Attentional selection and communication through coherence: Scope and limitations.

Synchronous neural oscillations are strongly associated with a variety of perceptual, cognitive, and behavioural processes. It has been proposed that the role of the synchronous oscillations in these processes is to facilitate information transmission between brain areas, the 'communication through coherence,' or CTC hypothesis. The details of how this mechanism would work, however, and its causal status, are still unclear. Here we investigate computationally a proposed mechanism for selective attention that directly implicates the CTC as causal. The mechanism involves alpha band (about 10 Hz) oscillations, originating in the pulvinar nucleus of the thalamus, being sent to communicating cortical areas, organizing gamma (about 40 Hz) oscillations there, and thus facilitating phase coherence and communication between them. This is proposed to happen contingent on control signals sent from higher-level cortical areas to the thalamic reticular nucleus, which controls the alpha oscillations sent to cortex by the pulvinar. We studied the scope of this mechanism in parameter space, and limitations implied by this scope, using a computational implementation of our conceptual model. Our results indicate that, although the CTC-based mechanism can account for some effects of top-down and bottom-up attentional selection, its limitations indicate that an alternative mechanism, in which oscillatory coherence is caused by communication between brain areas rather than being a causal factor for it, might operate in addition to, or even instead of, the CTC mechanism.

Stochastic resonance in the sensory systems and its applications in neural prosthetics.

Noise is generally considered to be detrimental. In the right conditions, however, noise can improve signal detection or information transmission. This counterintuitive phenomenon is called stochastic resonance (SR). SR has generated significant interdisciplinary interest, particularly in physics, engineering, and medical and environmental sciences. In this review, we discuss a growing empirical literature that suggests that noise at the right intensity may improve the detection and processing of auditory, sensorimotor, and visual stimuli. We focus particularly on applications of SR in sensory biology and investigate whether SR-based technologies present a pathway to improve outcomes for individuals living with sensory impairments. We conclude that there is considerable evidence supporting the application of SR in developing sensory prosthetics. However, the progression of SR-based technologies is variable across the sensory modalities. We suggest opportunities for further advancements in each modality, considering the best approaches to maximise benefits and capitalise on progress already made. Overall, SR can offer opportunities to improve existing technologies or to motivate innovations.

Does stochastic resonance improve performance for individuals with higher autism-spectrum quotient?

While noise is generally believed to impair performance, the detection of weak stimuli can sometimes be enhanced by introducing optimum noise levels. This phenomenon is termed 'Stochastic Resonance' (SR). Past evidence suggests that autistic individuals exhibit higher neural noise than neurotypical individuals. It has been proposed that the enhanced performance in Autism Spectrum Disorder (ASD) on some tasks could be due to SR. Here we present a computational model, lab-based, and online visual identification experiments to find corroborating evidence for this hypothesis in individuals without a formal ASD diagnosis. Our modeling predicts that artificially increasing noise results in SR for individuals with low internal noise (e.g., neurotypical), however not for those with higher internal noise (e.g., autistic, or neurotypical individuals with higher autistic traits). It also predicts that at low stimulus noise, individuals with higher internal noise outperform those with lower internal noise. We tested these predictions using visual identification tasks among participants from the general population with autistic traits measured by the Autism-Spectrum Quotient (AQ). While all participants showed SR in the lab-based experiment, this did not support our model strongly. In the online experiment, significant SR was not found, however participants with higher AQ scores outperformed those with lower AQ scores at low stimulus noise levels, which is consistent with our modeling. In conclusion, our study is the first to investigate the link between SR and superior performance by those with ASD-related traits, and reports limited evidence to support the high neural noise/SR hypothesis.

Qualia and Phenomenal Consciousness Arise From the Information Structure of an Electromagnetic Field in the Brain.

In this paper we address the following problems and provide realistic answers to them: (1) What could be the physical substrate for subjective, phenomenal, consciousness (P-consciousness)? Our answer: the electromagnetic (EM) field generated by the movement and changes of electrical charges in the brain. (2) Is this substrate generated in some particular part of the brains of conscious entities or does it comprise the entirety of the brain/body? Our answer: a part of the thalamus in mammals, and homologous parts of other brains generates the critical EM field. (3) From whence arise the qualia experienced in P-consciousness? Our answer, the relevant EM field is "structured" by emulating in the brain the information in EM fields arising from both external (the environment) and internal (the body) sources. (4) What differentiates the P-conscious EM field from other EM fields, e.g., the flux of photons scattered from object surfaces, the EM field of an electro-magnet, or the EM fields generated in the brain that do not enter P-consciousness, such as those generated in the retina or occipital cortex, or those generated in brain areas that guide behavior through visual information in persons exhibiting "blindsight"? Our answer: living systems express a boundary between themselves and the environment, requiring them to model (coarsely emulate) information from their environment in order to control through actions, to the extent possible, the vast sea of variety in which they are immersed. This model, expressed in an EM field, is P-consciousness. The model is the best possible representation of the moment-to-moment niche-relevant (action-relevant: affordance) information an organism can generate (a Gestalt). Information that is at a lower level than niche-relevant, such as the unanalyzed retinal vector-field, is not represented in P-consciousness because it is not niche-relevant. Living organisms have sensory and other systems that have evolved to supply such information, albeit in a coarse form.

