Self-reported view on work capacity predicts abnormal Oxford Sleep Resistance Test results in patients with obstructive sleep apnea

STUDY OBJECTIVES

The Oxford Sleep Resistance Test is an objective vigilance test based on behavior. It is a modified version of the maintenance of wakefulness test and is considered less burdensome and less expensive than the maintenance of wakefulness test. Although professional drivers with obstructive sleep apnea in Europe must be assessed for their ability to maintain adequate wakefulness on a yearly basis, Oxford Sleep Resistance Test results are usually normal in this population. In this retrospective observational study, we searched for predictive factors of abnormal Oxford Sleep Resistance Test sleep latency.

METHODS

We included 1,071 Oxford Sleep Resistance Test results of patients with obstructive sleep apnea (95% men, aged 21-74 years). Mean sleep latency < 40 minutes was considered abnormal.

RESULTS

Sleep latency was abnormal in 12.0% of tests. Participants at risk for abnormal test results self-reported as being sleepy, depressed, on sick leave, unemployed, or retired or considered themselves unable to work. In a logistic regression model, the self-reported view on work capacity was the most important predictor of abnormal Oxford Sleep Resistance Test sleep latency (odds ratio, 3.5). Ongoing sick leave was also an important predictor for abnormal test results.

CONCLUSIONS

A self-reported good ability to work predicts that a patient with sleep apnea can maintain wakefulness in a vigilance test. This may help in reducing the increasing challenge with frequent tests.

Mind Wandering Influences EEG Signal in Complex Multimodal Environments

The phenomenon of mind wandering (MW), as a family of experiences related to internally directed cognition, heavily influences vigilance evolution. In particular, humans in teleoperations monitoring partially automated fleet before assuming manual control whenever necessary may see their attention drift due to internal sources; as such, it could play an important role in the emergence of out-of-the-loop (OOTL) situations and associated performance problems. To follow, quantify, and mitigate this phenomenon, electroencephalogram (EEG) systems already demonstrated robust results. As MW creates an attentional decoupling, both ERPs and brain oscillations are impacted. However, the factors influencing these markers in complex environments are still not fully understood. In this paper, we specifically addressed the possibility of gradual emergence of attentional decoupling and the differences created by the sensory modality used to convey targets. Eighteen participants were asked to (1) supervise an automated drone performing an obstacle avoidance task (visual task) and (2) respond to infrequent beeps as fast as possible (auditory task). We measured event-related potentials and alpha waves through EEG. We also added a 40-Hz amplitude modulated brown noise to evoke steady-state auditory response (ASSR). Reported MW episodes were categorized between task-related and task-unrelated episodes. We found that N1 ERP component elicited by beeps had lower amplitude during task-unrelated MW, whereas P3 component had higher amplitude during task-related MW, compared with other attentional states. Focusing on parieto-occipital regions, alpha-wave activity was higher during task-unrelated MW compared with others. These results support the decoupling hypothesis for task-unrelated MW but not task-related MW, highlighting possible variations in the "depth" of decoupling depending on MW episodes. Finally, we found no influence of attentional states on ASSR amplitude. We discuss possible reasons explaining why. Results underline both the ability of EEG to track and study MW in laboratory tasks mimicking ecological environments, as well as the complex influence of perceptual decoupling on operators' behavior and, in particular, EEG measures.

Sustained attention to response task performance trajectories in Down syndrome

BACKGROUND

Sustained attention (SA) has been reported to be a unitary construct in youth with Down syndrome (DS), but additional analyses of how auditory and visual SA change over task presentation time are warranted.

METHOD

The current study was a secondary data analysis employing multilevel modeling. Specifically, we compared auditory and visual sustained attention to response task (SART) performance trajectories within a group of 42 youth with DS aged 10 to 22 years.

RESULTS

We found that auditory omission errors increased at a faster rate than visual omission errors over increasing SART block presentations in youth with DS.

CONCLUSIONS

Youth with DS experience more SA lapses over time in the auditory than visual modality. Results have implications for academic instruction and assessment.

