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Sexually selected vigilance behaviour of the grey partridge is affected by plasma androgen levels

In the grey partridge, Perdix perdixvigilance and calling activity are two sex-dimorphic behaviours that are critical for mate choice. To ascertain whether circulating levels of testosterone directly affect vigilance (i.e. the occurrence of upright alert posture), we compared vigilance scores of testosterone-implanted versus control males both during the normal activity of the flock and after the passage of a raptor silhouette; in the latter case, the calling activity was also recorded. Hormone-treated males were more vigilant than controls in both experimental situations. Vigilance was correlated with calling rate. Testosterone seems to act as a link, relating conspicuous behaviours involved in sexual selection to male quality and physical condition, because of the costs of having high levels of both signalling and androgens.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

Journal Article↗

Vigilance as a benefit of intermittent locomotion in small mammals

In many animal species, locomotion is frequently interrupted by brief pauses. This intermittent locomotion is usually considered a mode of prey search, but other possible functions include reduced detection or attack by predators and improved endurance. We tested the hypothesis that pauses also serve to improve vigilance for predators in two species of sciurid rodent. Videotaping animals travelling between food-collecting and food-hoarding sites revealed that numerous short pauses comprise 5-38% of the time spent 'moving' in grey squirrels, Sciurus carolinensis, and 0-41% in eastern chipmunks, Tamias striatus. In this situation, search for food items did not occur, and pausing did not reduce the total time spent as a moving stimulus for predators. It also appeared that speed while running was too slow and the pauses too brief to provide an endurance advantage. As predicted by the vigilance hypothesis, both species spent more time pausing when moving away from forest cover (presumably towards areas of higher risk) than when travelling back towards forest cover. In control trials within forest cover, squirrels did not differ in time pausing when approaching and leaving patches, but chipmunks paused more when approaching patches than when leaving them. We conclude that one function of pausing in squirrels is to improve anti-predator vigilance. The occurrence of pausing by chipmunks did not match a priori predictions of the vigilance hypothesis. Because it also failed to match predictions of previous alternative hypotheses, we suggest that studies are needed to examine whether the risk of attacks by conspecifics and predators is higher for chipmunks approaching than leaving food patches in forest habitat. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗

A communication-based spatial model of antipredator vigilance.

Many animals spend their lives performing two often mutually exclusive tasks: feeding and watching out for predators (anti-predator vigilance). There have been many theoretical and empirical studies investigating this trade-off, especially for birds. An important characteristic of a flock of real birds is the area occupied by the flock. Individuals feeding close together experience increased competition so that the feeding rate decreases. Widely spaced individuals may suffer a loss in vigilance efficiency, since communication between individuals is more difficult, such that the predation risk increases. A vigilance model is developed which allows birds to control their spacing (and so the area of the flock) as well as their vigilance rate. The best strategy for the birds is found under a variety of environmental conditions, under the assumption that each individual acts selfishly to maximize its own fitness.

Animal Communication↗

The structure of vigilance.

Vigilance is understood as a primarily behavioral category. Identical stimuli tend to evoke more or less differentiated behavioral responses dependent on a low or high state of vigilance. The rise of vigilance from coma to full attention moves along with increasing differentiation of evoked behavioral responses. With heterogeneous physical, figurative, and verbal stimuli, responses are elicited which can be arranged on an additive (Guttman) scale. Thus, vigilance is suggested to represent a one-dimensional function of the brain.

Arousal↗

Benzodiazepines and vigilance performance: a review.

The literature on the effects of anxiolytic and hypnotic drugs on performance in tasks requiring sustained attention is confusing. This review is an attempt to evaluate the usefulness of vigilance tasks in the assessment of adverse effects of benzodiazepines. The long, monotonous, character of these tasks may be more relevant to many tasks performed in everyday life than the short, and often stimulating, tasks commonly employed in test batteries. From 37 available studies, 26 were examined in detail. In young, normal volunteers, vigilance tasks were found to be sensitive, often dose dependently, to the impairing effects of drugs, even in low doses (2.5 mg diazepam). With these subjects the tasks may be successfully used to compare different benzodiazepines with respect to residual activity. Both accuracy and speed of performance appear to be affected. However, in people actually using the drugs ("patients"), adverse effects on performance are usually not found. There is no evidence that benzodiazepines aggravate the vigilance decrement occurring under normal conditions. They do affect overall level of perceptual sensitivity, but show less effects on response criterion. The drugs do not seem to interact with anxiety or sleep quality in their effect on performance, but there are few studies with patients, and the assessment of anxiety is not without problems. It is unlikely that impairments in vigilance are simply a byproduct of global, sedative effects, but there is uncertainty regarding measures of general sedation. Developing tolerance with repeated doses has been noted only occasionally, but the opposite of tolerance, aggravated impairment, has also been reported.