Phase offset determines alpha modulation of gamma phase coherence and hence signal transmission.

We find conditions for optimal phase coherence among sums of phase-offset sine wave pairs of two frequencies, e.g., gamma and alpha. Optimal phase coherence occurs when the respective phase offsets match. Then, using stochastic rate models instead of firing models for both cortical and pulvinar activity, we show that for roughly matching phase offsets of alpha and gamma oscillations there is optimal phase coherence and information transmission between modelled cortical regions.

Reforming Physician Payments to Achieve Greater Equity and Value in Health Care: A Position Paper of the American College of Physicians.

Socioeconomic factors remain one of the most clinically significant contributors to health outcomes in this country, yet the current fee-for-service payment structure incentivizes volume and does not address such factors. The American College of Physicians proposes specific policy recommendations on reforming payment programs, including those designed to treat underserved patient populations, to better address value in health care and achieve greater equity. The proposal advocates that population-based prospective payment models, including hybrid models that combine fee-for-service with prospective payments, not only have the potential to achieve high-value care but can also be designed in such a way as to adjust for the social drivers that impact health outcomes. The need to recognize health care disparities and inequities in the implementation of the Quality Payment Program in particular and risk scoring in general and the need for social policies to improve access to health information technology are further examples of policy prescriptions that can advance equity. Evidence-based services and programs in Medicare Part B that are shown to preserve the Medicare trust fund through savings in Part A should be able to be scored as offsets for the cost of those new programs. The approach of building a health care system that is smarter about how dollars are spent to make people healthier must shift to one with a clear intention of decreasing health inequities and addressing social drivers of health.

Electrophysiological evidence of sustained attention to music among conscious participants and unresponsive hospice patients at the end of life.

OBJECTIVE: To characterize electrophysiological activity, and likely neural sources of that activity, associated with listening to music in both healthy participants and in a small group of hospice patients both when responsive and when unresponsive hours before death. METHODS: Young, healthy participants (N = 22) were asked to attend to (Active condition) and to ignore (Passive condition) brief (6 s) music excerpts. A smaller group (N = 13) of hospice patients was asked to attend to the same musical excerpts (Active condition only), both when they were responsive (N = 8) and again when they became unresponsive (N = 4) only hours before death. EEG-derived event-related spectral perturbations (ERSPs) to music stimuli, and their approximate neural sources, were computed for each individual in both groups. RESULTS: In the healthy participants, alpha-band ERSP during the music excerpts in a group-level analysis was significantly lower in posterio-parietal brain areas in the Active condition than in the Passive condition (event-related desynchronization, ERD). Moreover, in an analysis of individual ERSP data, most (18 of 22 or 84%) healthy participants showed meaningful sustained (4 or more seconds) alpha-band suppression in one or more posterio-parietal brain areas when they were asked to attend to the music, whereas far fewer healthy participants (only 7 of 19 or 37%) generated the same response when asked to ignore the music, indicating that posterio-parietal alpha-band ERD could be a useful marker of music listening. Similarly, 75% of eight responsive hospice patients, and 100% of four unresponsive hospice patients showed sustained posterio-parietal alpha-band suppression when asked to attend to the music, indicating that they could be listening to the music covertly even when overtly unresponsive. CONCLUSIONS: Some (but likely not all, as other patients will vary from those we studied) unresponsive patients at the end of life might be able to listen to music, despite being unable to overtly indicate their awareness. SIGNIFICANCE: Music stimulation may be a promising way to engage unresponsive patients.

Frequency of Statin Prescription Among Individuals with Coronary Artery Calcifications Detected Through Lung Cancer Screening.

Individuals eligible for lung cancer screening (LCS) are at risk for atherosclerotic cardiovascular disease (ASCVD) due to smoking history. Coronary artery calcifications (CAC), a common incidental finding on low-dose CT (LDCT) for LCS, is a predictor of cardiovascular events. Despite findings of high ASCVD risk and CAC, a substantial proportion of LCS patients are not prescribed primary preventive statin therapy for ASCVD. We assessed the frequency of statin prescription in LCS patients with moderate levels of CAC. Among 259 individuals with moderate CAC, 95% had ASCVD risk ≥ 7.5%. Despite this, 27% of patients were statin-free prior to LDCT and 21.2% remained statin-free after LDCT showing moderate CAC. Illustratively, while a substantial proportion of LCS patients are statin-eligible, many lack a statin prescription, even after findings of CAC burden. CAC reporting should be standardized, and interdisciplinary communication should be optimized to ensure that LCS patients are placed on appropriate preventive therapy.

