Local but not global graph theoretic measures of semantic networks generalize across tasks.

"Dogs" are connected to "cats" in our minds, and "backyard" to "outdoors." Does the structure of this semantic knowledge differ across people? Network-based approaches are a popular representational scheme for thinking about how relations between different concepts are organized. Recent research uses graph theoretic analyses to examine individual differences in semantic networks for simple concepts and how they relate to other higher-level cognitive processes, such as creativity. However, it remains ambiguous whether individual differences captured via network analyses reflect true differences in measures of the structure of semantic knowledge, or differences in how people strategically approach semantic relatedness tasks. To test this, we examine the reliability of local and global metrics of semantic networks for simple concepts across different semantic relatedness tasks. In four experiments, we find that both weighted and unweighted graph theoretic representations reliably capture individual differences in local measures of semantic networks (e.g., how related pot is to pan versus lion). In contrast, we find that metrics of global structural properties of semantic networks, such as the average clustering coefficient and shortest path length, are less robust across tasks and may not provide reliable individual difference measures of how people represent simple concepts. We discuss the implications of these results and offer recommendations for researchers who seek to apply graph theoretic analyses in the study of individual differences in semantic memory.

Barriers and facilitators to the administration of prehospital tranexamic acid: a paramedic interview study using the theoretical domains framework.

BACKGROUND: Tranexamic acid (TXA) is an antifibrinolytic drug used to prevent bleeding. It was introduced as an intervention for post-traumatic haemorrhage across emergency medical services (EMS) in the UK during 2012. However, despite strong evidence of effectiveness, prehospital TXA administration rates are low. This study used the theoretical domains framework (TDF) to identify barriers and facilitators to the administration of TXA to trauma patients by EMS providers (paramedics) in the UK. METHODS: Interviews were completed with 18 UK paramedics from a single EMS provider organisation. A convenience sampling approach was used, and interviews continued until thematic saturation was reached. Semistructured telephone interviews explored paramedics' experiences of administering TXA to trauma patients, including identifying whether or not patients were at risk of bleeding. Data were analysed inductively using thematic analysis (stage 1). Themes were mapped to the theoretical domains of the TDF to identify behavioural theory-derived barriers and facilitators to the administration of TXA to trauma patients (stage 2). Belief statements were identified and assessed for importance according to prevalence, discordance and evidence base (stage 3). RESULTS: Barriers and facilitators to paramedics' administration of TXA to trauma patients were represented by 11 of the 14 domains of the TDF. Important barriers included a lack of knowledge and experience with TXA (Domain: Knowledge and Skills), confusion and restrictions relating to the guidelines for TXA administration (Domain: Social/professional role and identity), a lack of resources (Domain: Environmental context and resources) and difficulty in identifying patients at risk of bleeding (Domain: Memory, attention and decision processes). CONCLUSIONS: This study presents a behavioural theory-based approach to identifying barriers and facilitators to the prehospital administration of TXA to trauma patients in the UK. It identifies multiple influencing factors that may serve as a basis for developing an intervention to increase prehospital administration of TXA.

Clinical and Serological Features in Latin American IgG4-Related Disease Patients Differ According to Sex, Ethnicity, and Clinical Phenotype.

BACKGROUND/OBJECTIVE: Data on IgG4-related disease (IgG4-RD) come almost exclusively from cohorts from Asia, Europe, and North America. We conducted this study to describe the clinical presentation, phenotype distribution, and association with sex, ethnicity, and serological markers in a large cohort of Latin American patients with IgG4-RD. METHODS: We performed a multicenter medical records review study including 184 Latin American IgG4-RD patients. We assigned patients to clinical phenotypes: group 1 (pancreato-hepato-biliary), group 2 (retroperitoneal/aortic), group 3 (head and neck-limited), group 4 (Mikulicz/systemic), and group 5 (undefined). We focused the analysis on how sex, ethnicity, and clinical phenotype may influence the clinical and serological presentation. RESULTS: The mean age was 50.8 ± 15 years. Men and women were equally affected (52.2% vs 48.8%). Fifty-four patients (29.3%) were assigned to group 1, 21 (11.4%) to group 2, 57 (30.9%) to group 3, 32 (17.4%) to group 4, and 20 (10.8%) to group 5. Male sex was associated with biliary tract (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.36-8.26), kidney (OR, 3.4; 95% CI, 1.28-9.25), and retroperitoneal involvement (OR, 5.3; 95% CI, 1.45-20). Amerindian patients presented more frequently with atopy history and gallbladder involvement. Group 3 had a female predominance. CONCLUSIONS: Latin American patients with IgG4-RD were younger, and men and women were equally affected compared with White and Asian cohorts. They belonged more commonly to group 1 and group 3. Retroperitoneal and aortic involvement was infrequent. Clinical and serological features differed according to sex, ethnicity, and clinical phenotype.

