning effects were comparable when responding to the word and to the colour (contrary to predictions). However, an asymmetry appeared in a second experiment with vocal responses, with a contingency effect only present for colour identification. In a third experiment, the colour was preexposed, and contingency effects were again roughly symmetrical. In their report, they suggested that a simple speed-of-processing (or "horserace") model might explain when contingency effects are observed in colour and word identification. In the present report, an alternative view is presented. In particular, it is argued that the results are best explained by appealing to the notion of relevant stimulus-response compatibility, which also resolves discrepancies between horserace model predictions and participant results. The article presents simulations with the Parallel Episodic Processing model to demonstrate this case.

The Parallel Episodic Processing (PEP) model 2.0: A single computational model of stimulus-response binding, contingency learning, power curves, and mixing costs.

The current paper presents an extension of the Parallel Episodic Processing model. The model is developed for simulating behaviour in performance (i.e., speeded response time) tasks and learns to anticipate both how and when to respond based on retrieval of memories of previous trials. With one fixed parameter set, the model is shown to successfully simulate a wide range of different findings. These include: practice curves in the Stroop paradigm, contingency learning effects, learning acquisition curves, stimulus-response binding effects, mixing costs, and various findings from the attentional control domain. The results demonstrate several important points. First, the same retrieval mechanism parsimoniously explains stimulus-response binding, contingency learning, and practice effects. Second, as performance improves with practice, any effects will shrink with it. Third, a model of simple learning processes is sufficient to explain phenomena that are typically (but perhaps incorrectly) interpreted in terms of higher-order control processes. More generally, we argue that computational models with a fixed parameter set and wider breadth should be preferred over those that are restricted to a narrow set of phenomena.

4H-Thieno[3,2-c]chromene based inhibitors of Notum Pectinacetylesterase.

A group of small molecule thienochromenes inhibitors of Notum Pectinacetylesterase are described. We developed SAR on three series based on carbon, oxygen and sulfur replacement of the 5-position. In each series, highly potent Notum Pectinacetylesterase inhibitors were identified.

Stimulation of cortical bone formation with thienopyrimidine based inhibitors of Notum Pectinacetylesterase.

A group of small molecule thienopyrimidine inhibitors of Notum Pectinacetylesterase are described. We explored both 2-((5,6-thieno[2,3-d]pyrimidin-4-yl)thio)acetic acids and 2-((6,7-thieno[3,2-d]pyrimidin-4-yl)thio)acetic acids. In both series, highly potent, orally active Notum Pectinacetylesterase inhibitors were identified.

Congruency sequence effects and previous response times: conflict adaptation or temporal learning?

In the present study, we followed up on a recent report of two experiments in which the congruency sequence effect-the reduction of the congruency effect after incongruent relative to congruent trials in Stroop-like tasks-was observed without feature repetition or contingency learning confounds. Specifically, we further scrutinized these data to determine the plausibility of a temporal learning account as an alternative to the popular conflict adaptation account. To this end, we employed a linear mixed effects model to investigate the role of previous response time in producing the congruency sequence effect, because previous response time is thought to influence temporal learning. Interestingly, slower previous response times were associated with a reduced current-trial congruency effect, but only when the previous trial was congruent. An adapted version of the parallel episodic processing (PEP) model was able to fit these data if it was additionally assumed that attention "wanders" during different parts of the experiment (e.g., due to fatigue or other factors). Consistent with this assumption, the magnitude of the congruency effect was correlated across small blocks of trials. These findings demonstrate that a temporal learning mechanism provides a plausible account of the congruency sequence effect.

Autism gene variants disrupt enteric neuron migration and cause gastrointestinal dysmotility.