Anti-Anxiety Agents↗

Manual record keeping is not necessary for anesthesia vigilance.

OBJECTIVE: The goal of this study was to determine whether the intraoperative vigilance of anesthesia residents is different when they keep a manual record than when an assistant performs the charting. METHODS: A total of 9 anesthesia residents were studied during 36 general anesthesia cases on ASA class 1 or 2 patients. In half of the cases, the resident performed all record keeping. In the other half, the anesthesia record was kept by a human assistant. Vigilance was measured as detection rate and response time for the resident to detect a simulated abnormal value displayed on the physiologic monitor. For analysis, anesthesia cases were divided into stages of induction, maintenance, and emergence. RESULTS: Response times and detection rates were not different when record keeping was performed by an assistant, rather than by the clinician. Shorter cases were associated with longer median response times (i.e., lower vigilance) during the maintenance phase, but only when record keeping was done manually. CONCLUSIONS: The results demonstrate that anesthesia residents are equally attentive to an experimental signal displayed on an electronic monitor while manually charting as they are when an assistant keeps the record. This brings into question the contention that eliminating the record-keeping task will result in a reduced level of vigilance.

Ambulatory Surgical Procedures↗

Effects of pentazocine and acetylsalicylic acid on pain-rating, pain-related evoked potentials and vigilance in relationship to pharmacokinetic parameters.

Achieving objective and quantitative measurement of experimental pain in human volunteers and establishing the impact of drugs remains a difficult task. This problem may be overcome by employing a method which allows the simultaneous measurement of pain ratings elicited by standardized stimulation of the nasal mucosa by carbon dioxide, together with pain-related chemo-somatosensory evoked potentials (CSSEP) and vigilance. We assessed the effect of pentazocine and acetylsalicylic acid on these parameters in 14 human volunteers and related the effects to the pharmacokinetic parameters of the drugs measured at the same time. Pentazocine was found to reduce the pain ratings as well as the amplitudes of the pain-related evoked potentials and to increase their latencies. Vigilance (measured by EEG power spectra and performance of a tracking task) was also significantly reduced. These effects were observed during the distribution phase and the first period of the terminal elimination phase of the drug. Acetylsalicylic acid had no significant effects on pain ratings, but reduced the amplitudes of the event-related potentials when compared to placebo controls. At the same time a slight, but significant, effect on vigilance (reduced performance of the tracking task) was observed. These effects could not be related to the presence of unmetabolized acetylsalicylic acid in the plasma. They appeared at later times when only salicylic acid was left. It is concluded that chemical stimuli of sufficient intensity produce pain which may be suppressed by opioid analgesics such as pentazocine. The effect of acetylsalicylic acid on this experimental pain did not reach significance for all measured parameters under the experimental conditions chosen. The changes in vigilance and in the amplitudes of pain-related chemo-somatosensory evoked potentials indicated as yet unknown CNS-effects of this non-steroidal anti-inflammatory drug.

Adult↗

Alcohol and vigilance performance: a review.

In the literature on the effects of alcohol on driving-related skills, it is sometimes claimed that vigilance tasks are insensitive instruments whereas divided-attention tasks are extremely sensitive to the effects of alcohol. The results of the present review, based on the analysis of 38 comparisons of alcohol and placebo in vigilance tasks, require that these claims be restated. Both types of attentional task (concentrated and divided) are indispensable in test batteries, although not all types of vigilance and divided-attention task are equally sensitive, e.g. some types of vigilance task, using spatial stimuli, were sensitive to BAC levels of 0.03% whereas other types were insensitive to levels of 0.10%. In contrast, the usefulness of tasks of questionable validity and/or low sensitivity (such as the DSST, CFF, digit span, simple RT and choice RT) is questioned. Apart from issues of validity and sensitivity of tests, the ways in which alcohol may affect performance are also discussed. The main effect of moderate doses of alcohol is on attention and information processing. The capacity to divide and sustain attention is already impaired at BAC levels of 0.02-0.03%. Further, alcohol effects appear to some extent to be time-dependent, and are greatest during periods of sleepiness (the early afternoon and after midnight). Some current BAC levels concerning drinking and driving are far too generous. There is sufficient evidence from the literature on performance indicating that the BAC standard for driving should be lowered to 0.02% for driving after midnight and for special risk groups (young and less experienced drivers).