Effects of containment and closure policies on controlling the COVID-19 pandemic in East Asia

Growing efforts have been made to pool coronavirus data and control measures from countries and regions to compare the effectiveness of government policies. We examine whether these strategies can explain East Asia's effective control of the COVID-19 pandemic based on time-series data with cross-correlations between the Stringency Index and number of confirmed cases during the early period of outbreaks. We suggest that multidisciplinary empirical research in healthcare and social sciences, personality, and social psychology is needed for a clear understanding of how cultural values, social norms, and individual predispositions interact with policy to affect life-saving behavioural changes in different societies.

The ANT Executive Control Index: No Evidence for Temporal Decrement

OBJECTIVE

This study tested whether indices of executive control, alertness, and orienting measured with Attention Network Test (ANT) are vulnerable to temporal decrement in performance.

BACKGROUND

Developing the resource theory of sustained attention requires identifying neurocognitive processes vulnerable to decrement. Executive control processes may be prone to impairment in fatigue states. Such processes are also highlighted in alternative theories. Determining the role of executive control in vigilance can both advance theory and contribute to practical countermeasures for decrement in human factors contexts.

METHOD

In Study 1, 80 participants performed the standard ANT for an extended duration of about 55 to 60 min. Study 2 (160 participants) introduced manipulations of trial blocking and stimulus degradation intended to increase resource depletion. Reaction time and accuracy measures were analyzed. Subjective stress and workload were assessed in both studies.

RESULTS

In both studies, the ANT induced levels of subjective workload and task disengagement consistent with previous sustained attention studies. No systematic decrement in any performance measure was observed.

CONCLUSION

Executive control assessed by the ANT is not highly vulnerable to temporal decrement, even when task demands are elevated. Future work should differentiate executive control processes; proactive control may be more implicated in sustained attention decrement than in reactive control.

APPLICATION

Designing systems and interfaces to reduce executive control demands may be generally beneficial but will not directly mitigate temporal performance decrement. Enhancing design guidelines and neuroergonomic methods for monitoring operator attention requires further work to identify key neurocognitive processes for decrement.

The effects of carbon dioxide exposure concentrations on human vigilance and sentiment in an enclosed workplace environment

In this study, fifteen participants were exposed to different carbon dioxide (CO₂ ) concentrations in an enclosed environmental chamber to investigate the potential effects of elevated CO₂ concentrations on human vigilance and sentiment. The psychomotor vigilance test (PVT), the Karolinska Sleepiness Scale (KSS), and the Positive and Negative Affect Schedule (PANAS) were measured before and after each 4-hour CO₂ exposure session. The statistical analyses of the PVT performance metrics showed that the human vigilance decreased significantly with the elevated CO₂ concentration from 1500 ppm to above 3500 ppm, but no significant change was observed in the KSS score. Moreover, although the participants reported less positive and more negative emotions as the CO₂ exposure concentration increased, the effect of CO₂ concentration on human sentiment was not potent. In sum, the findings suggested a detrimental effect of CO₂ exposure concentration on human vigilance at the CO₂ concentration of 3500 ppm, which is below the current occupational exposure limit of 5000 ppm. It is worth noting that the order of CO₂ exposures was not balanced among the participants, which remains a major limitation of this study.

Visual lateralization in artiodactyls: A brief summary of research and new evidence on saiga antelope

The visual system and lifestyle characteristics make the even-toed ungulates an excellent model for the studies of behavioural lateralization. Recent research has focused on these mammals providing evidence of lateralization in a wide range of behaviours. This provides an opportunity for the collation of the current theoretical assumptions and the existing empirical evidence for visual lateralization in artiodactyls. In the present study, we aim first to gain a fuller picture of hemispheric specializations in saiga antelopes by investigating the lateralization of vigilance and novel object inspection in the wild. Second, we summarized the results of the research into visual lateralization in even-toed ungulates and attempted to assess the applicability of two popular hypotheses about the division of hemispheric roles. The results on saigas show a significant preference for head turns to the right visual field during vigilance which was more robust in individuals in larger groups. When an unfamiliar artificial object was placed in their natural setting, saigas preferentially viewed it predominantly with the right eye. These results, together with the cumulative evidence in artiodactyls, do not follow either the approach-withdrawal or positivity-negativity dichotomous patterns widely used to explain the division of functions between the hemispheres.

