Low Vigilance Level Research Articles

Sensory gating and gaining in sleep: the balance between the protection of sleep and the safeness of life (a review).

Sleep is a brain state characterised by a low vigilance level and diminished consciousness. Reaction to and processing of external stimuli is attenuated in sleep. During sleep, the reticular thalamic nucleus reduces the flow of sensory activity to the cerebral cortex through inhibition of the thalamus. This sensory gating process facilitates sleep. After reaching the afferent layers of primary cortex, the reduced sensory flow is adjusted, gained, and processed within various cortical layers before being transferred by the corticofugal system back to appropriate subdivisions of the thalamus as feedback. Thalamic subdivisions then dispatch this sensory information to related areas of the cerebral cortex, where it is (sub)consciously perceived. When necessary, a sleeping individual can be awakened by a wake-up call, either by stimuli indicating danger, or by personally meaningful stimuli. It is safe for a sleeping individual that it can be aroused when necessary. Evidently, there are two processes by which the brain adjusts the response to sensory stimuli before entering (sub)consciousness. Firstly 'sensory gating', a process favourable to the maintenance of sleep by reducing the sensory input to the brain through the reticular thalamic nucleus and secondly 'sensory gaining', a process implying that the gained preserved sensory input is continuously analysed by the corticofugal system to detect dangerous and relevant environmental elements, indispensable for safeness and well-being of the sleeper.

Facial Emotion Recognition in Insomnia: Mechanisms and Consequences

Insomnia is a sleep disorder that is closely related with various physiological and psychological problems. Facial emotion recognition (FER) is an important part of social function, and has been found impaired in individuals with insomnia. This paper aims to explore the mechanisms of the correlation between insomnia and FER impairment, and the possible consequences of impaired FER for people with insomnia. Impaired expression expressivity and amygdala dysfunction are proposed as potential mechanisms underlying the link between insomnia and impaired FER. FER impairment in insomnia patients might lead to overlooking danger and lower levels of vigilance and arousal, which could result in disastrous outcomes. Moreover, impaired FER could lead to social function disturbance, making insomnia patients vulnerable to bullying.

Artificial intelligence-enabled non-intrusive vigilance assessment approach to reducing traffic controller’s human errors

To be vigilant is highly required for traffic controllers in transportation fields, such as air traffic management, vessel traffic service, and railway management, as they need to monitor traffic conditions and notice any potential hazards. Hence, emerging studies have been conducted to develop an objective and non-intrusive approach to assessing vigilance levels and generate warnings if needed. This study aims to investigate the effects of impaired vigilance on human performance via non-intrusive data analysis, namely spatial and temporal gaze pattern analytics, and develop an objective model for vigilance assessment accordingly. A novel four-phase framework, including vigilance test design, non-intrusive data collection, spatial and temporal gaze pattern analytics, and a shallow neural network-based model was proposed to achieve this aim. Meanwhile, an illustrative experiment in the maritime industry was conducted to verify the proposed method. The spatial and temporal gaze patterns analytics revealed that low vigilance levels impacted comprehension time but not perception time, with longer fixations duration but stable time-to-the-nearest-fixation under a low vigilance level. It is found that even a person with impaired vigilance can quickly notice abnormal events. The effectiveness and empirical implications of this model can help traffic controllers avoid fatigue-induced vigilance reduction. In addition, it provides evidence, references, and solutions for designing human–computer interfaces to reduce human errors caused by low vigilance.

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.

Cingulate infarction: A neuropsychological and neuroimaging study

Background and purposeIschemic lesions rarely affect the cingulate cortex (CC) in isolation, restricting human lesion/behavioural change correlational analysis. The aim of this study was to determine clinical, neuropsychological and neuroimaging features of isolated cingulate infarcts. MethodsWe studied, 3800 patients with first-ever ischemic stroke included in our Stroke Registry between 2012 and 2018. Among them we studied 7 patients with an acute isolated cingulate infarct confirmed by MRI. ResultsAmong all patients, 7 patients (0.01%) showed ischemic lesions in the territory of cingulate cortex territory, allowing us to delineate 2 substantial distributions; (1) Anterior cingulate cortex (ACC) infarction (4 patients [57%]) was presented low vigilance level with apathy, mutism, deficits in executive function, attention, and disturbances of working, episodic and verbal memory; (2) Posterior cingulate cortex (PCC) infarction (3 patients [43%]) developed topographic disorientation, visual memory deficit and affective-emotional behavioural changes. ConclusionsAccording rarely seen CC infarction events, we suggest that anterior and posterior CC are functionally separated and differences in clinical presentation are explained by considering; ACC plays a role in executive functions, episodic and working memory, set maintenance, and PCC is focused on spatial and verbal attention, and memory system. We considered that different patterns of cingulate infarcts are the result of variation in cingulate arterial supply or suggest a source of embolism.