The comorbidity of autism spectrum disorders and severe gastrointestinal symptoms is well-established, yet the molecular underpinnings remain unknown. The identification of high-confidence large-effect autism risk genes offers the opportunity to identify convergent, underlying biology by studying these genes in the context of the gastrointestinal system. Here we show that the expression of these genes is enriched in human prenatal gut neurons as well as their migratory progenitors, suggesting that the development and/or function of these neurons may be disrupted by autism-associated pathogenic variants, leading to gastrointestinal dysfunction. Here we document the prevalence of gastrointestinal issues in patients with large-effect variants in sixteen of these genes, highlighting dysmotility, consistent with potential enteric neuron dysfunction. Using the high-throughput diploid frog Xenopus tropicalis , we individually target five of these genes ( SYNGAP1, CHD8, SCN2A, CHD2 , and DYRK1A ) and observe disrupted enteric neuronal progenitor migration for each. More extensive analysis of DYRK1A reveals that perturbation causes gut dysmotility in vivo , which can be ameliorated by treatment with a selective serotonin reuptake inhibitor (escitalopram) or a serotonin receptor 6 agonist, identified by in vivo drug screening. This work suggests that atypical development of enteric neurons contributes to the gastrointestinal distress commonly seen in individuals with autism and that increasing serotonin signaling may be a productive therapeutic avenue.

Evidence for using air or fluid when identifying the epidural space.

Lumbar epidural analgesia is frequently employed to provide pain relief for women during labor. Anesthesia providers use various methods to identify the epidural space. Some providers use air, some use fluid, and others use a combination of air and fluid during the loss of resistance technique. Loss of resistance to air has been speculated to result in a lesser quality of analgesia compared with loss of resistance to only fluid. A search strategy focusing on preappraised sources was used to locate evidence from interventional and observational studies. Four evidence sources were located, including a systematic review with meta-analysis of 4 older studies. The evidence reviewed was inconclusive in determining whether a difference in analgesia quality results from the use of air or fluid during the loss of resistance technique. Future studies should include an adequate number of subjects and address other problems such as operator experience, observer blinding, equivalence of subject characteristics, outcomes definition and measurement, and composition of epidural solution. Providers should consider other factors when selecting loss of resistance medium, such as the reported complications of large amounts of air injected into the epidural space and surrounding structures.

Predicting success in nurse anesthesia programs: an evidence-based review of admission criteria.

Nurse anesthesia programs strive to minimize attrition due to academic reasons and maximize student success. The authors examined the evidence for evaluating applicants to nurse anesthesia programs that may help predict success in the program and on the National Certification Examination for Nurse Anesthetists. A search strategy guided gathering of evidence from peer-reviewed journals. Evidence from non-anesthesia graduate nursing programs was included because of the suspected lack of evidence specifically examining nurse anesthesia programs. Eight sources involved solely graduate nurse anesthesia programs, 9 involved graduate nursing programs without stu-graduate nursing programs with student registered Nurdent registered nurse anesthetists, and 2 pertained to nurse anesthetists. Most of the evidence sources were descriptive studies. The evidence overall supports current commonly used admissions criteria such as undergraduate grade point averages. The requirement for applicants to take the Graduate Record Examination should be examined closely. Programs should also consider the length of time the applicant has been out of a formal educational setting. Based on these findings, programs may cautiously explore revising the admission policy. Further investigations are proposed to explore the predictive value of various admission criteria.

Is conflict adaptation adaptive? An introduction to conflict monitoring theory and the ecological problems it faces.

Attending to a single stimulus (or dimension of a stimulus) requires filtering out distracting stimuli to avoid producing an incorrect response. The conflict monitoring (or conflict adaptation) account proposes that experience of conflict results in a shift of attention away from distracting stimuli and/or towards the target stimulus. The proportion congruent and congruency sequence effects are two findings often used to argue in favour of the conflict monitoring account. However, there are several potential limitations with conflict monitoring theory. This article explores some of the previously unarticulated (or rarely articulated) supplementary assumptions that must be made for the conflict monitoring account to be consistent with several important findings in the literature, some of which might undermine the initial intuitive appeal of the theory. Indeed, this opinion paper presents the view that conflict adaptation may not actually be particularly adaptive for performance. This article also discusses alternative interpretations of so-called "attentional control" phenomena. According to this view, participants may simply be learning regularities in the task structure that are unintentionally introduced when manipulating conflict (e.g., contingent regularities between distracting stimuli and responses). This sort of learning does benefit performance and is inherent for our functioning in the world, making this a more parsimonious view. Although simplicity is not everything, this article will present the case that the assumptions (often hidden or non-obvious) of conflict monitoring theory are non-trivial and, in many cases, imply relatively non-adaptive processes.

