Causal phase-dependent control of non-spatial attention in human prefrontal cortex.

Non-spatial attention is a fundamental cognitive mechanism that allows organisms to orient the focus of conscious awareness towards sensory information that is relevant to a behavioural goal while shifting it away from irrelevant stimuli. It has been suggested that attention is regulated by the ongoing phase of slow excitability fluctuations of neural activity in the prefrontal cortex, a hypothesis that has been challenged with no consensus. Here we developed a behavioural and non-invasive stimulation paradigm aiming at modulating slow excitability fluctuations of the inferior frontal junction. Using this approach, we show that non-spatial attention can be selectively modulated as a function of the ongoing phase of exogenously modulated excitability states of this brain structure. These results demonstrate that non-spatial attention relies on ongoing prefrontal excitability states, which are probably regulated by slow oscillatory dynamics, that orchestrate goal-oriented behaviour.

Supporting Equity and Inclusion of Deaf and Hard-of-Hearing Individuals in Professional Organizations.

Disability is an important and often overlooked component of diversity. Individuals with disabilities bring a rare perspective to science, technology, engineering, mathematics, and medicine (STEMM) because of their unique experiences approaching complex issues related to health and disability, navigating the healthcare system, creatively solving problems unfamiliar to many individuals without disabilities, managing time and resources that are limited by physical or mental constraints, and advocating for themselves and others in the disabled community. Yet, individuals with disabilities are underrepresented in STEMM. Professional organizations can address this underrepresentation by recruiting individuals with disabilities for leadership opportunities, easing financial burdens, providing equal access, fostering peer-mentor groups, and establishing a culture of equity and inclusion spanning all facets of diversity. We are a group of deaf and hard-of-hearing (D/HH) engineers, scientists, and clinicians, most of whom are active in clinical practice and/or auditory research. We have worked within our professional societies to improve access and inclusion for D/HH individuals and others with disabilities. We describe how different models of disability inform our understanding of disability as a form of diversity. We address heterogeneity within disabled communities, including intersectionality between disability and other forms of diversity. We highlight how the Association for Research in Otolaryngology has supported our efforts to reduce ableism and promote access and inclusion for D/HH individuals. We also discuss future directions and challenges. The tools and approaches discussed here can be applied by other professional organizations to include individuals with all forms of diversity in STEMM.

Efficacy and tolerability of a modified pediatric-inspired intensive regimen for acute lymphoblastic leukemia in older adults.

Although acute lymphoblastic leukemia (ALL) is most common in pediatric and adolescent and young adult (AYA) patients, 20% of cases are diagnosed in patients ≥ 55 years old. Use of intensive pediatric regimens in AYA populations has demonstrated excellent tolerability and significant improvements in event-free survival (EFS) and overall survival (OS). The backbone of pediatric regimens includes asparaginase and corticosteroids, both of which are associated with more toxicity in older patients and those with body mass index (BMI) ≥ 30 kg/m which leads to poor tolerance of these regimens. We tested the safety and efficacy of a dose-modified The Cancer and Leukemia Group B 10403 regimen using reduced doses of pegylated (PEG)-asparaginase (ASP) and corticosteroids (RD-10403) in 30 patients with Philadelphia-chromosome negative ALL who were ≥50-year-old and younger adults with significant metabolic or hepatic co-morbidities. The complete remission rate on day 28 was 77%, 3-year EFS was 54%, and estimated 3-year OS was 55%. Grade 3+ toxicity was noted in 40% of patients during induction, and induction-related mortality was 3%. Additional prospective evaluation of RD-10403 is merited to determine efficacy and safety of this regimen and to serve as a framework for chemoimmunotherapy combination therapy.

Efficient sampling and noisy decisions.

Human decisions are based on finite information, which makes them inherently imprecise. But what determines the degree of such imprecision? Here, we develop an efficient coding framework for higher-level cognitive processes in which information is represented by a finite number of discrete samples. We characterize the sampling process that maximizes perceptual accuracy or fitness under the often-adopted assumption that full adaptation to an environmental distribution is possible, and show how the optimal process differs when detailed information about the current contextual distribution is costly. We tested this theory on a numerosity discrimination task, and found that humans efficiently adapt to contextual distributions, but in the way predicted by the model in which people must economize on environmental information. Thus, understanding decision behavior requires that we account for biological restrictions on information coding, challenging the often-adopted assumption of precise prior knowledge in higher-level decision systems.

Weber's Law: A Mechanistic Foundation after Two Centuries.