P19. Vigilance regulation pattern in children with attention-deficit/hyperactivity disorder (ADHD) and depression measured by electroencephalography (EEG)

Objective Disturbed regulation of vigilance in wake state seems to play a key role in the development of mental disorders. In an actual model by Hegerl et al. (2014) hyperactivity in ADHD is assumed to be an attempt to increase a general low vigilance level via external stimulation. 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 only been tested in a pilot study with children diagnosed for ADHD so far and was not compared to children with diagnosis of depression. Routine or assisted EEGs are not recommended for assessing vigilance (Sander et al., 2015) but the question remains if brain arousal can still be measured with it. If yes, it might be useful for clinical praxis, if relevant diagnostic conclusions can be drawn sufficiently from routine EEG measures. Methods 137 reting state EEG (10 min) measures from two groups of psychiatric patients (age: 13 ± 3.7 years) diagnosed with either ADHD or depression were analyzed. Vigilance classifications are compared between both groups via two-sample t-tests and chi-square tests. We used n-mean cluster analysis to detect EEG-patterns of vigilance regulation. In an ANOVA model, the relation between vigilance regulation and mental health symptoms (child behaviour check list, CBCL/6-18) was analyzed. Results We found more classification of low arousing stage B2/3 in ADHD compared to depression (50–20%) p Conclusion This study revealed that vigilance classification based on MTA assisted routine EEG of children showed results which are in accordance to the assumptions of hypo-aroused brain activity in ADHD and a more hyper-aroused brain state in depression. Therefore similar brain arousal states in children in these diagnostic groups can be assumed as has been showed for adults before. Interestingly, we could assign these different brain arousal states directly to attentional problems in our study sample. In order to analyze the validity of vigilance regulation analysis from a routine EEG in more detail a further direct comparison to EEG assessment according to the VIGALL protocol is still needed.

Research on vigilance detection based on pulse wave

This paper studied the rule for the change of vigilance based on pulse wave. 10 participants were recruited in a 95-minute Mackworth clock test (MCT) experiment. During the experiment, the vigilance of all participants were evaluated by Karolinska sleepiness scale (KSS) and Stanford sleepiness scale (SSS), and behavior data (the reaction time and the accuracy of target) and pulse wave signal of the participants were recorded simultaneously. The result indicated that vigilance of the participants can be divided into 3 classes: the first 30 minutes for high vigilance level, the middle 30 minutes for general vigilance level, and the last 30 minutes for low vigilance level. Besides, time domain features such as amplitude of secondary peak, amplitude of peak and the latency of secondary peak decreased with the decrease of vigilance, while the amplitude of troughs increased. In terms of frequency domain features, the energy of 4 frequency band including 8.600 ~ 9.375 Hz, 11.720 ~ 12.500 Hz, 38.280 ~ 39.060 Hz and 39.060 ~ 39.840 Hz decreased with the decrease of vigilance. Finally, under the recognition model established by the 8 characteristics mentioned above, the average accuracy of three-classification results over the 10 participants was as high as 88.7%. The results of this study confirmed the feasibility of pulse wave in the evaluation of vigilance, and provided a new way for the real-time monitoring of vigilance.

Age-Related Characteristics of Foraging Habitats and Foraging Behaviors in the Black Phoebe (Sayornis nigricans)

Abstract We studied how age affects selection of foraging microhabitats, foraging behaviors, and rates of vigilance in the black phoebe (Sayornis nigricans). Juveniles generally perched higher in trees than adults and in areas with higher intensity of light, which may increase the difficulty of visually tracking prey. Juveniles allocated more effort to visual searching prior to a foraging attempt and flew farther than adults to capture a prey item. When at rest on a perch, juveniles monitored the environment more slowly than adults, suggesting lower levels of vigilance. In general, our results suggest that differences between ages in foraging behavior of visually guided predators may be influenced by intensity of ambient light in their foraging territories.

Évaluer la vivacité des images mentales dans différentes populations françaises

The aim of this article is to evaluate the vividness of visual imagery from three different sample groups: a contemporary dance group ( n = 24), a group of modified state of consciousness experts ( n = 24) and a group of students ( n = 48). We argue that the mental imagery activity into low vigilance level and into a modified state of consciousness has a closed link mechanism with vividness of visual imagery. We show that the modified state of consciousness experts reached a significantly higher level of vividness open-eyes score than the group of students. This could mean that higher open-eyes score is a cognitive trait of hypnotic susceptibility linked to specific training. These results stem from research into the close relationship between imagery and perception. We present a French adaptation and a French translation of Vividness of Visual Imagery Questionnaire, too. The VVIQ [Br. J. Psychol. 64 (1973) 17–24] is a questionnaire very used in clinical psychology and in cognitive psychology.