Age Factors↗

[Analysis of the anesthesiologist's vigilance with an eye-tracking device. A pilot study for evaluation of the method under the conditions of a modern operating theatre].

INTRODUCTION: With the inclusion of new monitoring devices over the last two decades, the distribution of the anesthesiologists vigilance has changed which might influence the ergonomic profile of an optimal anesthesia workstation. The aim of this pilot study was the evaluation of an eyetracking device to analyze the vigilance distribution of an anesthesiologist during routine cases in an operating theatre of the 21st century. MATERIAL AND METHODS: Five anesthesiologist with different levels of training were followed during different types of surgery using a video camera-based eye-tracking system. The films were analyzed by an independent observer and rated according to defined regions of interest (ROI). Then typical scan-paths were identified and quantitatively analyzed. RESULTS: The eye-tracking studies proved to be technically of high quality but were time-consuming. Only few disturbances to the operating room (OR) personnel were recorded according to their subjective impressions but bias of behaviour due to the measurement procedure itself cannot be completely excluded. The vigilance of the anesthesiologist towards different factors was dependent on the level of professional training, the type of anesthesia and the type of surgery. Certain factors such as documentation (10-15%) or external disturbances (approximately 20%) proved to be relatively constant. Typical scan-paths could also be identified. CONCLUSION: Eye-tracking studies proved to be a suitable way to analyze the distribution of vigilance of anesthesiologists in a modern operating theatre. For further studies examining the influence of detailed modifications of the OR environment, a standardized study design with the same level of education, the same anesthesia technique and the same surgical procedure needs to be chosen.

Adult↗

Long-term exposure to solvents impairs vigilance and postural control in serigraphy workers.

OBJECTIVES: To investigate the effects of solvent exposure (mainly aromatic hydrocarbons) on central regulation of vigilance and postural control, particularly in occasional difficult situations that provide sensorial conflicts. METHODS: Twenty-two workers occupationally exposed to solvents for an average of approximately 6 years and 21 controls were compared by the use of a questionnaire on their state of vigilance and quality of sleep and on performance measurements of postural control under six different sensorimotor conditions. Their current median exposure levels to aromatic hydrocarbons was 80.1 mg/m(3). RESULTS: Exposed workers reported reduced alertness but not disturbance of sleep quality compared with controls. Moreover, they had the worst postural performance in all sensory conditions and demonstrated a reduced ability to resolve sensory conflict situations. The precision of stance was clearly affected by solvent exposure in contrast with energy consumption required to regulate proper balance control. CONCLUSIONS: The depressive effect of aromatic hydrocarbon exposure on cortical and subcortical structures controlling vigilance and postural stability could lead to increased risk of occupational accident, especially due to falls. The detection of central neurotoxic effects by posturographic and vigilance tests could be useful in preventive strategies.

Adult↗

Mental effort causes vigilance decrease due to resource depletion.

The resource view on vigilance performance was tested. First, a low demanding task was compared with a similar low demanding task in which stimulus presentation was less monotonous due to added, irrelevant, stimuli. The resource view, maintaining that vigilance is lowered by hard mental work, predicts that addition of irrelevant stimuli will not affect performance. The classic arousal theory, however, states that arousal drops due to monotonous stimulus presentation and predicts that decreasing monotony will enhance performance. Results showed that performance was unaffected by added stimuli. Second, we tested whether a high-demanding task (with identical stimulus presentation as the low demanding task, but different instruction) would cause a greater decline in performance than the low demanding task. Indeed, in the high-demanding task performance was affected most. In sum, it appears that vigilance decreases due to hard mental work, which requires many resources. Both overall performance and decrement in performance can be explained in terms of resources, and this suggests that vigilance tasks should be resource-demanding tasks, which do not have to be of long duration.

Adult↗

Effect of two noncompetitive AMPA receptor antagonists GYKI 52466 and GYKI 53405 on vigilance, behavior and spike-wave discharges in a genetic rat model of absence epilepsy.