Weber's law appears to be a universal principle describing how we discriminate between physical magnitudes. However, this law remained purely descriptive for nearly two centuries. A study by Pardo-Vazquez et al. finally provides a mechanistic explanation, revealing how both accuracy and reaction-time performance lawfully emerge during sensory discrimination tasks.

Immune-Related Adverse Events Requiring Hospitalization: Spectrum of Toxicity, Treatment, and Outcomes.

PURPOSE: Immune checkpoint inhibitors (ICIs) cause immune-related adverse events (irAEs). The proportion of patients who are hospitalized for irAEs and their spectrum, management, and outcomes are not well described. METHODS: We report the proportion of hospitalized patients in an academic center who were treated with ICIs from May to December 2017. Patient characteristics, toxicities, management, and outcomes for confirmed irAE admissions are reported. Associations between patient features and irAE hospitalizations are examined. RESULTS: Twenty-three percent (n = 100) of 443 patients who were admitted to an academic oncology center over 6 months had ever received ICIs. Of these patients, 41% were admitted for suspected irAEs and 23% were confirmed irAEs. IrAEs accounted for 5% of all oncology hospitalizations (n = 23). Ninety-one percent of patients with confirmed irAEs prompted a medicine subspecialist consultation, most commonly gastroenterology (22%). Fifteen patients (65%) had their irAEs improve/resolve, seven (30%) had worsening irAEs, and three (13%) died of their irAEs. The majority of patients (n = 20; 87%) discontinued ICIs after discharge. Among ICI-treated patients who required admission, an increased likelihood of irAE-related hospitalization was associated with patient age older than 65 years (odds ratio, 5.4; 95% CI, 1.6 to 17.8) and receipt of combination immunotherapy (OR, 6.8; 95% CI, 2.0 to 23.2). CONCLUSION: A notable proportion of ICI-treated patients are hospitalized for irAEs, and these patients have a high demand for multidisciplinary management. Older age and combination ICI treatment were associated with an increased risk of irAE-related hospitalization. Whereas these data are from an academic center and include patients in clinical trials, with expanding use of ICIs, these data have important implications for inpatient service planning and risk stratification.

Measuring transient phase-amplitude coupling using local mutual information.

Here we demonstrate the suitability of a local mutual information measure for estimating the temporal dynamics of cross-frequency coupling (CFC) in brain electrophysiological signals. In CFC, concurrent activity streams in different frequency ranges interact and transiently couple. A particular form of CFC, phase-amplitude coupling (PAC), has raised interest given the growing amount of evidence of its possible role in healthy and pathological brain information processing. Although several methods have been proposed for PAC estimation, only a few have addressed the estimation of the temporal evolution of PAC, and these typically require a large number of experimental trials to return a reliable estimate. Here we explore the use of mutual information to estimate a PAC measure (MIPAC) in both continuous and event-related multi-trial data. To validate these two applications of the proposed method, we first apply it to a set of simulated phase-amplitude modulated signals and show that MIPAC can successfully recover the temporal dynamics of the simulated coupling in either continuous or multi-trial data. Finally, to explore the use of MIPAC to analyze data from human event-related paradigms, we apply it to an actual event-related human electrocorticographic (ECoG) data set that exhibits strong PAC, demonstrating that the MIPAC estimator can be used to successfully characterize amplitude-modulation dynamics in electrophysiological data.

A Retrospective Observational Study of Anesthetic Induction Dosing Practices in Female Elderly Surgical Patients: Are We Overdosing Older Patients?

BACKGROUND/OBJECTIVES: Despite guidelines suggesting a 25-50 % reduction in induction doses of intravenous anesthetic agents in the elderly (≥65 years), we hypothesized that practitioners were not sufficiently correcting drug administration for age, contributing to an increased incidence of hypotension in older patients undergoing general anesthesia. STUDY DESIGN: We conducted a retrospective, observational study in a tertiary-care academic hospital. The study included 768 female patients undergoing gynecologic surgeries who received propofol-based induction of general anesthesia. MAIN OUTCOME MEASURES: Weight-adjusted anesthetic induction dosing, age-associated differences in dosing by ASA-PS (American Society of Anesthesiology-Physical Status), and hemodynamic outcomes between younger (18-64 years, n = 537) and older (≥65 years, n = 231) female patients were analyzed. RESULTS: Older patients received lower doses of propofol and midazolam than younger patients (propofol: 2.037 ± 0.783 vs 2.322 ± 0.834 mg/kg, p < 0.001; midazolam: 0.013 ± 0.014 vs 0.023 ± 0.042 mg/kg, p < 0.001). However, practitioners still consistently exceeded the FDA recommended dose (1-1.5 mg/kg) of propofol for elderly patients. There was no significant difference in the doses of fentanyl administered between the two age groups (1.343 ± 0.744 vs 1.363 ± 0.763 µg/kg, p = 0.744), and doses of fentanyl in older patients exceeded the recommended dose (0.5-1.0 µg/kg). Corresponding to observed overdosing of induction agents, older patients experienced larger decreases in post-induction blood pressure and were more likely to receive vasopressor therapy. CONCLUSIONS: Anesthetic induction doses of fentanyl and propofol were not sufficiently corrected in older patients in accordance with recommendations. Significantly greater frequency of post-induction hypotension occurred amongst older patients. Quality improvement efforts may lead to improved outcomes in this vulnerable population.