The Function of Fear Chemosignals: Preparing for Danger

It has been shown that the presence of conspecifics modulates human vigilance strategies as is the case with animal species. Mere presence has been found to reduce vigilance. However, animal research has also shown that chemosignals (e.g., sweat) produced during fear-inducing situations modulate individuals' threat detection strategies. In the case of humans, little is known about how exposure to conspecifics' fear chemosignals modulates vigilance and threat detection effectiveness. This study (N = 59) examined how human fear chemosignals affect vigilance strategies and threat avoidance in its receivers. We relied on a paradigm that simulates a "foraging under threat" situation in the lab, integrated with an eye-tracker to examine the attention allocation. Our results showed that the exposure to fear chemosignals (vs. rest chemosignals and a no-sweat condition) while not changing vigilance behavior leads to faster answers to threatening events. In conclusion, fear chemosignals seem to constitute an important warning signal for human beings, possibly leading their receiver to a readiness state that allows faster reactions to threat-related events.

On-the-road driving performance of patients with central disorders of hypersomnolence

INTRODUCTION

Excessive Daytime Sleepiness is a core symptom of narcolepsy and idiopathic hypersomnia, which impairs driving performance. Adequate treatment improves daytime alertness, but it is unclear whether driving performance completely normalizes. This study compares driving performance of patients with narcolepsy and idiopathic hypersomnia receiving treatment to that of healthy controls.

METHODS

Patients diagnosed with narcolepsy type 1 (NT1, n = 33), narcolepsy type 2 (NT2, n = 7), or idiopathic hypersomnia (IH, n = 6) performed a standardized one-hour on-the-road driving test, measuring standard deviation of lateral position (SDLP).

RESULTS

Results showed that mean SDLP in patients did not differ significantly from controls, but the 95%CI of the mean difference (+1.02 cm) was wide (-0.72 to +2.76 cm). Analysis of subgroups, however, showed that mean SDLP in NT1 patients was significantly increased by 1.90 cm as compared to controls, indicating impairment. Moreover, four NT1 patients requested to stop the test prematurely due to self-reported somnolence, and two NT1 patients were stopped by the driving instructor for similar complaints.

CONCLUSION

Driving performance of NT1 patients may still be impaired, despite receiving treatment. No conclusions can be drawn for NT2 and IH patients due to the low sample sizes of these subgroups. In clinical practice, determination of fitness to drive for these patients should be based on an individual assessment in which also coping strategies are taken into account.

A context analysis of bobbing and fin-flicking in a small marine benthic fish

Most antipredator strategies increase survival of individuals by signaling to predators, by reducing the chances of being recognized as prey, or by bewildering a predator's perception. In fish, bobbing and fin-flicking are commonly considered as pursuit-deterrent behaviors that signal a predator that it has been detected and thus lost its surprise-attack advantage. Yet, very few studies assessed whether such behavioral traits are restricted to the visual presence of a predator. In this study, we used the yellow black-headed triplefin Tripterygion delaisi to investigate the association between these behaviors and the visual exposure to (a) a black scorpionfish predator (Scorpaena porcus), (b) a stone of a size similar to that of S. porcus, (c) a conspecific, and (d) a harmless heterospecific combtooth blenny (Parablennius sanguinolentus). We used a laboratory-controlled experiment with freshly caught fish designed to test for differences in visual cues only. Distance kept by the focal fish to each stimulus and frequency of bobbing and fin-flicking were recorded. Triplefins kept greater distance from the stimulus compartment when a scorpionfish predator was visible. Bobbing was more frequent in the visual presence of a scorpionfish, but also shown toward the other stimuli. However, fin flicks were equally abundant across all stimuli. Both behaviors decreased in frequency over time suggesting that triplefin become gradually comfortable in a nonchanging new environment. We discuss why bobbing and fin-flicking are not exclusive pursuit-deterrent behaviors in this species, and propose additional nonexclusive functions such as enhancing depth perception by parallax motion (bobbing) or signaling vigilance (fin-flicking).