Resting state network activation and functional connectivity in the dying brain.

OBJECTIVE: To characterize electrophysiological functional connectivity within both the default mode network (DMN) and the task-positive network (TPN) among a small group of unresponsive hospice patients at the end of life. METHODS: EEG recordings from resting state were analysed to identify brain regions in the DMN and TPN of 30 young, healthy controls, and of 9 hospice patients when they were responsive and of 5 patients when they became unresponsive during the last hours of life. RESULTS: The prevalence of activation and connectivity within the DMN was similar across all participant groups. Overall functional connectivity was higher between brain regions within the DMN than between brain regions within TPN for all participant groups. The number of functional connections within the DMN, however, was greater than those within the TPN among controls and responsive hospice patients but not among unresponsive hospice patients. CONCLUSIONS: Some unresponsive patients may have the functional architecture to support internally-oriented thought at the end of life. Resting state default mode - task positive network anticorrelations may be present among some unresponsive hospice patients. SIGNIFICANCE: Some unresponsive end of life patients may be able to mind-wander. Implications for internally-oriented awareness at the end of life are discussed.

Plastic systemic inhibition controls amplitude while allowing phase pattern in a stochastic neural field model.

We investigate oscillatory phase pattern formation and amplitude control for a linearized stochastic neuron field model by simulating Mexican-hat-coupled stochastic processes. We find, for several choices of parameters, that spatial pattern formation in the temporal phases of the coupled processes occurs if and only if their amplitudes are allowed to grow unrealistically large. Stimulated by recent work on homeostatic inhibitory plasticity, we introduce static and plastic (adaptive) systemic inhibitory mechanisms to keep the amplitudes stochastically bounded. We find that systems with static inhibition exhibited bounded amplitudes but no sustained phase patterns. With plastic systemic inhibition, on the other hand, the resulting systems exhibit both bounded amplitudes and sustained phase patterns. These results demonstrate that plastic inhibitory mechanisms in neural field models can dynamically control amplitudes while allowing patterns of phase synchronization to develop. Similar mechanisms of plastic systemic inhibition could play a role in regulating oscillatory functioning in the brain.

Effect of a 6 am-9 am Dedicated Orthopaedic Trauma Room on Hip Fracture Outcomes in a Community Level II Trauma Center.

OBJECTIVE: To assess the outcomes of elderly hip fracture surgeries performed 12 months before and 12 months after the implementation of a daily 6 am-9 am dedicated orthopaedic trauma room (DOTR) at a Level II community trauma center. DESIGN: Retrospective cohort study. SETTING: Level II academic trauma center. PATIENTS: A total of 431 consecutive trauma patients undergoing surgical management of isolated low-energy hip fractures from January 1, 2018, to December 31, 2019. INTERVENTION: Implementation of a 6 am-9 am DOTR Monday through Friday. MAIN OUTCOME MEASURES: Time to surgery, number of cases performed after hours, surgical time, 90-day morbidity and mortality, and time to therapy. RESULTS: Retrospective analysis showed that despite a 24% increase in surgical hip fracture volume, implementation of a part-time DOTR led to a decrease in after-hours surgery (32.4% vs. 19.6%; P = 0.008) and patients requiring the intensive care unit postoperatively (7% vs. 3.8%; P = 0.036). Surgeries performed after hours were longer than that of surgeries performed during the daytime (82.0 vs. 68 minutes; P = 0.003) and had more complications (pneumonia, pulmonary embolism, and surgical site infection; P = 0.002, 0.047, 0.024, respectively). CONCLUSIONS: Our results show that a part-time DOTR in a community Level II hospital is associated with improvement in patient care. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Warped rhythms: Epileptic activity during critical periods disrupts the development of neural networks for human communication.

It is well established that temporal lobe epilepsy-the most common and well-studied form of epilepsy-can impair communication by disrupting social-emotional and language functions. In pediatric epilepsy, where seizures co-occur with the development of critical brain networks, age of onset matters: The earlier in life seizures begin, the worse the disruption in network establishment, resulting in academic hardship and social isolation. Yet, little is known about the processes by which epileptic activity disrupts developing human brain networks. Here we take a synthetic perspective-reviewing a range of research spanning studies on molecular and oscillatory processes to those on the development of large-scale functional networks-in support of a novel model of how such networks can be disrupted by epilepsy. We seek to bridge the gap between research on molecular processes, on the development of human brain circuitry, and on clinical outcomes to propose a model of how epileptic activity disrupts brain development.

Electrophysiological evidence of preserved hearing at the end of life.