Memory Fidelity Reveals Qualitative Changes in Interactions Between Items in Visual Working Memory.

Memory for objects in a display sometimes reveals attraction-the objects are remembered as more similar to one another than they actually were-and sometimes reveals repulsion-the objects are remembered as more different from one another. The conditions that lead to these opposing memory biases are poorly understood; there is no theoretical framework that explains these contrasting dynamics. In three experiments (each N = 30 adults), we demonstrate that memory fidelity provides a unifying dimension that accommodates the existence of both types of visual working memory interactions. We show that either attraction or repulsion can arise simply as a function of manipulations of memory fidelity. We also demonstrate that subjective ratings of fidelity predict the presence of attraction or repulsion on a trial-by-trial basis. We discuss how these results bear on computational models of visual working memory and contextualize these results within the literature of attraction and repulsion effects in long-term memory and perception.

Is there a K in capacity? Assessing the structure of visual short-term memory.

Visual short-term memory (VSTM) is a cognitive structure that temporarily maintains a limited amount of visual information in the service of current cognitive goals. There is active theoretical debate regarding how limits in VSTM should be construed. According to discrete-slot models of capacity, these limits are set in terms of a discrete number of slots that store individual objects in an all-or-none fashion. According to alternative continuous resource models, the limits of VSTM are set in terms of a resource that can be distributed to bolster some representations over others in a graded fashion. Hybrid models have also been proposed. We tackled the classic question of how to construe VSTM structure in a novel way, by examining how contending models explain data within traditional VSTM tasks and also how they generalize across different VSTM tasks. Specifically, we fit theoretical ROCs derived from a suite of models to two popular VSTM tasks: a change detection task in which participants had to remember simple features and a rapid serial visual presentation task in which participants had to remember real-world objects. In 3 experiments we assessed the fit and predictive ability of each model and found consistent support for pure resource models of VSTM. To gain a fuller understanding of the nature of limits in VSTM, we also evaluated the ability of these models to jointly model the two tasks. These joint modeling analyses revealed additional support for pure continuous-resource models, but also evidence that performance across the two tasks cannot be captured by a common set of parameters. We provide an interpretation of these signal detection models that align with the idea that differences among memoranda and across encoding conditions alter the memory signal of representations in VSTM.

Knowledge, skills and attitudes of older people and staff about getting up from the floor following a fall: a qualitative investigation.

BACKGROUND: Falls are the most common reason for ambulance callouts resulting in non-conveyance. Even in the absence of injury, only half of those who fall can get themselves up off the floor, often remaining there over an hour, increasing risk of complications. There are recognized techniques for older people to learn how to get up after a fall, but these are rarely taught. The aim of this study was to develop an understanding of attitudes of older people, carers and health professionals on getting up following a fall. METHODS: A qualitative focus group and semi-structured interviews were conducted with 28 participants, including community-dwelling older people with experience of a non-injurious fall, carers, physiotherapists, occupational therapists, paramedics and first responders. Data were transcribed and analysed systematically using the Framework approach. A stakeholder group of falls experts and service users advised during analysis. RESULTS: The data highlighted three areas contributing to an individual's capability to get-up following a fall: the environment (physical and social); physical ability; and degree of self-efficacy (attitude and beliefs about their own ability). These factors fell within the wider context of making a decision about needing help, which included what training and knowledge each person already had to manage their fall response. Staff described how they balance their responsibilities, prioritising the individual's immediate needs; this leaves limited time to address capability in the aforementioned three areas. Paramedics, routinely responding to falls, only receive training on getting-up techniques from within their peer-group. Therapists are aware of the skillset to breakdown the getting-up process, but, with limited time, select who to teach these techniques to. CONCLUSION: Neither therapists nor ambulance service staff routinely teach strategies on how to get up, meaning that healthcare professionals largely have a reactive role in managing falls. Interventions that address the environment, physical ability and self-efficacy could positively impact on peoples' capability to get up following a fall. Therefore, a more proactive approach would be to teach people techniques to manage these aspects of future falls and to provide them easily accessible information.

The action is in the task set, not in the action.

