Integration of Simultaneous Resting-State Electroencephalography, Functional Magnetic Resonance Imaging, and Eye-Tracker Methods to Determine and Verify Electroencephalography Vigilance Measure

Background/Introduction: Concurrent electroencephalography and resting-state functional magnetic resonance imaging (rsfMRI) have been widely used for studying the (presumably) awake and alert human brain with high temporal/spatial resolution. Although rsfMRI scans are typically collected while individuals are instructed to focus their eyes on a fixated cross, objective and verified experimental measures to quantify degree of vigilance are not readily available. Electroencephalography (EEG) is the modality extensively used for estimating vigilance, especially during eyes-closed resting state. However, pupil size measured using an eye-tracker device could provide an indirect index of vigilance. Methods: Three 12-min resting scans (eyes open, fixating on the cross) were collected from 10 healthy control participants. We simultaneously collected EEG, fMRI, physiological, and eye-tracker data and investigated the correlation between EEG features, pupil size, and heart rate. Furthermore, we used pupil size and EEG features as regressors to find their correlations with blood-oxygen-level-dependent fMRI measures. Results: EEG frontal and occipital beta power (FOBP) correlates with pupil size changes, an indirect index for locus coeruleus activity implicated in vigilance regulation (r = 0.306, p < 0.001). Moreover, FOBP also correlated with heart rate (r = 0.255, p < 0.001), as well as several brain regions in the anticorrelated network, including the bilateral insula and inferior parietal lobule. Discussion: In this study, we investigated whether simultaneous EEG-fMRI combined with eye-tracker measurements can be used to determine EEG signal feature associated with vigilance measures during eyes-open rsfMRI. Our results support the conclusion that FOBP is an objective measure of vigilance in healthy human subjects. Impact statement We revealed an association between electroencephalography frontal and occipital beta power (FOBP) and pupil size changes during an eyes-open resting state, which supports the conclusion that FOBP could serve as an objective measure of vigilance in healthy human subjects. The results were validated by using simultaneously recorded heart rate and functional magnetic resonance imaging (fMRI). Interestingly, independently verified heart rate changes can also provide an easy-to-determine measure of vigilance during resting-state fMRI. These findings have important implications for an analysis and interpretation of dynamic resting-state fMRI connectivity studies in health and disease.

Attentional processing of information related to illness: Biases and associations with emotional response in young adults with different levels of illness anxiety

This study investigated attentional processing of illness-related information and associations with emotional reactivity. 100 young adults with low to high illness anxiety levels underwent free and cued viewing tasks, while eye-tracking and emotional reactivity were recorded. During free viewing, participants showed early orienting bias and sustained vigilance bias toward illness vs neutral pictures. Increased illness anxiety predicted vigilance bias to illness vs fearful pictures. During cued viewing, participants showed avoidance bias for illness vs neutral pictures, predicted by greater cardiac acceleration. Task nature appears to influence attentional processing patterns of illness stimuli. Preliminary evidence supports that attention allocation may be an emotion regulation mechanism.

The Italian National Surveillance System for Occupational Injuries: Conceptual Framework and Fatal Outcomes, 2002-2016

Background: A national database of work-related injuries has been established in Italy since 2002, collecting information on the injured person, his/her work tasks, the workplace and the risk factors contributing to incident dynamics, according to a model called Infor.Mo. Methods: A descriptive study of occupational fatal injuries, excluding work-related fatal traffic injuries, that occurred in Italy from 2002 to 2016 (15 years) was performed. Results: Among 4874 victims involved, all were males, mainly >51 years of age (43.2%), predominantly self-employed (27.8%) or workers with non-standard contracts (25%). About 18.4% and 17.3% of fatal events occurred in micro-enterprises belonging to, respectively, construction and agriculture. A wide range of nationalities (59 countries in addition to Italy) was identified. Overall, 18.9% of work-related fatal injuries were due to some form of hazardous energy—mechanical, thermal, electrical or chemical—that was normally present in the workplace. Workers’ falls from height (33.5%), heavy loads falling on workers from height (16.7%) and vehicles exiting their route and overturning (15.9%) were the events causing the greatest proportion of occupational fatal injuries in the present study (from 2002 to 2016) and in the initial pilot phase, focused on years 2002–2004, with a similar distribution of fatal events between the two time periods. The activity of the injured person made up 43.3% of 9386 risk factors identified in 4874 fatalities. Less common risk factors were related to work equipment (20.2%), work environment (14.9%), third–party activity (9.8%), personal protective equipment/clothing (8.0%) and materials (3.7%). The activity of the injured person remained the most relevant contributing factor even when the incident was caused by two or more risk factors. Discussion: Occupational fatal injuries occurred mainly in small size firms (up to nine employees) in hazardous workplaces. Small companies, which account for 68% (2888/4249) of all firms in the present study, generally have fewer resources to remain current with the continuously evolving health and safety at work regulations; moreover, these firms tend to be less compliant with health and safety at work regulations since they are less likely to be inspected by occupational vigilance services. Perspectives: An approach being introduced in Italy relies on the use of economic incentives to promote safe and healthy workplaces. The comparison of pre-intervention and post-intervention rates of work-related injuries by means of interrupted time series analyses could detect whether the intervention will have an effect significantly greater than the underlying secular trend.

