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At least 19 recordsLinked to original sources
PubMed1984

[Biochemistry and pharmacology of vigilance: role of neurotransmitters within the framework of vigilance control].

Biochemical, pharmacological and neurophysiological research has produced an ever increasing amount of evidence that a variety of (putative) neurotransmitter (NT) mechanisms is implicated in the gross regulation of the many waking behaviours as well as in the organization of sleep. Yet, few of these experimental findings have yielded information as to the exact--specific and detailed--role played by anyone of these "wet" transmission systems in this whole regulatory and organizational function. Based on a new "Universal Concept of Vigilance" we were led to conclude that the actions and influences of at least some of these humoral transmission instruments are considerably better understood, if they are interpreted as being the main controlling instruments of the many local vigilances--the individual levels of responsiveness in the many behavioral systems that are responsible for the making of the many behavioral components. In this new "model" the noradrenergic, cholinergic, dopaminergic, serotonergic, and, possibly, some traceaminergic ascending (and descending) pathways constitute the Output-Component of a larger, reflex-type Vigilance-Controlling Apparatus (VCA). The NA-, Ach-, and the DA-systems are assumed to upregulate (local) vigilance by enhancing reactivity in the neuronal networks that subserve the organization of said behavioral components. In particular, NA- and Ach-pathways can be assumed to enhance mainly (but not exclusively) vigilance in systems of higher functions, whereas DA-fibers probably handle upregulation of reactivity (i.e. eventually vigilance) in the various motor systems. The efficacy of these various aminergic transmission systems is assumed to be further enhanced by a variety of polypeptidergic agents (e.g. TRH, Vasopressin, 4-10-ACTH, enkephalin). In turn, serotonergic pathways are involved as vigilance-reducing instruments. To explain the production of the, for the various waking activities as well as for the various phases and stages of sleep, proper and characteristic vigilance-profiles one has to assume that the activity of these output-channels is per se controlled by a coordinating central apparatus--the very "center"--of VCA.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1999

Thirteen-lined ground squirrel (Sciuridae: Spermophilus tridecemlineatus) antipredator vigilance decreases as vigilance cost increases.

Vigilance is a commonly studied antipredator phenomenon. However, little research has been conducted on the effects of visual obstruction coupled with a manipulation of the cost of performing vigilance behaviours. We tested the hypothesis that antipredator vigilance decreases as the cost of performing antipredator vigilance increases in free-ranging thirteen-lined ground squirrels. We presented adult ground squirrels with peanut butter within six rectangular Plexiglas boxes (opaque on all sides; clear on top) ranging in length from 15.2 to 91.4 cm. Squirrels repeatedly entered and withdrew from the boxes, to scan visually the surrounding area. As box length increased and, therefore, the cost of the vigilance behaviour increased, the ground squirrels increased their mean time within the box per entry and decreased their alertness per unit of trial time. Squirrels took longer to traverse the longer boxes, but their travel time into the boxes was significantly slower than their travel time out of the boxes. We interpreted this difference in travel time to indicate a behavioural conflict that occurred only when the squirrels entered the box (food versus vigilance) and did not exist once the squirrels had begun to exit from the box. The hypothesis that a decrease in ground squirrel antipredator vigilance would benefit the squirrels by decreasing their time exposed to predators (i.e. decreased trial duration, which was determined by the squirrels' behaviour), was not supported. Copyright 1999 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1997

Functional relationship between the hypothalamic vigilance area and PAG vigilance area.

The vigilance reaction is characterized by a large bradycardia, a pressor response, and inspiratory apnea in anesthetized rabbits and the inhibition of movement in conscious rabbits. This affective response pattern can be elicited by electrical stimulation of the dorsolateral hypothalamus (the hypothalamic vigilance area) or the ventrolateral periaqueductal gray (the periaqueductal gray vigilance area). The present study sought to advance our understanding of the functional relationship between the hypothalamic vigilance area (HVA) and the periaqueductal gray vigilance area (PVA) by measuring the effects of transverse transections of the caudal portion of the ventrolateral PAG (vlPAG) upon the cardiovascular responses elicited from the dorsolateral hypothalamus and the rostral vlPAG. Selective transverse transections of the caudal vlPAG significantly reduced the magnitudes of the bradycardia and pressor response elicited by stimulation of the PVA rostral to the transection site, but had minimal impact on the cardiovascular responses evoked by stimulation of the HVA. These findings suggest that the cardiovascular responses elicited by stimulation of the vlPAG are mediated by a neural pathway that is parallel, at least in part, to the one that subserves the response elicited from the HVA. The results also provide support for the view that the PAG is not an essential structure in the mediation of the autonomic components of affective behaviors involving behavioral inhibition.