In 7 experiments we contrasted two accounts for novel sources of attentional bias. According to the action-based account, executing a motor response towards an object causes people to allocate attention preferentially towards properties of that object in a subsequent task even when properties of the acted-on object are task irrelevant. This remarkable view entails that motor processing is in itself sufficient to affect later attentional processing, in the absence of stimulus evaluation and motor preparation. In contrast, the attentional template matching account posits that observing an external object that matches one's prior attentional settings increases processing of that object even when properties of the item are no longer task relevant. Our findings indicate that when properties of a stimulus are task irrelevant, acting towards that object does not produce priming effects over and above what is observed from passive viewing of the object. Furthermore, when properties of the stimulus are task relevant, effects on attention are observed only when participants have sufficient information to generate a task based attentional template of the upcoming stimulus, regardless of whether they act towards the stimulus or not. Finally, effects on attention are found under conditions when participants are likely to experience an attentional template match but do not produce a response. Collectively, these results reveal that previously reported motor-based effects on attention instead reflect the effects of attentional bias towards objects that serve as prior targets. Our findings thus provide strong support for the attentional template view and no support for the action-based view.

Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial.

Importance: The optimal approach to airway management during out-of-hospital cardiac arrest is unknown. Objective: To determine whether a supraglottic airway device (SGA) is superior to tracheal intubation (TI) as the initial advanced airway management strategy in adults with nontraumatic out-of-hospital cardiac arrest. Design, Setting, and Participants: Multicenter, cluster randomized clinical trial of paramedics from 4 ambulance services in England responding to emergencies for approximately 21 million people. Patients aged 18 years or older who had a nontraumatic out-of-hospital cardiac arrest and were treated by a participating paramedic were enrolled automatically under a waiver of consent between June 2015 and August 2017; follow-up ended in February 2018. Interventions: Paramedics were randomized 1:1 to use TI (764 paramedics) or SGA (759 paramedics) as their initial advanced airway management strategy. Main Outcomes and Measures: The primary outcome was modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest, whichever occurred sooner. Modified Rankin Scale score was divided into 2 ranges: 0-3 (good outcome) or 4-6 (poor outcome; 6 = death). Secondary outcomes included ventilation success, regurgitation, and aspiration. Results: A total of 9296 patients (4886 in the SGA group and 4410 in the TI group) were enrolled (median age, 73 years; 3373 were women [36.3%]), and the modified Rankin Scale score was known for 9289 patients. In the SGA group, 311 of 4882 patients (6.4%) had a good outcome (modified Rankin Scale score range, 0-3) vs 300 of 4407 patients (6.8%) in the TI group (adjusted risk difference [RD], -0.6% [95% CI, -1.6% to 0.4%]). Initial ventilation was successful in 4255 of 4868 patients (87.4%) in the SGA group compared with 3473 of 4397 patients (79.0%) in the TI group (adjusted RD, 8.3% [95% CI, 6.3% to 10.2%]). However, patients randomized to receive TI were less likely to receive advanced airway management (3419 of 4404 patients [77.6%] vs 4161 of 4883 patients [85.2%] in the SGA group). Two of the secondary outcomes (regurgitation and aspiration) were not significantly different between groups (regurgitation: 1268 of 4865 patients [26.1%] in the SGA group vs 1072 of 4372 patients [24.5%] in the TI group; adjusted RD, 1.4% [95% CI, -0.6% to 3.4%]; aspiration: 729 of 4824 patients [15.1%] vs 647 of 4337 patients [14.9%], respectively; adjusted RD, 0.1% [95% CI, -1.5% to 1.8%]). Conclusions and Relevance: Among patients with out-of-hospital cardiac arrest, randomization to a strategy of advanced airway management with a supraglottic airway device compared with tracheal intubation did not result in a favorable functional outcome at 30 days. Trial Registration: ISRCTN Identifier: 08256118.

Shifts of attention bias awareness of voluntary and reflexive eye movements.

Current theories regarding factors that influence people's awareness of their actions have underscored the role of peripheral signals (e.g., proprioceptive feedback) and central commands (e.g., the intention to make a response). The role of covert attention has been largely underexplored, even though attention and awareness have been tightly linked. The aim of the current study was to directly examine the impact of shifts of visual attention on people's awareness of their eye movements as they performed the antisaccade task. People tend to be unaware of a high percentage of erroneous eye movements on this task, thus lending it to the study of variables that might modulate people's awareness of their actions. In addition, this task provides the opportunity to compare two classes of actions, voluntary (antisaccade) and involuntary (erroneous prosaccade) eye movements, and thus to assess whether shifts of covert attention can or cannot override sources of information that may be present when people make voluntary but not reflexive responses. We found that shifts of visual attention did indeed influence participants' awareness of their own eye movements, leading them to misperceive reflexive and voluntary movements alike, suggesting that covert attention may override both peripheral and central signals to bias awareness.