Food restriction induces functional resilience to sleep restriction in rats

STUDY OBJECTIVES

Sleep restriction (SR) leads to performance decrements across cognitive domains but underlying mechanisms remain largely unknown. The impact of SR on performance in rodents is often assessed using tasks in which food is the reward. Investigating how the drives of hunger and sleep interact to modulate performance may provide insights into mechanisms underlying sleep loss-related performance decrements.

METHODS

Three experiments were conducted in male adult Wistar rats to assess: (1) effects of food restriction on performance in the simple response latency task (SRLT) across the diurnal cycle (n = 30); (2) interaction of food restriction and SR (11 h) on SRLT performance, sleep electroencephalogram, and event-related potentials (ERP) (n = 10-13); and (3) effects of food restriction and SR on progressive ratio (PR) task performance to probe the reward value of food reinforcement (n = 19).

RESULTS

Food restriction increased premature responding on the SRLT at the end of the light period of the diurnal cycle. SR led to marked impairments in SRLT performance in the ad libitum-fed group, which were absent in the food-restricted group. After SR, food-restricted rats displayed a higher amplitude of cue-evoked ERP components during the SRLT compared with the ad libitum group. SR did not affect PR performance, while food restriction improved performance.

CONCLUSIONS

Hunger may induce a functional resilience to negative effects of sleep loss during subsequent task performance, possibly by maintaining attention to food-related cues.

Nebulous Intentioning - Acute hospital nurses' struggle to deliver core nursing care

AIM

To explore the influences on nursing practice in acute hospital care.

DESIGN

A Classic Grounded Theory study.

METHODS

Data collection (2013-2015) was through interviews and non-participant observations. Analysis was undertaken using constant comparative data analysis and theoretical sampling. Memo writing was used as an aid to understanding and conceptualizing data during analysis. Theoretical coding served to integrate emerging concepts.

RESULTS

This theory explains core nursing as a nebulous intention, an idea which acute care nurses retain throughout each shift, that they will nurse their patients fully when they have the opportunity. It reveals this as the resolution of their main problem which is the constant deferral of core nursing care. This study explains its two sub-core categories, accommodating and integrity eroding.

CONCLUSION

The theory highlights nurses' attitudes towards their role, demonstrated by deferring it to accommodate the work of others, but offers a new perspective on the significant contribution nurses make to the safe and cohesive transition of patients through the acute healthcare system.

IMPACT

The theory adds a new understanding of the unique contribution nurses make to patient health and safety in acute care environments. It also provides insight into nurses' attitudes towards their own professional work. It explains the consequences of attitudes which undermine core nursing when it competes for priority with accommodating. Accommodating indicates a greater workload for nurses than has been previously understood in explaining the activities, additional to core nursing care, which nurses undertake to contribute safety and cohesion to the patient's acute care journey. These new insights suggest a role for managers in recognizing accommodating in decisions about staffing and resources and for educators in improving the profession's regard for its theoretical underpinnings and for its self-image.

Amphetamine reduces reward encoding and stabilizes neural dynamics in rat anterior cingulate cortex

Psychostimulants such as d-amphetamine (AMPH) often have behavioral effects that appear paradoxical within the framework of optimal choice theory. AMPH typically increases task engagement and the effort animals exert for reward, despite decreasing reward valuation. We investigated neural correlates of this phenomenon in the anterior cingulate cortex (ACC), a brain structure implicated in signaling cost-benefit utility. AMPH decreased signaling of reward, but not effort, in the ACC of freely-moving rats. Ensembles of simultaneously recorded neurons generated task-specific trajectories of neural activity encoding past, present, and future events. Low-dose AMPH contracted these trajectories and reduced their variance, whereas high-dose AMPH expanded both. We propose that under low-dose AMPH, increased network stability balances moderately increased excitability, which promotes accelerated unfolding of a neural 'script' for task execution, despite reduced reward valuation. Noise from excessive excitability at high doses overcomes stability enhancement to drive frequent deviation from the script, impairing task execution.