Computer Vision in the Operating Room: Opportunities and Caveats

Effectiveness of computer vision techniques has been demonstrated through a number of applications, both within and outside healthcare. The operating room environment specifically is a setting with rich data sources compatible with computational approaches and high potential for direct patient benefit. The aim of this review is to summarize major topics in computer vision for surgical domains. The major capabilities of computer vision are described as an aid to surgical teams to improve performance and contribute to enhanced patient safety. Literature was identified through leading experts in the fields of surgery, computational analysis and modeling in medicine, and computer vision in healthcare. The literature supports the application of computer vision principles to surgery. Potential applications within surgery include operating room vigilance, endoscopic vigilance, and individual and team-wide behavioral analysis. To advance the field, we recommend collecting and publishing carefully annotated datasets. Doing so will enable the surgery community to collectively define well-specified common objectives for automated systems, spur academic research, mobilize industry, and provide benchmarks with which we can track progress. Leveraging computer vision approaches through interdisciplinary collaboration and advanced approaches to data acquisition, modeling, interpretation, and integration promises a powerful impact on patient safety, public health, and financial costs.

Caffeine enhances sustained attention among adolescents

Despite the growing interest in caffeine use and its effects among adolescents, and a large literature on caffeine and attention among adults, there is a lack of experimental work examining the impact of caffeine on sustained attention among adolescents. We evaluated the acute effects of caffeine (vs. placebo) during a long (33-min) classic vigilance task among 31 adolescents (aged 12-17; 15 female; median caffeine use = 28 mg/day). We predicted a dose-dependent effect of caffeine, which would attenuate declines in target detection over time (i.e., a vigilance decrement). In each of 3 visits, participants completed an identical pairs continuous performance task beginning ∼25 min after consumption of noncaloric flavored water containing placebo, 1 mg/kg, or 3 mg/kg caffeine (order counterbalanced). Percent hits for low probability targets across 12 100-trial blocks was the primary outcome measure. As predicted, the linear decline in hits across trial blocks was attenuated by caffeine (Caffeine vs. Placebo × Block Linear, p = .01), with significant improvements in Blocks 9-12 (ps < .03). Compared to 1 mg/kg, 3 mg/kg caffeine resulted in earlier improvement in target detection (Drug Dose × Block Quadratic, p = .001). This study demonstrated that caffeine acutely and dose-dependently improves sustained attention among adolescents. These results were likely due to the attention-enhancing effect of caffeine, rather than withdrawal reversal, as our sample was characterized by light to moderate caffeine use. This study provides the foundation for further work on the impact of chronic caffeine consumption on cognitive function during adolescence. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Assessment of the Awareness, Perception, Attitudes, and Preparedness of Health-care Professionals Potentially Exposed to COVID-19 in the United Arab Emirates

BACKGROUND

Since COVID-19 surfaced in December 2019, health-care organizations across the globe have struggled to maintain the safety and well-being of health-care professionals (HCPs).

PURPOSE

This study investigates the HCPs' general understanding of the health risks of COVID-19 and to what extent they are equipped with the knowledge to protect themselves and others against this contagion.

METHODS

This cross-sectional study used a web-based structured questionnaire posted on the UAE government electronic survey portal. A collection of 941 HCPs from diverse general and specialty hospitals in the UAE responded to an electronic participation invite.

RESULTS

Our analysis showed that the majority of HCPs (97.6%) had updated information about COVID-19 modes of transmission, risks of contamination, high-risk groups, and the potential consequences of testing positive. Furthermore, the results of the chi-squared testing revealed that the HCPs' confidence and vigilance of the COVID-19 threats were significantly increased (p< 0.01) by being experienced, having had infection control training, or/and having undergone COVID-19 education.