The present study was conducted to investigate the effects of two noncompetitive alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, GYKI 52466 and GYKI 53405 (the racemate of talampanel) on the generation of spike-wave discharges (SWD) parallel with the vigilance and behavioral changes in the genetic absence epilepsy model of WAG/Rij rats. Intraperitoneal (i.p.) administration of GYKI 52466 (1-[4-aminophenyl]-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine; 3, 10 and 30 mg/kg, i.p.), the prototypic compound of the 2,3-benzodiazepine family, caused a fast dose-dependent increase in the number and cumulative duration of SWD. These changes were accompanied by dose-dependent increase in duration of light slow wave sleep (SWS1) and passive awake, vigilance states associated with the presence of SWD. In addition a short, transient behavioral activation occurred that was followed by strong ataxia and immobility, decrease of active wakefulness and increase in deep slow wave sleep. GYKI 53405 (7-acetyl-5-(4-aminophenyl)-8-methyl-8,9-dihydro-7H-1,3-dioxolo[4,5-b][2,3]benzodiazepine, the racemate of talampanel, 16 mg/kg, i.p.) failed to affect any measure of SWD and vigilance. When used as a pretreatment, GYKI 52466 (10 mg/kg) slightly attenuated SWD-promoting effects of the 5-HT1A receptor agonist 8-OH-DPAT, it decreased cumulative duration and average time of paroxysms. In conclusion, AMPA receptors play moderate role in regulation of epileptic activity, and some of these effects are connected to their effects on vigilance in this model.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

The role of neuroticism, pain catastrophizing and pain-related fear in vigilance to pain: a structural equations approach.

The present study aimed at clarifying the precise role of pain catastrophizing, pain-related fear and personality dimensions in vigilance to pain and pain severity by means of structural equation modelling. A questionnaire survey was conducted in 122 patients with chronic or recurrent low back pain. Results revealed that pain catastrophizing and pain-related fear mediated the relationship between neuroticism and vigilance to pain. Furthermore, vigilance to pain was found to be associated with heightened pain severity. Finally, we found that neuroticism moderated the relationship between pain severity and catastrophic thinking about pain. The results strongly support the idea that vigilance to pain is dependent upon catastrophic thinking and pain-related fear. Neuroticism is best conceived of as a vulnerability factor; it lowers the threshold at which pain is perceived as threatening, and at which catastrophic thoughts about pain emerge.

Adult↗

Vigilance: the experience of parents staying at the bedside of hospitalized children.

Although the incorporation of a family-centered model of care delivery and open visitation policies have supported parents at the bedside of hospitalized children, little research has been conducted exploring the daily experience of vigilant parents. The purpose of this qualitative ethnographic study was to explore the experience of vigilance and specifically to examine the meaning, patterns, and day-to-day rhythms of parents who stay at the bedside of their hospitalized children. Ten parents of hospitalized children on a general pediatric unit were purposively selected to participate in the study. Qualitative data analysis supported the themes generated by previous studies of vigilance: commitment to care, resilience, emotional upheaval, dynamic nexus, and transition (Carr & Clarke, 1997; Carr & Fogarty, 1999). The knowledge generated from this study helps to support the theoretical understanding of vigilance and enhances the ability of health care providers to provide care that is congruent with the needs of parents and their children.

Adaptation, Psychological↗

The impact of extended sleep on daytime alertness, vigilance, and mood.

BACKGROUND AND PURPOSE: To measure the effects of prolonged sleep extension on daytime alertness, vigilance, and mood in healthy young adults. Little research has documented the effects of increased sleep on daytime function despite a high prevalence of daytime fatigue and sleepiness in the adult population. Past extension studies report conflicting results with regard to Multiple Sleep Latency Test (MSLT) scores, vigilance, and mood ratings. No study has challenged subjects to maximum sleep extension, defined by an MSLT score of 20. PATIENTS AND METHODS: Fifteen healthy college students reporting minimal daytime sleepiness were allowed to sleep as much as possible during a sleep extension period. MSLT scores, psychomotor vigilance task (PVT) reaction times, and profile of mood states (POMS) ratings were measured at baseline, mid-extension, and end-extension. RESULTS: There was a significant increase in both journal and actigraphy sleep totals during all extension segments (P<0.01). MSLT scores increased significantly from baseline to both mid- and end-extension (P<0.01). Five of eight tabulated PVT measures also improved significantly at mid- and end-extension with respect to baseline (P<0.05). POMS vigor and fatigue scores showed a similar improvement (P<0.01). Seven subjects achieved an MSLT score of 20. Six subjects showed substantial improvements while two subjects obtained relatively little extra sleep and showed little or no MSLT improvement. The maximum extension group displayed exceptional improvements in vigilance and POMS ratings. CONCLUSIONS: Extended sleep leads to substantial improvements in daytime alertness, reaction time, and mood.