Attention and Functional Connectivity Among Patients With Early-Stage Subcortical Ischemic Vascular Disease and Alzheimer's Disease

The current study compared attention profiles and functional connectivity of frontal regions in patients with early-stage subcortical ischemic vascular disease (SIVD) and Alzheimer's disease (AD). Twenty patients with SIVD, 32 patients with AD, and 23 subjects with normal cognition (NC) received cognition and resting-state functional MRI (rs-fMRI) evaluations. The Cognitive Abilities Screening Instrument (CASI) was used to assess global cognition, and simple attention, processing speed, divided attention, and vigilance/sustained attention were evaluated using the Digit Span Forward, Trail Making Test, Symbol Digit Modality Test, and Conners Continuous Performance Test, respectively. Voxel-based regional homogeneity (ReHo) derived from rs-fMRI data was analyzed to identify significant clusters, which were further correlated with attention profiles. Although the patients with SIVD and AD had comparable global cognitive ability, those with SIVD exhibited worse divided attention and vigilance/sustained attention than those with AD. Compared with the NC group, the patients with SIVD exhibited decreased ReHo within the right middle frontal gyrus (MFG) and left anterior cingulate gyrus (ACG), whereas the patients with AD exhibited increased ReHo within the right orbital part of frontal regions. Correlations between these three clusters with attention exhibited distinct patterns according to the dementia subtype, as did attention indices with significance in predicting global cognition. In summary, our study suggested that worse attention performance was associated with functional disconnection within the frontal regions among patients with SIVD than in those with AD. Frontal functional disconnection may underlie the pathogenesis responsible for defective divided attention, vigilance/sustained attention, and notable within-group variations identified in SIVD.

The Human Touch: Using a Webcam to Autonomously Monitor Compliance During Visual Field Assessments

Purpose

To explore the feasibility of using various easy-to-obtain biomarkers to monitor non-compliance (measurement error) during visual field assessments.

Methods

Forty-two healthy adults (42 eyes) and seven glaucoma patients (14 eyes) underwent two same-day visual field assessments. An ordinary webcam was used to compute seven potential biomarkers of task compliance, based primarily on eye gaze, head pose, and facial expression. We quantified the association between each biomarker and measurement error, as defined by (1) test–retest differences in overall test scores (mean sensitivity), and (2) failures to respond to visible stimuli on individual trials (stimuli −3 dB or more brighter than threshold).

Results

In healthy eyes, three of the seven biomarkers were significantly associated with overall (test–retest) measurement error (P = 0.003–0.007), and at least two others exhibited possible trends (P = 0.052–0.060). The weighted linear sum of all seven biomarkers was associated with overall measurement error, in both healthy eyes (r = 0.51, P < 0.001) and patients (r = 0.65, P < 0.001). Five biomarkers were each associated with failures to respond to visible stimuli on individual trials (all P < 0.001).

Conclusions

Inexpensive, autonomous measures of task compliance are associated with measurement error in visual field assessments, in terms of both the overall reliability of a test and failures to respond on particular trials (“lapses”). This could be helpful for identifying low-quality assessments and for improving assessment techniques (e.g., by discounting suspect responses or by automatically triggering comfort breaks or encouragement).

Translational Relevance

This study explores a potential way of improving the reliability of visual field assessments, a crucial but notoriously unreliable clinical measure.

Reducing the use of screen electronic devices in the evening is associated with improved sleep and daytime vigilance in adolescents

The use of screen electronic devices in the evening negatively affects sleep. Yet, sleep is known to be essential for brain maturation and a key factor for good academic performance, and thus is particularly critical during childhood and adolescence. Although previous studies reported associations between screen time and sleep impairment, their causal relationship in adolescents remains unclear. Using actigraphy and daily questionnaires in a large sample of students (12 to 19 years old), we assessed screen time in the evening and sleep habits over 1 month. This included a 2 week baseline phase, followed by a 40 min sleep education workshop and a 2 week interventional phase, in which participants were asked to stop using screen devices after 9 pm during school nights. During the interventional phase, we found that the reduction of screen time after 9 pm correlated with earlier sleep onset time and increased total sleep duration. The latter led to improved daytime vigilance. These findings provide evidence that restricting screen use in the evening represents a valid and promising approach for improving sleep duration in adolescents, with potential implications for daytime functioning and health.

The Sustained Attention to Response Task Shows Lower Cingulo-Opercular and Frontoparietal Activity in People with Narcolepsy Type 1: An fMRI Study on the Neural Regulation of Attention

Vigilance complaints often occur in people with narcolepsy type 1 and severely impair effective daytime functioning. We tested the feasibility of a three-level sustained attention to response task (SART) paradigm within a magnetic resonance imaging (MRI) environment to understand brain architecture underlying vigilance regulation in individuals with narcolepsy type 1. Twelve medication-free people with narcolepsy type 1 and 11 matched controls were included. The SART included four repetitions of a baseline block and two difficulty levels requiring moderate and high vigilance. Outcome measures were between and within-group performance indices on error rates and reaction times, and functional MRI (fMRI) parameters: mean activity during the task and between-group activity differences across the three conditions and related to changes in activation over time (time-on-task) and error-related activity. Patients—but not controls—made significantly more mistakes with increasing difficulty. The modified SART is a feasible MRI vigilance task showing similar task-positive brain activity in both groups within the cingulo-opercular, frontoparietal, arousal, motor, and visual networks. During blocks of higher vigilance demand, patients had significantly lower activation in these regions than controls. Patients had lower error-related activity in the left pre- and postcentral gyrus. The time-on-task activity differences between groups suggest that those with narcolepsy are insufficiently capable of activating attention- and arousal-related regions when transitioning from attention initiation to stable attention, specifically when vigilance demand is high. They also show lower inhibitory motor activity in relation to errors, suggesting impaired executive functioning.