This study attempts to answer the question: "Is hearing the last to go?" We present evidence of hearing among unresponsive actively dying hospice patients. Individual ERP (MMN, P3a, and P3b) responses to deviations in auditory patterns are reported for conscious young, healthy control participants, as well as for hospice patients, both when the latter were conscious, and again when they became unresponsive to their environment. Whereas the MMN (and perhaps too the P3a) is considered an automatic response to auditory irregularities, the P3b is associated with conscious detection of oddball targets. All control participants, and most responsive hospice patients, evidenced a "local" effect (either a MMN, a P3a, or both) and some a "global" effect (P3b) to deviations in tone, or deviations in auditory pattern. Importantly, most unresponsive patients showed evidence of MMN responses to tone changes, and some showed a P3a or P3b response to either tone or pattern changes. Thus, their auditory systems were responding similarly to those of young, healthy controls just hours from end of life. Hearing may indeed be one of the last senses to lose function as humans die.

Clinical Transformation in Care for Patients With Sickle Cell Disease at an Urban Academic Medical Center.

This article demonstrates effects on utilization of a clinical transformation: changing locus of care from a dedicated sickle cell day unit to an approach that "fast-tracks" patients through the emergency department (ED) into an observation unit with 24/7 access. Retrospective quantitative analyses of claims and Epic electronic medical record data for patients with sickle cell disease treated at Thomas Jefferson University (inpatient and ED) assessed effects of the clinical transformation. Additionally, case studies were conducted to confirm and deepen the quantitative analyses. This study was approved by the Thomas Jefferson University Institutional Review Board. The quantitative analyses show significant decreases in ED and inpatient utilization following the transformation. These effects likely were facilitated by increased observation stays. This study demonstrated the impact on utilization of transformation in care (from dedicated day unit to an approach that fast-tracks patients into an observation unit). Additional case studies support the quantitative findings.

Noise sharing and Mexican-hat coupling in a stochastic neural field.

A diffusion-type coupling operator that is biologically significant in neuroscience is a difference of Gaussian functions (Mexican-hat operator) used as a spatial-convolution kernel. We are interested in pattern formation by stochastic neural field equations, a class of space-time stochastic differential-integral equations using the Mexican-hat kernel. We explore quantitatively how the parameters that control the shape of the coupling kernel, the coupling strength, and aspects of spatially smoothed space-time noise influence the pattern in the resulting evolving random field. We confirm that a spatial pattern that is damped in time in a deterministic system may be sustained and amplified by stochasticity. We find that spatially smoothed noise alone causes pattern formation even without direct spatial coupling. Our analysis of the interaction between coupling and noise sharing allows us to determine parameter combinations that are optimal for the formation of spatial pattern.

Search asymmetry in a serial auditory task: Neural source analyses of EEG implicate attention strategies.

Here we report a detailed analysis of the fast network dynamics underlying P3a and P3b event-related potential (ERP) subcomponents generated during an unconventional serial auditory search paradigm. We dissect the electroencephalographic (EEG) data from an earlier study of ours, using a variety of advanced signal processing techniques, in order to discover how the brain is processing auditory targets differently when they possess a rare, salient, unpredictable feature not shared with distractors than when targets lack this feature but distractors have it. We find that brain regions associated with the Ventral Attention Network (VAN) are the primary neural generators of the P3a subcomponent in response to feature-present targets, whereas regions associated with the Dorsal Attention Network (DAN), as well as regions associated with detecting auditory oddball stimuli (ODD), may be the primary neural generators of the P3b, in the context of our study, and perhaps in search paradigms in general. Moreover, measurements of the time courses of oscillatory power changes and inter-regional synchronization in theta and low-gamma frequency bands were consistent with the early activation and synchronization within the VAN associated with the P3a subcomponent, and with the later activation and synchronization within the DAN and ODD networks associated with the P3b subcomponent. Implications of these finding for the mechanisms underlying search asymmetry phenomena are discussed.

A Multidisciplinary Approach to Impact Acute Care Utilization in Sickle Cell Disease.

Sickle cell disease (SCD), an inherited red blood cell disorder, is characterized by anemia, end-organ damage, unpredictable episodes of pain, and early mortality. Emergency department (ED) visits and hospitalizations are frequent, leading to increased burden on patients and increased health care costs. This study assessed the effects of a multidisciplinary care team intervention on acute care utilization among adults with SCD. The multidisciplinary care team intervention included monthly team meetings and development of individualized care plans. Individualized care plans included targeted pain management plans for management of uncomplicated pain crisis. Following implementation of the multidisciplinary care team intervention, a significant decrease in ED utilization was identified among those individuals with a history of high ED utilization. Findings highlight the potential strength of multidisciplinary interventions and suggest that targeting interventions toward high-utilizing subpopulations may offer the greatest impact.