Animals↗
PubMed1996

The use of diurnal vigilance changes in the EEG to verify vigilance-enhancing effects of memantine in a clinical pharmacological study.

In elderly subjects there is a vigilance decrease from morning to noon which was used in a clinical pharmacological model as a state condition to verify vigilance-enhancing effects of an antidementia drug. In this model the effects of Memantine (20 mg, single-dose application) on the quantified EEG were investigated in 16 elderly (mean age: 65 +/- 5 years), healthy subjects (10 females, 6 males) in a randomised, twofold cross-over design vs. placebo under double-blind conditions. EEG was recorded before medication, and 2 and 4 h after medication under reaction time (RT) and resting (RS) conditions. EEG data were subjected to spectral analysis and the topographic distribution of the amplitude values was mapped. The results show that a time-dependent decrease (from morning to noon) in vigilance (indicated by an increase in average EEG amplitudes caused by increased synchronisation in the alpha and beta range and an increase in delta) occurred under placebo which was counteracted by Memantine. The diurnal variations of the EEG and their compensation by a pharmacological agent represent an effective model for investigating the vigilance-enhancing effects of antidementia drugs.

Aged↗
PubMed1980

Vigilance paradigm for preschool children used to relate vigilance behavior to IQ and prenatal exposure to alcohol.

A methodology for investigating vigilance behavior in preschool children was developed. The administration of the task was adapted to young children and a scoring system was devised to adjust for the higher level of random responding found in this sample of preschoolers. 28 3- and 4-yr.-olds were given the Stanford-Biner Intelligence Test and a 12-min. vigilance task. The children, drawn from a sample used in a larger study, were the offspring of three groups of mothers: recovered alcoholics who drank during pregnancy, recovered alcoholics who did not drink during pregnancy, and nonalcoholics who drank litt or nothing during pregnancy. A significant correlation was found between the number of correct responses on the vigilance task and IQ (r26 = . 53, p less than .01). The conclusions that can be drawn regarding the relationship of vigilance to maternal alcohol use (chi 2 = 4.82, p less than .09) are limited by small sample size.

Alcohol Drinking↗
PubMedDate not supplied

[Effect of night medical guard on following day vigilance. Influence of hypnotic drug on recovery night and on the vigilance during the following day].

The consequences of sleep deprivation on vigilance and mood were evaluated in six healthy medical students the day after being on night duty and the following day, after recovering from a full night's sleep. Diurnal vigilance was studied using the Multiple Sleep Latency Test (MSLT) and mood was assessed on an anxiety self-evaluation scale. The study was conducted by means of a double-blind randomized trial to measure the effects of benzodiazepine (lormetazepam, 2 mg) compared to a placebo administered before the night recovery/full night's sleep. Sleep deprivation induced a significant decrease in vigilance the day following the night duty. Sleep latencies were shortened during the morning following the night of recovery/full night's sleep. The values obtained after administering the lormetazepam did not differ significantly from those obtained after administering the placebo. There were no considerable differences in the anxiety evaluation scores before and after the night of recovery/full night's sleep between the two sequences of the trial. This study suggests that a significant lack of sleep (a 36-hour sleep deficit) modifies diurnal vigilance over two nyctohemeral periods. Administration of benzodiazepine with a short half-life after occasional sleep deprivation does not change the reorganization of the sleep-waking cycle.

Adult↗
PubMed2001

Vigilance scoring in children with acquired brain injury: Vienna Vigilance Score in comparison with usual coma scales.