Distinguishing vigilance decrement and low task demands from mind-wandering: A machine learning analysis of EEG

Mind‐wandering is a ubiquitous mental phenomenon that is defined as self‐generated thought irrelevant to the ongoing task. Mind‐wandering tends to occur when people are in a low‐vigilance state or when they are performing a very easy task. In the current study, we investigated whether mind‐wandering is completely dependent on vigilance and current task demands, or whether it is an independent phenomenon. To this end, we trained support vector machine (SVM) classifiers on EEG data in conditions of low and high vigilance, as well as under conditions of low and high task demands, and subsequently tested those classifiers on participants' self‐reported mind‐wandering. Participants' momentary mental state was measured by means of intermittent thought probes in which they reported on their current mental state. The results showed that neither the vigilance classifier nor the task demands classifier could predict mind‐wandering above‐chance level, while a classifier trained on self‐reports of mind‐wandering was able to do so. This suggests that mind‐wandering is a mental state different from low vigilance or performing tasks with low demands—both which could be discriminated from the EEG above chance. Furthermore, we used dipole fitting to source‐localize the neural correlates of the most import features in each of the three classifiers, indeed finding a few distinct neural structures between the three phenomena. Our study demonstrates the value of machine‐learning classifiers in unveiling patterns in neural data and uncovering the associated neural structures by combining it with an EEG source analysis technique.

Dissociable Effects of Reward on P300 and EEG Spectra Under Conditions of High vs. Low Vigilance During a Selective Visual Attention Task

The influence of motivation on selective visual attention in states of high vs. low vigilance is poorly understood. To explore the possible differences in the influence of motivation on behavioral performance and neural activity in high and low vigilance levels, we conducted a prolonged 2 h 20 min flanker task and provided monetary rewards during the 20- to 40- and 100- to 120-min intervals of task performance. Both the behavioral and electrophysiological measures were modulated by prolonged task engagement. Moreover, the effect of reward was different in high vs. low vigilance states. The monetary reward increased accuracy and decreased the reaction time (RT) and number of omitted responses in the low but not in the high vigilance state. The fatigue-related decrease in P300 amplitude recovered to its level in the high vigilance state by manipulating motivation, whereas the fatigue-related increase in P300 latency was not modulated by reward. Additionally, the fatigue-related increase in event-related spectral power at 1-4 Hz was sensitive to vigilance decrement and reward. However, the spectral power at 4-8 Hz was only affected by the decrease in vigilance. These electrophysiological measures were not influenced by motivation in the state of high vigilance. Our results suggest that neural processing capacity, but not the timing of processing, is sensitive to motivation. These findings also imply that the fatigue-related impairments in behavioral performance and neural activity underlying selective visual attention only partly recover after manipulating motivation. Furthermore, our results provide evidence for the dissociable neural mechanisms underlying the fatigue-related decrease vs. reward-related increase in attentional resources.

Comparison of the Effects of Automated and Manual Record Keeping on Anesthetists' Monitoring Performance: Randomized Controlled Simulation Study

Background

Anesthesia information management systems (AIMSs) automatically import real-time vital signs from physiological monitors to anesthetic records, replacing part of anesthetists’ traditional manual record keeping. However, only a handful of studies have examined the effects of AIMSs on anesthetists’ monitoring performance.

Objective

This study aimed to compare the effects of AIMS use and manual record keeping on anesthetists’ monitoring performance, using a full-scale high-fidelity simulation.

Methods

This simulation study was a randomized controlled trial with a parallel group design that compared the effects of two record-keeping methods (AIMS vs manual) on anesthetists’ monitoring performance. Twenty anesthetists at a tertiary hospital in Hong Kong were randomly assigned to either the AIMS or manual condition, and they participated in a 45-minute scenario in a high-fidelity simulation environment. Participants took over a case involving general anesthesia for below-knee amputation surgery and performed record keeping. The three primary outcomes were participants’ (1) vigilance detection accuracy (%), (2) situation awareness accuracy (%), and (3) subjective mental workload (0-100).

Results

With regard to the primary outcomes, there was no significant difference in participants’ vigilance detection accuracy (AIMS, 56.7% vs manual, 56.7%; P=.50), and subjective mental workload was significantly lower in the AIMS condition than in the manual condition (AIMS, 34.2 vs manual, 46.7; P=.02). However, the result for situation awareness accuracy was inconclusive as the study did not have enough power to detect a difference between the two conditions.

Conclusions

Our findings suggest that it is promising for AIMS use to become a mainstay of anesthesia record keeping. AIMSs are effective in reducing anesthetists’ workload and improving the quality of their anesthetic record keeping, without compromising vigilance.