Dynamic measurement of gas flow using acoustic resonance tracking.

The National Institute of Standards and Technology measured gas flows exiting large, unthermostated, gas-filled, pressure vessels by tracking the time-dependent pressure P(t) and resonance frequency fN(t) of an acoustic mode N of the gas remaining in each vessel. This is a proof-of-principle demonstration of a gas flow standard that uses P(t), fN(t), and known values of the gas's speed of sound w(p,T) to determine a mode-weighted average temperature ⟨T⟩φ of the gas remaining in a pressure vessel while the vessel acts as a calibrated source of gas flow. To track fN(t) while flow work rapidly changed the gas's temperature, we sustained the gas's oscillations using positive feedback. Feedback oscillations tracked ⟨T⟩φ with a response time of order 1/fN. In contrast, driving the gas's oscillations with an external frequency generator yielded much slower response times of order Q/fN. (For our pressure vessels, Q ∼ 103-104, where Q is the ratio of the energy stored to the energy lost in one cycle of oscillation.) We tracked fN(t) of radial modes in a spherical vessel (1.85 m3) and of longitudinal modes of a cylindrical vessel (0.3 m3) during gas flows ranging from 0.24 to 12.4 g/s to determine the mass flows with an uncertainty of 0.51 % (95 % confidence level). We discuss the challenges in tracking fN(t) and ways to reduce the uncertainties.

Incidental learning in music reading: The music contingency learning task.

The present report investigated whether nonmusicians can incidentally learn musical skills needed for sight-reading. On each trial, participants identified a note name written inside of a note on the musical staff. In Experiment 1, each note was presented frequently with the congruent note name (e.g., "do" with the note for "do") and rarely with the incongruent names (e.g., "do" with the note for "fa"). With or without deliberate learning instructions, a robust contingency learning effect was observed: faster responses for congruent trials compared with incongruent trials. Participants also explicitly identified the meaning of the note positions more accurately than chance. Experiment 2 ruled out the potential influence of preexisting knowledge on the contingency learning effect by presenting notes most often with an incongruent note name. Robust learning was again observed, suggesting that participants acquired sufficient knowledge of musical notation to produce automatic influences on behaviour (e.g., akin to the interference effect previously found in skilled musicians). A congruency effect was additionally observed in Experiment 2, however. Experiment 3 further explored to what extent this congruency effect might be due to prior music knowledge and/or spatial stimulus-response compatibility between note and response locations (analogous to the SMARC effect). Overall, our results open up new avenues for investigating the incidental learning of complex material, musical or otherwise, and for reinforcing learning even further.

Optimizing Recognition and Management of Patients at Risk for Infection-Related Decompensation Through Team-Based Decision Making.

INTRODUCTION: Pediatric sepsis is a leading cause of death among children. Electronic alert systems may improve early recognition but do not consistently result in timely interventions given the multitude of clinical presentations, lack of treatment consensus, standardized order sets, and inadequate interdisciplinary team-based communication. We conducted a quality improvement project to improve timely critical treatment of patients at risk for infection-related decompensation (IRD) through team-based communication and standardized treatment workflow. METHODS: We evaluated children at risk for IRD as evidenced by the activation of an electronic alert system (Children at High Risk Alert Tool [CAHR-AT]) in the emergency department. Outcomes were assessed after multiple improvements including CAHR-AT implementation, clinical coassessment, visual cues for situational awareness, huddles, and standardized order sets. RESULTS: With visual cue activation, initial huddle compliance increased from 7.8% to 65.3% ( p < .001). Children receiving antibiotics by 3 hours postactivation increased from 37.9% pre-CAHR-AT to 50.7% posthuddle implementation ( p < .0001); patients who received a fluid bolus by 3 hours post-CAHR activation increased from 49.0% to 55.2% ( p = .001). CONCLUSIONS: Implementing a well-validated electronic alert tool did not improve quality measures of timely treatment for high-risk patients until combined with team-based communication, standardized reassessment, and treatment workflow.