Does intravenous induction dosing among patients undergoing gastrointestinal surgical procedures follow current recommendations: a study of contemporary practice.

STUDY OBJECTIVE: It is recommended to correct intravenous induction doses by up to 50% for patients older than 65 years. The objectives were to determine (a) the degree to which anesthesia providers correct induction doses for age and (b) additionally adjust for American Society of Anesthesiologists physical status (ASA-PS) class (severity of illness) and (c) whether postinduction hypotension is more common among patients aged >65. DESIGN: Retrospective chart review. SETTING: Academic medical center. PATIENTS: A total of 1869 adult patients receiving general anesthesia for GI surgical procedures from February 2013 to January 2014. MEASUREMENTS: Patients were divided into 3 age groups (age <65, 65-79, ≥80 years) and then further stratified into ASA-PS class (I/II vs III/IV). Multiple pairwise comparisons were conducted using Welch t tests for continuous variables to determine whether dosing was different for the older groups vs the younger group; separate analyses were performed within and across ASA-PS class. This approach was also used to determine differences in mean arterial pressure change in the older groups vs the younger group, whereas the rates of hypotension among different age groups were compared by Cochran-Armitage trend test. MAIN RESULTS: No significant decrease in dosing between age groups was observed for fentanyl and midazolam. For propofol, there was a significantly lower dosing for older patients: 17% for patients aged 65-79 and 29% for those aged >80, which was still in less than the recommendations. An inverse relationship was observed between propofol dosing and ASA-PS class, but no consistent relationship was noted for fentanyl and midazolam. There were a significantly larger drop in mean arterial pressure and a greater likelihood of hypotension following induction in patients aged 65-79 years and >80 years as compared with those aged <65 years. CONCLUSIONS: This study shows that the administered dose of anesthetic induction agents is significantly higher than that recommended for patients older than 65 years. This failure to age-adjust dose may contribute to hypotensive episodes.

Impaired perception of temporal fine structure and musical timbre in cochlear implant users.

Cochlear implant (CI) users demonstrate severe limitations in perceiving musical timbre, a psychoacoustic feature of sound responsible for 'tone color' and one's ability to identify a musical instrument. The reasons for this limitation remain poorly understood. In this study, we sought to examine the relative contributions of temporal envelope and fine structure for timbre judgments, in light of the fact that speech processing strategies employed by CI systems typically employ envelope extraction algorithms. We synthesized "instrumental chimeras" that systematically combined variable amounts of envelope and fine structure in 25% increments from two different source instruments with either sustained or percussive envelopes. CI users and normal hearing (NH) subjects were presented with 150 chimeras and asked to determine which instrument the chimera more closely resembled in a single-interval two-alternative forced choice task. By combining instruments with similar and dissimilar envelopes, we controlled the valence of envelope for timbre identification and compensated for envelope reconstruction from fine structure information. Our results show that NH subjects utilize envelope and fine structure interchangeably, whereas CI subjects demonstrate overwhelming reliance on temporal envelope. When chimeras were created from dissimilar envelope instrument pairs, NH subjects utilized a combination of envelope (p = 0.008) and fine structure information (p = 0.009) to make timbre judgments. In contrast, CI users utilized envelope information almost exclusively to make timbre judgments (p < 0.001) and ignored fine structure information (p = 0.908). Interestingly, when the value of envelope as a cue was reduced, both NH subjects and CI users utilized fine structure information to make timbre judgments (p < 0.001), although the effect was quite weak in CI users. Our findings confirm that impairments in fine structure processing underlie poor perception of musical timbre in CI users.