Vigilance, Inhibitory Control and Regional Cerebral Blood Oxygenation in the PFC - Differences in ADHD Types of Presentations

It is commonly believed that proven abnormalities in the structure and functioning of the prefrontal lobes affect cognitive deficits in children with ADHD. The purpose of the current study was to assess vigilance, inhibitory control, and regional cerebral blood oxygenation (rCBO2) in the prefrontal cortex (PFC) of children with ADHD. The study included 150 children with ADHD and 51 typically developing (TD) children aged 9-12 years. Children with ADHD showed a deficit in vigilance (assessed by the shortened version of the Mackworth clock task), inhibitory control (the Stroop task), different rCBO2 patterns in the PFC, as well as lower cortical activation during cognitive tasks. These differences are discussed in the context of the types of ADHD presentations.

Call-specific patterns of neural activation in auditory processing of Richardson's ground squirrel alarm calls

INTRODUCTION

Richardson's ground squirrels use alarm calls to warn conspecifics about potential predatory threats. Chirp calls typically indicate high levels of threat from airborne predators, while whistle calls are associated with lower levels of threat from terrestrial predators. These types of calls primarily elicit escape behaviors and increased vigilance in receivers, respectively. While much is known about the neural mechanisms involved in the production of vocalizations, less is known about the mechanisms important for the perception of alarm calls by receivers, and whether changes in perceived risk are associated with unique patterns of neuronal activation. Thus, to determine whether alarm calls associated with different levels of predation risk result in differential neuronal activation, we used immunohistochemistry to identify and quantify c-Fos immunopositive cells in brain regions important in stress, fear, danger, and reward, following alarm call reception.

METHODS

We exposed 29 female Richardson's ground squirrels (10 control, 10 whistle receivers, and 9 chirp receivers) to playbacks of whistles, chirps, or a no-vocalization control. We then assessed neuronal activation via c-Fos immunohistochemistry in 12 brain regions.

RESULTS

Ground squirrels receiving high-threat "chirp" vocalizations had reduced neuronal activation in the medial amygdala and superior colliculus compared with controls. It is likely that changes in activity in these brain regions serve to alter the balance between approach and avoidance in turn promoting escape behaviors.

CONCLUSIONS

Thus, we conclude that in Richardson's ground squirrels, these brain regions are important for the perception of risk resulting from receiving alarm calls and allow for appropriate behavioral responses by receivers.

The Influence of Sleep Quality, Vigilance, and Sleepiness on Driving-Related Cognitive Abilities: A Comparison between Young and Older Adults

Background: Driving performance is strongly vulnerable to drowsiness and vigilance fluctuations. Excessive sleepiness may alter concentration, alertness, and reaction times. As people age, sleep undergoes some changes, becoming fragmented and less deep. However, the effects of these modifications on daily life have not been sufficiently investigated. Recently, the assessment of sleepiness became mandatory in Europe for people at risk who need the driving license release. Moreover, considering the expectation that people around the world are rapidly aging, it is necessary to investigate the relationships between senescence sleep changes, vigilance levels, and driving-related cognitive skills. Method: 80 healthy subjects (40 young adults and 40 elders) participated in the study. Sleep quality, sleepiness, and vigilance levels were assessed through the Pittsburgh Sleep Quality Index, the Karolinska Sleepiness Scale, the Epworth Sleepiness Scale, and the Psychomotor Vigilance Task (PVT). Driving-related cognitive abilities were assessed through Vienna Test System TRAFFIC, investigating selective attention, tachistoscopic perception, and risk assumption. Results: 2 × 2 between-subject ANOVAs showed less habitual sleep efficiency and worse performances in PVT in the older group. Unexpectedly, younger subjects show higher self-rated sleepiness. Moreover, older adults have lower performance in attention and perception tests, but they appear to be more cautious in situations involving traffic. Finally, the multiple regressions show age to be the only robust predictor of cognitive driving-related abilities. Conclusions: This is the first study that investigates the relationships among sleepiness/vigilance and specific driving-related cognitive skills on a sufficiently large sample. Nevertheless, the study should be considered preliminary and does not allow us to understand how specific changes in sleep architecture impact performances in the elders' everyday life and, specifically, on driving skills.

The Neuropsychological Profile of Attention Deficits of Patients with Obstructive Sleep Apnea: An Update on the Daytime Attentional Impairment