Dilution games: use of protective cover can cause a reduction in vigilance for prey in groups

Antipredatory vigilance usually decreases in groups. The generally accepted ‘‘collective detection’’ explanation implies that because there are more eyes to scan the surroundings for predators, individuals in a group can lower their personal investment in vigilance without increasing their predation risk. The role of other factors, such as numerical risk dilution caused by the mere presence of companions, has been neglected. In a model, we explore a dilution game when foragers in groups have access to protective cover. We show that foragers can take advantage of risk dilution and that this leads to changes in vigilance with group size without the need to invoke collective detection. We identify a cost to maintaining high levels of vigilance as less vigilant foragers gather food faster and so depart the group sooner (to reach cover) leaving more vulnerable stragglers behind. In groups, there is a scramble to reach safe sites that can induce a reduction in vigilance levels. Such a mechanism operates less forcefully in large groups because individuals in these groups are less vulnerable to the departure of an individual. We also demonstrate that individuals should adopt lower levels of vigilance, to reach safe sites sooner, when predator evasion is compromised or when the rate of food intake is high. The model provides new insights into the mechanisms underlying changes in vigilance with group size in animals. Key words: antipredatory vigilance, collective detection, ESS model, group size, protective cover, risk dilution. [Behav Ecol]

Diurnal spectral EEG fluctuations in narcoleptic patients during rest and reaction time tasks

Narcolepsy is associated with lowered vigilance. Diurnal variation in vigilance appears altered, but the exact nature of this change is unclear. It was hypothesized that the homeostatic sleep drive is increased in narcolepsy. Decreased levels of vigilance are reflected in low frequency band power in the electroencephalogram (EEG), so these frequencies were expected to be increased in the narcolepsy group. Furthermore, it was expected that low frequency power should increase over the day. Narcoleptic patients and healthy controls participated (36 participants in total); they were not allowed to take medication or naps on the experimental day. EEG was measured at 9:00, 11:00, 13:00, 15:00, and 17:00 hours, during rest and during reaction time tasks. In the narcolepsy group, alpha power was lower at rest at all times. Delta and theta power during rest and task performance increased steadily over the day in this group, from 11:00 hours onwards. Additionally, in the narcolepsy group beta1 and beta2 power during rest appeared increased at the end of the day. The effects in the lower frequency bands strongly suggest that vigilance is low at all times. The progressive increase in low frequency power indicates that the sleep drive is enhanced. It is not clear whether this pattern reflects an extreme state of low vigilance, or a pathological brain condition. The effects in the higher frequencies suggest that narcoleptic patients may make an effort to counteract their low vigilance level.

Sustained Attention in Mild Alzheimer's Disease

The vigilance decrement in perceptual sensitivity was examined in 10 patients with mild Alzheimer's disease (AD) and 20 age-matched controls. A visual high-event rate digit-discrimination task lasting 7.2 min. (six 1.2 min blocks) was presented at different levels of stimulus degradation. Previous studies have shown that sensitivity decrements (d') over time at high-stimulus degradation result from demands on effortful processing. For all degradation levels, the overall level of vigilance (d') was lower in AD patients than in controls. All participants showed sensitivity decrement over blocks, with greater decrement at higher degradation levels. AD patients exhibited greater sensitivity decrement over time at the highest degradation level they all could perform relative to control participants. There were no concomitant changes in either response bias (C) or response times. The results indicate that mild AD patients have overall lower levels of vigilance under conditions that require both automatic and effortful processing. Mild AD patients also exhibit a deficit in the maintenance of vigilance over time under effortful processing conditions. Although the sample of AD patients was small, results further suggest that both possible and probable AD patients had greater sensitivity decrement over time at the highest degradation level than did control participants, but only probable AD patients had lower overall levels of vigilance. In the possible AD patients as a group, the decrement in vigilance occurred in the absence of concurrent deficits on standard attentional tasks, such as the Stroop and Trail Making tests, suggesting that deficits in vigilance over time may appear earlier than deficits in selective attention.

Inversion de polarite de la variation contingente negative au cours d'etats d'endormissement

In 25 subjects repeated examination of contingent negative variation (S1 - S2 = 1 sec) under relatively unconstrained experimental conditions (simple, monotonous task, long recording sessions with eyes closed) favorized drowsiness and falling asleep. These periods of low vigilance level, observed in 7 subjects, are characterized by: (1) a global reduction in spontaneous EEG, measured by a diminution in the alpha/theta + delta index (FFT on bipolar leads P3--P4); (2) an inversion in alpha reactivity in the S1 - S2 interval, which, instead of diminishing, tends to augment 'paradoxically'; and (3) an inversion in the polarity of the CNV, which can reach a positive value as high as + 15 to + 20 microV. These electrophysiological phenomena are not accompanied by significant modifications in reaction time. The results are interpreted as the translation of an active 'internal inhibition' process, induced by repetition of monotonic stimuli. They are compared with animal data obtained by MARCZYNSKI and SHERRY (1972) and SKINNER and YINGLING (1977).