CONCLUSION

We conclude that HCPs have an evidence-based understanding of the ways their own health is at risk while they are performing their duties in hospital setups. Further, the study found that HCPs who undergo special infection control training and who are kept posted on the official updates on COVID-19 are more likely to remain vigilant at all times to minimize the risks to themselves and their patients. Although the generalizability of the study findings should be considered with caution, the results could be generalizable to health-care professionals who received similar COVID-19 related training in the UAE or other regional countries.

Brain Arousal as Measured by EEG-Assessment Differs Between Children and Adolescents With Attention-Deficit/Hyperactivity Disorder (ADHD) and Depression

Objective: Disturbed regulation of vigilance in the wake state seems to play a key role in the development of mental disorders. It is assumed that hyperactivity in adult ADHD is an attempt to increase a general low vigilance level via external stimulation in order to avoid drowsiness. For depression, the avoidance of stimulation is interpreted as a reaction to a tonic increased vigilance state. Although ADHD is assumed to start during childhood, this vigilance model has been barely tested with children diagnosed for ADHD so far. Methods: Resting-state EEG (8 min) measures from two groups of children diagnosed with either ADHD [N = 76 (16 female, 60 male), age: (mean/SD) 118/33 months] or depression [N = 94 (73 female, 21 male), age: 184/23 months] were analyzed. Using the VIGALL toolbox, EEG patterns of vigilance level, and regulation were derived and compared between both groups. In correlation analysis, the relations between vigilance measures, attentional test performance (alertness and inhibition), and mental health symptoms were analyzed. Results: Children with ADHD differed from children with most prominent depressive symptoms in brain arousal regulation and level, but EEG vigilance was not related to behavior problems and not related to the attentional test performance. Brain arousal was dependent on the age of the participant in the whole sample; younger children showed lower vigilance stages than teenagers; this effect was not present when analyzed separately for each diagnostic group. EEG assessment time and received medication had no effect on the EEG vigilance. Discussion: Although based on a small sample, this explorative research revealed that EEG vigilance level is different between children with ADHD and with depression. Moreover, even the standard procedure of the clinical routine EEG (resting state) can be used to differentiate brain arousal states between participants with ADHD and depression. Because routine EEG is not specialized to vigilance assessment, it may not be sufficiently sensitive to find vigilance-symptomatology associations. Further research should address developmental changes in EEG measurements in children and use bigger samples of participants within the same age range.

A Blue-Enriched, Increased Intensity Light Intervention to Improve Alertness and Performance in Rotating Night Shift Workers in an Operational Setting

PURPOSE

This study examined the efficacy of a lighting intervention that increased both light intensity and short-wavelength (blue) light content to improve alertness, performance and mood in night shift workers in a chemical plant.

PATIENTS AND METHODS

During rostered night shifts, 28 workers (46.0±10.8 years; 27 male) were exposed to two light conditions each for two consecutive nights (~19:00-07:00 h) in a counterbalanced repeated measures design: traditional-spectrum lighting set at pre-study levels (43 lux, 4000 K) versus higher intensity, blue-enriched lighting (106 lux, 17,000 K), equating to a 4.5-fold increase in melanopic illuminance (24 to 108 melanopic illuminance). Participants completed the Karolinska Sleepiness Scale, subjective mood ratings, and the Psychomotor Vigilance Task (PVT) every 2-4 hours during the night shift.

RESULTS

A significant main effect of time indicated KSS, PVT mean reaction time, number of PVT lapses (reaction times > 500 ms) and subjective tension, misery and depression worsened over the course of the night shift (p<0.05). Percentage changes in KSS (p<0.05, partial η²=0.14) and PVT mean reaction time (p<0.05, partial η²=0.19) and lapses (p<0.05, partial η²=0.17) in the middle and end of night shift, expressed relative to start of shift, were significantly improved during the lighting intervention compared to the traditional lighting condition. Self-reported mood did not significantly differ between conditions (p>0.05).

CONCLUSION

Our findings, showing improvements in alertness and performance with exposure to blue-enriched, increased intensity light, provide support for light to be used as a countermeasure for impaired alertness in night shift work settings.