Introduction: Patients with obstructive sleep apnea (OSA) suffer from several neurocognitive disturbances. One of the neuropsychological processes most investigated in OSA patients is attention, but the results have been controversial. Here, we update the attention profile of OSA patients with the final aim to improve attention assessment, with a possible impact on clinical and medical-legal practices, in terms of which attention subdomains and parameters need consideration and which one is a high-risk OSA phenotype for attention dysfunctions. Method: For this purpose, we assessed 32 previously untreated OSA patients (26 men and 6 women) under 65 years of age (mean age 53.2 ± 7.3; mean education level 10.4 ± 3.4 years) suffering from moderate to severe sleep apnea and hypopnea (mean apnea-hypopnea index (AHI) 45.3 ± 22.9, range 16.1–69.6). A control group of 34 healthy participants matched with OSA patients for age, education level, and general cognitive functioning were also enrolled. The OSA patients and healthy participants were tested through an extensive computerized battery (Test of Attentional Performance, TAP) that evaluated intensive (i.e., alertness and vigilance) and selective (i.e., divided and selective) dimensions of attention and returned different outcome parameters (i.e., reaction time, stability of performance, and various types of errors). Data analysis: The data were analyzed by ANCOVA which compared the speed and accuracy performance of the OSA and control participants (cognitive reserve was treated as a covariate). The possible mechanisms underlying attention deficits in OSA patients were examined through correlation analysis among AHI, oxygenation parameters, sleepiness scores, and TAP outcomes and by comparing the following three phenotypes of patients: severe OSA and severe nocturnal desaturators (AHI⁺⁺D⁺), severe OSA nondesaturators (AHI⁺⁺D⁻), and moderate OSA nondesaturators (AHI⁺D⁻). Results: The results suggest that the OSA patients manifest deficits in both intensive and selective attention processes and that reaction time (RT) alone is ineffective for detecting and characterizing their problems, for which error analysis and stability of performance also have to be considered. Patients with severe OSA and severe hypoxemia underperformed on alertness and vigilance attention subtests. Conclusions: The data suggest the importance of evaluating attention deficits among OSA patients through several parameters (including performance instability). Moreover, the data suggest a multifaceted mechanism underlying attention dysfunction in OSA patients.

Vigilance Effects in Resting-State fMRI

Measures of resting-state functional magnetic resonance imaging (rsfMRI) activity have been shown to be sensitive to cognitive function and disease state. However, there is growing evidence that variations in vigilance can lead to pronounced and spatially widespread differences in resting-state brain activity. Unless properly accounted for, differences in vigilance can give rise to changes in resting-state activity that can be misinterpreted as primary cognitive or disease-related effects. In this paper, we examine in detail the link between vigilance and rsfMRI measures, such as signal variance and functional connectivity. We consider how state changes due to factors such as caffeine and sleep deprivation affect both vigilance and rsfMRI measures and review emerging approaches and methodological challenges for the estimation and interpretation of vigilance effects.

Differential effects of split and continuous sleep on neurobehavioral function and glucose tolerance in sleep-restricted adolescents

Study Objectives

Many adolescents are exposed to sleep restriction on school nights. We assessed how different apportionment of restricted sleep (continuous vs. split sleep) influences neurobehavioral function and glucose levels.

Methods

Adolescents, aged 15–19 years, were evaluated in a dormitory setting using a parallel-group design. Following two baseline nights of 9-hour time-in-bed (TIB), participants underwent either 5 nights of continuous 6.5-h TIB (n = 29) or 5-hour nocturnal TIB with a 1.5-hour afternoon nap (n = 29). After two recovery nights of 9-hour TIB, participants were sleep restricted for another three nights. Sleep was assessed using polysomnography (PSG). Cognitive performance and mood were evaluated three times per day. Oral glucose tolerance tests (OGTT) were conducted on mornings after baseline sleep, recovery sleep, and the third day of each sleep restriction cycle.

Results

The split sleep group had fewer vigilance lapses, better working memory and executive function, faster processing speed, lower level of subjective sleepiness, and more positive mood, even though PSG-verified total sleep time was less than the continuous sleep group. However, vigilance in both sleep-restricted groups was inferior to adolescents in a prior sample given 9-hour nocturnal TIB. During both cycles of sleep restriction, blood glucose during the OGTT increased by a greater amount in the split sleep schedule compared with persons receiving 6.5-hour continuous sleep.

Conclusions

In adolescents, modest multinight sleep restriction had divergent negative effects on cognitive performance and glucose levels depending on how the restricted sleep was apportioned. They are best advised to obtain the recommended amount of nocturnal sleep.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT03333512

Effect of group size and reproductive status on faecal glucocorticoid concentration and vigilance in a free-ranging population of Przewalski's gazelle

Elevated glucocorticoid (GC) concentration and increased vigilance are two common responses to predation risk in mammals. Chronic high-level GC concentration and vigilance occur at the expense of other life maintenance and reproduction activities, reflecting a trade-off between individual survival and future fecundity. Przewalski's gazelle (Procapra przewalskii) is a group-living ungulate endemic to the high-altitude Qinghai Lake region of China. Group-size effect on gazelle vigilance has been examined, yet little is known about how their GC concentration is affected by group size or reproductive status. In this study, we examined the effect of group size and reproductive status on faecal glucocorticoid metabolite (FGM) concentrations and individual vigilance during different stages of the reproduction cycle (i.e. non-breeding, lambing and rutting) in free-ranging adult female Przewalski's gazelles. Group size did not influence FGMs significantly, but mean vigilance duration increased with group size. The gazelles' FGMs and vigilance peaked in lambing season. FGMs showed no difference between rutting season and non-reproductive season, but vigilance was lowest in the rutting season. FGMs correlated with vigilance frequency and vigilance duration. Antipredator responses of female Przewalski's gazelles appear to change with reproductive status but not with group size in free-ranging females. Management measures should be taken in the lambing season to minimize stress on mother gazelles.