Adolescent↗

Vigilance troubles in Parkinson's disease: a subjective and objective polysomnographic study.

BACKGROUND AND PURPOSE: To assess the prevalence of vigilance disorders in Parkinson's disease patients, relate the observed phenomena to potential causes and confirm these troubles with polysomnographic analysis. PATIENTS AND METHODS: A questionnaire was used to gather information on demographic data, previous and current treatments, disease characteristics, sleep and vigilance troubles. Somnolence was measured using the Epworth Sleepiness Scale (ESS). Nocturnal polysomnography (PSG) and multiple sleep latency tests (MSLT) were performed for a sample of parkinsonian patients. RESULTS: Two hundred twenty-two parkinsonian patients completed the questionnaire, and 36 patients had objective analyses. Of the patients, 43.2% had an ESS score >10, and 28.4% reported somnolence in the hour after taking dopaminergic drugs, whereas 6.8% reported unintended sleep episodes. In view of questionnaire data, these vigilance disorders may be partly explained not only by the impact of nocturnal sleep disorders (e.g. sleep apnea syndromes) but also by dopaminergic therapy (especially with dopaminergic agonists). With PSG and MSLT results, we have shown a significant correlation between mean sleep latency and ESS score. Patients with unintended sleep episodes have severe sleepiness in MSLT compared with others patients. CONCLUSIONS: Vigilance disorders are frequently observed in Parkinson's disease. We recommend informing patients of the risk of occurrence of such conditions, notably for patients with unintended sleep episodes and with sleepiness in the hour after taking dopaminergic drugs.

Aged↗

Daytime vigilance after morning bright light exposure in volunteers subjected to sleep restriction.

This study was designed to test the hypothesis that bright light (BL) can have a stimulating effect on vigilance even in the absence of suppression of melatonin secretion and that this effect can be detected when measured in subjects with low vigilance levels. Seven normal subjects were exposed to bright-white light (BL group) and seven to dim-red light (DL group) on 2 consecutive days, each following a night of 4-h sleep restriction. The light treatment was administered in the late morning, between 0900 and 1330 hours. Salivary melatonin measurements indicated that BL did not suppress melatonin secretion or induce circadian phase shifts. The effects of the two treatments were compared on validated measures of daytime vigilance: immediate effects were evaluated on subjective alertness during the light treatment, whereas short-term (0.5-10.5 h) and long-term (20.5-34.5 h) carryover effects were measured on subjective alertness, daytime sleep latencies (DSL), and psychomotor performance. After two nights of sleep restriction, subjective alertness and daytime sleep latencies decreased significantly, but there was no effect of the light treatment. BL treatment did not affect global performance, but there was an effect on the strategy used by the subjects, as shown by faster reaction times and increased percentage of errors in the BL group. It was concluded that daytime BL exposure did not have a stimulating effect on our measures of vigilance even in sleep-deprived subjects but that it may increase physiological arousal and affect the subjects' behavior in some specific performance tasks.

Adult↗

Diurnal variations in alpha power density and subjective sleepiness while performing repeated vigilance tasks.

OBJECTIVE: Diurnal variations in EEG activity and subjectively rated sleepiness while performing repeated vigilance tasks were examined. METHODS: Nine diurnally active healthy males underwent repeated vigilance tasks at 08:00, 11:00, 14:00, 17:00 and 20:00 h. An electroencephalogram (EEG) was taken while the subjects performed the tasks with their eyes open. The alpha power spectra (8.6-13.3 Hz) of EEG was integrated. Subjectively rated sleepiness, reaction time and oral temperature were also measured. RESULTS: Significant diurnal variations were found for alpha power, subjectively rated sleepiness and oral temperature. The alpha power was significantly smaller at 08:00 than at 11:00, 14:00, 17:00 and 20:00 h. The subjectively rated sleepiness was significantly larger at 08:00 than at 11:00, 17:00 and 20:00 h. The diurnal variation in alpha power did not correspond to that in subjectively rated sleepiness. On the other hand, repeated vigilance tasks increased the alpha power, subjectively rated sleepiness and reaction time at each time of day. The increase in alpha power was significantly greater at 14:00 than at 08:00 and 20:00 h. CONCLUSIONS: The diurnal variation was found in alpha power while performing vigilance tasks. Furthermore, the increase in alpha power with repetition of the task depended on the time of day.

Adult↗