During vigilance to painful stimuli: slower response rate is related to high trait anxiety, whereas faster response rate is related to high state anxiety

A pathological increase in vigilance, or hypervigilance, may be related to pain intensity in some clinical pain syndromes and may result from attention bias to salient stimuli mediated by anxiety. During a continuous performance task where subjects discriminated painful target stimuli from painful nontargets, we measured detected targets (hits), nondetected targets (misses), nondetected nontargets (correct rejections), and detected nontargets (false alarms). Using signal detection theory, we calculated response bias, the tendency to endorse a stimulus as a target, and discriminability, the ability to discriminate a target from nontarget. Owing to the relatively slow rate of stimulus presentation, our primary hypothesis was that sustained performance would result in a more conservative response bias reflecting a lower response rate over time on task. We found a more conservative response bias with time on task and no change in discriminability. We predicted that greater state and trait anxiety would lead to a more liberal response bias. A multivariable model provided partial support for our prediction; high trait anxiety related to a more conservative response bias (lower response rate), whereas high state anxiety related to a more liberal bias. This inverse relationship of state and trait anxiety is consistent with reports of effects of state and trait anxiety on reaction times to threatening stimuli. In sum, we report that sustained attention to painful stimuli was associated with a decrease in the tendency of the subject to respond to any stimulus over time on task, whereas the ability to discriminate target from nontarget remains unchanged.NEW & NOTEWORTHY During a series of painful stimuli requiring subjects to respond to targets, we separated response willingness from ability to discriminate targets from nontargets. Response willingness declined during the task, with no change in subjects' ability to discriminate, consistent with previous vigilance studies. High trait anxious subjects were less willing to respond and showed slower reaction times to hits than low anxious subjects. This study reveals an important role of trait anxiety in pain vigilance.

Vigilance and sleepiness in nurses working 12-hr shifts and their coping strategies

AIM

To describe the progression of vigilance and sleepiness over the shift and the coping strategies of nurses working 12-hr day or night shifts.

BACKGROUND

The spread of 12-hr shift work in nursing raises the question of whether sufficient vigilance can be maintained to ensure quality of care.

METHOD

18 nurses working 12-hr shifts filled out a Karolinska Sleepiness Scale questionnaire and a Brief Psychomotor Vigilance Test, at the beginning of the shift and then every 3 hr. Coping strategies and quality of care were assessed on self-administered questionnaires, filled out at 3 hr, 6 hr, 9 hr and 12 hr after the start of the shift.

RESULTS

The present investigation did not show significantly excessive sleepiness or vigilance impairment or poor self-perception of quality of work during 12-hr nursing work shifts, although Psychomotor Vigilance Test results gradually deteriorated slightly over duty time (from start to end of shift). Certain coping strategies were preferred such as 'having a nap' later in the night shift.

CONCLUSION

Attention needs to be paid to the health status of nurses working 12-hr shifts, with regular medical monitoring by the occupational health service.

IMPLICATIONS FOR NURSING MANAGEMENT

Coping strategies to maintain sufficient vigilance to ensure quality of care should be facilitated.

The protective effect of daytime sleep on planning and risk-related decision-making in emerging adults

We assessed the effect of a daytime sleep opportunity on planning and risk-related decision-making in emerging adults using multiple neurobehavioral assessments. A total of 136 healthy emerging adults (20.0 ± 1.5 years), 65% female, performed the Risky-Gains Task and the Tower of London test twice. Between these assessments, they were randomized to either have a sleep opportunity monitored by polysomnography (Sleep group, n = 101) or to stay awake (Wake group, n = 35). During Test 2, in comparison to the Sleep group, the Wake group showed increased sleepiness, worse planning ability and more decrease in reaction times when selecting risky choices. Changes in Tower of London test steps used and Risky-Gains Task response time correlated with the number of central and frontal fast sleep spindles, respectively. These results indicate that among emerging adults who commonly have poor sleep patterns, a daytime sleep opportunity was related to better planning ability, better psychomotor vigilance and stable response speeds in risk-related decision-making. Changes in planning and risk-related decision-making correlated with the number of sleep spindles during the nap, supporting a specific role for sleep in modulating planning and potentially other higher-order cognitive functions.