EEG effective connectivity networks for an attentive task requiring vigilance based on dynamic partial directed coherence

An effective network perspective focused on measuring directional interactions of electroencephalographic in different cortical regions during a sustained attentive task requiring vigilance. A novel measure referred to as dynamic partial directed coherence was used to map the cognitive state of vigilance based on graph theory. In the right parieto-occipital area, the area is significantly higher than in other regions of interest (the areas are 0.601 and 0.632 for out-degree and in-degree, respectively). A similar analysis in the right fronto-central area revealed significant differences in the different cognitive states. Across the six regions of interest, significant differences of in-degree and out-degree based alpha band are observed in the right fronto-central and the right parieto-occipital (P < 0.05). The performance was compared with those from a support vector machine using different network-based phase-locking values, partial directed coherence, and dynamic partial directed coherence. Results show that dynamic partial directed coherence can provide more information about direction (compared with phase-locking values) and accuracy (when compared with partial directed coherence). The graph theoretical analysis shows that the effective network based dynamic partial directed coherence has a small-world property for synchronizing neural activity between brain regions. Moreover, the alpha band is well correlated with the cognitive state compared to other frequency bands.

Mixed-species herding levels the landscape of fear

Prey anti-predator behaviours are influenced by perceived predation risk in a landscape and social information gleaned from herd mates regarding predation risk. It is well documented that high-quality social information about risk can come from heterospecific herd mates. Here, we integrate social information with the landscape of fear to quantify how these landscapes are modified by mixed-species herding. To do this, we investigated zebra vigilance in single- and mixed-species herds across different levels of predation risk (lion versus no lion), and assessed how they manage herd size and the competition-information trade-off associated with grouping behaviour. Overall, zebra performed higher vigilance in high-risk areas. However, mixed-species herding reduced vigilance levels. We estimate that zebra in single-species herds would have to feed for approximately 35 min more per day in low-risk areas and approximately 51 min more in high-risk areas to compensate for the cost of higher vigilance. Furthermore, zebra benefitted from the competition-information trade-off by increasing the number of heterospecifics while keeping the number of zebra in a herd constant. Ultimately, we show that mixed-species herding reduces the effects of predation risk, whereby zebra in mixed-species herds, under high predation risk, perform similar levels of vigilance compared with zebra in low-risk scenarios.

Medical device active surveillance of spontaneous reports: A literature review of signal detection methods

PURPOSE

The collection and analysis of real-world data for the active monitoring of medical device performance and safety has become increasingly important. Spontaneous reports, such as those in the Food & Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE), provide early warning of potential issues with marketed devices. This review synthesizes the current literature on medical device surveillance signal detection and provides a framework for application of methods to active surveillance of spontaneous reports.

METHODS

Ovid MEDLINE, Ovid Embase, Scopus, and PubMed databases were systematically searched up to January 2019. Additionally, five methods articles from pharmacovigilance were added that had potential applications to medical devices.

RESULTS

Among 105 articles included, the most common source of data (84%) was registries; median time between data collection and publication was 8 years. Surgical procedure outcome signal detection articles comprised 83% while 14% were on device outcome signal detection. The most common family of methods cited (70%) was Sequential Probability Ratio.

CONCLUSION

Application of any signal detection algorithm requires careful consideration of influential factors, data limitations, and algorithmic assumptions. We recommend approaches using disproportionality, statistical process control, and sequential probability tests and provide R packages to further development efforts. The small number of published examples suggest that further development of statistical methods and technological solutions to analyze large amounts of data for device safety and performance is needed. Fundamental differences in products, data infrastructure, and the regulatory landscape suggest that medical device vigilance requires its own body of research distinct from pharmacovigilance.

ART in Europe, 2015: results generated from European registries by ESHRE

STUDY QUESTION

What are the European trends and developments in ART and IUI in 2015 as compared to previous years?

SUMMARY ANSWER

The 19th ESHRE report on ART shows a continuing expansion of treatment numbers in Europe, and this increase, the variability in treatment modalities and the rising contribution to the birth rates in most participating countries all point towards the increasing impact of ART on European society.

WHAT IS KNOWN ALREADY

Since 1997, the ART data generated by national registries have been collected, analysed and reported in 18 manuscripts published in Human Reproduction.

STUDY DESIGN, SIZE, DURATION

Collection of European data by the European IVF-Monitoring Consortium (EIM) for ESHRE. The data for treatments performed between 1 January and 31 December 2015 in 38 European countries were provided by national registries or on a voluntary basis by clinics or professional societies.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

From 1343 institutions in 38 countries offering ART services a total of 849 811 treatment cycles, involving 155 960 with IVF, 385676 with ICSI, 218098 with frozen embryo replacement (FER), 21 041 with preimplantation genetic testing (PGT), 64 477 with egg donation (ED), 265 with IVM and 4294 with FOR were recorded. European data on IUI using husband/partner’s semen (IUI-H) and donor semen (IUI-D) were reported from 1352 institutions offering IUI in 25 countries and 21 countries, respectively. A total of 139 050 treatments with IUI-H and 49 001 treatments with IUI-D were included.