An instrument in neurologic rehabilitation for the assessment of a person's clarity of consciousness must fulfill the need to provide the rehabilitation team with some information regarding the structuring of the rehabilitation process. The Vienna Vigilance Score is oriented toward cooperation within the rehabilitation team with the specific advantage of focus on the subject status of the patient on the basis of the dialogue. It does not use painful stimuli and is oriented toward the next developmental step of the rehabilitation process. The first extensive application of the Vienna Vigilance Score was carried out in a 3-year study of 38 children and adolescents. We report the comparison with other coma scales (Glasgow Coma Scale, Children's Coma Score, and Modified Glasgow Coma Scale) on 24 children and adolescents (1.4-16.8 years of age). The results showed satisfying statistical parameters: measuring range comparable with other scales; a Kendall tau correlation of .59 on both the Modified Glasgow Coma Scale and the Children's Coma Scale and of .66 on the Glasgow Coma Scale; a Spearman's rank order correlation of .70 to both the Modified Glasgow Coma Scale and the Children's Coma Scale and of .78 on the Glasgow Coma Scale. By accepting the Glasgow Coma Scale as a gold standard for classification of the level of coma, we can confirm satisfactory measuring qualities for the Vienna Vigilance Score.

Adolescent↗
PubMed1992

The performance of hyperactive and control preschoolers on a new computerized measure of visual vigilance: the Preschool Vigilance Task.

This study examines the ability of a new visual vigilance task, the Preschool Vigilance Task (PVT), to differentiate between hyperactive and control preschoolers. The PVT was designed to be an objective measure of attention specifically for use with the preschool-age population. Hyperactive and control preschoolers were tested on the PVT and the Continuous Performance Task (CPT). Results indicated that both were useful in differentiating between hyperactive and control preschoolers. Implications for the utility of the PVT and future research directions are discussed.

Attention↗
PubMed2006

Can a shorter psychomotor vigilance task be used as a reasonable substitute for the ten-minute psychomotor vigilance task?

The 10 min psychomotor vigilance task (PVT) is commonly used in laboratory studies to assess the impact of sleep loss, sustained wakefulness, and/or time of day on neurobehavioral performance. In field settings, though, it may be impractical for participants to perform a test of this length. The aim of this study was to identify a performance measure that is sensitive to the effects of fatigue but less burdensome than a 10 min test. Sixteen participants (11 female, 5 male; mean age = 21.7 years) slept in the sleep laboratory overnight then remained awake for 28 h from 08:00 h. During every second hour, participants completed three PVTs of differing duration (10 min, 5 min, 90 sec). For the 5 min/10 min comparison, ANOVA indicated that response time was significantly affected by test length (F1,14 = 26.9, p < .001) and hours of wakefulness (F13,182 = 46.1, p < .001) but not by their interaction (F13,182 = 1.7, ns). There was a strong correlation between response time on the 5 and 10 min PVTs (r = .88, p < .001). For the 90 sec/10 min comparison, ANOVA indicated that response time was significantly affected by test length (F1,14 = 65.9, p < .001) and hours of wakefulness (F13,182 = 29.7, p < .001) as well as by their interaction (F13,182 = 6.0, p < .001). There was a strong correlation between response time on the 90 sec and 10 min PVTs (r = .77, p < .001). The effects of hours of wakefulness on neurobehavioral performance were similar for the 5 min and 10 min PVTs. In contrast, performance on the 90 sec PVT was less affected by hours of wakefulness than on the 10 min PVT. In addition, performance on the 10 min PVT was more highly correlated with the 5 min PVT than the 90 sec PVT. These data indicate that the 5 min PVT may provide a reasonable substitute for the 10 min PVT in circumstances where a test shorter than 10 min is required.

Adult↗
PubMed2000

Theory and method in studies of vigilance and aggregation.

Predation is considered one of the most important selective pressures on free-ranging animals. Our understanding of it derives mainly from studies of individual vigilance (visual scanning of the surroundings beyond the immediate vicinity) and aggregation in prey. Vigilance bears a direct relationship to aggregation, because animals in groups may rely on associates for early warning of danger. This review addresses the relationship between vigilance and aggregation with particular attention to the prediction that individual vigilance declines with increasing group size. Contrary to most other animals studied, primates do not support the prediction. Exploring this, I examined the assumptions underlying vigilance theory in the light of primate behaviour. First I tested whether manual harvesting and upright processing of food as seen among primates might permit them to feed and scan simultaneously. I found no support for this idea. Next I examined the targets of primate vigilance and found that one component (within-group vigilance) might explain the differences between primates and other animals. Finally, I evaluated whether individual primates in large groups face a lower risk of predation than those in small groups. A conclusion was impossible, but by separating group-level from individual-level risk, I was able to identify several common circumstances in which group size would not predict individual risk or vigilance. These circumstances arose for primates and nonprimates alike. I concluded that the relationship of vigilance to aggregation is not straightforward. The absence of a group-size effect on vigilance among primates is probably due to functional differences in vigilance behaviour or safety in groups, not to methodological differences. Furthermore, future work on animal vigilance and aggregation must fully consider both the targets of glances, and the assumption that larger groups are safer from predators. I predict that animals will not relax vigilance in larger groups if conspecific threat increases with group size. Group size will not predict individual risk of predation nor individual vigilance rates when predators do not rely on surprise, or when predators select a small subset of highly vulnerable group members. Copyright 2000 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

The function of vigilance in sympatric marsupial carnivores: the eastern quoll and the Tasmanian devil.