Selective impairment of auditory attention processing in idiopathic generalized epilepsies: Implications for their cognitive pathophysiology

The neuropsychological characteristics of Idiopathic Generalized Epilepsies (IGEs) as a wide syndrome encompassing different clinical entities have been as yet not well understood. We have studied neuropsychological performance in patients suffering Juvenile Myoclonic Epilepsy (JME) and Generalized Tonic Clonic Seizures (IGE-GTCS-only) to provide indirect-cognitive evidence on the pathophysiology of IGE-related neuropsychological dysfunction. Greater arousal-related impairments were expected for the auditory modality, by drawing on previous anatomo-clinical and neuro-evolutionary accounts. We have studied neurocognitive functioning in 26 IGE patients, suffering either JME (n = 16) or IGE-GTCS-only (n = 10), and their healthy counterparts consisted of 26 (18 females) demographically matched participants. IGE patients (JME and IGE-GTCS-only) did worse with respect to HC (healthy controls) in visual- and auditory- speed of information processing (reaction time), auditory-vigilance and -response inhibition, visuo-motor coordination, visual working memory and motor speed, delayed visual recall, immediate- and delayed verbal episodic recall, lexical access and retrieval, semantic associative processing, auditory-verbal memory span and verbal learning. Although both IGE-GTCS-only and JME patients delayed episodic recall was defective, the former did significantly worse. We believe that IGE patients' neuropsychological derailments represent indirect-secondary manifestations of a primary cortical tone deregulation inherent to IGEs' pathophysiology. In particular, IGE patients' worse-dissociated performance in auditory TOVA-also seen previously in TBI and schizophrenia-may implicate a grater vulnerability of the auditory information processing system, as well as a possibly shared cognitive pathophysiological component between IGE and the above nosologies.

Amplitude of fNIRS Resting-State Global Signal Is Related to EEG Vigilance Measures: A Simultaneous fNIRS and EEG Study

Recently, functional near-infrared spectroscopy (fNIRS) has been utilized to image the hemodynamic activities and connectivity in the human brain. With the advantage of economic efficiency, portability, and fewer physical constraints, fNIRS enables studying of the human brain at versatile environment and various body positions, including at bed side and during exercise, which complements the use of functional magnetic resonance imaging (fMRI). However, like fMRI, fNIRS imaging can be influenced by the presence of a strong global component. Yet, the nature of the global signal in fNIRS has not been established. In this study, we investigated the relationship between fNIRS global signal and electroencephalogram (EEG) vigilance using simultaneous recordings in resting healthy subjects in high-density and whole-head montage. In Experiment 1, data were acquired at supine, sitting, and standing positions. Results found that the factor of body positions significantly affected the amplitude of the resting-state fNIRS global signal, prominently in the frequency range of 0.05-0.1 Hz but not in the very low frequency range of less than 0.05 Hz. As a control, the task-induced fNIRS or EEG responses to auditory stimuli did not differ across body positions. However, EEG vigilance plays a modulatory role in the fNIRS signals in the frequency range of less than 0.05 Hz: resting-state sessions of low EEG vigilance measures are associated with high amplitudes of fNIRS global signals. Moreover, in Experiment 2, we further examined the epoch-to-epoch fluctuations in concurrent fNIRS and EEG data acquired from a separate group of subjects and found a negative temporal correlation between EEG vigilance measures and fNIRS global signal amplitudes. Our study for the first time revealed that vigilance as a neurophysiological factor modulates the resting-state dynamics of fNIRS, which have important implications for understanding and processing the noises in fNIRS signals.

The Physiological and Perceptual Effects of Stochastic Simulated Rugby League Match Play

PURPOSE

To examine responses to a simulated rugby league protocol designed to include more stochastic commands, and therefore require greater vigilance, than traditional team-sport simulation protocols.