Are prehospital treatment or conveyance decisions affected by an ambulance crew's ability to access a patient's health information?

BACKGROUND: A shift from a predominantly emergency service, towards one where a wide range of conditions are managed and treated on scene presents numerous challenges for ambulance services and clinicians. The effective management of a broad range of patients and conditions in the ambulance setting will have an impact on other parts of the health service including emergency departments and primary care. METHODS: A two part online survey was distributed to operational staff working for a regional UK ambulance service. Clinicians were asked to report their experiences of accessing patient information and making decisions about patient management based on four hypothetical patient scenarios. RESULTS: A survey of clinical staff (n = 302) revealed that (i) the vast majority experienced difficulties in accessing patients' health information, (ii) this was particularly true in the out of hours period and (iii) They felt that better access would likely lead to more appropriate selection of care pathways. CONCLUSIONS: Decisions regarding the most appropriate care for patients presenting to the ambulance service are best informed by access to accurate and complete health information and records. An understanding of patients' pre-existing medical conditions, recent treatments and health information is needed for the selection of the most appropriate care; this information is often difficult to obtain in the ambulance service setting.

Scleredema diabeticorum.

We present a case of scleredema with a leonine facies in a 56-year-old man with a history of poorly controlled diabetes mellitus. The patient initially presented with erythematous, edematous papules and plaques on the face, neck, and upper back.

Pemphigoid gestationis.

We present a 21-year-old primigravida woman with a several-week history of pruritic, edematous, targetoid plaques that appeared initially on the abdomen, flanks, and legs and that progressed to involve the inner aspects of the upper arms and lateral aspects of the chest. The histopathologic findings showed perivascular and interstitial dermatitis with eosinophils and vacuolar changes with linear C3 deposition at the basement-membrane zone on direct immunofluorescence study. A diagnosis of pemphigoid gestationis was made. Pemphigoid gestationis is a rare, bullous dermatosis of pregnancy that may be associated with prematurity and small-for-gestational age birth weights. The diagnosis is often made with direct immunofluorescence studies of perilesional skin. Oral glucocorticoids remain the gold standard of therapy in moderate-to-severe cases. The edematous papules and plaques of pemphigoid gestationis may be particularly difficult to distinguish from polymorphic eruption of pregnancy; therefore, immunofluorescence studies are prudent. Prompt recognition and appropriate management may reduce morbidity of this disease, which often recurs with subsequent pregnancies.

What Your Dermatopathologist Wants You to Know.

The skin biopsy and histologic examination are an important part of providing dermatologic care. Effective communication with your dermatopathologist on the biopsy requisition form helps provide clinicopathological correlation and facilitates accurate and timely histopathologic diagnosis of the biopsy.

Direct Immunofluorescence.

Direct immunofluorescence (DIF) is a valuable diagnostic tool in the dermatology clinic. The proper use of a biopsy for DIF is dependent on several factors, including appropriate clinical indication, correct clinical site selection, and proper specimen handling and transport. Improper use of DIF can lead to false negatives, decreased diagnostic yield, and poor resource utilization. This article provides instruction on the appropriate indications and biopsy site selection for DIF. Three examples of skin diseases in which DIF would be particular useful when making a diagnosis are provided.

A quantitative model of ensemble perception as summed activation in feature space.

Ensemble perception is a process by which we summarize complex scenes. Despite the importance of ensemble perception to everyday cognition, there are few computational models that provide a formal account of this process. Here we develop and test a model in which ensemble representations reflect the global sum of activation signals across all individual items. We leverage this set of minimal assumptions to formally connect a model of memory for individual items to ensembles. We compare our ensemble model against a set of alternative models in five experiments. Our approach uses performance on a visual memory task for individual items to generate zero-free-parameter predictions of interindividual and intraindividual differences in performance on an ensemble continuous-report task. Our top-down modelling approach formally unifies models of memory for individual items and ensembles and opens a venue for building and comparing models of distinct memory processes and representations.

Linking computational models of two core tasks of cognitive control.

Cognitive control refers to the ability to maintain goal-relevant information in the face of distraction, making it a core construct for understanding human thought and behavior. There is great theoretical and practical value in building theories that can be used to explain or to predict variations in cognitive control as a function of experimental manipulations or individual differences. A critical step toward building such theories is determining which latent constructs are shared between laboratory tasks that are designed to measure cognitive control. In the current work, we examine this question in a novel way by formally linking computational models of two canonical cognitive control tasks, the Eriksen flanker and task-switching task. Specifically, we examine whether model parameters that capture cognitive control processes in one task can be swapped across models to make predictions about individual differences in performance on another task. We apply our modeling and analysis to a large scale data set from an online cognitive training platform, which optimizes our ability to detect individual differences in the data. Our results suggest that the flanker and task-switching tasks probe common control processes. This finding supports the view that higher level cognitive control processes as opposed to solely strategies in speed and accuracy tradeoffs, or perceptual processing and motor response speed are shared across the two tasks. We discuss how our computational modeling substitution approach addresses limitations of prior efforts to relate performance across different cognitive control tasks, and how our findings inform current theories of cognitive control. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

There Is no Theory-Free Measure of "Swaps" in Visual Working Memory Experiments.