MAIN RESULTS AND THE ROLE OF CHANCE

In 18 countries (14 in 2014) with a population of approximately 286 million inhabitants, in which all institutions contributed to their respective national registers, a total of 409 771 treatment cycles were performed, corresponding to 1432 cycles per million inhabitants (range: 727–3068 per million). After IVF the clinical pregnancy rates (PRs) per aspiration and per transfer were slightly lower in 2015 as compared to 2014, at 28.5 and 34.6% versus 29.9 and 35.8%, respectively. After ICSI, the corresponding PR achieved per aspiration and per transfer in 2015 were also slightly lower than those achieved in 2014 (26.2 and 33.2% versus 28.4 and 35.0%, respectively). On the other hand, after FER with own embryos the PR per thawing continued to rise from 27.6% in 2014 to 29.2% in 2015. After ED a slightly lower PR per embryo transfer was achieved: 49.6% per fresh transfer (50.3% in 2014) and 43.4% for FOR (48.7% in 2014). The delivery rates (DRs) after IUI remained stable at 7.8% after IUI-H (8.5% in 2014) and at 12.0% after IUI-D (11.6% in 2014). In IVF and ICSI together, 1, 2, 3 and ≥4 embryos were transferred in 37.7, 53.9, 7.9 and in 0.5% of all treatments, respectively (corresponding to 34.9, 54.5, 9.9 and in 0.7% in 2014). This evolution towards the transfer of fewer embryos in both IVF and ICSI resulted in a proportion of singleton, twin and triplet DR of 83.1, 16.5 and 0.4%, respectively (compared to 82.5, 17.0 and 0.5%, respectively, in 2014). Treatments with FER in 2015 resulted in twin and triplet DR of 12.3 and 0.3%, respectively (versus 12.4 and 0.3% in 2014). Twin and triplet delivery rates after IUI-H were 8.9 and 0.5%, respectively (in 2014: 9.5 and 0.3%), and 7.3 and 0.6% after IUI-D (in 2014: 7.7 and 0.3%).

LIMITATIONS, REASONS FOR CAUTION

The methods of data collection and reporting vary among European countries. The EIM receives aggregated data from various countries with variable levels of completeness. Registries from a number of countries have failed to provide adequate data about the number of initiated cycles and deliveries. As long as incomplete data are provided, the results should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The 19th EIM report on ART shows a continuing expansion of treatment numbers in Europe. The number of treatments reported, the variability in treatment modalities and the rising contribution to the birth rates in most participating countries point towards the increasing impact of ART on reproduction in Europe. Being the largest data collection on ART worldwide, detailed information about ongoing developments in the field is provided.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests.

Pharmacokinetics of Intravenous and Oral Phenobarbital Sodium in Healthy Goats

Phenobarbital is a common drug used to manage epilepsy in goats. However, the recommended dose and dosing frequency are based on studies in dogs and horses. Studies describing the pharmacokinetics of phenobarbital when administered orally and assessing changes in behavior with concurrent electroencephalogram (EEG) readings are warranted in goats. The objectives of this study were to determine the bioavailability of orally administered phenobarbital and determine the effect of phenobarbital on brain activity using EEG in healthy goats. A cross-over design with 8 non-pregnant goats was performed. The goats were administered phenobarbital intravenously at 10 mg/kg, followed by a 2 week wash out period, and then administered phenobarbital, orally, at 10 mg/kg. Plasma sample determination of phenobarbital concentrations were collected at 13 time points. Continuous EEG readings with simultaneous video recording for 12 h was performed to determine the state of vigilance using a behavior scoring system prior to and after phenobarbital administration. Bioavailability of phenobarbital was 24.9%. Mean ± SD for half-life was similar between the oral (3.80 ± 0.826 h) and intravenous (4.0 ± 0.619 h) routes. Time to observed maximum concentration (T_max), and maximum plasma concentration (C_max) for the oral administration were 1.75 ± 0.46 h and 4,478.7 ± 962.4 ng/mL, respectively. Clearance was 152.5 ± 102.7 ml/h/kg. Area under the curve from zero to infinity (AUC_0→∞) was 155,813 ± 218,448 and 38,763 ± 9,832 h^*ng/mL for the intravenous and oral administration routes, respectively. Behavior score at 3 h after phenobarbital administration was different (P = 0.0002) from the score prior to administration for the oral administration route. In contrast, behavior scores before administration of phenobarbital and each time point after administration were not different (P >0.05) for the intravenous administration route or other oral administration route time points. Bioavailability of phenobarbital was poor, and the half-life was very short due to a high clearance. Doses >10 mg/kg should be considered when phenobarbital is administered orally in goats.