METHODS

Eleven male university rugby players completed 2 trials (randomized and control [CON]) of a rugby league movement simulation protocol, separated by 7 to 10 d. The CON trial consisted of 48 repeated ∼115-s cycles of activity. The stochastic simulation (STOCH) was matched for the number and types of activity performed every 5.45 min in CON but included no repeated cycles of activity. Movement using GPS, heart rate, rating of perceived exertion, and Stroop test performance was assessed throughout. Maximum voluntary contraction peak torque, voluntary activation (in percentage), and global task load were assessed after exercise.

RESULTS

The mean mental demand of STOCH was higher than CON (effect size [ES] = 0.56; ±0.69). Mean sprint speed was higher in STOCH (22.5 [1.4] vs 21.6 [1.6] km·h-1, ES = 0.50; ±0.55), which was accompanied by a higher rating of perceived exertion (14.3 [1.0] vs 13.0 [1.4], ES = 0.87; ±0.67) and a greater number of errors in the Stroop test (10.3 [2.5] vs 9.3 [1.4] errors; ES = 0.65; ±0.83). Maximum voluntary contraction peak torque (CON = -48.4 [31.6] N·m and STOCH = -39.6 [36.6] N·m) and voluntary activation (CON = -8.3% [4.8%] and STOCH = -6.0% [4.1%]) was similarly reduced in both trials.

CONCLUSIONS

Providing more stochastic commands, which requires greater vigilance, might alter performance and associated physiological, perceptual, and cognitive responses to team-sport simulations.

Natural Odor Inhalers (AromaStick®) Outperform Red Bull® for Enhancing Cognitive Vigilance: Results From a Four-Armed, Randomized Controlled Study

Two recent publications demonstrated that specifically designed essential odor inhalers can enhance performance through (a) better selective attention and scanning speed and (b) physiological changes of increased heart rate variability and blood oxygenation. In this study, we compared two natural odor inhalers with a popular energy drink (Red Bull®) with regard to their ability to improve vigilance on a computerized attention test. We employed a four-armed, randomized controlled experimental design and used a modified version of the CompACT-Vi test module to investigate whether deep inhalations of essential oil scents improved vigilance. Both inhalers markedly improved the number of correctly identified targets and participants' reaction time when compared to a control condition and consumption of Red Bull® (0.9 < d < 1.3). Additionally, the number of correctly solved mathematical sums during the second half of the vigilance test was substantially higher (d = 1.3) with the use of inhalers than for the control and Red Bull participants. Inhaler use was also associated with relatively increased heart rate variability (d = 1.0) as a mechanism of adapting to the experimental demands. Thus, short and deep inhalations of essential oil scents delivered directly to the nose improved vigilance, while a popular energy drink failed to show an effect beyond that of a control group receiving no stimulant.

Enhanced Vigilance Stability during Daytime in Insomnia Disorder

Central nervous hyperarousal is as a key component of current pathophysiological concepts of chronic insomnia disorder. However, there are still open questions regarding its exact nature and the mechanisms linking hyperarousal to sleep disturbance. Here, we aimed at studying waking state hyperarousal in insomnia by the perspective of resting-state vigilance dynamics. The VIGALL (Vigilance Algorithm Leipzig) algorithm has been developed to investigate resting-state vigilance dynamics, and it revealed, for example, enhanced vigilance stability in depressive patients. We hypothesized that patients with insomnia also show a more stable vigilance regulation. Thirty-four unmedicated patients with chronic insomnia and 25 healthy controls participated in a twenty-minute resting-state electroencephalography (EEG) measurement following a night of polysomnography. Insomnia patients showed enhanced EEG vigilance stability as compared to controls. The pattern of vigilance hyperstability differed from that reported previously in depressive patients. Vigilance hyperstability was also present in insomnia patients showing only mildly reduced sleep efficiency. In this subgroup, vigilance hyperstability correlated with measures of disturbed sleep continuity and arousal. Our data indicate that insomnia disorder is characterized by hyperarousal at night as well as during daytime.

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.