Visual working memory is highly limited, and its capacity is tied to many indices of cognitive function. For this reason, there is much interest in understanding its architecture and the sources of its limited capacity. As part of this research effort, researchers often attempt to decompose visual working memory errors into different kinds of errors, with different origins. One of the most common kinds of memory error is referred to as a "swap," where people report a value that closely resembles an item that was not probed (e.g., an incorrect, non-target item). This is typically assumed to reflect confusions, like location binding errors, which result in the wrong item being reported. Capturing swap rates reliably and validly is of great importance because it permits researchers to accurately decompose different sources of memory errors and elucidate the processes that give rise to them. Here, we ask whether different visual working memory models yield robust and consistent estimates of swap rates. This is a major gap in the literature because in both empirical and modeling work, researchers measure swaps without motivating their choice of swap model. Therefore, we use extensive parameter recovery simulations with three mainstream swap models to demonstrate how the choice of measurement model can result in very large differences in estimated swap rates. We find that these choices can have major implications for how swap rates are estimated to change across conditions. In particular, each of the three models we consider can lead to differential quantitative and qualitative interpretations of the data. Our work serves as a cautionary note to researchers as well as a guide for model-based measurement of visual working memory processes.

Measuring memory is harder than you think: How to avoid problematic measurement practices in memory research.

We argue that critical areas of memory research rely on problematic measurement practices and provide concrete suggestions to improve the situation. In particular, we highlight the prevalence of memory studies that use tasks (like the "old/new" task: "have you seen this item before? yes/no") where quantifying performance is deeply dependent on counterfactual reasoning that depends on the (unknowable) distribution of underlying memory signals. As a result of this difficulty, different literatures in memory research (e.g., visual working memory, eyewitness identification, picture memory, etc.) have settled on a variety of fundamentally different metrics to get performance measures from such tasks (e.g., A', corrected hit rate, percent correct, d', diagnosticity ratios, K values, etc.), even though these metrics make different, contradictory assumptions about the distribution of latent memory signals, and even though all of their assumptions are frequently incorrect. We suggest that in order for the psychology and neuroscience of memory to become a more cumulative, theory-driven science, more attention must be given to measurement issues. We make a concrete suggestion: The default memory task for those simply interested in performance should change from old/new ("did you see this item'?") to two-alternative forced-choice ("which of these two items did you see?"). In situations where old/new variants are preferred (e.g., eyewitness identification; theoretical investigations of the nature of memory signals), receiver operating characteristic (ROC) analysis should be performed rather than a binary old/new task.

How do people build up visual memory representations from sensory evidence? Revisiting two classic models of choice.

In many decision tasks, we have a set of alternative choices and are faced with the problem of how to use our latent beliefs and preferences about each alternative to make a single choice. Cognitive and decision models typically presume that beliefs and preferences are distilled to a scalar latent strength for each alternative, but it is also critical to model how people use these latent strengths to choose a single alternative. Most models follow one of two traditions to establish this link. Modern psychophysics and memory researchers make use of signal detection theory, assuming that latent strengths are perturbed by noise, and the highest resulting signal is selected. By contrast, many modern decision theoretic modeling and machine learning approaches use the softmax function (which is based on Luce's choice axiom; Luce, 1959) to give some weight to non-maximal-strength alternatives. Despite the prominence of these two theories of choice, current approaches rarely address the connection between them, and the choice of one or the other appears more motivated by the tradition in the relevant literature than by theoretical or empirical reasons to prefer one theory to the other. The goal of the current work is to revisit this topic by elucidating which of these two models provides a better characterization of latent processes in m -alternative decision tasks, with a particular focus on memory tasks. In a set of visual memory experiments, we show that, within the same experimental design, the softmax parameter ß varies across m -alternatives, whereas the parameter d ' of the signal-detection model is stable. Together, our findings indicate that replacing softmax with signal-detection link models would yield more generalizable predictions across changes in task structure. More ambitiously, the invariance of signal detection model parameters across different tasks suggests that the parametric assumptions of these models may be more than just a mathematical convenience, but reflect something real about human decision-making.