Sympatric marsupial carnivore (Marsupialia: Dasyuridae) species experience different levels of risk of predation and competition as a consequence of different body size and feeding adaptations. The small eastern quoll, Dasyurus viverrinus, is preyed upon by owls and is aggressively displaced from carcasses by its larger competitor and potential predator, the Tasmanian devil, Sarcophilus laniarius. Devils have no known predators but this specialized scavenger experiences intense intraspecific competition. I studied the vigilance behaviour of individuals of these species feeding on carcasses. (1) Eastern quolls were more vigilant in the presence than in the absence of devils, suggesting that their vigilance functions to detect predators/competitors. (2) Devils showed a decrease in vigilance with increasing body size and age, and a trend towards a decrease with increasing group size. These are the same patterns expected if vigilance was in response to predation risk, although devils have no predators. Vigilance behaviour did not change in the presence of eastern quolls, suggesting that vigilance is not directed towards interspecific competitors. (3) As expected from their greater risk of predation and injury from a larger competitor, eastern quolls appeared to invest more in vigilance than devils did: they used vigilance postures that gave better visibility but disrupted feeding more. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1997

Body vigilance in panic disorder: evaluating attention to bodily perturbations.

Body vigilance, consciously attending to internal cues, is a normal adaptive process. The present report investigated whether body vigilance is exaggerated among those with panic disorder, a condition characterized by intense fear and worry regarding bodily sensations. The Body Vigilance Scale is validated in nonclinical and anxiety disorder samples. Study 1 suggests that body vigilance is normally distributed in a nonclinical sample (n = 472) but vigilance is related to a history of spontaneous panic attacks, anxiety symptomatology, and anxiety sensitivity. Study 2 suggests that body vigilance is elevated in panic disorder patients (n = 48) relative to social phobia patients (n = 18) and nonclinical controls (n = 71). During cognitive-behavioral treatment, panic disorder patients show substantial reductions in body vigilance associated with reductions in anxiety symptomatology. Anxiety sensitivity was found to be related to body vigilance and to predict changes in body vigilance during treatment.

Adolescent↗
PubMed1987

COMSTAT rule for vigilance classification based on spontaneous EEG activity.

For the classification of sleep stages, international standards based on visual EEG analysis have been established and are in common use, although we are well aware of their limitations. Several authors have suggested different procedures for classifying the stages of vigilance during the waking stages. No universally accepted paradigm, however, has yet been developed. The proposed vigilance classification procedures are based either on visual or automatic analysis procedures. Even though the EEG activity and patterns that reflect vigilance changes have been identified and described as indicators of the state of alertness, opinion is divided on how these should be combined in a vigilance classification rule. Automatic methods, on the other hand, have up to now used only part of the information available, the relationship of which to vigilance indicators has only been partially explored. The COMSTAT (Dept. of Computation and Statistics, AFB-Arzneimittelforschung, Berlin, FRG) rule combines visual and automatic analysis procedures. Different vigilance-dependent EEG patterns, such as the proportion of occipital background rhythm under resting conditions and its replacement by either faster or slower waves, the frequency range of the occipital rhythm and the anteriorization phenomena, have been used as information for a latent class analysis (LCA5) with 5 classes (stages of vigilance). There is a high correlation between the results of the LCA5 with visual classification rules made by experts. Using a robust discriminant analysis function which takes into account prior probabilities of the classes, and with a linear cost function for misclassification, an automatic rule with power spectrum variables was fitted to the results of the LCA5. Reclassification and split-half classification showed a high overlap between LCA5 and automatic classification. The result of this procedure is a new vigilance classification rule that is based on an objective mathematical rationale for the combination of different vigilance-indicative EEG activities and patterns but which can be applied to power-spectral estimators in an automatic EEG analysis procedure.

Aged↗